Formic acid needs very careful handling, since it's highly corrosive and volatile. There are more safe reagents that can produce CO by reacting with concentrated sulfuric acid, f.e., sodium formate, citric acid, and potassium ferrocyanide. Since concentrated sulfuric acid may be difficult to obtain, alternative reactions are worth considering as well. F.e., CO can be made by thermal decomposition of sodium oxalate.
I've seen you mention sodium oxalate before, but I'm not sure if or how this could work.
The Wikipedia article on sodium oxalate states that decomposition begins at 290°C, but that doesn't necessarily mean that we can produce sufficient amounts of CO at this temperature. The paper that is referenced in the Wikipedia and from which the 290° number is taken suggests that "the thermal decomposition of sodium oxalate may be incomplete at temperatures up to 740°". They achieve 100% CO recovery after a heating time of 20 minutes at 750°, but only 87,7% after a heating time of 30 minutes at 740° which seems quite drastic for a 10° difference. Most heating plates and mantles only achieve 450°, more expensive ones 650°. That's pretty far from the 750° and so I'd expect the decomposition to take much longer and remain incomplete at these temperatures.
And it's not like we can tolerate a partial decomposition that gives us, say, only 10% since the amount of CO produced is already realtivly low compared with the acid method. I tried to calculate it earlier and if I recall correctly we get about 16 liters of CO from 100g of sodium oxalate assuming a perfect reaction, whereas we get roughly 50 liters from 100g of formic acid.
Also, you seem to know some chemistry. Do you think it would be possible to use phosphorus pentoxide instead of sulfuric acid (haven't found a source for this) as a dehydrating agent for formic acid?
