Simulation and optimization of net energy production in a swine waste digestion system.

ABSTRACT A dynamic model to simulate net energy production from a swine waste digestion system is developed and validated with experimental data from two operating swine waste digesters. The validated model is used to determine the best system configuration, the optimal operating point, and the sensitivity of net energy production to key inputs and system parameters. It is found that mesophilic operation produces more net energy than thermophilic, but that the optimal operating point is in the psychrophilic region. It is also found that net energy production is most sensitive to the efficiencies of manure collection and the end use of the produced methane.