摘要
Upgrading biogas into biomethane not only improves the biogas utilization as vehicle fuel or natural gas substitute,but also reduces the greenhouse gases emissions.Considering the principle of engineering green energy process,the renewable aqueous ammonia(RAA)solution obtained from biogas slurry was used to remove H_(2)S and CO_(2) simultaneously in the hollow fiber membrane contactor.RAA was mimicked in this study using the ammonia aqueous solution mixed with some typical impurities including ethanol,acetic acid,propionic acid,butyric acid and NH4HCO_(3).Compared with the typical physical absorption(i.e.,pure water)removing 48%of H_(2)S from biogas,RAA with 0.1 mol·L^(−1) NH_(3) could remove 97%of H_(2)S.Increasing the NH3 concentration from 0.1 to 0.5 mol·L^(−1) could elevate the CO_(2) absorption flux from 0.97 to 1.72 mol·m^(−2)·h^(−1) by 77.3%.Among the impurities contained in RAA,ethanol has a less impact on CO_(2) absorption,while other impurities like CO_(2) and acetic acid have significant negative impacts on CO_(2) absorption.Fortunately,the impurities have a less influence on H_(2)S removal efficiency,with more than 98%of H_(2)S could be removed by RAA.Also,the influences of operating parameters on acid gases removal were investigated to provide some engineering suggestions.
基金
supports from the Natural Science Foundation of Hubei Province of China(2020CFA107,2020CFB209)
the National Natural Science Foundation of China(32002222,52076101)
the Fundamental Research Funds for the Central Universities(2662021JC004).
