Abstract
The fuel gas obtained from organic waste gasification process or methane fermentation contains several hundreds to one thousand ppm of hydrogen sulfide. Hydrogen sulfide not only makes equipment corrode but also reduces an electromotive force of a fuel cell. Therefore, it is very important to remove hydrogen sulfide to a single ppm order before the generated gas is used as the fuel. Conventional process of hydrogen sulfide removal is classified into two main techniques. One is the wet method and the other is the dry method. The wet method has a big advantage in the removal efficiency, but the treatment facility usually is big and complex. On the other hand, the dry method is able to make the equipment small. As the one of the dry method, de-hydrogen sulfide process by the activated carbon manufactured from coconut shell or coal is attracted attention recently. However, the commercial activated coke is very expensive, so it may be necessary re-carbonization process for reuse. In this study, the disposable low-cost activated coke was manufactured from ligneous biomass by a simple heating treatment in the fixed bed reactor. The hydrogen sulfide adsorption performance was evaluated by the experiments using the fixed bed adsorption equipment. From the previous report, the activated coke heated with steam of 923 K for 60 min showed the best adsorption performance, so the activated coke manufactured on this condition was used in the adsorption experiment. Adsorption experiments were carried out in various conditions such as weight of the activated coke, bed temperature and concentration of hydrogen sulfide. In consequence, this activated coke showed high hydrogen sulfide adsorption performance and hydrogen sulfide was removed under 1 ppm for several times.
