12V DC to 220V DC Boost Converter
Read the comments first, they are all true.

Now suppose that a circuit like this would be used to generate 220V DC at 70W. The voltage at the drain of your mosfet would reach 220V. The poor thing is rated for only 100V :(

Next, 70W at 12V is ~ 6A average. Due to losses it will be higher, and because it is switched the peak will be much higher. Your mosfet is rated up to 1A :( 

You have an 1N5817 diode in your circuit. It is rated for a reverse voltage of 20V, so it would probably break even in the original use of generating 30-60V.

With a more suitable diode the output elco (100V/33uF) would not survive 220VDC.

On the topic of elco's: for a circuit like this you can't grab just any elco, it would not survive the peak currents for long.

Your circuit seems to lack any form of feedback, so without a load the generated voltage might be totally off the scale. 

Those are some problems I could find quickly. I am not an expert in SMPS design, far from that. But I do know that I should not attempt to build one for such voltages and power.