What would be good preservatives for chili to give it a longer shelf life?
The only way that I know to put up chili for storage other than freezing is pressure canning.

The National Center for Home Food Preservation has a recipe for pressure canning, in which they process it for 75 minutes (which doesn't include the ramp up &amp; pressure release times), so you're looking at close to 2 hrs per batch, when you include the time to set all of the cans in the pot, remove 'em, etc.

I've never tried it, so I have no idea what pressure canning ends up doing to the texture and flavor of the chili.  I also don't do pressure canning, so I have no idea what all of the issues are (eg, if acid levels are as significant as with normal canning) and thus how much you can vary a recipe without risking problems.