Experimental Study Of Natural Gas Adsorption Storage System

Study of adsorbed natural gas is based on gathering of scattered natural gas produced off shore of Shengli Oilfield. In fact, adsorbed natural gas may also be used as clean substitute fuel for automobile industry. Study is mainly focused on the following two aspects of natural gas adsorption storage in the paper:Firstly, methane adsorption capacity of powder active carbon and formed active carbon are respectively studied. Adsorption isotherm of powder active carbon is obtained by means of static volumetric method. Effect of active carbon structure on adsorption capacity is studied as well. Experiment shows that micro-pore volume plays a significant role in determining adsorptive capacity of active carbon. Then methane adsorption capacity of formed active carbon is studied on emphasis. Experiments on selection of parameters of molding technique including percentage of bonding agent and molding pressure are performed. It is showed that volumetric adsorption capacity is increased as an injection of bonding agent, while gravimetric adsorption capacity reduced. A fluctuation of variation of methane adsorption capacity with molding pressure is observed in laboratory.Effect on adsorption heat produced in adsorption process and solution is another core problem of natural gas adsorption storage. Simulation analysis of temperature field in two adsorptive tanks, namely cylinder tank and cylinder tank with heat exchanging pipe in center, are made by means of numerical simulation in the paper. Simulation result is used for guidance of subsequent experimental study. On basis of simulation result, experimental set-up for heat effect of methane adsorption is designed and installed. Experimental analysis and comparison of temperature field in adsorptive tank with/without heat exchanging structure during methane charge is made to supply reference data for expansion study of natural gas adsorption storage in future. Comparison by means of experiment shows that temperature reduction at the measuring point near axle center is as large as 34.64℃after heat exchanging structure is installed to adsorptive tank. Volumetric adsorption capacity of formed active carbon bed is 61, and methane desorption rate in desorption process is 80% for adsorption tank with heat exchanging structure; the two values are respectively raised to 74 and 89% after improvement of heat exchanging structure, which are increased by 21% and 11% by percentage.