The chemistry, process technology and production economics for six different routes to “green” propylene are presented.  Feedstocks for the various approaches include ethanol, biobutanol, biomass, and vegetable oil.  Regional supply/demand forecasts for propylene are also provided.

Various approaches for biomass gasification are assessed including pyrolysis, staged gasification, and indirect gasification. Associated issues such as biomass availability and downstream syngas-based technologies, such as fermentation, mixed alcohols synthesis and FT syntheses are presented. A case study comparing the production economics of n-butanol via biomass gasification versus conventional propylene oxo synthesis is given.

Conversion costs of sugar-cane and corn-based ethanol to ethylene and then to polyethylene are compared to the costs of polyethylene made from ethylene produced in an ethane cracker.  The costs of biomass gasification to syngas to methanol to ethylene (via MTO) and finally to polyethylene are compared to the above routes.

The process technology and production economics of both synthetic and fermentation ethanol is presented. Supply/demand issues in key ethanol producing countries is also provided.