Application analysis of layered pressure swing adsorption method for offshore floating natural gas purification

In view of the particularity of offshore operations, a new layered pressure swing adsorption (PSA) method for natural gas purification was proposed. CH4 is enriched in the three-component CH4/CO2/N2 crude mixed gas. The pressure swing adsorption process is based on the traditional method. The adsorption bed is divided into two layers, which are the first layer with activated carbon as the adsorbent to remove CO2 impurities, and the second layer with molecular sieve as adsorbent to remove N2 impurities. The process of PSA was simulated by Aspen Adsorption software. The simulation results show that after the process of double layered PSA, the purity of the product gas CH4 reached 98.7%, and the recovery rate of gas production was 89%. The concentration of CO2 was successfully reduced to 0.23% in the activated carbon layer, and the concentration of N2 was reduced to 1.2% in the molecular sieve layer of the first Tower.

CO2/CH4 and H2/CH4 Gas Separation Performance of CTA-TNT@CNT Hybrid Mixed Matrix Membranes

This study explored the underlying synergy between titanium dioxide nanotube (TNT) and carbon nanotube (CNT) hybrid fillers in cellulose triacetate (CTA)-based mixed matrix membranes (MMMs) for natural gas purification. The CNT@TNT hybrid nanofillers were blended with CTA polymer and cast as a thin film by a facile casting technique, after which they were used for single gas separation. The hybrid filler-based membrane depicted a higher CO2 uptake affinity than the single filler (CNT/TNT)-based membrane. The gas separation results indicate that the hybrid fillers (TNT@CNT) are strongly selective for CO2 over CH4 and H2 over CH4. The increment in the CO2/CH4 and H2/CH4 selectivities compared to the pristine CTA membrane was 42.98 from 25.08 and 48.43 from 36.58, respectively. Similarly, the CO2 and H2 permeability of the CTA-TNT@CNT membrane increased by six- and five-fold, respectively, compared to the pristine CTA membrane. Such significant improvements in CO2/CH4 and H2/CH4 separation performance and thermal and mechanical properties suggest a feasible and practical approach for potential biogas upgrading and natural gas purification.

Pollutant Sources and Foaming Control Measures of Decarbonization Solution in Natural Gas Purification Plant

Yanbei project of Schlumberger Copower Oilfield Engineering Co., Ltd. - natural gas purification plant decarbonization unit is equipped with two sets of decarbonization systems (parallel operation). The two sets of systems adopt two tower process, full lean liquid circulation regeneration process, one tower absorption (absorption pressure 5.4mpag), one tower regeneration (regeneration temperature 95 oC~ 110 oC), purified natural gas carbon dioxide content <= 2.5vol%, single set The treatment capacity is 2300 KM3 / d. This paper introduces the problems existing in the decarbonization solution of the decarbonization unit in the natural gas purification plant in recent three years, analyzes the causes of pollutants affecting the quality of the decarbonization solution, and probes into the control measures for the pollution of the decarbonization solution, so as to provide reference.

DEVELOPMENT OF A CALCULATION METHODFOR TWO-STAGE NATURAL GAS PURIFICATION PLANTS FROM MECHANICAL IMPURITIES

Statement of the problem. Currently, there is no methodology for calculating the degree of clogging of a multilayer filter cartridge taking into account the prevention of deposition of mechanical impurities in the gap between the coarse and fine filter cylindrical filter cartridges. In this regard, the development of such a technique is an urgent task. Results. In this paper, we propose a calculation method for determining the average integral degree of clogging of multilayer cylindrical filter cartridges with mechanical impurities and pressure loss on them which take into account the prevention of sedimentation of mechanical impurities in the gap between the coarse and fine filter cartridges.Conclusions. The results obtained make it possible to determine the pressure loss and the average integral degree of clogging of the multilayer filter cartridge depending on the decrease in the living cross-section of all filter meshes in the process of clogging and to prevent the deposition of solids in the gap between the coarse and fine filter cartridges.