Study Of Experiment And Simulation On Enrichment Of Mine Gas Byadsorption

In this paper, the lower concentration of gas drainage is as the main object of study, andthe possibilities of the lowconcentrationgas enriched by the multilevelPSA technology isexplored with the methods of combining experiments and computer simulation. The twodifferent types of the adsorption materials carbon fiber molecular sieve and MCM41molecular sieve are firstly selected as a combination adsorbent. The materials are prepared,and the adsorption and computer molecular modeling of the gases on the materials areseparately carried out. On this basis, the adsorption and separation characteristics of the maingas components, including CH4, N2, O2 and CO2 on two adsorption materials are morecomprehensive studied. Through the piecewise constant pressure simulation to the PSAprocess including two level and three stages constituted by the two materials, the keytechnicals and problems.have been explained that the multistagepressure swing adsorptiontechnology is used to achieve increased concentration of low density gas.The two kinds of adsorbents are prepared by the inexpensive PITCHbasedcarbon fibersand industrial water glass. The pore size, BET surface area and pore volume of the adsorptionmaterials were 0.9nm ~ 0.98nm and 3.60nm ~ 3.68nm , 1545m 2 /g and 1207m 2 /g, and 0.359cm 3 /g and 1.03cm 3 /g.The adsorbed test of the gases proceed on the homemadedevice. The adsorptioncomponents are CH4, N2 and CO2, the adsorption temperature and pressure were respectivelythe room temperature and the normal pressure ~ 1500kPa. The test include monocomponentand bicomponent adsorptions. The molecular simulation of the adsorption properties of thematerials is completed on the Material Studio software platform. According to the actual porestructure of the carbon fiber molecular sieve and the MCM41,two pore models wereestablished, being respectively the wedgeshapedslit pore model and the cylindrical pore model. Simulation gases are CH4, N2, O2 and CO2, the analog temperature and pressures arenormal temperature and atmospheric pressure ~ 5000kPa, the simulations include singlecomponent, two component, three component and four component analog? and the methoduses grand canonical Monte Carlo method. The experimental and simulation results show thatthe adsorptive capacity of CO2 on the two kinds of materials is largest, CH4, followed, and N2(or N2 and O2) minimum? and the adsorption of the each gas component on the carbonmolecular sieve adsorption was significantly higher than on the MCM41.The CO2/N2,CO2/O2 and CH4/CO2 has better separation characteristics whether on the carbon molecularsieve or on the MCM41.The CH4/N2 and CH4/O2 on the carbon fiber, respectively, andMCM41molecular sieve has certain separation characteristics. The O2/N2 (or N2/O2) on thecarbon molecular sieve and MCM41is not be effectively separated. Both thethreecomponentor four components, as long as the gas contains CO2, it will affect the purityand yield of CH4 to varying degrees.The two step and three phase PSA by the two types of the absorbent materials based onthe Petluyk PSA process. The simulation methods adopt the GCMC simulation of fixedpressure. two The two kinds of the threecomponentCH4/N2/CO2 and CH4/N2/O2 wererespectively simulated. The temperature and pressure were respectively normal temperature,100kPa (preseparation)and 2000kPa. The results show that both the CH4/N2/CO2 orCH4/N2/O2, the strong absorption component can to varying degrees be enriched in the firsthighvoltagestep. The CH4 in the CH4/N2/CO2 was enriched in the side of the stream gas, andthe outlet is almost nonCH4.The N2 and O2 in the CH4/N2/O2 are both enriched in the exportgas, and the their contents no significant changes in lateral flow components. When the feedgas with CO2, the higher CO2 levels help to improve the purity and yield of CH4. The O2/N2Ratio in CH4 concentration is not significantly affected in the CH4/N2/O2.