Most all of it comes as a side product. The amount of CO2 used for the applications listed pales in comparison to the amount used for urea (fertilizer) production.
What is different is that urea requires a power source that creates more CO2 than the chemical process uses. So you will certainly (as long as you are using fossil fuels) have a source available.
Those things I mentioned buy their CO2 on the market. I have no idea where it comes from.
Urea production requires ammonia, and the production of ammonia produces co2 in large quantities. It's not without reason the two are almost always loacted closely
Great point & not so often talked about. Something like 230Mton of CO2 are used each year, a little more than half goes straight to urea production. By contrast only about 10% goes to the food/bev, medical, and other applications we are more familiar with on a day-to-day basis.
Those things I mentioned buy their CO2 on the market. I have no idea where it comes from.