Efficient Process for the Production of a Drop-in Diesel Fuel Oxygenate from Bio-succinic Acid

This SBIR project will develop a new process to produce diesel fuel oxygenates from bio-succinic acid and bio-butanol, which are produced in existing biorefineries.Biorefineries produce large quantities of C5 sugars, which are now commercially fermented to bio-succinic acid (C4O4H10) and bio-butanol (C4OH10). What is needed is an efficient means to convert these biomolecules into useful products such as diesel fuel oxygenates.TDA Research is developing a new catalytic reactive distillation process to convert succinic acid and bio-butanol into the diesel fuel oxygenate dibutyl succinate (DBS), DBS is an excellent solvent and is miscible in both diesel fuel and biodiesel. It acts as an oxygenate to reduce particulate emissions. It also is an excellent low temperature additive, reducing the cloud point and improving winter weather use, especially for biodiesel. The formation of dibutyl succinate is equilibrium limited, thus a reactive distillation process offers the advantage of greatly simplifying the process and maximizing the product yield. TDA Research is developing an extremely efficient and environmentally friendly conversion process based on reactive distillation using our proprietary water-tolerant, high stability solid acid catalyst. The use of a solid catalyst vastly improves the environmental impacts, and simplifies the process making it more efficient. Our catalyst is unique because it is stable in the presence of water at elevated temperature, whereas virtually all solid acid catalysts suffer from degradation and loss of activity under these process conditions.The proposed DBS fuel additive will liely be cost competitive because not only is our process very efficient, but the raw materials are based on existing bio-based production having suitable costs for the application.