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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
Membrane gas separation is based on the selective permeation of definite species in a gas mixture across a membrane. In such process, the pressurized feed gas is put into contact with the surface of the membrane inside a membrane module conceived for the given application. Alternatively, vacuum can be applied on the other side of the membrane to create the driving force necessary for mass transport. Two outlet streams are recovered after treatment in a continuous process: a permeate stream consists of gas that has traversed the membrane and is thus enriched in more permeable components, whereas the retentate stream consists of residual gas that did not traverse the membrane and is hence enriched in the less permeable components. Membranes in such cases mainly consist of dense layers with no porosity, unlike ultrafiltration or nanofiltration membranes (Mohanty and Purkait, 2011; Purkait et al., 2018; Purkait and Singh, 2018), where separation capabilities are based on pore size. Although research is carried out worldwide to develop novel membrane materials, only dense polymeric membranes are used commercially for gas separation at industrial scale. Transport in dense polymeric membranes is described by a solution-diffusion mechanism. In general, a gas component with higher solubility and diffusion coefficient in the polymer matrix has more permeability.
Two-phase and Three-phase Permeability Models for Mixed Matrix Membrane Gas Separation
Published in Zeinab Abbas Jawad, 2 Sequestration and Separation, 2019
To combat global warming, CO2 Capture and Storage (CCS) has been acknowledged as one of the most promising strategies (Roussanaly et al. 2016, Aminu et al. 2017, Song et al. 2018). Among various available technologies for capturing CO2 capture, membrane gas separation has been considered as one of the most effective solutions because of its energy efficiency, physical size and operation simplicity compared to its solvent based absorption technologies (Roussanaly et al. 2016, He et al. 2017, Merkel et al. 2010, Mat and Lipscomb 2017). Moreover, membrane gas separation has also been successfully applied in H2/N2 separation, H2/CO, O2/N2, H2/hydrocarbon, CO2/CH4 and other gas mixtures in the natural gas production, refinery operations and petrochemical processes (Ismail et al. 2015). Consequently, high performance membranes, especially Mixed Matrix Membranes (MMMs) have become a subject of interest for many researchers due to their important role in gas separation processes. This trend is indicated by extensive research works and publications on the developments and performance assessments of MMMs for CO2 mitigation found in the literature (Bernardo et al. 2009, Aroon et al. 2010, Zhang et al. 2013, Baker and Low, 2014, Bastani et al. 2013, Rezakazemi et al. 2014, Rafiq et al. 2015, Vinh-Thang and Kaliaguine 2013).
Ceramic Membrane Processes
Published in Chandan Das, Sujoy Bose, Advanced Ceramic Membranes and Applications, 2017
Membrane gas separation is attractive because of its simplicity and low energy cost, but it has one major drawback: the reverse relationship between selectivity and permeability. Petrochemical waste streams may contain phenolic compounds or aromatic amines. These are highly toxic and, at high concentrations, inhibit biological treatment. The membrane aromatic recovery system (MARS) is a relatively new process for recovery of aromatic acids and bases. Wastewater in the petrochemical industry is currently treated by an activated sludge process with pretreatment of oil/water separation [57]. Tightening effluent regulations and increasing need for reuse of treated water have generated interest in the treatment of petrochemical wastewater with the advanced membrane bioreactor process.
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).
The influence of cellulose acetate butyrate membrane structure on the improvement of CO2/N2 separation
Published in Chemical Engineering Communications, 2020
Jia Qiang Ngo, Shin Tien Lee, Zeinab Abbas Jawad, Abdul Latif Ahmad, Ren Jie Lee, Swee Pin Yeap, Jing Yao Sum
The membrane gas separation technology is getting more attention because it has several advantages such as low costs and energy requirements, simple and easy to operate as well as high selectivity and fluxes, which are achievable (Kim 2007; Kim and Lee 2015; Rahmani et al. 2016). In the membrane gas separation process, the performance of membrane gas separation is strongly dependent on the effect of membrane casting thickness and polymer concentration (Jawad et al. 2014). The polymer concentration and casting thickness have simultaneous effects on controlling the morphology of the membrane layer. Thus, the permeation flux is influenced by both of them (Ngang et al. 2012). Various polymer concentrations have different effects on the membrane gas separation performance. Besides, the polymer concentration has an important effect on membrane permeation flux (Naim and Ismail 2013). The structure of the membrane may also change depending on the different membrane casting thickness (Azari et al. 2010).
Potential for helium recovery and purification in Australia through membrane gas separation
Published in Australian Journal of Multi-Disciplinary Engineering, 2020
Conventionally, helium is extracted from the off-gas of the nitrogen rejection unit (NRU) in a natural gas process. The primary purpose of this unit is to remove nitrogen from the natural gas and has the secondary effect of concentrating helium. Hence, helium recovery is primarily a process of separation from nitrogen (Rufford et al. 2014; Scholes and Ghosh 2016). Traditional helium recovery and purification is undertaken through liquefaction, where the NRU off-gas is cryogenically cooled to below the boiling temperature of nitrogen (−195°C or 77 K). Helium remains a gas and is separated from the liquid nitrogen. Further purification is achieved through pressure swing adsorption (PSA), which is able to purify the helium to >99.9% by removing trace amounts of oxygen and hydrogen. However, for low grade reservoirs where the helium concentration is very low, liquefaction separation is very energy intensive because of the amount of nitrogen that must be condensed. Hence, alternative technologies are required that can undertake helium recovery and purification. A potential technology is membrane gas separation, which is based on a semi-permeable membrane, generally a polymeric film, which enables selective gases to pass through while other gases and vapours experience the membrane as a barrier (Ho and Sirkar 1992). The main driving force for separation is the partial pressure difference across the membrane, and hence the technology lends itself to the high pressure gases associated with natural gas processing. The solution-diffusion mechanism that is used to explain gas permeation through non-porous membranes is not viable for helium, because the gas’s chemically inert state means that no chemical interactions with the polymeric membrane occurs; and hence mass transport is through diffusion alone (Scholes and Ghosh 2017). Membrane gas separation is currently commercialised in the natural gas industry for acidic gas removal and hydrocarbon vapour recovery (Baker 2002), and there is potential for membrane gas separation to also recovery and purify helium. Indeed, helium separation was one of the first applications proposed for membranes when the technology was first developed in the 1960s (Stern et al. 1965). However, to date membranes have been limited to small scale helium recycling processes in niche industries, such as recovering helium from air mixtures used in deep sea diving.