Experimental Study on Dry Reforming of Biogas for Syngas Production over Ni-Based Catalysts

Syngas production from dry reforming of biogas (DRB) is studied experimentally in this work. Ni/Al 2 O 3 , Pt/Al 2 O 3 , and Pt-Ni/Al 2 O 3 are used as catalysts to examine the effect of CO 2 content in biogas and H 2 O addition on DRB performance for reaction temperatures in the 600-800 °C range. It is found that the bimetallic Pt-Ni catalyst exhibits the best activity and thermal stability among the three types of catalysts studied due to better carbon deposition resistance. Because CO 2 functions as the oxidant in combustion, CH 4 conversion is enhanced when the biogas contains more CO 2 . One hundred percent CO 2 conversion can be reached for biogas containing a less amount of CO 2 at high temperatures. With H 2 O addition in DRB, the steam reforming of methane (SRM) reaction is the dominant reaction, resulting in higher H 2 and CO yields with biogas containing lesser amounts of CO 2 . However, lower CH 4 conversion and negative CO 2 conversion do result. With higher CO 2 content in the biogas, higher CH 4 and CO 2 conversions can be obtained. Lower yields of H 2 and CO are obtained due to less SRM dominance. With H 2 O addition in biogas, the H 2 /CO ratio with a value greater than 1 can be obtained from DRB. It is also found that the H 2 /CO ratio with a value of 2.1 can be obtained for reactant composition with a molar ratio of CH 4 /CO 2 /H 2 O = 1:0.25:1 and reaction temperature of 800 °C.