High-pressure Separation Research Articles

Energy-Efficient Three-Wheel Bleedless Electrical Environmental Control System for a Passenger Aircraft

Abstract The environmental control system (ECS) of an aircraft is designed to create a comfortable and suitable atmosphere for both passengers and crew, as well as the avionics. Additionally, the ECS represents the highest power consumers within nonpropulsive systems in an aircraft. With sustainable technology development for aircraft, secondary systems such as the ECS are evolving from conventional bleed air to electric-type to improve energy efficiency by reducing fuel consumption. This study introduces a novel electrically driven ECS (EECS) that is designed to replace the existing bleed-air-driven three-wheel air cycle system (ACS) and the high-pressure water separation subsystem (HPWS) of the Airbus 320 (A320) passenger aircraft's ECS during cruise conditions. matlab was used to construct the system component model of the ECS to verify the accuracy of the data from A320. The performance of the proposed EECS was compared with that of the existing bleed-air system in terms of cabin requirements. The conventional ECS's bleed-air off-take from the engine caused a 50% higher fuel mass penalty for missions lasting 5–15 h, which exceeds the shaft power off-take of the EECS. The energy required for the conventional ECS and EECSs was 3.59 MJ and 1.78 MJ, respectively.

Направления совершенствования сероочистки, осушки и переработки природного газа

The results of the work of the staff of the Department of “Chemical Technology of Oil and Gas Refining” of Astrakhan State Technical University in the field of separation of three-phase reservoir mixture, increasing the efficiency of desulfurization, improving the process of drying gas and the production of continuous hydrocarbons – raw materials for petrochemistry. The influence of the quality of raw materials entering processing on the formation of deposits in technological equipment has been studied. Reconstruction of the inlet and three-phase separators of high-pressure reservoir mixture separation plants by installing a vibration damper and a depulsor on the reservoir mixture supply line to the installation, as well as reconstruction of the input of raw materials into the separator of the installation. The use of the KPG-200 defoamer and the KPG-200 AV antifoamer made it possible to reduce the consumption rate of defoaming reagents several times in gas purification plants from acidic components. The influence of various impurities on the foaming of working amine solutions (mechanical impurities, coal dust, products of thermal destruction of amine, thermostable salts, corrosion inhibitors) has been determined. It was revealed that the products of thermal degradation of amine have the greatest effect at concentrations above 3% by weight. A method for reducing the content of mechanical impurities in a solution of diethanolamine in a constant magnetic field has been developed and introduced into an industrial desulfurization plant. The filtration efficiency increases 2.6 times, the foam height is halved, and the foam stability is quadrupled. At the same time, the activity of the defoamer increases by 1.7 times. The mathematical dependence of the height of the protective layer of aluminum oxide in an adsorber with zeolite on impurities of diethanolamine has been experimentally found. The effectiveness of the developed improved distribution ring device is shown, the use of which makes it possible to practically eliminate dead zones in the zeolite layer and thereby increase the efficiency of the adsorption process and increase the inter-regeneration period on the drying unit. Studies of the catalytic pyrolysis of the butane fraction using CVM-type pentasils modified with the introduction of chromium can reduce the process temperature compared with the thermal decomposition of raw materials by more than one hundred degrees 100 °C.

Collaborative sorting: integrating pneumatic separation and manipulator techniques for efficient coal gangue sorting

ABSTRACT Coal is one of the important sources to meet the global energy demand. The intelligent treatment of coal gangue is of great significance to environmental protection and resource recycling. In the treatment of gangue, the use of manipulator sorting alone faces the challenge of being difficult to adapt to the increasing sorting intensity and high cost of use. In this study, we propose a hybrid sorting system that combines pneumatic separation and manipulator sorting to address the limitations of pneumatic separation sorting and manipulator. We design a task assignment algorithm based on genetic algorithms to realize their collaborative work for optimal overall sorting efficiency in a sequence of gangue. Experimental results demonstrate that the collaborative sorting system, incorporating both manipulator and high-pressure pneumatic separation, outperforms the single pneumatic separation sorting system with an average increase in sorting efficiency of 20.66%. Furthermore, the collaborative system increased sorting efficiency by up to 76.09% compared to single manipulator sorting. These findings validate the effectiveness of our proposed approach in achieving efficient sorting of coal gangue.

Thermal performance of three-wheel and split-wheel air cycle systems for a civil aircraft environmental control system (ECS)

The conventional approach of regulating cabin temperature and pressure on aircraft is to utilize engine-bleed air through an environmental control system (ECS). The extraction of bleed air from the engine leads to a decrease in thrust and an increase in drag on the ECS ram air duct, resulting in higher fuel consumption. Consequently, the ECS transitioned from being engine-powered to being electrically powered. In this study, the thermodynamic characteristics of three-wheel and split-wheel air cycle systems (ACSs) with a high-pressure water separation system (HPWS) were investigated by developing a parameter decomposition model and an iterative algorithm using MATLAB for a state-of-the-art electrically driven ECS (EECS) on the Boeing 787 Dreamliner. The efficiency of the ACS was assessed by establishing analytical correlations for the coefficient of performance (COP) using relevant literature on endo-reversible thermodynamic model (ETM). By employing these analytical correlations, the thermal performance of both ACSs can be accurately predicted without the need for system modeling and simulation, considering variations in the input variables and operating conditions, such as the temperatures of fresh air and ram air, the ratio of the mass flow rates of ram air and fresh air, and component parameters, including the efficiencies of the primary and secondary heat exchangers and the pressure ratios of the fan and compressor. The implementation of a split-wheel ACS instead of three-wheel ACS in the Boeing 787 EECS led to an improvement in the COP from 0.31 to 0.43, and also resulted in a reduction of 14.35 % in the input power.

Static state synthesis of STT zeolite membranes for high-pressure H2/CH4 separation

STT zeolite membrane with seven-membered rings (7 MR) and nine-membered rings (9 MR) is an ideal alternative for the separation of hydrogen (H2) and methane (CH4). However, the successful synthesis is only possible in rotation conditions, which is difficult to achieve at an industrial scale. Herein we developed a static synthesis approach to prepare high-quality STT zeolite membranes. The precursor transformed in-situ from a liquid state to a semi-solid state to efficiently suppress the nucleation in the bulk gel. This did not affect the growth of the seed layer to form a continuous membrane. The water content was modulated between y = 44 and y = 124 in the molar composition of 1 SiO2: 0.2 TMAdaOH: y H2O. The precursor could be re-used one more time to reduce the total amount of chemical waste. The optimal H2 permeance and H2/CH4 mixture selectivity was up to 6.1 × 10−8 mol m−2 s−1 Pa−1 and 115 at atm pressure. The H2 permeation flux monotonically increased to 2.0 Nm3 m−2 h−1 under feed pressure up to 2.1 MPa. This paves the way for zeolite membranes to high-pressure H2 separation in practical applications.

Turbulence model augmented physics-informed neural networks for mean-flow reconstruction

Experimental measurements and numerical simulations of turbulent flows are characterized by a tradeoff between accuracy and resolution. In this study, we combine accurate sparse pointwise mean velocity measurements with the Reynolds-averaged Navier-Stokes (RANS) equations using data assimilation methods. Importantly, we bridge the gap between data assimilation (DA) using physics-informed neural networks (PINNs) and variational methods based on classical spatial discretization of the flow equations, by comparing both approaches on the same turbulent flow case. First, by constraining the PINN with sparse data and the underdetermined RANS equations without closure, we show that the mean flow is reconstructed to a higher accuracy than a RANS solver using the Spalart-Allmaras (SA) turbulence model. Second, we propose the SA turbulence model augmented PINN (PINN-DA-SA), which outperforms the former approach by up to 73% reduction in mean velocity reconstruction error with coarse measurements. The additional SA physics constraints improve flow reconstructions in regions with high velocity and pressure gradients and separation. Third, we compare the PINN-DA-SA approach to a variational data assimilation using the same sparse velocity measurements and physics constraints. The PINN-DA-SA achieves lower reconstruction error across a range of data resolutions. This is attributed to discretization errors in the variational methodology that are avoided by PINNs. We demonstrate the method using high-fidelity measurements from direct numerical simulation of the turbulent periodic hill at Re=5600. Published by the American Physical Society 2024

Digital light processing 3D printing of microfluidic devices targeting high-pressure liquid-phase separations.

This paper focuses on 3D printing using digital light processing (DLP) to create microchannel devices with inner diameters of100, 200, and 500 µm and cater flow-through applications within the realm of analytical chemistry, in particular high-pressure liquid chromatographic separations. Effects of layer thickness and exposure time on channel dimensions and surface roughness were systematically investigated. Utilizing a commercially accessible 3D printer and acrylate resin formulation, we fabricated 100-500 µm i.d. squared and circular channel designs minimizing average surface roughness (< 20%) by applying a 20-µm layer thickness and exposure times ranging from 1.1 to 0.7s. Pressure resistance was measured by encasing microdevices in an aluminum chip holder that integrated flat-bottom polyetheretherketon (PEEK)nanoports allowing to establish the micro-to-macro interface to the HPLC instrument. After thermal post-curing and finetuning the clamping force of the chip holder, a maximum pressure resistance of 650bar (1.5% RSD) was reached (n = 3). A polymer monolithic support structure was successfully synthesized in situ with the confines of a 500 µm i.d. 3D printed microchannel. A proof-of-concept of a reversed-phase chromatographic gradient separation of intact proteins is demonstrated using an aqueous-organic mobile-phase with isopropanol as organic modifier.

High-Pressure Separation: New Technology in the Subsea Toolbox

_ Subsea production systems have come far in the more than 60 years since the first deployment in the US Gulf of Mexico, helping many countries unlock their offshore hydrocarbon riches in the years that followed. For Brazil, it was a combination of advances in subsea technologies and floating production, storage, and offloading vessel (FPSO) designs that supported the growth of its offshore oil and gas prowess. From those first forays into the Sergipe-Alagoas basin in the northeast during the 1970s, the country’s offshore oil and gas footprint has grown significantly, with today’s production from the pre-salt Campos and Santos basins—located farther from shore and in much deeper water—launching state-run oil company Petrobras to a top spot among the ranks of global producers. The ongoing development of its offshore fields will continue to boost the country’s oil and natural gas production in 2024. Since December 2022, five FPSOs have been brought online, with four installed in 2023 delivering record output. The fifth one—the FPSO Sepetiba—delivered a New Year’s Day surprise when it came online at Mero 2 oil field on 31 December 2023. HISEP, a new subsea technology currently being readied for pilot testing, could potentially ensure continued future production of the Mero field and others by capturing CO2-rich dense gases directly from the wellstream and reinjecting it into the reservoir. The technology also frees up much-needed space and reduces weight on the FPSO’s topside by moving the separation process to the seafloor. Challenges and Solutions Brazil’s challenging offshore pre-salt region—first explored by Petrobras in 2005—contains estimated reserves of 30 to 40 billion BOE and comes with an extensive list of development challenges. Its Santos Basin, for example, lies in ultradeep water with hydrocarbon reservoirs located at extreme depths ranging from 5500 to 7600 m below sea level and under salt layers more than 2000 m thick. But the challenges do not end there. Managing the basin’s high gas/oil ratio (GOR) and CO2 content leaves a significant operational footprint. In OTC 29762, authors from Petrobras noted that developing the pre-salt reservoirs requires “large production facilities with complex gas processing plants that limit the oil processing and storage capacities.” In the paper presented at the 2019 Offshore Technology Conference (OTC) Brasil, the authors said that the gas processing plants for some pre-salt fields with high production indexes, GOR, and CO2 content account for nearly 60% of the total FPSO topsides area. The Santos Basin is home to the Mero oil field, the country’s third-largest pre-salt field and the first under a production-sharing contract awarded to the Petrobras-led Libra Consortium. The field is considered one of the largest hydrocarbon discoveries in the past decade, covering about 320 km2 of the Libra block and with a net pay zone reaching 420 m filled with 29 °API oil and high productivity, according to Ana Luiza Neder, et al. (OTC 32784).

High-pressure separation performance of Ni(TMBDC)(DABCO)0.5 featured low-polarity channel for CH4/N2 mixture

Developing adsorbents with exceptional CH4/N2 selectivity under high pressure is a crucial commercial requirement and a significant technical challenge for the industrial high-pressure swing adsorption (HPSA) in CH4/N2 separation. Only a few adsorbents were reported to address this issue. In this work, we aimed to explore two microporous MOFs with low-polarity channels for high-pressure CH4/N2 separation. The Ni(BDC)(DABCO)0.5 and its isostructural analog Ni(TMBDC)(DABCO)0.5 were synthesized, characterized, and examined for high-pressure CH4/N2 adsorption property. Due to the lower polarity channel originating from tetramethyl groups, Ni(TMBDC)(DABCO)0.5 exhibited an exceptional methane capacity of 4.23 mmol/g and an IAST selectivity of 5.1 for the CH4/N2 binary mixture at a pressure of 10 bar, surpassing the majority of previously reported materials. The GCMC simulation revealed that the low-polarity pore surfaces in both materials exhibited a higher affinity for CH4 molecules compared to N2 molecules, under both ambient and high pressures. The breakthrough experiments showed that Ni(TMBDC)(DABCO)0.5 exhibited excellent dynamic separation towards CH4/N2 under both 1 bar and 5 bar, indicating great potential as an emerging candidate for the recovery of CH4 from coal-mine methane in industrial PSA processes.

Evaluation of Aircraft Environmental Control System Order Degree and Component Centrality

Air cycle systems (ACSs) are primarily used in aircraft environmental control systems (ECSs) to provide a suitable cabin temperature and pressure environment for passengers and avionics. It comprises heat exchangers, compressors, turbines, water separators, and various other components that are interconnected to form an information-transmission network. Traditional research on ACSs has focused primarily on their thermal performance. This study abstracted ACSs into network graphs based on their information-transmission characteristics, determined the weight of each information-transmission route using the fuel weight penalty method, calculated and compared the order degree of different ACSs using the structure entropy method, and measured the importance of each component using centrality for the first time. The results showed that the order degree of the ACSs gradually increased with an increase in the number of wheels in the air cycle machine (ACM), and ACSs with high-pressure water separation had a higher order degree under wet conditions than under dry conditions. Moreover, based on the centrality of each vertex in the graphs, the ACM and secondary heat exchanger in the ACS were fundamentally important and should be focused on during the system design. The methodology proposed in this study provides a theoretical basis for the evaluation of the ACS organizational structure and the design performance of components.

The isolation of anthocyanin monomers from blueberry pomace and their radical-scavenging mechanisms in DFT study

This study explored the isolation of anthocyanin monomers using a medium- and high-pressure separation technique as a means to increase the added value of a by-product of the blueberry juice industry. Six anthocyanin monomers were isolated with a purity of 95% and identified as mono-galactoside, glucoside, and isomers of delphinidin, malvidin, and even malvidin-3-O-arabinoside, malvidin-3-(6″-acetyl)-O-glucoside by LC-MS and 1H NMR. Following the conformation search, the computer calculation manifested the active sites of six anthocyanins (C4′-OH) and their stabilities based on the structural and energy parameters. The DPPH tests demonstrated that delphinidin glycoside’s free radical scavenging ability (89.93 ± 2.03 % and 86.50 ± 3.16 %) was significantly higher than that of malvidin (80.39 ± 1.30 % and 81.02 ± 0.45 %), and that malvidin’s capacity was improved by conjugation arabinoside (87.48 ± 2.39 %) and acetylated glucoside (88.39 ± 1.37 %), which was compatible with the computer calculation.

Результаты исследований по идентификации причин нестабильной работы криогенной воздухоразделительной установки ТКДС-100В

The article presents the main results of an experimental study of the operation of a nitrogen rectification column of a high-pressure air separation unit TKDS-100V developed by JSC "NPO "Geliymash" as an alternative to the installations of the previous generation AKDS-70M. The declared productivity of these units is much higher in comparison with the predecessor, the concentration of the products obtained meets the requirements and is ensured by the use of efficient heat and mass transfer devices of its own production. However, the experience of operating the TKDS-100V air separation unit has revealed a number of significant disadvantages. The unstable operation of the air separation unit of the TKDS-100V unit, caused by both constructive miscalculations and errors in the operational documentation, leads to operational disadvantages. The evaluation of the mass productivity of the TKDS-100V unit in the mode of liquid nitrogen production has been carried out. Based on a detailed analysis of empirical data, the reason for the oscillatory nature of the processes occurring in the column has been established, which significantly complicate the operator’s work, exclude the possibility of maintaining a rational mode and often lead to emergency situations associated with the parameters going beyond the limits of acceptable values. Deficiencies in the design of the rectification column leading to a pulsating supply of reflux from the pockets of the condenser to the upper rectification plate are identified and solutions are proposed

Performance analysis of partial closed-loop air cycle system with a power turbine

In this paper, a new architecture of Air Cycle System (ACS) is presented based on advanced F-15 ACS, F-35 ACS and other air cycle systems. The new architecture is a high-pressure water separation (HPWS) system driven by power turbine with a compressor as an independent air-supplying resource. In new ACS, the engine bleed air after driving power turbine is discharged into the atmosphere and the power turbine supplies shaft work to two compressors of the system. One compressor is the component of HPWS, and the other is the resource of pressurized cabin air supply which isolates the engine bleed air from ACS and improve supply air quality. The system performance is analysed which concludes energy consumption, adaptability, adjustability. The research is carried out in many aspects, such as cabin supply air flow, circulating pressure and airflow, flight altitude, flight speed and avionics heat loads. The results show that the new-type architecture reduces the engine leed air and it is adjustable and adaptable which makes it flexible. The work done in the paper provides a new reference for ACS or integrated aircraft thermal management.

Molecular Design of Poly(imide–oxadiazole) Membranes for High-Pressure Mixed-Gas Separation

Molecular Design of Poly(imide–oxadiazole) Membranes for High-Pressure Mixed-Gas Separation

High-pressure CO2 permeation properties and stability of ceramic-carbonate dual-phase membranes

CO 2 permeation properties and stability of ceramic-carbonate dual-phase membranes at high pressures/temperatures are critical to their CO 2 separation and membrane reactor applications, but such data are not available in the literature. This work aims to study the effect of high transmembrane pressure on CO 2 permeation flux and the stability of molten carbonate in the dual-phase samarium-doped ceria (SDC) and molten-carbonate (MC) membranes. Dead-end porous SDC tubular supports were made by a cold isostatic press (CIP)/sintering method with a low porosity (below 7%), and gas-tight SDC-MC membranes were prepared by direct infiltration of molten lithium and sodium carbonate mixture into SDC pores, with a MC volume fraction less than 7%. CO 2 permeation/separation tests were performed on the SDC-MC membranes using feed gas of equal molar CO 2 /N 2 mixture at feed pressures up to 15 atm and sweep gas of helium at 1 atm. CO 2 permeation flux for the SDC-MC membranes depends logarithmically on feed/permeate CO 2 pressure ratio in 660–810 o C. The temperature dependence of CO 2 permeation shows activation energy of 30 kJ/mol. Due to the small MC volume fraction and hence low effective carbonate conductivity, CO 2 permeation of the SDC-MC membranes is dominated by the carbonate ionic conduction in the MC phase. The SDC-MC membranes remain in the same structure, morphology, and gas-tightness after CO 2 separation tests at high feed pressures and temperatures, showing high stability of SDC-MC membranes for high-temperature, high-pressure separation and chemical reaction applications. • Strong ceramic-carbonate dual-phase membranes can be made by the cold isostatic press method. • High-pressure CO 2 permeation flux depends logarithmically on feed/permeate CO 2 partial pressure ratio controlled by carbonate ionic conduction. • Samarium-doped ceria-molten carbonates membranes are stable at high pressures/high temperatures.

Analytical strategies in venomics

Snakebite envenoming is a major issue in certain developing parts of the world, with tens of thousands of deaths and a multitude of lingering permanent medical conditions on a yearly basis as a result. Venoms consist of a plethora of biologically active compounds, mainly peptides and proteins, that can induce these effects. Snake venom characterisation, in terms of identifying and quantifying the venom toxin proteins in crude venoms, can aid in pinpointing the venom toxins responsible for pathologies observed in snakebite victims. It can also assist in developing a new generation of efficient antivenoms. To facilitate this characterisation process, several approaches have been developed, of which venomics, toxicovenomics and antivenomics are the most important ones and aim to map venom toxin composition, their toxic effects, and antivenom efficacy, respectively. Most venomics approaches include peptide-centric analyses of protein digests in combination with advanced separation and detection hardware and involve the use of generic and dedicated software tools for data processing. However, a shift towards protein-level, and even proteoform-level, analysis can be observed over the last few years. A variety of hyphenated intact protein separation techniques, including gel-eluted liquid fraction entrapment electrophoresis, OFFGEL, gel filtration and several (ultra)high pressure and nanoscale chromatographic separations can be named, which allow retention of intact or native states of toxin proteins with ever increasing resolutions. Similarly, rapid detection hardware advances on the mass spectrometry side, and labelling techniques, allow for increasingly sensitive and quantitative venom analysis and characterisation. Most venomics research includes several complementary analytical techniques performed in parallel, with each technique often leading to exclusive protein identifications but also showing significant overlap. The original venomics approach, developed by the Calvete group and termed “Snake venomics”, is used most frequently and is the most profound methodology that has been advanced over the years, thereby resulting in sequentially further identification of venom toxin proteins based on previous results using increasingly in-depth characterisation approaches. The latest advances in this regard nowadays allow for quantitative analysis of all venom toxins in crude venoms, named “Absolute venomics”. This review will focus on the analytical aspects of venomics for which sample preparation, separation, detection and quantitation techniques are discussed. Finally, a comparison between recently published venomics studies is made.

Low- and High-Pressure Membrane Separation in the Production of Process Water for Coke Quenching.

Although the time for operating mines and coking plants in many countries is coming to an end due to climate change, we must still ensure that the pollution generated by this source of the economy is minimized. Despite the several stages of treatment of the coke-oven effluent, completed with nitrification and denitrification processes preceding final sedimentation, the stream obtained does not meet the requirements of water for coke quenching. That is why the stream after biodegradation and sedimentation was treated on membrane units to ensure water reusing in the coking plant. As the subjected stream contained both solid and dissolved pollutants, a two-stage system was proposed: low- and high-pressure membrane filtration. Industrial modules were tested on pilot units operating under industrial plant conditions. In the case of the ultrafiltration process, all the tested ultrafiltration modules fulfilled the primary task. All of them separated almost completely the turbidities present in the stream, which would have disturbed the operation of the high-pressure plant. Considering the decrease in permeate flux and the possibility of cleaning, a PCI membrane made of PVDF tubes with a diameter of 12.5 mm and pore size of 20 μm was selected. Regarding the high-pressure membrane filtration, the reverse osmosis membrane was significantly better in the removal efficiency of both organic and inorganic dissolved substances. An operating pressure of 3 MPa was chosen for the system. Hence, membrane processes, which are not used as stand-alone treatment units for coke-oven effluents, function well as a final treatment stage.

Copolyimide membranes with improved H2S/CH4 selectivity for high-pressure sour mixed-gas separation

Natural gas purification is a challenging task due to the existing number of contaminants in the mixture. Sour natural gas, in particular, presents an even higher challenge due to the presence of the highly toxic hydrogen sulfide (H2S) gas. These contaminants level must be reduced to meet the sales gas specifications. In this paper, three DAM-based random copolymers were prepared for simultaneous improvement of the acid gases (CO2 and H2S) separation properties of their corresponding membranes. While the developed membranes exhibit high CO2/CH4 selectivity in a non-sour mixed-gas, their unconventional behavior during sour gas separation is difficult to predict. Therefore, their membranes were subjected to sour mixed-gas separation tests a quinary gas mixture including 20 vol% H2S at different upstream pressures up to 34.5 bar. Each membrane demonstrated one or more improved properties in terms of acid gases permeability and selectivity coefficients. Taking into consideration the overall performance, membranes prepared from 6FDA-DAM/6FpDA (1:3) exhibited the most attractive separation properties among the series prepared. However, based on the relatively high H2S/CH4 selectivity obtained of 6FDA-DAM/CARDO (1:3) membranes, a block 6FDA-DAM/6FDA-CARDO (1:1) copolyimide was prepared, and the sour mixed-gas separation properties were evaluated. The overall block copolymer membrane demonstrated very attractive productivity and efficiency, compared to the standard industrially used glassy polymer, cellulose acetate, thereby rendering it a potential candidate for sour natural gas purification.

Analysis on the corrosion failure of U-tube heat exchanger in hydrogenation unit

Unscheduled shutdown often occurs in diesel hydrogenation unit due to the corrosion leakage of heat exchanger. After a series of analyses of technological and flow processes, failure causes of the U-tube heat exchanger were investigated. The inside and outside mediums of heat exchanger tubes were hot high-pressure separation (HHPS) gas and cold low-pressure separation oil, respectively. A detailed examination shows that the corrosion occurs in shell side and was caused by under-deposit corrosion of NH4Cl. Through the numerical simulation, it is found that the leakage location is at the place where water tends to accumulate. Thus, in order to prevent the corrosion of heat exchanger, the water content carried in the cold low-pressure separation oil should be reduced.

Low to high-pressure CO2 separation using amine-functionalized Mobile Composite Matter, isotherm modelling and heat of adsorption study

ABSTRACT Adsorptive CO2 separation is an effective process in carbon capture and sequestration. In this work, Benzylamine, Monoethanolamine, and Aminoethylethanolamine impregnated MCM-48 are used to enhance CO2 adsorption capacity. The materials are characterized using BET, XRD, TGA, FT-IR, FESEM and elemental analysis techniques. The CO2 uptakes are measured using high pressure sorption equipment in the temperature and pressure ranges of 25–80°C and 0–30 bar. The effect of amine loadings is pronounced in the chemisorption of CO2. The Sips isotherm model is better to correlate the experimental data than that of in Freundlich, Langmuir and Toth models. The isosteric heat of adsorption is calculated using Van’t Hoff plot in the temperature range of 25–60°C to understand the degree of heterogeneity and the surface energy distribution of the adsorbents. The CO2 adsorption capacity (3.33 mmol CO2/g) and amine efficiency (14.1 mmol CO2/g amine) of 30% AEEA impregnated MCM-48 is highest among the amine-functionalized MCM-48 adsorbents reported till date in the open literature. The MCM-48-30%AEEA shows 5.2 times higher CO2 adsorption capacity than that of in MCM-48 (0.637 mmol/g) at 25°C and 1 bar pressure. The MCM-48-30%AEEA is proposed as a promising adsorbent in low- to high-pressure post-combustion flue gas and natural gas purification.