(225a) Estimation of Synthetic Diesel Fuel Production from California's Carbonaceous Waste Streams Using Steam Hydrogasification

Research on alternative sustainable fuels is gaining momentum around the world due to the depletion of fossil fuel reserves, especially crude oil, combined with the surging global demand and also environmental concerns. A new three step thermochemical process for the co-production of synthetic fuel and electricity is being developed in the College of Engineering ? Center for Environmental Research and Technology (CE-CERT) at the University of California, Riverside. Most carbonaceous feedstocks such as coal, wood, agricultural residues, municipal solid wastes, etc can be converted to sulfur free liquid diesel fuel using this process. A detailed description of the technology will be presented. This study also provides life cycle and energy analyses and impact of global climate change on the production of synthetic fuels using CE-CERT's thermo-chemical process with several feedstocks; (1) carbonaceous biomass wastes; such as agricultural residues; municipal solid waste (MSW) and forest residues (2) coal with and without carbon sequestration (3) a non-food crop such as switch grass. The application area considered is California although the energy and life cycle analyses are applicable everywhere. The major findings of the study are:

1. The annually generated carbonaceous waste streams in California which include agriculture residues, municipal solid waste and forest residues account for over 27 million Mg of carbon per annum;

2. The estimated annual production of sulfur free diesel fuel utilizing this material is 53 million barrels which can replace 74% of California's crude oil based diesel fuel used for transportation. It should be emphasized that this includes feedstock estimates that maintain sustainable agriculture but does not include growth of a light duty diesel fleet.

3. Well to wheel analyses of green house gas emissions and range were calculated for 10 feedstock/fuel/vehicle combinations. It was found that a conversion to a diesel fleet of passenger vehicles using a synthetic diesel fuel generated with biomass (switch grass) as the feedstock would provide the most efficient fuel/vehicle mix for reduction of green house gas emissions and cost/km using a fully sustainable feedstock (switch grass). Cellulosic ethanol with spark ignited engine technology was the second most efficient scenario.