The need for transition to a hydrogen-based economy includes national energy security and the mitigation of likely global changes due to greenhouse gas emissions resulting from fossil fuel use. The utilization of animal manure and other organic residuals as a source of hydrogen generation will serve the dual purpose of pollution prevention and renewable energy production.
This study includes a rigorous analysis of the various biogas utilization options that exist on a large confined animal feeding operation (CAFO). The research undertaken draws from a demonstration project examining the feasibility of hydrogen production from biogas on a dairy farm. This work is also an illustration of the use of a geographical information system to enable a thorough analysis of systems of centralized anaerobic digesters for hydrogen production from dairy manure collected from clusters of dairy farms in New York State.
In this dissertation, it was found that hydrogen production from biogas is an economically viable option. Compared to other utilization routes investigated, namely production of electricity, production of heat and production of pipeline quality substitute natural gas, renewable hydrogen production was found to be the best economic option, especially on farms with 500 cows or more. Increased yields of hydrogen can be achieved by the addition of food processing waste to be co-digested with manure. In this study, it was also found that 203 dairy farms in NYS with 500 or more cows have the potential to supply 6.9 million Kg/y renewable hydrogen, which represents over 53% of all merchant hydrogen produced in NYS. It is recommended, based on a review of scientific literature as well as market availability, that steam reforming of cleaned biogas, followed by the water gas shift reaction, accompanied by the use of a membrane reactor allowing for the selective removal of high purity product hydrogen is the best thermo-chemical option to convert biogas to hydrogen. There exist clusters of dairy farms which permit more efficient and economic ways to handle not only manure but also other organic waste which can be co-digested in community scale digesters.