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Recent Progress on Asymmetric Membranes Developed for Natural Gas Purification
Published in Zeinab Abbas Jawad, 2 Sequestration and Separation, 2019
Gongping Liu, Zhi Xu, Wanqin Jin
Natural gas is a naturally formed hydrocarbon gas mixture consisting primarily of methane, but commonly including a certain amount of carbon dioxide, hydrogen sulfide, higher alkanes and other inert gases(Baker and Lokhandwala 2008). The composition of gas delivered to commercial pipeline must be controlled to avoid undesired corrosion. For instance, raw gas usually requires treatment to reduce the CO2 concentration to less than 2% and H2S concentration below 4 ppm according to the U.S. natural gas pipeline specifications. Until now, processing of natural gas has been the largest industrial gas separation application. Conventional separation technologies such as amine sorption are very energy-consuming and non-environmental friendly. Ninety percent energy will be saved if applying membrane technology for removing CO2 from the industrial streams (Leung et al. 2014). The key of this membrane process is developing high-performance asymmetric gas separation membranes—highly permeable and selective for CO2 molecules. Polymers, inorganic materials, mixed-matrix materials and carbon molecular sieves have been processed into asymmetric membranes via different techniques. This chapter will discuss the latest progresses in design and preparation of asymmetric membranes for natural gas purification, particularly focusing on the CO2/CH4 separation.
Technologies and Advancements for Gas Effluent Treatment of Various Industries
Published in Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang, Treatment of Industrial Effluents, 2019
Mihir Kumar Purkait, Piyal Mondal, Chang-Tang Chang
Several gas separation technologies are available for the capture step; these can be broadly grouped into the following process categories: chemical absorption, physical absorption, adsorption, cryogenics, and membrane separation. The broad characteristics of each technology along with the results of their application to steelmaking gases based on available references are presented in the following sections.
Effects of L-lysine-conjugated-graphene oxide as a nanofiller on the CO2 separation performance of mixed matrix chitosan membrane
Published in Indian Chemical Engineer, 2023
Aviti Katare, Swapnil Sharma, Bishnupada Mandal
Temperature and pressure have a major impact on the gas separation process. Initially, the influence of operating temperature on the gas permeation properties was examined. At temperatures between 25 and 115°C with a sweep-to-feed water supply ratio of 1.67, an absolute pressure of 2 bar for feed water supply, and a 1.21 bar sweep pressure, CO2 flux, CO2 permeance and CO2/N2 selectivity were studied. Figure 10 compares the bare CS and the Lys-c-GO@CS (1%) membranes. At 25°C, the CS membrane's CO2 flux, CO2 permeance and CO2/N2 selectivity were 251 cm3 (STP)/cm2s, 17.29 GPU and 32.8, respectively. These values increased to 753 cm3 (STP)/cm2s, 44.10 GPU and 82.5 at 85°C, respectively When the membrane’s temperature increases, the polymer chains become more flexible, resulting in an increase in their diffusivity. Carbon dioxide (CO2) permeability increased rapidly as the temperature increases for both membranes, with the Lys-c-GO@CS (1%) membrane showing much faster CO2 transport [19]. There is less energy barrier for the Lys-c-GO@CS (1%) membrane, which is more evidence that the CO2 separation efficiency was improved by using GO laminates rather than just bare CS membrane. With increasing temperature, CO2/N2 selectivity for both the unmodified CS and the Lys-c-GO@CS (1%) membranes was reduced. However, this was still higher than the bare CS, which had a lower CO2/N2 performance.
Enhanced CO2/N2 separation by supported ionic liquid membranes (SILMs) based on PDMS and 1-ethyl-3-methylimidazolium acetate
Published in Chemical Engineering Communications, 2021
As an alternative, membrane gas separation is considered an attractive technology because of its simplicity, small size, low cost and low energy consumption (Baker 2002; Meriläinen et al. 2012; Omidkhah et al. 2013; Zamani Pedram et al. 2014; Ranjbaran et al. 2015). Membrane technology does not emit gases or require solvents and is considered as an environmentally friendly technology (Ismail and Matsuura 2012). Polymeric membranes are the most widely used membranes in the industry because of the competitive economy and performance (Green and Perry 2007). The main problems in the case of polymeric membranes are limitations in selectivity and permeability, thermal and chemical stability, swelling, plasticizing and aging tendency (Baker 2004; Sridhar et al. 2007), presence of impurities, contaminants and water (Madaeni et al. 2011; Stern et al. 1987).
Investigation of premature aging of zeolites used in the drying of gas streams
Published in Chemical Engineering Communications, 2019
Rafaelle Gomes Santiago, Bianca Ferreira dos Santos, Isabela Gomes Lima, Karine Oliveira Moura, Dárley Carrijo Melo, Wilson Mantovani Grava, Moises Bastos-Neto, Sebastião Mardônio Pereira de Lucena, Diana Cristina Silva de Azevedo
The processing of natural gas is the largest industrial gas separation application due to the variable content of impurities and high consumption of the clean gas in the world. Methane is the major component, typically 75–90% of the total, but natural gas also contains significant amounts of ethane, propane, butane, and other higher hydrocarbons. In addition, undesirable impurities, such as water, carbon dioxide, nitrogen, and hydrogen sulfide are also commonly present (Baker and Lokhandwala, 2008).