Hydrogenolysis is a reaction where hydrogen is added to a compound and breaks that compound’s bonds, forming two molecules as a result.
Johnson Matthey's DAVY™ hydrogenolysis technology reacts hydrogen gas (H2) with a vapour-phase carbonyl compound.
We employ DAVY hydrogenolysis in various flowsheets, including our natural detergent alcohols (NDA) process, which converts fatty acid methyl esters (FAME) to fatty alcohols:
In addition, our DAVY butanediol (BDO) process employs hydrogenolysis to convert dimethyl maleate or dimethyl succinate to BDO and gamma-butyrolactone (GBL) products:
Also, our DAVY n-methyl-2-pyrrolidone (NMP) process employs the route to GBL shown above.
In the examples above, an esterification step precedes hydrogenolysis to convert an acidic feed to a non-acidic ester.
An ester feed greatly simplifies the process, as DAVY ester hydrogenolysis can proceed in the vapour phase over a fixed catalyst bed. This is in contrast to acid hydrogenolysis, which usually requires a more complex, slurry-based procedure.
Hydrogenolysis also drives our propylene glycol flowsheet, where a fast dehydration reaction converts glycerol feed to a carbonyl, before reaction with hydrogen completes the process.
The overall reaction proceeds as shown: