Biogas from anaerobic digestion of biological wastes is a renewable energy resource. H2S in biogas may cause corrosion or other damage to engines if it is not removed from the gas before utilization. Because the solub...Biogas from anaerobic digestion of biological wastes is a renewable energy resource. H2S in biogas may cause corrosion or other damage to engines if it is not removed from the gas before utilization. Because the solubility of H2S in water is higher than methane, water can be used as an adsorbent to remove H2S from biogas. A simple water scrubbing column to reduce the H2S content was designed in this study. The biogas purification process took place in the scrubbing column with water where the gas was continuously fed from the bottom of the column through the diffuser which could produce bubbles. The biogas bubbles and the water can accelerate the reaction inside the column. The water in the column was circulated by means of a pump. H2S content in raw biogas was about 6000 ppm. First, the efficiencies of H2S removal for different biogas flow rate and water level were conducted at 30 and 90 sec. Second, the efficiencies of H2S removal with water recycling system were induced. The results showed that the concentration of H2S in biogas decreased significantly with water level and increased with biogas flow rate through the water scrubbing. It was an effective technique for removing H2S in a short operation time, but absorption capability of water declined rapidly with time. To maintain high absorption rate, water scrubbing after adsorption needed to be replaced or regenerated. The water scrubbing system is a simplest and cheapest method. This work is investigated the feasibility of water scrubbing system and its application to a small hog farm.展开更多
The efficiency of removing inhalable particles in a conventional spray scrubber was examined by the theory of wetting dust removal,and condensation growth properties of inhalable particles in the supersaturated vapor ...The efficiency of removing inhalable particles in a conventional spray scrubber was examined by the theory of wetting dust removal,and condensation growth properties of inhalable particles in the supersaturated vapor environments were investigated using a condensation growth dynamic model.The results show that the removal efficiency of inhalable particles is only 16% for the conventional spray scrubber,and vapor condensation is able to cause the submicron particles to grow rapidly into big dusty droplets in very short time.For case with vapor saturation of 1.3 and particle number concentration of 105 cm-3,the fine particles with diameter less than 0.5 μm can shoot to around 0.8 μm in 50 ms.The final diameters of condensation droplets are little affected by the initial particle diameter,but depend mainly on initial vapor saturation and particle number concentration.It is found that the final droplet diameter increases with increase of saturation degree of vapor,while it decreases with increase of particle number concentration.These results could be used as a theoretical basis and technical guidance for practical application of vapor heterogeneous condensation to promote condensation growth and effective removal of inhalable particles.展开更多
文摘Biogas from anaerobic digestion of biological wastes is a renewable energy resource. H2S in biogas may cause corrosion or other damage to engines if it is not removed from the gas before utilization. Because the solubility of H2S in water is higher than methane, water can be used as an adsorbent to remove H2S from biogas. A simple water scrubbing column to reduce the H2S content was designed in this study. The biogas purification process took place in the scrubbing column with water where the gas was continuously fed from the bottom of the column through the diffuser which could produce bubbles. The biogas bubbles and the water can accelerate the reaction inside the column. The water in the column was circulated by means of a pump. H2S content in raw biogas was about 6000 ppm. First, the efficiencies of H2S removal for different biogas flow rate and water level were conducted at 30 and 90 sec. Second, the efficiencies of H2S removal with water recycling system were induced. The results showed that the concentration of H2S in biogas decreased significantly with water level and increased with biogas flow rate through the water scrubbing. It was an effective technique for removing H2S in a short operation time, but absorption capability of water declined rapidly with time. To maintain high absorption rate, water scrubbing after adsorption needed to be replaced or regenerated. The water scrubbing system is a simplest and cheapest method. This work is investigated the feasibility of water scrubbing system and its application to a small hog farm.
文摘The efficiency of removing inhalable particles in a conventional spray scrubber was examined by the theory of wetting dust removal,and condensation growth properties of inhalable particles in the supersaturated vapor environments were investigated using a condensation growth dynamic model.The results show that the removal efficiency of inhalable particles is only 16% for the conventional spray scrubber,and vapor condensation is able to cause the submicron particles to grow rapidly into big dusty droplets in very short time.For case with vapor saturation of 1.3 and particle number concentration of 105 cm-3,the fine particles with diameter less than 0.5 μm can shoot to around 0.8 μm in 50 ms.The final diameters of condensation droplets are little affected by the initial particle diameter,but depend mainly on initial vapor saturation and particle number concentration.It is found that the final droplet diameter increases with increase of saturation degree of vapor,while it decreases with increase of particle number concentration.These results could be used as a theoretical basis and technical guidance for practical application of vapor heterogeneous condensation to promote condensation growth and effective removal of inhalable particles.
