Formic Acid: Oxalic Acid Heated with Glycerol, Lorin's Method

Crystallised oxalic acid warmed with glycerol at 75–90 °C gives off carbon dioxide and turns into formic acid; each fresh portion of oxalic acid frees more, which distils over at 87–88 % (Lorin, in Thorpe 1912). The glycerol is formed again each time, so it can be used over and over. The picture: our diagram of the cycle.