Expert: Dr. Henry Boyter, Jr. - 8/2/2007

Question
Hi, I'm also an expert here (general cancer-oncology, brain tumors, breast cancer, colon cancer, history & military history). I'm considering writing a story. In it it is important for the main character to be able to produce sulphuric acid under VERY primitive conditions and with very simple means. He has access to gypsum (calcium sulphate). Is it possible to drive out SO3 from gypsum by only using heat and turn it into sulphuric acid by combining it with water. I do understand that that will be somewhat dangerous due to the high heat produced when SO3 reacts with water but the problem is can SO3 be obtained from gypsum just by the application of heat just as it can be from iron vitriole or alum. He needs the sulphuric acid in order to make nitric acid usin salpetre from manure. The end result of these efforts is to make gun cotton from linen. Possible? Sorry to bother you with this. But even my old school chemistry books almost 50 years old were too high tech for this. Thanks!


Answer
Your problem is going to be the high heat needed.  Some sources say 1000C.  You can never do that with primitive conditions and catching the SO2 involved would be problematic.  You would be much better off burning sulfur to get the SO2 and you do it at a lower temp.  The products formed will be more pure also.

http://www.cellchem.com/docs/products-services/sulfur_dioxide.htm

One method using gypsum is given in the reference.

http://www.patentstorm.us/patents/5842853-description.html

Then you will need a way to distill the sulfuric acid you form.

http://www.oki.com/en/otr/html/nf/otr-160-10-3.html


So the answer is that it is possible, but under primitive conditions, you may need the professor from Gilligan's Island.