BEEF: A Sustainable Process Concerning Negative CO2 Emission and Profit Increase of Anaerobic Digestion

In organic wastes utilization, negative CO, emission and increase of profit can be achieved simultaneously based on anaerobic digestion (AD) through a novel Bio-Energy, Electricity, and NH4HCO3 Fertilizer (BEEF) system. In the BEEF concept, organic wastes are anaerobically digested to produce biogas, and then renewable ammonia recovered from biogas slurry is used to upgrade biogas. Negative CO, emission can be acquired by transferring the separated CO, into greenhouse plants or other carbon sinks. Compared with the baseline scenario that all the biogas from AD plant is combusted in a CHP unit, this study found that the average negative CO, emission with similar to'277 N m(3)/h and net profit with similar to RMBY 365/h were acquired simultaneously by adopting BEEF system where animal manures were digested in a 1000 N m(3)-biogas/h AD plant. Meanwhile, BEEF system output the useful energy about 100% higher than the baseline scenario. Reducing the energy consumption of ammonia recovery could increase both the negative CO, emission and the net profit. Overall, this system provides a pathway to the sustainable nutrients and carbon management to deal with the climate and environmental problems.