Dehydroxylation of glycerol on nickel-containing catalysts as a way to utilize it in the biodiesel production

Abstract

Catalytic dehydroxylation of glycerol in the flow regime is one way of recycling its surplus accumulating in the production of biodiesel. For the first time the possibility of glycerol dehydroxylation on the Raney Ni catalysts and Ni–Cr2O3 in flow units was investigated. It’s found that the Raney Ni catalyst is more active in the glycerol dehydroxylation compared with Ni-Cr2O3. The conversion of glycerol and 1,2-propanediol yield on Raney Ni are respectively 88 and 35 %, and on Ni–Cr2O3 –16 and 6,5 % at 220 °C and a 2 MPa hydrogen pressure. However, there is by-products large formation – ethylene glycol, simple alcohols and methane. Yield of by-product acetol significantly reduces, what is ultimately increases the efficiency of process at a hydrogen pressure more than 2 MPa. The Raney Ni catalyst can be used for glycerol dehydroxylation in the flow-through units in relatively mild conditions – at temperatures up to 240 °C and pressures up to 2 MPa.