(466b) Sustainable Energy and Transportation: Engineering the 21st Century | AIChE

(466b) Sustainable Energy and Transportation: Engineering the 21st Century


Holtzapple, M. T. - Presenter, Texas A&M University

With the world's population and standard of living rapidly rising, the demand for petroleum-based fuels is increasing at record pace. Given the time required to develop and implement new energy sources, failure to develop sustainable alternative fuels now could mean widespread energy shortages and other economic and ecological problems by mid-century.

This presentation describes the MixAlco process, a novel method for producing fuels from biomass, such as municipal solid waste, agricultural residues, sewage sludge, and manure. In this process, the biomass is treated with lime and air to enhance digestibility. Then, the lime-treated biomass is fed to a mixed-culture of microorganisms that produce carboxylic acids (e.g., acetic acid). In the fermentor, the carboxylic acids react with calcium carbonate buffer to form carboxylate salts (e.g., calcium acetate). The salts are dried and thermally converted to ketones (e.g., acetone). Finally, the ketones are hydrogenated to alcohols (e.g., isopropanol), which may be used as motor fuel.

In addition, the presentation will include the high-efficiency StarRotor engine, which could triple automotive fuel economy while reducing pollution. It employs the Brayton cycle, the same thermodynamic cycle used in jet engines. It uses a positive-displacement compressor and expander, which gives it more operational flexibility than conventional jet engines.