Glycerin from the biodiesel production process could have a new use, and it’s coming from a likely place: engines. ASTM is currently reviewing a series of new standards for glycerin that would allow the product to replace ethylene glycol in antifreeze. The standards are currently in the Subcommittee D15.93 on Research and Long Range Planning. In the 1920s glycerin was used in antifreeze but in the ‘30s it was replaced based on higher costs, according to a statement by ASTM.

The biodiesel industry has been searching for economically viable uses for the product for a number of years, and companies like Renewable Energy Group Inc. have also recently stated their interest to pursue use of glycerin as an additive in biobased chemicals. Deborah Baldwin, product manager for glycerin at Vantage Oleochemicals, said in a statement on the glycerin standards that the committee needs to determine what the appropriate grade of refined glycerin would need to be to ensure engine compatibility and use with engine seals. “We settled on 99.5 percent pure glycerin,” Baldwin said. In addition to engine compatibility issues, she also said the committee still needs to determine the impurities present in the glycerin that “need to be controlled and measured.”

To this point the committee has developed two test methods to look at the glycerin, ASTM WK22966, Test Method for Determination of Glycerin Assay by Titrimetric (Sodium Meta periodate) and ASTM WK22967, Test Method for Determination of Fatty Acids and Esters in Glycerin. The inter-laboratory studies have already been completed and are currently on ballot. 

Along with these two standards, ASTM has also formed studies to look at specifications for engine coolant grades 1,2,3 propanetriol, specifications for glycerin base engine coolant for automobile and light-duty service and even specifications for fully-formulated glycerin base engine coolants for heavy-duty engines.

The glycerin committee is meeting May 18-19 in St. Louis to review the standards relating to glycerin as a possible option for antifreeze applications.