[ $H_2S$ ]in biogas was removed by sludge-loaded biofiltration, rendering the biogas suitable for catalytic reforming into a mixture of CO and $H_2$ syngas that was then applied for the generation of electricity using a solid oxide fuel cell or for the chemical synthesis of methanol. The biogas was anaerobically produced in a 2 $m^3$ bioreactor at $35^{circ}C$ for 2 years using restaurant food waste from Korea Advanced Institute of Science and Technology (KAIST), and the concentration of $H_2S$ in the biogas ranged from 612 to 1,500 ppmv (Avg. 1,060 ppmv). Two immobilized cell bioreactors 0.2 and 8.5 L in volume were loaded with aerobic sludge and used to study characteristics of $H_2S$ removal from biogas. At a retention time of 400 sec, the removal efficiency of $H_2S$ was over 99% following initial stabilization for 7 days in the 8.5 L bioreactor installed at the on-site biogas facility. The maximum rate of $H_2S$ removal in this study was 359 g-$H_2S/m^3/h$ with an average mass loading rate of 14.7 g-$H_2S/m^3/h$ (kinetic analysis: $V_m$ = 842.6 g-$H_2S/m^3/h$ and $K_s$ = 2.2 mg/L). Therefore, purified biogas with a negligible concentration $H_2S$ was efficiently reformed to syngas. This study demonstrates the feasibility of biogas purification as a part of high-quality syngas production.