Separation and Purification Technology, Vol.210, 80-92, 2019
Biogas cleaning: Trace compounds removal with model validation
High energy efficiency SOFCs generators can be adopted for local and distributed micro-generation systems to promote the reduction of greenhouse gas emissions with their high fuel flexibility, long-term stability also at partial load and low noise. One of the main drawbacks for such generators, fed by biogenous gas is the impact of trace compounds on the anode compartment. For this reason, a gas clean-up section is mandatory. The effect of temperature and gas moisture was investigated through experiments on the removal performance of the tested sorbents. An increase in the operating temperature caused lower values of the maximum capacity of the adsorbent. The decrease of removal performance considering a humidified gas is connected to the interference of water in the pores of activated carbons. Biochar, compared to the other commercial sorbent materials showed the lowest removal performance, even if with activated biochar the adsorption capacity growth to commercially available materials. The highest adsorption capacity at 1% of the initial concentration was showed by commercial carbons with 1.75 mg/g for H2S and 20.4 mg/g for HCl. Experimental data were employed in a porous particle diffusion model to estimate the breakthrough time. Low values of errors validate the model in the first part of the breakthrough curve, even for competitive adsorption case.