(532g) Synthetic Natural Gas Production Based on Steam Hydrogasification of Agriculture-Derived Waste Streams

California is the largest producer of agricultural products in the U.S. and holds almost all of the nation's top ten agricultural counties according to the Census of Agriculture by the USDA. In particular, the Central Valley of California is one of the world's most productive agricultural regions and many Valley’s counties (e.g. Tulare, Kern) are at the top of the nation's agriculture producing counties. Accordingly, California generates more than 20 million dry tons of agricultural residues per year and the Central Valley has the highest concentration of agricultural wastes (e.g. orchard and vineyard pruning, crop residues, animal manure). In addition, the Valley is home to the largest concentration of dairies in California. For example, Tulare County is the largest milk producer in the United States. Hence, treating regional agricultural wastes and dairy wastewater sustainably to mitigate the negative environmental impact is highly needed. Steam hydrogasification reaction (SHR) based process is an advanced and self-sustainable technology that can convert high moisture content feedstock into renewable energy and fuels without costly drying process. In particular, SHR-based process does not need external hydrogen and water supply (i.e. internal recycle) except for the startup. The Department of Energy National Energy Technology Laboratory has performed an in-depth techno-economic analysis of the SHR-based process and confirmed that it has the potential for 12% higher efficiency at 18% lower capital costs compared to other state-of-the-art gasification technologies. In this study, the SHR-based process was used to synergistically treat the commingled agricultural wastes (e.g. dairy wastewater, orchard pruning) for the first time. The experimental data showed that SHR-based process led to high carbon conversion and desired syngas composition for further downstream upgrading. An Aspen model will be developed to evaluate the techno-economic feasibility of this new process on a pilot scale.