Biological and Agricultural Engineering

Energy Systems Engineering

Energy is fundamental to all human activities, and its ready availability in agriculture, industry, transportation, and commerce is crucial to the California, US, and world economies. After remaining nearly constant for two decades, US per capita consumption of energy has begun to climb again, echoing trends of the period from 1950 to 1970. Simultaneously, world demand for petroleum and other premium fuels is increasing in concert with world population growth and industrial development in the third world, with consequent concerns over local as well as global environmental impacts and energy supply and cost. Deregulation and restructuring of the electric power industry provides new opportunities for unconventional energy resources and technologies. New energy resources and improved energy technologies and consumption strategies are needed to meet increasing demands for energy and environmental quality. Research in biological and agricultural energy systems is associated with both energy generation and optimization of use. Related activities focus on pollution control and waste management, often combining a potential to generate useful energy with methods to improve the environment.

Photosynthesis is currently our primary industrial conversion path for solar energy. In addition to food, fiber, animal feeds, and other commercial commodities, agriculture and forestry produce plant biomass, either as residue or as the primary crop product, that can be utilized as a renewable fuel resource. Biomass production and utilization have important environmental benefits, including near neutral greenhouse gas emissions due to annual recycling of carbon and oxygen where biomass production is sustained. Engineering of biomass energy systems is still far from mature, however, and there are a number of key technical issues for which research is needed in both thermal conversion methods, such as combustion, pyrolysis, and gasification, as well biological conversion methods, such as anaerobic digestion and fermentation. Current research issues include understanding and mitigating undesirable transformations among inorganic elements in biomass materials that create problems in combustion and advanced thermal power generation systems, effective design of digesters to optimize the environment of microorganisms and handle a wider variety of feedstocks, methods to pretreat and hydrolyze lignocellulosic materials so as to produce simple sugars for fermentation, integration of higher efficiency power converters such as fuel cells, improving forest health through biomass management, and many others. Energy research includes other renewable technologies as well, including solar, thermal, photovoltaic, and wind systems.

Energy conservation and optimization of energy use constitute critical research topics for agriculture and other biological industries. End use optimization, like energy conservation, seeks to improve the energy use efficiency in production, but employs a broader system objective in meeting the energy and material needs of a process or industry. Energy use research extends to crop production, irrigation, greenhouse and other plant environments, postharvest handling, and quality control issues in fresh market fruits and vege-tables, food manufacturing, animal environment, ma-chine utilization, and applications in precision agriculture.

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Crop solid residues may be utilized as renewable resources for production of fuels and chemicals. Effective biological conversion systems are being developed in this project to convert crop residues into methane gas.

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Fouling and corrosion are important inhibitors to the economic and efficient generation of power from biomass, especially agricultural residues. In addition to laboratory research, experiments on ways to mitigate these effects have been conducted at full-scale, such as in this Woodland plant near UC Davis

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Deposition probes are installed in full scale boilers to investigate strategies for mitigating fouling and corrosion. This researcher has finalized the installation of a probe in a nearby biomass plant.