Techno-economic Analysis of Anaerobic Biogas Resource Utilization of Wet Waste
With the maturation of anaerobic digestion technology in the treatment of wet waste projects,the resource utilization of anaerobic biogas has become a significant method for the resource recovery of wet waste.The principles,processes and characteristics of four utilization technologies for anaerobic biogas were summarized,including biogas purification for natural gas production,biogas cogeneration,direct combustion of biogas for heating,and hydrogen production.Based on the data from four typical engineering cases,an economic model was established for cost and benefit analysis with the biogas utilization scale of 3 000 m3/h.The comprehensive benefit ranking of the four typical cases was biogas cogeneration(with electricity price subsidies)>biogas purification for natural gas production>biogas cogeneration(without electricity price subsidies)>direct combustion of biogas for heating.The final selection of the biogas resource utilization schemes for wet waste projects should fully consider various factors such as the scale of the wet waste project,site boundary conditions,project investment,electricity and steam costs,product market consumption and prices,and comprehensive economic benefits.The research results indicated that the product price was the most critical factor affecting the comprehensive benefits of biogas resource utilization schemes.When the sales price of natural gas exceeded 2.28/2.68 yuan/m3(under the conditions of collaborative low-cost power and heating in the park)or the sales price of steam exceeded 191.50/229.30 yuan/t,the comprehensive benefits of the corresponding biogas utilization scheme were higher than those of the cogeneration scheme without/with grid electricity price subsidies.