Pilot Study On Hydrogen Sulfide In The Biogas Removal With Biofilter

The biofilter reactor in this paper was a novel reactor used for removing H₂S in the biogas, the recycled liquid storage tank and the desulfurizer was in one. The biodesulfurization reactor was founded in a biogas plant nearby Chengdu city, It was used for removing part of H₂S in the biogas.In the testing, the main tasks were that Started up biodesulfurization reactor, searched the optimum operating conditions that the reactor removed H₂S from biogas, monitored some conditions changed on the influnce of biodesulfurization reactor, such as ambient temperature and pH of recycled liquid, found some problem in the reactor operation and improved on it.Main conclusions were as follows:(1) Before adding desulfurization sludge to biodesulfurization reactor, the amount of H₂S in the biogas removed was 100 mg·m^-3500 mg·m^-3, the removal efficiency of H₂S was 27%. After adding desulfurization sludge to biodesulfurization reactor, the removal efficiency of H₂S was more than 90% in the previous, After nearly a week, the removal efficiency of H₂S in the biogas was decreased, and then increased to 70% by aerating and sprinkling time after time.(2) The total aeration and sprinkling was controlled by time changing. the effect of biodesulfurization reactor operating was best in the conditions that the aeration time was 60 min, the sprinkling time was 30 min, the interval time of aeration and sprinkling was 30 min. In these conditions, the removal efficiency of H₂S in the biogas was more than 50%, the removal amount of H₂S in the biogas was 500 mg·m^-31000 mg·m^-3 by biodesulfurization reactor when the inlet concentration of H₂S was 1000 mg·m^-31500 mg·m^-3.(3) When ambient temperature dropped very large ,the removal efficiency of H₂S in the biogas was deceased, and then inceased. While the ambient temperature was as low as 5℃, biodesulfurization reactor operated normally, the removal efficiency of H₂S was more than 40%, up to 70% when the inlet concentration of H₂S was 1000 mg·m^-3. During the testing, the pH of recycled liquid was 7 all the time, so the pH was little influence on the biodesulfurization reactor operating.(4) When the ambient temperature was about 10℃, the inlet concentration of H₂S was more than 2000 mg.m^-3, the removal efficiency of H₂S was more than 30%, up to 45%, the removal amount of H₂S was up to 700 mg·m^-3, if controlling condition was as follows: air compressor aerated 60 min at 8 am, the sprinkling started after 30 min the end of aeration, the sprinkling time is 30 min. In the midday, biodesulfurization reactor didn't aerate and sprinkle. Air compressor aerated 60 min at 15:30 pm, the sprinkling started after 30 min the end of aeration, the sprinkling time is 30 min.