Study On Improving Gas Storage Capacity Of Wet Porous Material Fixed Bed

Gas hydrate technology is a new gas storage method developed in recent years and has great application potential.In the process of reaction,the slow hydrate formation kinetics and actual gas storage density,We believe that it is a potential method to prepare a fixed bed of porous materials containing water and improve the gas storage effect by utilizing the synergistic effect of adsorption and hydration.The main contents of this study are as follows:The porous material ZIF-8 was synthesized by hydrothermal method and characterized by XRD,SEM and N₂adsorption-desorption.The experimental results show that the synthesized material has good water stability,high crystallinity,and a specific surface area of1657.81m2/g.The formation of methane hydrate in wet and dry ZIF-8 bed was investigated.The results show that the gas storage effect of the wet activated carbon fixed bed is greater than that of the dry material at 274.15 K,and the gas storage capacity of the wet material is1.5 times that of the dry material at the equilibrium pressure of 9 MPa.The water conversion rate of the wet material can reach 100%at the low water content.The gas storage effect will be reduced when Rw=2,and the high water content will reduce the gas storage density of the bed.The hydration reaction rate decreases and there is an optimal water content condition.In this experiment,additives（THF,TBAB,diesel）were added to the activated carbon fixed bed to improve the gas storage capacity.The experimental results show that the gas storage performance of the bed was significantly improved after adding THF or TBAB.The gas storage efficiency is the best at the concentration of THF（7.5wt%）.The gas storage density（S_b）and gas storage capacity（S_w）of the bed were 128.66 V/V_band 194.26 V/V_w,respectively,which were 2.89 times and 3.07 times of the wet activated carbon fixed bed without additives.When TBAB（5 wt%）was added,the S_band S_wwere increased by 1.86times and 1.87 times,respectively.At the same time,diesel can establish gas channel in the fixed bed,improve the gas mass transfer rate between the body gas phase and the fixed bed,and also significantly improve the gas storage performance.The experiment shows that the gas storage effect is best when the oil-carbon ratio（R_o）was 0.5,S_band S_ware 97.97 V/V_band172.77 V/V_w,respectively.However,the increase in the amount of diesel fuel will increase the volume of the bed,thus reducing the gas storage density of the bed.When we added both diesel and THF to a wet fixed bed,we found that the results were not significantly better than those of a bed using either diesel or THF alone.Finally,the gas release and decomposition rate of the aqueous fixed bed with/without 7.5 wt%THF were investigated.The results show that the final gas recovery rate of 7.5 wt%THF bed reaches 95.01%,which has a good application prospect.