Economic and Systems Assessment of the Concept of Nearshore Kelp Farming for Methane Production

摘要

This is the final report of a study undertaken to quantify the cost of production of pipeline quality methane from the anaerobic digestion of California giant brown kelp, macrocystis. Utilizing state-of-the-art knowledge and techniques, kelp would be grown in nearshore farms in 20- to 80-ft-deep ocean waters off the coast of Southern California. It would be harvested, shredded, and pumped as slurry to a central anaerobic biodigestion plant. The kelp would be digested and the resulting gas refined to essentially pure methane. The residue would be a liquid effluent, which would be returned to sea as a nutrient for the kelp farm. Detailed capital and operating costs are estimated for several sizes of farm and plant and an economic model is developed that is capable of interacting between various system components so it can be used to test the effect of changes or improvements in individual subsystems on the levelized product cost of the total system.