Mandates for biofuels have resulted in the significant increase of biodiesel production in rural communities. Hawaii's Jatropha biodiesel production will produce nearly 650-700 kg of residues, consisting of Jatropha seedcake and fruit hulls for every metric ton of seeds harvested for oil production. In addition, the biodiesel conversion process will produce another 30-50 kg of crude glycerin, as a co-product for every metric ton of oilseed processed. In Hawaii, nearly 270 million gallons of petroleum diesel is consumed annually. As the local production of just one million gallons of Jatropha biodiesel will result in more than 20 metric tons of processed residuals each day. This substantial production of biofuels leaves a tremendous amount of low-value residues needing to be properly disposed of, on an island setting that is environmentally fragile. Thus, the onsite anaerobic digestion (AD) of these organic residues, into a methane gas, will not only generate energy - through the use of a combined heat and power (CHP) micro turbine - but will also resolve the issues of wastes disposal. The system will supply enough power and heat to efficiently operate a biodiesel production facility, as well as an adjacent solar dehydration plant, with all of its surplus power, sold to the utility grid. This integrated biogas-solar dehydration system is a natural progression, as Hawaii lays abundant in solar radiation, throughout the year. The project will build a scalable pilot system producing up to 50kW of electricity. Thermal recovery is integrated through the CHP for drying food and co-products. Design benefits will facilitate rural replication, to where the AD system will utilize a broad range of locally-available low-value residues and waste materials that relies on a simple technology, which can be developed and supported locally, while being designed to minimize operational costs. The plan is to set-up and utilizes an integrated biogas facility that will fully utilize and appropriately capitalize on all the synergies provided by a biogas plant. The system biologically converts organic waste and residues into energy-rich biogas that also provides nutrient-rich digested solids that is utilized as an organic fertilizer. Thus, local food production, processing and preservation are realized benefits from this biogas facility's electrical and thermal generation. Hence, food and energy security can now be achieved for our geographically isolated rural communities. Therefore, commercialization plans will focus on the main Hawaiian Islands, first. And thereafter, pursue the market potential that exists throughout the American Pacific Protectorates of Micronesia and American Samoa. Wherever imports of nutrients, food and energy have outpaced rural production, there is a similar biogas development opportunity that exists. While incentives are substantial for renewable energy projects and realizing the financial benefits of tax credits, environmental credits and loan programs can be complex. Hawaii's generous feed-in-tariff will ultimately provide the needed financial support for smaller projects that cannot benefit from the economies of scale principal. OBJECTIVES: The goal of the project is to definitively determine the design, construction and operation of a modular anaerobic digestion (AD) facility, or biogas plant, that will utilize Jatropha biodiesel residues that consists of Jatropha seedcake, glycerin and fruit hulls; to include other co-digestion substrates, such as Moringa oleifera, agricultural residues, processed food waste, MSW (municipal solid waste) organic residuals and commercial food-waste materials. The AD system will convert these low-value residues into a renewable energy, in the form of biogas to generate electricity and thermal energy. The system will also produce valued co-products in the form of organic fertilizers. The objectives of this project are to utilize crop production residues, as a feedstock, to rid the farm of its wastes stream accumulation. Thus, we can further process these organic waste materials, into value-added energy products to power our food and fuel processing facilities, while utilizing the resulting effluent nutrients to enhance crop production. An integrated biogas-solar dehydration system will be installed, on the farm, to illustrate the proper utilization of waste materials to produce several lines of value-added products and revenue streams. Therefore, the biogas that is generated by the AD system will be utilized to operate a combined heat and power (CHP) unit to produce electrical power that will efficiently operate a biodiesel production facility and solar dehydration plant - selling its surplus power to the local utility grid. The system will also generate a stream of nutrient-rich materials that can be utilized as an organic fertilizer for use on the farm or bagged for the wholesale market. Thus, the waste stream generated from both the biodiesel production facility and solar dehydration plant, will become the primary throughput feedstock for the AD system; augmented with other co-substrates, that will include the receipt of MSW food- and green-waste materials that also generates an additional revenue stream, through tipping fees. The expected output will be that of a whole-systems model for meeting many of our predictable needs; in decentralized green energy production, job creation, watershed protection, regional food production, agricultural nutrient cycling, reduced greenhouse gas production and carbon sequestration. This project is an innovative concept that will spawn replication elsewhere in Hawaii and the American Pacific. APPROACH: Anaerobic fermentation of Jatropha biodiesel residues is a specialized process. The large quantities of Jatropha seedcake, hulls and glycerin to be converted into biogas will need to be specifically studied to find an optimal efficiency of this biogas feedstock input and the design of the biodigester's capacity for handling this continuous waste stream. The objectives of this proposed development will be to identify the substrates' digestibility and to determine the efficacies of applying Jatropha seedcake, hulls and glycerin substrates within the biodigester. Specific objectives are expected to provide data and information about the proposed system, in which 1) to determine the appropriate quantities of each Jatropha bio-solids (seedcake and hulls), bio-liquid (crude glycerin) residues and other co-digestion substrates for loading and retention within the biodigester that would provide the most efficient production of methane gas; 2) to assure long term process stability; 3) to optimize throughput volume and size of the biodigester capacity that would prove to be the most efficient for the system and to adequately handle the volume of feedstock produced by the biodiesel production on a daily basis; 4) to measure rates of methane production that will sustain a power block's output of thermal and electrical energy to properly meet the demands of the biodiesel operation and the biogas-solar dehydration system; 5) to estimate whether or not the system could provide sufficient biogas output to become profitable in its surplus energy to be sold into the utility grid; 6) to optimize quantity and quality of thermal energy available to the integrated dehydrator. University of Hawaii resources will be utilized in technical evaluations of the system, detailed energy/co-product production/quality, monitoring process stability and optimization of the feedstock blend will be made, as the microbial community adapts and evolves, where knowledge transfer via training local operators, mechanics, etc can be developed. As part of the financial assessment, socioeconomic impact assessment and detailed financial assessment with sensitivity analysis will be done. Energy revenues, avoided costs (i.e., wastewater disposal and fuel purchases), renewable energy incentives, environmental credits, tax credit scenarios, financing options, co-product off-takes will be evaluated. Likewise, the Manufacturing Extension Partnership (MEP) program will analyze the viability of the proposed system by researching its socioeconomic impact using several variables, such as employment rate, quality of life and affordability of home ownership based on jobs created. The MEP program assists small-to-medium-sized businesses in improving their operational, financial, marketing strategy and economic analysis of industries across the United States. As the project progresses and meets its milestones, MEP will conduct market research of value-added products and opportunities that would be created with the proposed system. Through such a study combined with the results from the Phase I SBIR feasibility study, a financial projection and business plan will be developed.
