Q & A > Question Details
Glycerol is produced as by product in the Transesterification process for Biodiesel. Please give your views on the following:
1. What are the present practices for handling this glycerol?
2. Glycerol can be converted to Hydrogen. Have processes and catalysts been developed?
3. Does the above process for Glycerol to Hydrogen require any treatment of glycerol.
4. Any views/suggestions on the handling of glycerol?
 
Answers
01/07/2011 A: Rajeev Kumar, Bharat Petroleum Corporation, rajeevkumar@bharatpetroleum.in
Glycerol valorizations through chemical routes require to meet feedstock criteria for glycerol purity level. In this case, the processes opted for biodiesel is important. Hetrogeneous processes claim for glycerol purity high and thus, utilization of glycerol for either chemical and/or hydrogen production require no pretreatment. However, glycerol produced by conventional base-catalysed homogeneous transesterification processes contain many unwanted impurites e.g., soaps, caustic (up to 2-3%wt) etc and thus pretreatment would be essential.
Hydrogen production from glycerol would require detailed economic feasibility. Entry of natural gas sources for hydrogen has already affected the market. However, chemical routes are being attempted with pretreatment of glycerol obtained from biodiesel processes.
In general, glycerol reacts with organic and inorganic acids to form aldehydes, esters, ethers and many derivitives. The presence of multiple alcohol groups (OH) facilitates the formation of polymers and coatings (e.g., polyesters, polyethers and alkyd resins etc.). There are various ways to chemically modify the glycerol for value additions e.g., oxdiation, reduction, amination, halogenation, esterification and etherification etc.
24/04/2008 A: Amarjit Bakshi, Refining Hydrocarbon Technologies LLC, abakshi@rhtgulfcoast.com
Apart from some chemical routes to other chemical compounds the easiest way is to decompose Glycertine thermally to hydrogen and other light hydrocarbon in the range of LPG. Hydrogen will have to separated by PSA and other means to high purity if that is desired requirement. But if this not tied to a Refinery and hydrogen is not required but light gases from thermal decomposition can be used in power generation and other uses in the Bio-diesel plant.