The Flimsy Doorknob & The Forgettable Receipt - <AUTHOR> http://dustincurtis.com/two_stories.html <comment><USER2> Instead of packing slips we've been including cardstock 'receipts' with each of the orders we ship. We write the recipient's name, circle the merchandise they purchased, and include a hand-drawn sketch featuring characters from the game (example: <http://forum-files2.fobby.net/0012/7914/chimera.jpg> )

It was tedious at first, but people raved about them. Eventually we wised up and started offering store coupons to the community's artists in exchange for drawings. It's really added value to our products and simultaneously strengthened our community. Win/win!

<comment><USER3> Very cool. If you number them (the drawings), they could become collector's items.

</comment></comment><comment><USER4> I'm not entirely sure I agree with the point about the receipt. I want to be left with a memory of how awesome an experience was, not how much I paid for it. For something like Starbucks, having a stack of receipts that are nice to look at and inform me in a pleasant, easy to read font exactly how much money I'm spending there might make me reconsider my expenses in a hurry. Forgettable receipts might have an advantage after all.

Of course, this is all theory... I would love to see some actual data!

<comment><USER3> But luxury meals are enhanced by paying more for them. They are prestige purchases, and "prestige pricing" increases sales, according to data in marketing textbooks. How much you paid becomes a positive part of the experience, and worth remembering.

<comment><USER5> While I agree with your point, it gets lost when applied to Starbucks. There seems to be a groundswell of people who have suddenly realised that it's totally unreasonable to charge what they charge for a cup of coffee. The sheer ubiquity of Starbucks has also reduced their luxury allure. Might be nice to have a pretty receipt, but as far as Starbucks is concerned, they might want to reduce the font of the price and ensure it smudges easily.

<comment><USER3> OH yeah, his Starbucks example doesn't really make sense - I was thinking of the architecturally designed home and the $1000 restaurant meal. It's a bit weird how he starts with two compelling luxury data points, then overgeneralizing to... a $6.02 purchase.

</comment></comment></comment></comment><comment><USER6> "I make user interfaces...You can learn more about me here, here, and maybe here."

Hey Dustin, quick suggestion for a better user interface: put the name of the link in the original copy so that I don't have to mouse over the word "here" to see what it is.

<comment><USER7> Also the "You should follow me on twitter" remark at the bottom of the page sounds somewhat arrogant to me.

<comment><USER8> and go the extra step and actually say @dcurtis, since someone may need to look it up.

Suggested approach: "Follow me @dcurtis"

</comment></comment></comment><comment><USER9> Example of fancy, highfalutin' restaurant receipt:

<http://www.flickr.com/photos/peterme/3729304/>

<comment><USER10> I had a booking for last Friday, but my wife cancelled it just before the deadline for fee-free cancellation. I'm still disappointed, but the money we saved in not going literally afforded us a last-minute weekend in Hawaii instead.

<comment><USER11> I can't imagine a meal being better than a weekend in Hawaii.

</comment></comment></comment><comment><USER12> > The toilet paper is even custom made with the logo of the executive's > company embossed on each sheet

I am not sure what I would think if I were a shareholder, but "we're paying this guy too much, and this is how he shows it" would come to mind.

<comment><USER13> Really? Not the "20-foot-tall floor-to-ceiling windows that expose the entire San Francisco Bay"?

<comment><USER12> That's "nice", something someone would work hard for - hopefully the reward for a job well done. Company branded toilet paper is 'frivolous' and, as Ryan pointed out (I didn't want to say it), I'm not sure what kind of message it sends to have people cleaning their nether regions with your company's logo.

<comment><USER13> A personable one? Hopefully not a lasting one...

Its tacky to decide that someone is overpaid by your perception of how they spend their money. You make fun of a $10 roll of toilet paper, but they might have paid twice what their house was worth or gave most of their money to charity. Maybe the toilet paper was supposed to be funny, and you just didn't get the joke. Its better to justify salary by productivity to the company than by personal preferences.

</comment></comment></comment></comment><comment><USER14> One time, at Canoe in Atlanta, the server gave us a business card at the end of our meal (it was nice, as business cards go). Canoe also seems to use a CRM to keep track of their customers, as they said "Welcome back" when we did come back.

Those practices, just standard practices for any modern business really, made for a much better experience than a pretty receipt would.

<comment><USER15> I think you're hitting on the essential point of the article which is customer experience and creating a positive memory.

One of my clients is a high-end boutique. Their purchase experience is good by nice retail standards - high-quality bag, tissue with ribbon, etc. But then the do little extras like presenting your receipt in a little card stock slipcase and hand-writing you a thank-you note a few days later. It is the little things that matter.

I'd agree that the MASA receipt is pretty rudimentary, but as another commenter mentioned, it's largely a factor of the POS system. (And apparently not high on their selection criteria list.)

</comment></comment><comment><USER16> I bet if somebody made a receipt printer that could print nice, customizable receipts and interface with existing equipment, they'd get plenty of customers.

<comment><USER17> How about a pc inkjet printer? They can actually be hooked up to the nice touchscreen ones you see at restaurants. If size/perception is an issue, why not try a small photo-printer such as the new Polaroid PoGo.

Also, as a side note, Starbucks might not be the best fit since it's a relatively low-price-point commodity. Both previous examples were high-price- point, luxury experiences, which would benefit from 1) the lack of a bad reaction 2) receipt as a marketing tool since you create worth through creating a souvenir. Starbucks on the other hand, would only benefit through the latter, where you create worth through impressions (kind of like those annoying magazine signup forms). This is actually not helpful since Starbucks doesn't need any more impressions due to their many stores, and when you throw them away from the back seat of your car, you'll indirectly attribute the brand to junk.

It would be nice to see online services mimic retail merchandising techniques.

<comment><USER16> Using an inkjet printer is a good idea (maybe).

No offense, but your second paragraph is way too long for a comment.

<comment><USER18> _There is a strong correlation between comment quality and length; if you wanted to compare the quality of comments on community sites, average length would be a good predictor._

<http://www.paulgraham.com/hackernews.html>

<comment><USER16> I'm saying that a paragraph that long is uncomfortable to read, given that HN comments span most of the width of the page. It needed to be broken into multiple paragraphs.

Frankly, I'm offended that I got downmodded so much on this. People clearly did not carefully read what I said.

</comment></comment></comment></comment></comment><comment><USER19> Car manufacturers should take note as well : the ker-thunk of a door, and heft of a well damped indicator stalk, the soft-feel plastic of a door handler transmit quality, even if the rest of the car is run-of-the-mill. This is where VW leads in giving a quality feel, even though it's cars often feature badly in quality reports.

<comment><USER13> I've often felt that the best part of BMW's 325 is simply the lack of poor parts. The biggest annoyance that comes to mind is that the last door is hard to close because the cabin is air tight. Granted, I like a specific model year above others, but its interesting to note that slight luxury and a lack of deficiencies has produced a car with a legacy.

</comment></comment><comment><USER20> That receipt concept is a waste of paper mass and ink. Sure, they could improve receipts a lot, but that's not the way to do it.

<comment><USER21> Why not? I think it's at least worth experimenting with to see what happens.

<comment><USER20> You don't need to do any experimentation to know that a full-color receipt with lots of black on heavy stock is going to use more resources than thin thermal paper.

<comment><USER22> But, that's his whole point! He's saying that it's incongruous and inadvisable to cheap out on the design and production of the receipt when it's one of, if not the, final impression a diner will take away from your restaurant.

<comment><USER12> Ok, and that might work when it's a $1000 meal, but not for Starbucks.

Also, why does the receipt look like an iPhone app?

<comment><USER23> Um, because the iPhone is cool? Also note he said it was more a concept, not what you would actually impliment.

</comment></comment></comment></comment></comment></comment><comment><USER24> As far as restaurants go, I notice that the receipts have a way of sticking with me (pockets, etc.) long after I've forgotten about the meal. I'm sure I'm not the only one either.

<comment><USER25> I wonder if you can brand fat....

</comment></comment><comment><USER26> Another thing you touch and interact with in a home is light switches.

It's amazing to me how nice odd light switches are. Twisty knobs or metal buttons – anything besides the normal off-white plastic switch and cover.

They don't play as well with my muscle memory, but that inefficiency becomes a good thing somehow: it's something I remember.

<comment><USER27> Actually, whenever I've been in a place with odd lightswitches, it's been pretty annoying. First, if I have to figure out how to use it by trial and error in the dark, that's a problem. Second, if I'm expecting to live there for years, I'm going to have to replace them, and then, very likely, I'm going to have a bunch of wonderfully different switches, and one that stands out because I could get it at Home Depot, and I couldn't find anyplace to buy one like the others.

All that said, I prefer the wide rocker switches over the lever switches that I grew up with, so I'm not knocking change, just variety. :)

</comment></comment><comment><USER28> When I'm hunting through my papers for receipts, I want those things to look like what they are--receipts. The only drawback to the existing MASA receipt that I can see is that it's harder to make your web page look good when you're trying to show it off on your blog later.

</comment><comment><USER29> He makes a very good point. When you pay $500 for a meal it is very disappointing to see a receipt like that. I never really thought of the receipt as a marketing opportunity but now I realize how important receipts can be as a marketing vehicle.

<comment><USER30> Unless you're going to deliver a receipt that matches my meal in value, I don't particularly see the point. I don't want some stock-printed receipt merely intended to impress.

Receipts are just receipts, and there's no real value you can provide for me there. Instead, remember who I am, and welcome me back next time.

I should also note that the author's point could have been better elucidated without relying so heavily on braggart anecdote.

</comment></comment><comment><USER31> Houses are always works in progress. I'd like all my receipts to be digital. You touch furniture more than fixtures.

</comment><comment><USER32> Only got through the first half before my the flickering in my status bar was so irritating I had to stop reading. Sorry Dustin but if you're talking about user experience, please do not have my browser ajax your site every couple of seconds.

</comment><comment><USER33> I like this idea (would love to see test data). It reminds me of how Apple innovates in so many ways to create a better customer experience.

When you buy something from the Apple store they ask if you'd like the receipt emailed, printed, or both.

I generally opt for email only.

It's not quite the same thing as mentioned in the article, but it is similar in that it's much nicer than just getting handed a flimsy receipt.

</comment><comment><USER34> Great points and I'm still amazed by his article presentation.

</comment><comment><USER35> what about the crappy user experience of having a blog and no place for people to comment?

<comment><USER5> That's a good point, really. I mean, look at all the comments his work has gotten here on HN. That seems like one of those rather obvious details that was "intentionally" overlooked.

</comment></comment><comment><USER36> That writing is "Simple & Amazing"

</comment><comment><USER37> Excellent article. I usually don't log in to HN, or comment frequently, but I had to bump this one up.

</comment><comment><USER38> That shit at Masa better be damn good for $400 plus tax & tip.

And what's with the forced 20% service on dinner for two?</comment>


Ask HN: What small problems do you face frequently? - <AUTHOR>

I really am looking for small rants about a problem, and a possible solution to the problem.<p>Example: "I have trouble figuring out where all my time goes. I need an application that makes it really quick for me to keep a log of my activities." <comment><USER2> Oh, I have a rant. I have trouble hanging up on telemarketers who prey on entrepreneurs (VC associates, recruiters, biz dev, consulting firms). My problem was that hanging up violently put me in a violent mood. So I went as far as writing up scripts that were polite but moved toward hanging up within 10 seconds. Full rant/solution here:

[http://www.stubbleblog.com/index.php/2009/03/productivity- ha...](http://www.stubbleblog.com/index.php/2009/03/productivity-hack-hangup- politely/)

Why did you ask the question?

<comment><AUTHOR> I'm trying to think up some sort of quick project I could complete in a couple of months that would solve someone's problem :)

Also, it's kind of neat to hear how people would/have solve[d] these problems.

</comment></comment><comment><USER3> I have trouble finding the "Programming Pearls" of various topics. For example I'd like to find a book of similar quality and style that deals w/ networking computers. This applies to non-computer related subjects too... for example I'd love to find great books/lectures etc about caring for animals but I don't want to search a lot. Maybe my problem is I'm lazy :-p

I've noticed a recurring pattern where I'll find something really interesting every once in a while... for example I just discovered the Graphics Programming Black Book by accident. Would be nice to just have a list of learning materials that are highly likely to be good matches for me.

<comment><USER4> This was an idea I had for a website I while back - basically an aggregator for grouping learning resources by topic then ranking them by skill level and quality. (So you could find the best "beginner's guides to x" or "expert tips for x" and so on).

You can take a look at www.nohao.co.uk. It's very basic, and I haven't developed it for a while, mostly because no-one seemed interested. Wasn't sure if it was because the problem it attempted to solve wasn't really a problem, or lack of features, or just not promoting it to the right people.

What could be cool is a site that (using algorithms/crowdsourcing/whatever) generated guides like this one: <http://ruby-metaprogramming.heroku.com/> , where multiple resources are compiled into a programme you can follow. I had a few other ideas for the site, such as automatically setting up study groups. Though as I said, I'm not sure if I'd just be building something that no-one would use, so I haven't worked on it for a while.

</comment></comment><comment><USER5> If you're looking for good startup ideas watch Mixergy. Each episode gives me a few.

</comment><comment><USER6> I have a problem hooking up my TV to my PC

I have a problem making my playlist play good songs, but not just then keep repeating those songs till I got sick of them

I have a problem finding good accessories for my home that match the color, tone and style.

Socks & Underwear. Regular delivery. Cheap price.

Daily Expenditure: Hassle free non-detailed tracking.

Easy & short reading material for travelling. Something that pushes only interesting and current reading material based off an interest of mine - "business", "science fiction", "humour" and so on

</comment><comment><USER7> I have trouble finding interesting and attractive girls to go drinking with ;)

<comment><USER8> if your looking for a Web solution there is always dating sites ;)

<comment><USER9> True, but he/she said "interesting and attractive."

</comment></comment></comment><comment><USER10> windsurfer, are you trying to find startup ideas? ;)

<comment><AUTHOR> _looks around_

Is that a bad thing? ;)

<comment><USER11> Nope, not at all! Though this particular crowd may be a suboptimal one to ask that question of, as we are more likely than most to start our own startup (or at least write our own shell script) to solve our problems... :-)

Maybe next time you're at your local dry cleaner, ask this same question.

<comment><AUTHOR> I find that this crowd would be more willing to use or pay for a solution, as opposed to the average person would would just slug their way through the problem, ignoring any better or easier way of doing things. Most people aren't even aware of something being a problem until they are shown a solution. People here on HN are more apt to be thinking of easier and faster ways of doing things.

As I sometimes say: Most people don't know what they want.

</comment></comment></comment></comment><comment><USER12> i wonder about your example. is it that i don't know where my time goes, or that i lack the means to change my habits? perhaps both are occurring, since sometimes knowing just how much time is wasted on <foo> provides motivation to stop....but really, the means are the tough part.

how can we motivate positive change beyond simple tracking?

<comment><AUTHOR> Presumably one could store the data in an accessible format and create some interesting projects around it.

</comment></comment><comment><USER13> I have one problem - Recently launched products are always in need of spreading the word about them. One of the better ways to do it would be find blogs, articles or discussions going on to related to the product. I would like to setup a service which sends me some N urls everyday where I can go and add some useful insights to the discussions as well as put my service url there, so that it brings in some new users to my site. Let me know if you are interested in this.

<comment><USER14> Yeah. That is cool and I was thinking the same thing. I also thought that the more real time it will be the better, so you can get into the discussion while people are still reading it :).

I would love to talk more about it.

<comment><USER13> Hi Kleine2,

Please mail me at email@example.com. We can discuss more on the same idea. :)

</comment></comment></comment><comment><USER15> I would like one spot to go to remind me of when everything is going to expire. I have warranties, domain names, web services, SVN services, email accounts, airline miles -- all kinds of crap that has some sort of expiration date on it. And I can't keep track of any of it.

And I want the machine to do all the work -- heck if I want to go around entering everything. I want to answer a few questions, maybe have it "follow me" around as I surf, and then keep a list of when things are going to run out.

<comment><USER9> Can't deny it's a problem for you, but I add all that sort of stuff to my Google Calendar as it crops up. I have lots of things in my calendar years in advance. Works a treat.

<comment><USER15> Just trying to help out with a rant. As you said, there are lots of easy solutions to this.

But I find it hard to believe you track _everything_ this way. Things like airline miles expire 2 years from the last time you flew. Do you update Google every time you fly? When you buy a toaster, do you note whether it has a 90-day full replacement or a 30-day parts warranty? We got an email from Google last month with coupons for free AdSense -- they expired in a couple of weeks or so. Amazon sends out sale notices all the time. Little stuff like that adds up over time. It's easy for me to catch the big stuff, but do you really catch all the little stuff on Google calendar as well?

<comment><USER16> I agree that this would be an interesting problem to solve.

But I doubt it could be made conclusive without manual data-entry. Even a tool following you around the web can't possibly understand "Ah, he just ordered a toaster" - much less when that toaster actually arrives, gets returned etc.

I think at the bottom of this lies an interesting UI challenge. How to make data-entry painless enough so that you, me and others would actually use it?

<comment><USER17> Or, perhaps, instead of data entry, a more universal data format and communication protocol for exchanging and synchronizing date information, so that supermarket purchases, websites etc. automatically add the data to a person's centralized calendaring system. This is something I want to make a (small) part of my current project, so someone please beat me to it, and then you can make a plugin for my project once I've launched :).</comment></comment></comment></comment></comment>


Dynasaur: A DynamoDB ORM for Node.js   - <AUTHOR> http://tglines.github.com/dynasaur/

<comment><USER2> Looks great, Travis.

One thing: you should consider building this on jed/dynamo-client[1] instead of jed/dynamo. I refactored the former out of the latter last week, adding exponential back-off retry and the ability to specify custom hosts for better testability. Also, I'll be refactoring jed/dynamo myself in the near future, which will introduce breaking some API changes.

        [1] https://github.com/jed/dynamo-client

<comment><AUTHOR> Thanks Jed, I was unaware of dynamo-client ... I'll make sure to go off of that (exponential back off retry sounds awesome).

</comment></comment><comment><USER3> How are you dealing with the difference between scan and query? DynamoDB acts quite differently to other nosql databases. It seems in the find method, you are using scan? The reason why I'm asking, is that I've run into problems with DynamoDB for a small side-project. Stuff that I took for granted from a database system that I couldn't do or change!

ie, with scan, although more resource expensive than query, you can add filters on any keys, but you can't sort any of the data. With query you can, but only on the range key you specify, which is 1 per table. Also: it can't be changed after the table is created.

Seems like difficult problems to sort out for an ORM wrapper.

<comment><AUTHOR> There is quite a bit to make more clear. I'd like to see how far along I can get into abstracting away the dynamodb issues.

In your scan vs. query example I'd want to duplicate the data to two indicies ... and running both through a query call. If I can get even a decent amount of consistency this way (the real challenge to the multi-index problem using this method) for small/medium data sizes it would work and still be cost effective. At larger data sizes an application will most likely know which queries it needs to execute consistently in an indexed fashion and which could be farmed out through elastic map reduce.

As mentioned here:

        https://forums.aws.amazon.com/thread.jspa?messageID=332629

Amazon is looking into these concerns and I'd like my abstraction to stay constant throughout the transition. (while informing the user as to what its actually doing)

<comment><USER3> Ah okay. I understand. Looking forward to how you expand it! Will be watching the project.

</comment></comment></comment><comment><USER4> Crazy, I was looking for a similar tool earlier today. I've been using Mongoose for MongoDB validation/schema and wanted a similar system for DynamoDB.

</comment><comment><AUTHOR> Please check out the features to come, note that full test coverage is coming and feel free to ask any questions.</comment>


Ask HN: How to learn advanced C++ (atomics, memory ordering, etc.) - <AUTHOR> I want to learn the details of lock free programming, atomics, memory ordering, etc. I've been writing concurrent code in C++ for a long time, but not in an environment where I had to think about the memory model.
The problem is I haven't found much structured content on this. Is there a good book or class syllabus dedicated to this subject?
At this point I'm just piecing together CppCon talks on youtube and blog posts. <comment><USER2> Hello, Virginia Tech offers an online graduate course called "ECE/CS 5510 Multiprocessor Programming". It specifically focuses on addressing your exact question within this course and aims to help you understand the multithreaded programming concepts from the hardware level up to the software level.

I am just starting this course, but the first lecture looked promising and VT hasn't disappointed me with its ECE courses focused on programming yet.

Here's the book we will be using for the course: [https://www.elsevier.com/books/the-art-of-multiprocessor- pro...](https://www.elsevier.com/books/the-art-of-multiprocessor-programming- revised-reprint/herlihy/978-0-12-397337-5)

<comment><AUTHOR> Interesting, but looks like this book has examples in Java.

Probably the concepts carry over, but I'd prefer something more directly applicable to C++.

<comment><USER3> I usually refer to LLVM documentation. You can look at this [1] to begin with.

For sample code, etc, I would recommend to read D's atomic primitive implementations [2] instead of C++. C++ standard library is an unreadable monster. Fundamentally C++ atomic types are a flaw as std::atomic<int> is a type by itself, whereas in reality the operations has to be atomic. Also you can't get the value type for the type underneath the std::atomic template.

Whereas in D, the operations are atomic and you can operate them on the primitive types. You can see numerous examples in D's standard library implementation (which is readable than C++'s) [3][4]

[1] [https://llvm.org/docs/Atomics.html](https://llvm.org/docs/Atomics.html)

[2] [https://github.com/dlang/druntime/blob/master/src/core/atomi...](https://github.com/dlang/druntime/blob/master/src/core/atomic.d)

[3] [https://github.com/dlang/phobos/blob/master/std/concurrency....](https://github.com/dlang/phobos/blob/master/std/concurrency.d)

[4] [https://github.com/dlang/phobos/blob/master/std/parallelism....](https://github.com/dlang/phobos/blob/master/std/parallelism.d)</comment></comment></comment>


Mystery disease diagnosed at clinic of last resort - <AUTHOR> http://today.msnbc.msn.com/id/45327870/ <comment><USER2> Interesting.. like a real-world Doctor House.

<comment><USER3> That's just what I was getting ready to type. I wonder if this type of basic research pushes the boundary of knowledge.</comment></comment>


Even the Business Software Alliance now backpedaling on SOPA support - <AUTHOR> http://arstechnica.com/tech-policy/news/2011/11/even-the-business-software-alliance-now-backpedaling-on-sopa-support.ars <comment><USER2> I chalk this up to everyone who called out major technology companies for indirectly supporting SOPA through their membership in the BSA. Cheers!

It's finally starting to feel like the people who actually get what the internet is and how it works are being heard. It's about time.

</comment><comment><USER3> Let's hope SOPA dies a fiery death, but what about the next attempt? Will Congress and the public accept a watered down next-step towards a Great Firewall of America?

Take a look at the "fetal personhood movement" (ie, a shady corporate group looking to drop a legal nuke)... they lost the fight in Mississippi, but are now looking to 12 other states where they'll attempt to buy a constitutional amendment... if they succeed, they can now whore themselves out for whatever industry needs amendments that benefit their bottom line.

The root of the problem is that legislation is for sale and some of those 1% are interested in buying.

<comment><USER4> What? How does SOPA have _anything_ to do with an anti-abortion movement and constitutional amendments?

<comment><USER5> I think the point that the original poster was making is that corporations with lots of money behind them can keep trying to get similar laws passed, again and again, until they finally succeed.

<comment><USER6> Which is an extension of the broader problem with Congresspeople having often very-divided loyalties. On the one hand (usually the weak one) there are voters. On there other, there's the money. Backing this money up is the threat that favoring voters will mean someone else getting the money, which they will be expected to use attacking the person who had the temerity to refuse it.

It's an impossible situation - like depending on an employee whose salary and benefits are provided by your most direct competitors.

The logic of public election finance holds that all citizens, regardless of their political views, have a much greater interest in a legislative body responsive to voters alone than they do in possibly underwriting the campaign of a particular legislator who they oppose.

Put differently, would you rather (indirectly) fund the campaign of someone you don't want representing you, along with the campaign of someone you do, or would you rather have nobody you can trust to represent you on anything?</comment></comment></comment></comment>


How to beat the CAP theorem - <AUTHOR> http://nathanmarz.com/blog/how-to-beat-the-cap-theorem.html <comment><USER2> Article from 2011.

Previous discussion [https://news.ycombinator.com/item?id=3108087](https://news.ycombinator.com/item?id=3108087)</comment>


Sucking carbon dioxide from air is cheaper than scientists thought - <AUTHOR> https://www.nature.com/articles/d41586-018-05357-w <comment><USER4> Remember that, _a priori_ , you should be far more skeptical of studies with this sort of result than, say, studies showing that neocortinoids don't harm bees or that the latest blockbuster pharmaceutical has no side effects. The sheer mass of money in position to lobby for the "fossil fuel use is fine!" position dwarfs that of all other financially-fraught research questions put together.

To wit; the company behind the paper in question, Carbon Engineering, is noted by Wikipedia as having "oil sands financier N. Murray Edwards" as one of it's principal backers. And the article's "outside expert's opinion" quote comes from Stephen Pacal, co-director of the Carbon Mitigation Initiative at Princeton- which has an "extended partnership with BP" worth a great deal of money [1]. The financial conflicts behind this research are _staggering_.

[1] [https://www.princeton.edu/news/2010/11/18/carbon- mitigation-...](https://www.princeton.edu/news/2010/11/18/carbon-mitigation- initiative-receives-11-million-through-extended-partnership-bp)

<comment><USER5> this is kind of interesting as there's some reverse/upside down ideas that come out of it:

1\. the big oil companies and the massive political machine that supports them drops the whole "global warming isn't real" line, no more snowballs being taken in to congress and all that. Because now they can just say they'll suck it out of the air and they can continue to think they can keep burning all the coal and oil they want (which of course they should not). Once everyone is on the same page that global warming is real, they can't go back on that. If the approach here proves to be insufficient (which it probably is), a lot of political points have been scored in any case.

2\. the machinery to suck out the CO2 is another big "green" industry, like solar or wind, but _doesn 't_ compete with oil/coal! it's meant to mitigate the damage they do. So as you've noted, way more money and attention might end up going here, increasing the chance of its viability.

3\. No matter what happens with the rate of burning oil/coal, we _need_ this anyway. There's consensus that we're pretty much over the point of no return with warming due to all the ice that has melted, and if the permafrost goes that might be catastrophic.

<comment><USER6> Is anyone actually debating if climate change is happening? The debate is on the degree of human influence.

<comment><USER7> During the last ice age there is evidence that suggests the Earth's temperature rose 10-15 degrees in less than 10 years. In fact, during the last 110k years represented in the Greenland Ice Sheet Project the climate shifted dramatically multiple times over periods of a few years to maybe a couple of dozen years. During the last 110k years the most stable has been the last 11k years, which is kind of just dumb good luck for us living today.

Current anthropomorphic climate change models suggest we might see 2-3 degree changes in 100 years. I believe the science is likely accurate here. I support moving towards renewables and just about anything else generally supported by the climate change crowd. However, I think the panic button has been pushed a little too hard on this issue. I think things like overfishing the ocean and even plastics in the ocean are going to be bigger problems in the short run than human caused climate change.

Generally speaking this kind of nuance isn't allowed. The kind of response that says "If water rises a few feet, move a few feet inland, you've got a century of notice. If you have to farm over there instead of over here, then farm over there instead." is sacrilegious. To many, I would be considered a "climate denier."

<comment><USER8> The economic impact on the United States alone will be in the trillions. Relocating all of Manhattan, Toronto, London, Singapore, and other coastal economic centers is non-trivial, but would hopefully be gradual enough to be viable. It would be fantastic if we can avoid this loss of wealth by making a meaningful reduction in the rate of global warming.

Other nations are already experiencing famine due to permanent desertification. This has already exacerbated political and military conditions; drought is a major factor in the Syrian and other war zones.

To compare this to the range of human history is not meaningful. "They had it worse" isn't helpful for now. What matters is our response to the conditions that we are expected to experience.

Around the 120,000 BCE time, there was a "great filter" event that caused the mass death of most of humanity, causing a massive reduction in human genetic diversity. Yes, we may have it "easier," but today's problems are still real and must be dealt with.

I think it's useful to frame the climate change process solely in terms of human impact, and specifically economic, political, and security terms to governments.

I wouldn't consider you a denier, and it's important to share your perspective. I hope you consider mine.

<comment><USER9> The cost of the Iraq war is in the trillions. A cynic could argue that that war happened to secure burnable fossil fuels.

It isn't obvious that the cost being in the trillions is cause to blanch - <USER2> the scale we are talking, the cost of mitigating with more expensive energy is also likely to be in the trillions.

You might benefit from being more specific about how many trillions.

</comment></comment></comment></comment></comment></comment><comment><USER10> Doing a little math...

Considering 1100 Gtons in the atmosphere and $200 per ton would be roughly $220 trillions.

The current world's GDP is $78 trillions.

Even if the world invested $10 trillions every year it would still take 20 years to remove all the carbon emitted between 1850 and today.

Of course we would keep pumping about 37 Gtons per year (and growing).

[https://www.carbonbrief.org/analysis-global-co2-emissions- se...](https://www.carbonbrief.org/analysis-global-co2-emissions-set-to- rise-2-percent-in-2017-following-three-year-plateau)

<comment><USER11> This industrial approach to carbon dioxide removal is but one of several in our toolkit, and by no means the least expensive.

Project Drawdown ranks every approach in terms of tonnage of CO2 and cost. [http://www.drawdown.org/solutions-summary-by- rank](http://www.drawdown.org/solutions-summary-by-rank)

These approaches get amplified by a price on carbon. If you are interested in convincing your Member of Congress to price carbon, take a look at the most effective organization doing this work: [http://www.citizensclimatelobby.org](http://www.citizensclimatelobby.org)

<comment><USER12> Sure... educating specifically only the girls is #6 on the list.

Why would they have to bring feminism into that? I mean sure, it's a good thing to educate everyone. But why mix it?

How can I trust all the other points on the list now? What if they are also just pushing some other political agenda?

I can't. They just compromised the list's integrity by that.

<comment><USER13> Did you read that section to see why they think it'll help? It doesn't sound like politics to me.

<comment><USER12> Yes I did. Because educated people have fewer kids... Might be true, but what kind of reason is that even!?

Why not also establish a one-child policy in western countries? Or start actively killing sick people? /s

All the other reasons were basically how it makes lifes better for those women. Which is surely a good thing, but doesn't matter in that context.

</comment></comment></comment></comment></comment><comment><USER14> Apparently burning petrol releases about 2.31 kg of CO2 per liter. At 100 USD per tonne of CO2 it would cost 0.23 USD per liter of petrol if we captured every bit of CO2 released. That's within the realm of possibility.

<comment><USER15> Well that's a Holy Fuck moment for me.

I thought the parent here had made a off-by-orders of magnitude error - <USER3> can a liter of petrol (which itself is only a kg) produce 2.31kg of CO2 ... i mean work it out, all the carbon would have to attach to 2x oxygen ... ok that might just ... err ...

see this reference for a walk through of the calculation - [http://ecoscore.be/en/info/ecoscore/co2](http://ecoscore.be/en/info/ecoscore/co2)

Every time I pour petrol into my tank I am basically pouring twice that _weight_ of CO2 into the atmosphere.

I may be very dumb but I never thought if it like that before. I always assumed CO2 was a minor byproduct ... but like breathing.

oh dear.

<comment><USER16> > like breathing

When you eat 1kg of peanut butter, if I've done my math right, you'll breathe out about 2.3kg of CO2. Dry cereal would be about 1.5kg. Most foods have a lot of water in them, though.

<comment><USER17> I would think you're unlikely to produce sufficient bile to metabolise an entire kilogram of peanut butter at once. Most likely you'd get really nasty, oily runs at best, and quite possibly throw up.

</comment></comment></comment></comment><comment> 08-15 So they are talking about a plant, soon to be built, that will capture about 50.000 tons of CO2 per year. Amazing! A single coal fired power plant (1GW) emits 12 _million_ tons of CO2 per year.

Seriously, this stuff won't work, and it's pointless as long as fossil fuels are burned somewhere on Earth. It's bloody obvious what to do instead: (1) stop burning coal for electricity, (2) stop burning methane ("natural" gas) for electricity, (3) stop burning methane for process heat, (4) stop using methane to make fertilizer, (5) use electrified railways instead of trucks for most transportation.

 _Then_ it makes sense to talk about synthetic fuels, CO2 capture, electrifying the remaining transportation, etc, but not before.

<comment><USER18> Pointless? I wish I could back through history, and count how many times "experts" said certain ideas and endeavors were "pointless" just to have them become reality.

<comment><USER19> Just make sure you also tally up how many times they said 'pointless' and were proven right.

Spending time and resources on things that won't work (economically) does no one any good.

</comment></comment></comment><comment><AUTHOR> Substantial conversation on reddit: [https://www.reddit.com/r/science/comments/8pbuqv/sucking_car...](https://www.reddit.com/r/science/comments/8pbuqv/sucking_carbon_dioxide_from_air_is_cheaper_than/)

<comment><USER20> The r/science conversation crushes the HN conversation and is worth skimming.

</comment></comment><comment><USER21> Let's take this article at its word, which is that right now we can bury carbon for $600/tonne (forget the speculative $100/tonne) which equates to $1.32/liter of gas (based on the speculative $0.22/liter). In California right now gas costs ~$4/gallon (which is high compared to most of the US but low compared to most of the developed world), so it's not an insane amount to pay for carbon-neutral gas.

The interesting thing to me is that this is presumably something _ideal_ to do with excess solar power (e.g. it's a much better deal than paying other states to use it, which is what California is currently doing).

Another question is how does this compare, price-wise, to using solar power to create fuel (e.g. hydrogen) and truck it around the way we do with gas.

</comment><comment><USER22> All of the skepticism here in the top comments is well-placed.

This is basic thermodynamics: if you can burn fossil fuels to get energy/electricity, then putting the CO2 byproduct back into an inert form will cost exactly as much (or _more_ ; courtesy of the second law) as it would have to get that energy from a different source in the first place.

There is no technology - now or ever - that will make "scrubbing" CO2 more economical than simply leaving the oil in the ground, and using renewable energy sources.

<comment><USER23> Physics and thermodynamics don't actually use $ costs in their equations... e$ !== mc2

The costs you are referring to are in energy. It's entirely possible that the $ cost to put it back into the ground are cheaper than to get it out.

<comment><USER24> Hmm, mostly depends on where you put it. Putting it into ocean would probably be add hard as getting it out of there.

Except here we can put it into storage in a more convenient place.

The real problem is that we do not have enough energy to run this yet. A bunch of nuclear plants would solve it but these come with political baggage. Unfortunately CO2 recovery is very local.

</comment></comment></comment><comment><USER25> "The Paris Agreement's inclusion of 1.5°C has catalysed fervent activity amongst many within the scientific community keen to understand what this more ambitious objective implies for mitigation. However, this activity has demonstrated little in the way of plurality of responses. Instead there remains an almost exclusive focus on how future 'negative emissions technologies' (NETs) may offer a beguiling and almost free "get out of jail card". This presentation argues that such a dominant focus, evident for 2 and 1.5°C, reveals an endemic bias across much of the academic climate change community determined to voice a politically palatable framing of the mitigation landscape – almost regardless of scientific credibility."

Please read: [https://kevinanderson.info/blog/duality-in-climate- science/](https://kevinanderson.info/blog/duality-in-climate-science/)

The problem here is cultural, not scientific.

Real science about climate change is not politically palatable, NETs represent an easy way out.

<comment><USER26> And if we were trying to do real science we'd have to actually find proof of cause and effect. I still have yet to find convincing proof that CO2 is the culprit. Te level of CO2 in the ar should be addressed, but I am worried that we have culturally painted CO2 as such a bad guy that the underlying cause of global warming will never be found

</comment></comment><comment><USER27> The problem of climate change is the same as the obesity problem, if you phrase it like this: "There is something that is going to kill you in 20 years if you don't change your habits today".

Most people wait until they have a significant event (heart attack, they can't get up the stairs without being out of breath, etc) until they change.

I always figured it would take some sort of big event for people to change, and then when that happened, we would start working on retroactive fixes ( like sucking co2 out of the air ), rather than preventative fixes.

</comment><comment><USER28> The thermodynamics of this seems wrong to me. You would have to burn at least a ton of oil to draw a ton of carbon from the air, probably more like 2 tons due to inefficiencies. The cost of oil is 418 dollars a ton. So to make this even remotely plausible you have to assume access to an energy source which is 4 times cheaper than oil on a cost basis. So cheap, in fact, that unburning carbon from the air would be twice as cheap as mining it out of the ground.

<comment><USER29> hypothetically, if you burn 2 tons of oil and you get out of the atmosphere 1 ton of oil equivalent to burn, then if your emission-free energy cost is 1/2 the price of oil, you break even on cost, and reach carbon neutral, no?

Alternatively, if your emission-free energy cost is same as oil, you tax oil- based energy 100% and now you reach carbon-neutral?

I don't see why it has to be 4x cheaper, clarification would be helpful.

<comment><USER30> he's estimating the energetic i.e. objective cost. If the government subsidized to the point of us stopping pumping up oil or true fossil neutral rate (ignoring the CO2 already up there, which will over hundreds of years fall back to natural levels), then we would have to manufacture our fuels... with what energy? sure in the long term I think we can use renewable, but it isn't deployed yet. The only way this makes sense is if we deploy true renewable energy, and stop allowing fossil fuel industry to masquerade as green.

</comment></comment></comment><comment><USER31> Unless we stop burning fossil carbon, pulling carbon out of the atmosphere to create fuels that we will then burn makes zero sense, in terms of mitigating climate change; even if we used solar energy to do this, there would be no net decrease in carbon in the atmosphere. This only makes sense if we use a carbonless energy source and "permanently" sequester the carbon somehow.

</comment><comment><USER32> > The result, after further processing, is a calcium carbonate pellet that can > be heated to release the CO2. That CO2 could then be pressurized, put into a > pipeline and disposed of underground.

I'm curious why you wouldn't just bury the calcium carbonate pellets at this point (or sell them, since they have value). Pumping CO2 underground isn't a cheap or reliable process yet as far as I can tell.

> the company is planning instead to use the gas to make synthetic, low-carbon > fuels.

I suppose the answer is that the synthetic natural gas is more valuable than the calcium carbonate. Seems like adding more steps than strictly necessary though.

Edit:

> In the United States, Carbon Engineering is eyeing a recently expanded > subsidy for carbon capture and sequestration, which could provide a tax > credit of $35 per tonne for atmospheric CO2 that is converted into fuels.

Missed this bit in the article. Regulatory arbitrage, which is a very good reason to add another step in your process, even if it's not strictly optimal.

<comment><USER33> I haven't done chemistry in years, but I think you can fairly easily reuse the calcium carbonate pellet once it has been heated. I imagine the cost of energy is significantly less than the cost of the raw resources.

</comment></comment><comment><USER34> Economics and policies aside, I'm a bit skeptical about the approach described in that article regarding the use of potassium hydroxide (production, transportation) and it's subsequent processing (to re-release the captured carbon dioxide, somehow transform it into fuel, and let people release again!?); even just the logistics would most likely be releasing a good amount of CO2 if cost is such a huge factor in this.

It just __feels __like the carbon dioxide released would be a substantial offset to that captured. Ultimately, it would still be viable if the net outcome is a reduction in atmospheric carbon dioxide; but I'm not convinced, at least with the approach in question, that humanity's interest is at the top of the list.

It would be absolutely fantastic and very much appreciated if someone who knows about the actual "accounting" of carbon dioxide in this type of carbon sequestration technology can comment.

</comment><comment><USER35> Soooo, around $100/ton.

And google says we currently pump 40 billion tons per year.

Let's ballpark:

average 5 billion per year for 100 years.

500 billion excess tons.

50 trillion dollars to remove what we've already polluted.

\+ 4 trillion per year to offset what we're at already.

Yeah, nothing about that is "cheap". Maybe... slightly less astronomically expensive.

And a lot of cheap carbon capture is "pump it into the ground", which, while I'm not a geologist, but I'm guessing the petroleum folks aren't looking to hard for leaks back into the atmosphere.

But given those numbers, greening the sahara seems like a much better approach than any industrial approach.

</comment><comment><USER36> Based purely on numbers CO2 capture seems like a plausible idea. The article cites a cost of $0.22 cents per liter of fuel to capture an equivalent amount of CO2. Based on the current 93 million bbl or roughly 15 billion liters of oil consumed every day worldwide, the cost would be around 1.2 Trillion USD per year, or 1.5% of the global GDP. A lot but within the real of feasibility.

However to achieve that in practice we would need to build enough CO2 capture plants to capture the CO2 released by all human activity, and we've been building machines that release CO2 for decades. The effort to catch up is immense. The similar company Climeworks, cited in the article, has an example of such a plant here : [http://www.climeworks.com/our- products/](http://www.climeworks.com/our-products/). The DAC-18 variant, which looks like the prototype that they actually built, it is a complex 3 stories high structure with 90m^2 of ground area, and according to the product page it can capture 2460 kg per day, although that is probably under ideal conditions and in practice it could be considerably less. According to a quick search we released around 36.75 Gt of CO2 last year. To capture that, we would need to build 36.75e12/365/2460 = 41 million such plants, at the bare minimum. And that would be only break even, we'd need even more to start capturing the excess CO2 already in the atmosphere. That seems unrealistic.

<comment><USER37> Well, we could plant more trees, not deforest the Amazon.. Maybe grow some algae or something too.

</comment></comment><comment><USER38> Probably the most cost-effective way of sucking CO2 out of the air is planting trees on a huge scale.

<comment><USER39> A user on reddit did some napkin math on the r/science submission of this article. The tl;dr is we don't have enough land area for the amount of trees needed to sequester 1,100 gt of carbon.

[https://www.reddit.com/r/science/comments/8pbuqv/sucking_car...](https://www.reddit.com/r/science/comments/8pbuqv/sucking_carbon_dioxide_from_air_is_cheaper_than/e0aendn/)

<comment><USER38> Trees can't do it all, but they can help a lot and are cheap and we like trees!

</comment></comment></comment><comment><USER40> Bubblers and tubes of algae in the sun. The bubbles stir the algae to maximize growth. Add a few goldfish to help cycle nutrients[1]. You can get the algae so thick that a test stick (plastic spoon) can't be seen beyond a centimeter deep.[2]

At this stage you can remove _half_ of the algae each day and they'll regenerate within twenty-four hours.[3] The extracted algae biomass (mostly composed of atoms that used to be air or water) can be "upcycled" by feeding to higher organisms (fish, earthworms, etc.) or processed industrially for e.g. plastics, fuel, foodstuffs, whatever.

Ah, here we go, a few people are doing it already: [http://www.iflscience.com/environment/urban-algae-farm- gobbl...](http://www.iflscience.com/environment/urban-algae-farm-gobbles- highway-air-pollution/)

The important thing is it's cheap as heck and doesn't require fancy technology.

[1] Goldfish eat algae. Few in the tank makes it a simple aquaculture system.

[2] I looked for images of "tubes of algae in the sun" and most of them were transparent. If you can see through the tube you're doing it wrong.

[3] If conditions are optimal, otherwise you might have to be happy with 35-40%.

<comment><USER41> I'm bullish on algae but you may want to adjust your expectations. If you have a photobioreactor, with algae growing too densely to see through, in the sun, with goldfish, you're probably going to cook your goldfish.

You're talking about engineering an ecosystem, and it is fancy technology. pH, temperature, and salinity all need to be copacetic. There's a reason "everyone" does aquaponics with talapia and vascular plants. Aquaponic systems usually run at pretty abysmal water qualities, but talapia will live in mud and vascular plants don't mind having lots of nutrients in their water. Algae will have a hard time growing at that high density you're imagining if they're being shaded by murky brown water. Of course these systems will have pretty big algae blooms, but usually these are biofilms growing attached to the walls of the system, close to the surface.

If you feed the algae to other organisms, they're going to die and that carbon is going to turn into methane, which is 23 times more powerful a greenhouse gas than CO2.

There's also the matter of growing algae in tubes made of petroleum plastic. How much carbon went into mining & processing the petroleum, manufacturing your tubes, and transporting them out to where your facility is, 100 miles from the nearest Starbucks? How long will it take you to pay off that carbon debt? (If there's a biobased alternative I'd love to hear about it.)

But there are solutions as well as problems. Aquaponic systems don't have to be directly coupled, for instance. And those biofilms are much denser than planktonic growth (ie tubes). My main "research" area (calling me a researcher would be too generous) is attached growth cultivation systems, for a lot of these same reasons. Pyrolysis can be used to turn the carbon into a biochar with very low bioavailability, solving the issue with methane.

PS

Just to clarify, bubbling doesn't maximize growth as much as keep the algae alive. Keeping high-density algae well mixed does ensure that everyone gets their turn to be in the sun. But algae can't survive in an anoxic environment, and without aeration a tall column of water will quickly become anoxic. The algae on the bottom will rot and you're back to converting CO2 into methane (which, in most systems, would come right out of the top of the tube). Additionally, aeration provides CO2; no CO2 would mean no photosynthesis.

<comment><USER40> Thanks for the detailed response!

I'm on the crackpot spectrum but I'll try not to waste your time. :-)

As I mentioned in a different sub-thread, I started looking at algae as part of a system to reprocess oceanic plastic trash into biomass, so my particular ideas and designs are probably not going to be directly applicable to CO2 sequestration.

> I'm bullish on algae but you may want to adjust your expectations. If you > have a photobioreactor, with algae growing too densely to see through, in > the sun, with goldfish, you're probably going to cook your goldfish.

In the context of an ocean-going plastic recycling system I hadn't thought of heat pollution before because I assumed I would have the thermal mass of the ocean in which to dissipate excess heat.

To handle it you could: reduce the infrared light reaching the tubes; chill the incoming air with e.g. Ranque-Hilsch vortex tube [1]; put radiator fins on the shade side; use heat-tolerant fish; hang evaporative coolers in between the tubes; rotate the tube assemblies.

> You're talking about engineering an ecosystem, and it is fancy technology. > pH, temperature, and salinity all need to be copacetic. There's a reason > "everyone" does aquaponics with talapia and vascular plants. Aquaponic > systems usually run at pretty abysmal water qualities, but talapia will live > in mud and vascular plants don't mind having lots of nutrients in their > water. Algae will have a hard time growing at that high density you're > imagining if they're being shaded by murky brown water. Of course these > systems will have pretty big algae blooms, but usually these are biofilms > growing attached to the walls of the system, close to the surface.

I cheat: I went to a pond and scooped up water and some of the bottom muck. Start with a viable ecosystem; in the tank it wobbles but then stabilizes; my experimental system ran for months with no adjustments.

At scale, I'd adopt a kind of evolutionary attitude, any tube that went bad would be flushed and replaced with a colony from a healthy tube. Combine that with a simple automated feedback system to help keep tubes in the optimal ranges and I think it would be pretty stable overall (depending on the failure rate of the tubes.)

If you have one seawater tank in your living room you're gonna have to paper and baby that thing. If you have thousands of simple robust ecosystems in tubes and some go bad you can just flush 'em. (And if you're worried about contaminates, chemical or biological, you can flush them through the MSO reactor. Those things are used to dispose of ordinance and chemical weapons. They really _really_ break down molecules. _Mad cow prions_ wouldn't make it through. Heck, you could toss the tube in there.)

Biofilms are fascinating! FWIW, in the experiment I ran the fish kept the inner surfaces of the tube pretty clear, I didn't have to do any scrubbing.

> If you feed the algae to other organisms, they're going to die and that > carbon is going to turn into methane, which is 23 times more powerful a > greenhouse gas than CO2.

I want to experiment with feeding the algae to compost worms. These prefer just-slightly-decayed plant matter so I am thinking they would gobble up the algae as it died. Basically, you'd drain half the water in a tube directly into one end of a worm bed. The bed filters the algae out of water which also picks up nutrients. Some of the outflow would be put back into the tubes directly; the rest would be distilled to make a high grade fertilizer and the excess water condensed and returned to the tubes.

(The worms also eat their own dead. Gruesome, but it speaks to your point about turning into methane.)

> There's also the matter of growing algae in tubes made of petroleum plastic. > How much carbon went into mining & processing the petroleum, manufacturing > your tubes, and transporting them out to where your facility is, 100 miles > from the nearest Starbucks? How long will it take you to pay off that carbon > debt? (If there's a biobased alternative I'd love to hear about it.)

Well, bioplastic.[2] I'm also looking at drying out the algae in sheets and using [some kind of] glue to bond them into a membrane, as opposed to going through a chemical process to convert them into plastic. Once you've got sheets and glue you can build your structures out of inflatables. [3]

> But there are solutions as well as problems. Aquaponic systems don't have to > be directly coupled, for instance. And those biofilms are much denser than > planktonic growth (ie tubes). My main "research" area (calling me a > researcher would be too generous) is attached growth cultivation systems, > for a lot of these same reasons. Pyrolysis can be used to turn the carbon > into a biochar with very low bioavailability, solving the issue with > methane.

I hadn't heard of "attached growth cultivation systems" specifically but they make a lot of sense. Just skimming the wikipedia article I think I can see a lot of low-hanging fruit in terms of efficiency gains.

Are you aware of the "Living Machine" stuff?

> Living Machine is a trademark and brand name for a patented form of > ecological sewage treatment designed to mimic the cleansing functions of > wetlands. ... the latest generation of the technology is based on fixed-film > ecology and the ecological processes of a natural tidal wetland, one of > nature's most productive ecosystems.

~ [https://en.wikipedia.org/wiki/Living_machine](https://en.wikipedia.org/wiki/Living_machine)

To me biochar seems like a very exciting path for CO2 sequestration. Not so much on the ocean for obvious reasons, but if I had any land at all I would be trying it out.

> Just to clarify, bubbling doesn't maximize growth as much as keep the algae > alive. Keeping high-density algae well mixed does ensure that everyone gets > their turn to be in the sun.

Yeah, you explained it better than I did. Cheers. :-)

> But algae can't survive in an anoxic environment, and without aeration a > tall column of water will quickly become anoxic. The algae on the bottom > will rot and you're back to converting CO2 into methane (which, in most > systems, would come right out of the top of the tube). Additionally, > aeration provides CO2; no CO2 would mean no photosynthesis.

Well again, my ideas are developing in the context of a system that would have lots of CO2 already bubbling through a water column anyway. [4] If the bubbles are failing I've got bigger problems.

[1] [https://en.wikipedia.org/wiki/Vortex_tube](https://en.wikipedia.org/wiki/Vortex_tube) solid state; separates a presurized flow of air nito hot and cold portions. I suspect it has applications in separating gas mixtures.

[2] [https://en.wikipedia.org/wiki/Bioplastic](https://en.wikipedia.org/wiki/Bioplastic)

[3] [https://en.wikipedia.org/wiki/Tensairity](https://en.wikipedia.org/wiki/Tensairity)

[4] [https://en.wikipedia.org/wiki/Molten_salt_oxidation](https://en.wikipedia.org/wiki/Molten_salt_oxidation) MSO converts plastic to a mixture of H2 and CO; run that through a water column and you get CO + H2O -> CO2 + H2; so now you have a bunch of hydrogen and carbon dioxide. Run that through a vortex tube to separate the gasses, send the H2 to fuel cells and the CO2 to the algae tubes... Where there used to be oceanic plastic trash there is now power and biomass.

<comment><USER41> Thank you for your detailed response as well, it's always heartening to see people chipping at these problems. FWIW I've met plenty of crackpots and you are not one of them. You become a crackpot when you can't tell the difference between what is true and what you want to be true, not when your ideas are "out there".

Regarding your experiment with the fish, I suspect this is a difference in your environment, as you alluded to. I'm out here in the desert, and it is sunny and it is hot, and if you're maintaining a low evaporation rate there's no where for that heat to go. Algae don't usually mind though. If you deploy a tube out here it'll only be so long until it gets warped and won't accept a pig (basically a plug that moves along a pipeline & cleans the sides), so I'm very interested in this idea of having the fish clean the tube. But I suspect that the same technique would go belly-up for me, pun fully intended.

I completely agree with your evolutionary approach and with using ecosystems that are already functioning. I did the desert equivalent and found my attached growth culture under a rock.

I was not aware of Living Machine but thanks for pointing it out. I think a lot about a similar concept called Algae Turf Scrubbers ([http://algalturfscrubber.com/](http://algalturfscrubber.com/)) (also trademarked), which mimic coral reefs.

You clearly have put a lot of thought into this so I hope I'm not rehashing ideas you've already dismissed, but here it goes.

You may want to consider using fungi. They are the matchless experts in breaking down toxic material, and my inkling is that they will be the ones to crack the problem of digesting plastics. Some organisms have started to do this already. Fungi have the ability to learn and adapt as individuals, so they're more friendly to this sort of engineering than most complex lifeforms. Microalgae are of course fantastic because they evolve on human timescales.

Keep in mind that plastics aren't really pure hydrocarbons. It would be very nice if they were. But they'll come with paints and stabilizers and such, and you'll end up with heavy metals and other contamination (I won't pretend to understand the intricacies here). If this ends up in your biomass then it cannot be used for agriculture. Dirty biomass is usually fine for fuel production, however. I'm sure you've thought of this though and that I would see your reasoning if I understood MSO reactors better. What happens to this waste when it leaves your reactor is another big question.

Gas separation is hard. You might consider separating the nitrogen and calling that good. The more conventional approach would be to use a pressure swing absorber but I'm taking the impression you want to use your vortex tube for cooling as well as separation. I've never tried pumping pure CO2 through an algae culture, but I believe it will become toxic at some concentration.

Rather than feeding it to worms, you might consider an anaerobic digester. You'll still produce fertilizer but you'll also be able to capture methane, which you can blend with your H2 and send to a generator instead of a fuel cell. While they have the same problems with shading as aquaponic systems, AD effluents are a very good fertilization ratio for algae. (I'm remembering a lecture here so I don't have a source to cite & don't recall the ratio, I'm afraid.) Another advantage is that they can accept wet biomass, and harvesting is often the most expensive part of the process. The methane could be blended with hydrogen and fed into an off-the-shelf natural gas generator. But I imagine that you did choose fuel cells for a reason. My personal view is that developing technologies are expensive in terms of liability, and that you can only pick a few of them. So if I were you I wouldn't put fuel cells and a novel approach to gas separation in the same design. Of course methane can be converted to hydrogen through steam reformation, or it can also be used in a fuel cell. Maybe you can even put them in the same fuel cell, I don't understand this technology whatsoever.

I've also got some more open ended questions you might find interesting to think about.

Are you planning to do this on a barge or derrick? How will your process effect the chemistry of the ocean around you? How will that effect the marine life around you?

If you're concentrating metal contamination and taking water in from the ocean, can you recovery dissolved metals? Perhaps you can combine this with desalination?

Is there a way your project can help with ocean acidification?

This talk seems to paper over a lot of problems with this system (its one of those "CO2 to methane" systems), as a TED talk does, but it's an interesting idea & related to your problem space.

[https://www.youtube.com/watch?v=X-HE4Hfa- OY](https://www.youtube.com/watch?v=X-HE4Hfa-OY)

You're probably aware but some people are producing hydrogen from algae. Could enhance your yield.

[https://en.wikipedia.org/wiki/Biological_hydrogen_production](https://en.wikipedia.org/wiki/Biological_hydrogen_production)

</comment></comment></comment></comment><comment><USER42> This is good news, esp. given the context from this spectrum article why we need some technologies like these..

[https://spectrum.ieee.org/energy/renewables/what-it-would- re...](https://spectrum.ieee.org/energy/renewables/what-it-would-really-take- to-reverse-climate-change)

</comment><comment><USER43> I'm curious how this competes with a bunch of algae in a lake

</comment><comment><USER44> It seems like at $94/ton CO2, we're still a long way from where this becomes viable.

At that price, to offset humanity's annual 36 Gt CO2 emissions (36 _billion_ tons) we'd need to spend about $3.2 trillion. Per year.

Surely the cost of _reducing_ CO2 emissions - the cost of upgrading emissions sources to alternative, lower-carbon technologies - is much less than $94/ton. And that's where we should be focusing our efforts and funding for the foreseeable future.

</comment><comment><USER45> They say they can make synthetic fuel at $1/liter with CO2 input at $100/ton. There's plenty of CO2 available commercially at about $20/ton. If they can make synthetic fuel economically out of CO2, they should be doing that RIGHT NOW, not waiting until they've perfected the air extraction process.

They could use the money they made from the fuel to speed up R&D on the extraction process.

</comment><comment><USER46> Y Combinator is actively looking for companies working on this. If you are working on this yoiu should consider applying.

[https://www.ycombinator.com/rfs/#carbon](https://www.ycombinator.com/rfs/#carbon)

[https://www.greentechmedia.com/articles/read/y-combinator- is...](https://www.greentechmedia.com/articles/read/y-combinator-is-looking- for-carbon-removal-startups#gs.2Xq_2VI)

I'm the YC partner who wrote the RFS and have been pushing this. I also went to the first conference of Negative Emissions in world (I think) in Gothenburg, Sweden last month.

It's clear that much of what is needed for this to work is coming together 1) Research on underground storage is in a great place 2) Climeworks and Carbon engineering + Klaus Lackner are the pioneering companies/researchers working on Direct-Air-capture and they've shown the technology works. 3) California recently/are currently implementing legislation that will allow companies up to $180 per ton carbon removed and sequestered. This should be more than enough to build a business doing this at scale. 4) Perhaps the most important timing question is the fast drop in energy costs driven by solar. Energy is the number once scaling cost-factor if you want to scale this up to have a material impact on the climate. Solar is the obvious choice here since there is barely any scaling costs once installed. California incentives also allows you place your installations anywhere in the world. Mojave desert would be a good place.

What is needed right now is you guys. We need entrepreneurs and founders who want to start companies building both Direct-Air-Capture technology and sequestration technologies. I've met many investors over the last 6 months are looking actively to invest in these projects.

If you are working on these technologies you can email me email@example.com

Two other great resources here are

[http://www.centerforcarbonremoval.org](http://www.centerforcarbonremoval.org)

[http://www.airminers.org](http://www.airminers.org)

I'm convinced that whoever will build the most cost-effective way to remove carbon from the air will both have a shot at a $100B+ market while saving the earth at the same time. What could be more motivating?

<comment><USER40> Do you have any interest in algae-based solutions? (Cf. my comment in this thread I just left: [https://news.ycombinator.com/item?id=17268103](https://news.ycombinator.com/item?id=17268103) )

I've done some crude experiments and "back-of-the-envelope" calculations and I think there's "something there". FWIW)

<comment><USER46> We have interest in anything where cost-efficient carbon removal is the goal.

We're not picking technologies at this point since no-one really knows. Personally, I'm more excited about Direct-air-capture than I am about bio- energy with carbon capture for a bunch of reasons. Storing carbon in oceans is also interesting. Whatever path we see as a truly scalable way (like, can you 10000x your prototype and get costs benefits for example)

<comment><USER40> Okay, cool. If I come up with anything I'll drop you a line.

I started looking at algae as a way to convert oceanic plastic garbage to something organic.

You can use Molten Salt Oxidation [1] to convert plastic to "synthesis gas" [2] then feed that through a water column to convert CO+H2O to CO2+H2, then recover the hydrogen for power and feed the carbon dioxide to algae tanks.

I was going to try feeding the algae to e.g. _eisenia foetida_ compost worms [3] to make soil and then grow whatever in that. The basic idea was to turn oceanic plastic into biomass.

But then I learned that you can make plastic out of algae. In order to be able to scale the system (without capital) it should be designed to produce as much of its own structure (like a "reprap" self-replicating machine) as possible. The limiting factors should be CPUs and magnets (for motors.)

But this is predicated on being isolated in the middle of the ocean and not having access to capital. I can't evaluate the optimal way of using this stuff in the context of being close to the rest of the economy and with capital, as there are too many variables and I'm kind of ignorant and stupid. (In other words, in a hypothetical universe where someone gave me a big pile of money to try this, the first thing I would do is recuse myself in favor of someone who actually knew what they were doing.)

[1] An exothermic reaction [https://en.wikipedia.org/wiki/Molten_salt_oxidation](https://en.wikipedia.org/wiki/Molten_salt_oxidation)

[2] "fuel gas mixture consisting primarily of hydrogen, carbon monoxide, and very often some carbon dioxide" [https://en.wikipedia.org/wiki/Synthesis_gas](https://en.wikipedia.org/wiki/Synthesis_gas)

[3] [https://en.wikipedia.org/wiki/Eisenia_fetida](https://en.wikipedia.org/wiki/Eisenia_fetida)

<comment><USER41> It's called synthesis gas for a reason, if you have syngas, catalysts, and fricktons of energy you can do a lot of things, including making precursors for plastics through Fischer-Tropsch synthesis.

</comment></comment></comment></comment></comment><comment><USER47> What's that old saying... usually misattributed to Einstein... you can't solve a problem using the same frame of mind that created it? We have a problem of too much CO2 caused by massive deployment of complex, energy-intensive industrial facilities and processes, and they want to fix it using a fairly complex and energy-intensive industrial facility/process (with giant air blowers and all), that itself is dependent on other complex industrial processes for its manufacture, transport, construction and operation. And perpetual energy use to run the fans... I mean? Are we sure it's a net positive CO2 capture after all that? And if so, is it still a net positive after the CO2 they've captured is turned (by means of even more energy input) into "low carbon fuels" that are then burned, releasing CO2 back into the atmosphere?

I mean it's great if it works and all. I just feel like the real solution doesn't look like this.

</comment><comment><USER48> In a few years I'll probably have grandkids and when I read this, think it increases the chance that those kids will still be able to go to Disney World in Florida, i.e. it will not be submerged.

<comment><USER49> By that time Disney world will just be a VR app you load on your 8k VirtualStation via fiber optic link with others. Disney will long have replaced all their parks with simulation because focus groups found that while consumers preferred the real park, the amount of lost park sales was less than the gains of zero liability, shutting down the park and firing those employees who were eating into shareholder profits. The park now only exists as a museum and luxury apartment homes, with paid autonomous bus tours.

</comment></comment><comment><USER50> "Climeworks has also opened a second facility in Iceland that can capture 50 tonnes of CO2 a year and bury it in underground basalt formations. "

Taking Oxygen from our atmosphere (the gas we need to breathe) and pump it underground after we've combined it with Carbon seems like an atrociously bad idea.

Taking CO2 out is only half the battle. We're going to need that oxygen. Pumping it into greenhouses seems better, but not very cost effective: You need to build these machines, then build the greenhouses, then transport tonnes of CO2 to the greenhouses... Seems much more cost effective to build windmills, solar arrays and the like!

<comment><USER51> Earth's atmosphere is 20.946% O2 and .047% CO2. The amount of oxygen tied up in CO2 these days is really tiny.

</comment></comment><comment><USER52> Good. Then we should immediately require fossil fuel companies to do this or pay for someone else to do it as well as long-term storage and insurance for the storage.

</comment><comment><USER53> This machine does the work of six people. Unfortunately, it takes ten people to operate it.

</comment><comment><USER54> Yep, just plant a tree or two ;)

</comment><comment><USER55> What if we all plant 2 trees each in our lifetime?

</comment><comment><USER56> Are these machines cheaper than trees?

</comment><comment><USER57> Wouldn't it be likely that the greater than percentage of free CO2, the cheaper removing CO2 will get per ton? Trump's intransigence could make this technology viable.

</comment><comment><USER58> Here's a related article that circulated in finnish media a few days ago: [https://yle.fi/uutiset/osasto/news/finnish_researchers_use_a...](https://yle.fi/uutiset/osasto/news/finnish_researchers_use_air_solar_power_to_create_renewable_hydrocarbon/9661164)

This is about the apparent work of a Finnish researcher to come up with a scalable way to produce fuel from air such that it can be done locally. Think gas stations producing their own gas. Right now this would be relatively expensive because of energy cost but as those drop and the technology is improved, that cost can go down.

Stuff like this not surprising for anyone that has followed news around renewables lately and a very cool side effect of the fact that renewable energy prices have been dropping exponentially for quite some time now combined with the fact that the cost of lots interesting chemical processes are primarily driven by how much energy is required. As energy becomes cheaper, those chemical processes become more feasible and the demand for more energy causes people to invest in making that cheaper further. The same economic dynamic that is causing us to destroy our planet is also producing the solutions for saving it.

For example, producing clean water is a trivial process if you have cheap energy. This is why desalination plants are popping up in lots of places where clean water is scarce and they tend to be paired with wind/solar plants. You can also produce fuels out of water and the resulting fuels, whether it is hydrogen or hydrogen peroxide, are useful ways of storing energy.

Oil is a scarce resource that is hard to procure and therefore relatively expensive. If there's an energy intensive way to produce oil from CO2, that's great news because that means it's just a matter of time before the price of that energy drops enough to make that worthwhile.

Things like this can go from being too expensive to only slightly more expensive to being magnitudes cheaper in the near future.

What I love about this is that climate change can be countered with simple economics rather than idealism. Once we stop pumping new co2 in the atmosphere for cost reasons because we found a more cost effective way to just suck it from the atmosphere, nature will do it's thing and help us revert the effects of the past centuries. We don't actually need to actively clean up the atmosphere, our planet is fully capable of doing that by itself given enough time.

Also worth pointing out that oil is used for more than just fuel. So, stuff like this is relevant even if we switch to electric vehicles. We still need to produce plastics and other materials. All of that can in principle be done with co2 harvested straight from the air as well.

</comment><comment><USER59> It would be cool to have a country which used the rest of the world's pollution to create it's own energy.

</comment><comment><USER60> Its not profitable to clean: even if cleaning was paid for by the government, most cleaning efforts would be commercial enterprises simulating maximum cleaning effort(like the incentive to collect rat tails will result in rat breeding farms, the "environment cleaning industry" will be most profitable with more pollution and costlier cleaning incentives/bonuses ).

It will result in encouraging more pollution and removing all safeguards(clean coal? we'll clean it up later!) towards a new industry whose main interest would be preserving pollution forever to profit from cleaning it up.

Like a pharmaceutical industry, the symptoms are more profitable than curing the disease completely.

</comment><comment><USER61> I worry that well-meaning efforts at mass climate engineering will cause far more harm than letting nature run her course.

I'm not convinced there is a causal relationship between human activity and CO2 levels or average temperatures (ignoring urban heat island and similar effects). Sure there is a correlation, but we all know what that means. The kind of atmospheric engineering that scares me is exactly the tool that would be required to show a causal relationship.

Another point of concern is that none of the doom and gloom predictions are made by any climate model. All a climate model can do is make predictions about, well, climate. It takes an economic or some other sociological model to predict how that change in climate will affect human beings and societies, and what the costs (and benefits!) will be. Even if you trust the climate models 100% you'd be a fool to trust the economic or sociological models. How can one rationally justify an intervention is worth the cost when one can't know the cost of what is being prevented?

<comment><USER62> You should take a look at: [https://xkcd.com/1732/](https://xkcd.com/1732/)

If you still think that humans are not the cause, well…

<comment><USER63> Using a comic strip as an argument, well...

<comment><USER64> XKCD has a long history of citing their work, why can't an effective argument be made with visuals? I don't understand why the medium of the argument matters here.

<comment><USER63> There is no argument made, it's a comic strip.

<comment><USER64> There is definitely an argument made. It might not be in the form that you're looking for, but the argument is there. The graph clearly points to a high correlation between the industrial revolution and a fast and huge (relative to other changes) rise in temperatures. How is this not an argument?

<comment><USER63> Yes, very clearly, sure. You don't even know the very basics of scientific methodology, statistics, interpreting data, or critical thinking.</comment></comment></comment></comment></comment></comment></comment>