H ₂ S effect on dry reforming of biogas for syngas production

Abstract

Summary The effect of hydrogen sulfide (H2S) on dry reforming of biogas for syngas production was studied both experimentally and theoretically. In the experimental work, the H2S effect on Ni‐based catalyst activity was examined for reaction temperatures ranging from 600°C to 800°C. It was found that the presence of H2S deactivated the Ni‐based catalysts significantly because of sulfur poisoning. Although bimetallic Pt‐Ni catalyst has better performance compared with monometallic Ni catalyst, deactivation was still found. The time‐on‐stream measured data also indicated that sulfur‐poisoned catalyst can be regenerated at high reaction temperatures. In the theoretical work, a thermodynamic equilibrium model was used to analyze the H2S removal effect in dry reforming of H2S‐contained biogas. Calcium oxide (CaO) and calcium carbonate (CaCO3) were used as the H2S sorbent. The results indicated that H2S removal depends on the initial H2S concentration and reaction temperature for both sorbents. Although CO2 was also removed by CaO, the results from equilibrium analysis indicated that the dry reforming reaction in the presence of CaO was feasible similar to the sorption enhanced water‐gas shift and steam‐methane reforming reactions. The simulation results also indicated that CaO was a more preferable H2S sorbent than CaCO3 because syngas with an H2/CO ratio closer to 2 can be produced and requires lower heat duty.

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

“…Figure is the time-on-stream measured DRB performance for CH 4 /CO 2 /H 2 O = 1:1:0 (case 1 in Table S2) and various catalyst types for reaction temperatures ranging from 600 to 800 °C with an increment of 50 °C. The detail of data measurement is similar to that reported in our previous studies. , The performance of DRB is characterized using CH 4 conversion, CO 2 conversion, H 2 yield, CO yield, and H 2 /CO ratio determined according to the following equations …”

“…The detail of data measurement is similar to that reported in our previous studies. 45,46 The performance of DRB is characterized using CH 4 conversion, CO 2 conversion, H 2 yield, CO yield, and H 2 /CO ratio determined according to the following equations…”

“…The detail of data measurement is similar to that reported in our previous studies. 45,46 The performance of DRB is characterized using CH 4 conversion, CO 2 conversion, H 2 yield, CO yield, and H 2 /CO ratio determined according to the following equations In these equations, F i, in and F i, out are the molar flow rates of species i at the reactor inlet and outlet, respectively. Based on In Figure 4, the averaged DRB performance as functions of reaction temperature and catalyst type is shown based on the results obtained in Figure 3.…”

“…Details regarding the reaction temperature control, flow rate regulation, and test procedure were also described in the previous studies. 45,46 Before the reaction tests, the in situ catalyst reduction was carried out at a temperature determined by the H 2 -TPR test for 2 h in 50% H 2 /N 2 at a flow rate of 50 mL/min. The activity test was performed from 600 to 800 °C.…”

“…The preparation procedure and characterization of the catalyst were described in detail in the previous studies. 45,46 A schematic diagram of the experimental setup is shown in Figure S1. Details regarding the reaction temperature control, flow rate regulation, and test procedure were also described in the previous studies.…”