Pre-combustion Carbon Capture Research Articles

Analysis and comparison of the membrane-cryogenic hybrid process and multistage membrane process for pre-combustion carbon capture based on the superstructure method

The feed in pre-combustion carbon capture has a high CO2 concentration and high pressure, which gives membrane technology and membrane-based hybrid technology a strong separation driving force. Because the membrane-cryogenic hybrid method can inexpensively achieve the high CO2 purity and recovery, it offers a novel approach in addition to traditional separation methods. Nevertheless, it is uncommon to consider the combination of membrane materials and processes. Furthermore, investigations comparing multistage membrane processes with membrane-cryogenic hybrid processes under identical conditions are lacking. Therefore, this paper establishes separately the membrane-cryogenic hybrid processes and multistage membrane process by the superstructure method, which considers the number of membrane stage, membrane material type, and operating parameters simultaneously. The optimal process structures for three-stage membrane, cryogenic-membrane process, and membrane-cryogenic process are investigated and compared. The influences of membrane price and electricity price on the CO2 capture cost are also investigated. Results shows that the CO2 capture cost of cryogenic + membrane process is the lowest (11.69 $/t CO2) of the studied processes at 96 % CO2 purity and 90 % CO2 recovery. The system structure of the cryogenic + membrane process varies with CO2 purity and recovery. Electricity price has a more important impact on the CO2 capture cost than membrane price under the optimized conditions.

Carbon capture and utilization under EU law: impermanent storage of CO2 in products and pre-combustion carbon capture

Abstract The evolving regulatory landscape within the European Union demonstrates a transition from prioritizing carbon capture and storage over carbon capture and utilization towards a more equitable treatment of both approaches in relevant legislation and policy frameworks. Nevertheless, the ‘permanence’ criterion of carbon dioxide in the products remains an ongoing challenge. Within the current European legal framework, harnessing the regulatory incentives depends on how long carbon dioxide remains in carbon capture and utilization products. The study elucidates the evolving regulatory landscape surrounding carbon capture and utilization by examining recent legislative initiatives and amendments to key directives such as the Emissions Trading System Directive and the Renewable Energy Directive. Furthermore, it explores the implications of the European Union Net-zero Industry Act and the Carbon Removal Certification Framework. In addition, this article examines and explains the need for expanding the scope of carbon capture and utilization and storage by incorporating pre-combustion carbon capture through methane splitting into the definition.

Onboard pre-combustion carbon capture with combined-cycle gas turbine power plant architectures for LNG-fuelled ship propulsion

This paper investigates the concept of pre-combustion carbon capture (Pre-CCS) with a combined cycle gas turbine (CCGT) propulsion system to achieve energy efficient carbon capture onboard a Liquid Natural Gas fuelled vessel. A basic CCGT model with energy efficiency of 51.6 % when using LNG as fuel was integrated with a Pre-CCS system composed of a steam methane reformer, water–gas shift reactors, pressure swing adsorption (SMR-PSA), and liquid CO2 storage. Various waste heat utilisation schemes integrated with the CCGT-reformer were modelled in Aspen HYSYS. The modelling of the waste heat recovery networks as energy streams integrating between various processes and unit of operations has facilitated a closed-loop simulation of various systems. It was concluded that a proper utilisation of the high-grade heat from the gas turbine (GT) exhaust and from the reformer is crucial to improve the overall energy efficiency and carbon capture rate, exemplified by a scheme where the heating needs for the SMR and the cooling needs from the water–gas-shift reactors are fully integrated. When optimised, the integrated system had an overall energy efficiency of 41.5 % and 43.2 % (i.e. an efficiency loss of 10.2–10.5 percentage points from the base CCGT system) accompanied with specific GHG emission reduction of 51.2 % and 52.3 % for operation of the GT at a turbine entry temperature of 1700 K and 1850 K, respectively. Intermediate levels of reforming, where the GT uses a mix of LNG and reformate gases, were also simulated, showing an almost linear evolution from the 100 % LNG feed to the GT to the 100 % reformate case. Such a strategy could be used for gradual evolution to meet the required CO2 reduction timeline. It was determined that the 100 % reformate case provides the highest CO2 capture rate. Estimates of other emissions from the GT assuming typical combustor residence times for the whole range of fuel blends were also carried out, showing that the overall greenhouse gas emission is dominated by CO2, given that the GT emits negligible N2O and unburnt methane. Some capital cost estimates were also made to determine the unit price of hydrogen fuel produced onboard, suggesting that the CAPEX was not prohibitive. These findings support the pre-combustion CCS − CCGT integrated system as a promising long-term decarbonisation and propulsion strategy to comply with emissions regulations, displaying good performance in terms of cost, energy consumption, and CO2 reduction. The scalability and adaptability of the proposed system for existing and new-built ships across the decarbonisation timeline is also discussed.

A Thermodynamics Model for the Assessment and Optimisation of Onboard Natural Gas Reforming and Carbon Capture

The paper examines pre-combustion carbon capture technology (PreCCS) for liquefied natural gas (LNG) propelled shipping from thermodynamics and energy efficiency perspectives. Various types of LNG reformers and CCS units are considered. The steam methane reformer (SMR) was found to be 20% more energy efficient than autothermal (ATR) and methane pyrolysis (MPR) reactors. Pressure swing adsorption (PSA) had a lower energy requirement than membrane separation (MEM), cryogenic separation (CS), and amine absorption (AA) in pre-combustion carbon capture, with PSA needing 0.18 kWh/kg CO2. An integrated system combining SMR and PSA was proposed using waste heat recovery (WHR) from the engine, assuming similar efficiency for LNG and H2 operation, and cooling and liquefying of the CO2 by the LNG. The SMR-PSA system without WHR had an overall efficiency of 33.4% (defined as work at the propeller divided by the total LNG energy consumption). This was improved to 41.7% with WHR and gave a 65% CO2 emission reduction. For a higher CO2 reduction, CCS from the SMR heater could additionally be employed, giving a maximum CO2 removal rate of 86.2% with 39% overall energy efficiency. By comparison, an amine-based post-engine CCS system without reforming could reach similar CO2 removal rates but with 36.6% overall efficiency. The advantages and disadvantages and technology readiness level of PreCCS for onboard operation are discussed. This study offers evidence that pre-combustion CCS can be a serious contender for maritime propulsion decarbonization.Graphical

Application of Metal-Organic Frameworks (MOFs) in Carbon Capture

The rising levels of CO2 are unavoidably connected to climate change and its consequences on atmospheric temperatures throughout the world. Carbon capture and storage (CCS) is a dependable and practical method for capturing carbon emissions from industry. This article introduces the realms of direct air capture, post-combustion carbon capture, and pre-combustion carbon capture. Furthermore, the paper delves into the fascinating world of metal-organic frameworks (MOFs) materials with a high porosity, tunable structures, and exceptional adsorption capacities that can effectively absorb substantial quantities of CO2, qualifying them as promising candidates for reducing greenhouse gas emissions. The synthesis methods and performance evaluation of MOF materials concerning carbon capture were introduced. Some of the challenges associated with MOFs are also discussed, including their reduced stability at high temperatures and sensitivity to moisture. This paper provides a comprehensive overview of carbon capture technologies, highlighting the potential of MOFs while addressing current challenges and opportunities in the field.

Scalable Room-Temperature Synthesis of a Hydrogen-Sieving Zeolitic Membrane on a Polymeric Support

Synthesis of H2-sieving membranes for high-temperature applications is highly desired for improving the energy efficiency of H2 production from steam reforming and developing a low-cost solution for precombustion carbon capture. Zeolite-based membranes are ideal for this because they possess excellent hydrothermal stability. However, current methods to synthesize H2-sieving zeolite membranes rely on hydrothermal synthesis on expensive ceramic supports followed by postsynthetic functionalization to shrink the effective pore size. The scalable synthesis approach on a low-cost polymeric support implementable at room temperature is highly desired to advance applications based on H2-sieving membranes. Herein, we report the room-temperature fabrication of H2-sieving zeolitic membranes by simply assembling sodalite precursor, i.e., RUB-15 nanosheets, on a porous polybenzimidazole support. The presence of adsorbed surfactants on the nanosheets led to an entropically driven ordering of the nanosheets witnessed by a sharp (200) d-spacing peak by X-ray diffraction. The intersheet gap was successfully eliminated by the ion exchange of cationic surfactants by a diluted acetic acid solution. The resulting zeolitic films show attractive H2/CO2 and H2/CH4 separation performances at elevated temperatures. The fabrication of H2-sieving zeolitic membranes without resorting to hydrothermal synthesis or high-temperature activation is expected to push the efforts to scale up zeolite membranes for application in gas separation and membrane reactors.

Hydrogen-sieving zeolitic films by coating zeolite nanosheets on porous polymeric support

The synthesis of high-performance gas-sieving zeolitic film is challenging because it involves seeded secondary growth which is complex and difficult to reproduce. Additionally, expensive asymmetric inorganic porous supports are often needed for calcination of the zeolite films. Herein, scalable preparation of H2-sieving RUB-15 nanosheet films is reported bypassing the need for secondary growth and expensive supports. A novel, low-cost, thermally-robust, porous polybenzimidazole copolymer (PBI-AM Fumion®) support is prepared which allows deposition of thin, compact, and oriented RUB-15 nanosheets films without cracks or pinhole defects. The film hosts two transport pathways, H2-sieving six-membered silicate rings in the nanosheets and nonselective intersheet gaps maintained by the organic guest species in the gallery spacing. The latter is eliminated by a low-temperature (330 °C) calcination where the crystalline order in the nanosheets is preserved. The resulting zeolitic films yielded H2 permeances of 100–400 GPU and H2/CO2 selectivities above 20 at temperatures above 200 °C. The facile and scalable fabrication procedure with an attractive H2-sieving performance at elevated temperatures make these membranes promising for pre-combustion carbon capture.

Modeling of pre-combustion carbon capture with CO2-selective polymer membranes

CO2-selective polymer membranes were recently applied to pilot-scale and bench-scale pre-combustion capture and the obtained CO2 capture ratios were reported to be less than 90%, which limits their application in industrial processes such as IGCC plants. This work is aimed to explore the possibility of achieving a CO2 capture ratio >95% and CO2 purity >95% in a gas-separation unit equipped with currently-available CO2-selective polymer membranes. A mathematical model for single-stage membrane gas separation was developed, and the effect of membrane characteristics (permeance and selectivity), as well as the operating parameters such as feed and permeate pressure, and feed flow rate on the performance of CO2 capture was investigated. The simulation results reveal the optimal conditions that are necessary for a high-performance CO2 capture process using the real industrial syngas and highlight the potential of facilitated transport membranes for CO2 removal in both the oxygen-blown and air-blown IGCC processes.

Techno-economic assessment of blast furnace gas pre-combustion decarbonisation integrated with the power generation

Aiming at the iron and steel industry decarbonisation with blast furnace gas (BFG) utilisation, a techno-economic feasibility of the pre-combustion carbon capture with methyl diethanolamine (MDEA) is evaluated herein. The effectiveness of water gas shift (WGS) implementation on the capture performance is also investigated. The integration of a power plant with decarbonised fuel from the capture unit is taken into account from both technical and economic perspectives. Aspen Plus® is used to develop the process. The results obtained from the techno-economic analysis showed that the WGS implementation increases the capture efficiency from 46.5% to 83.8%, with increased CO2 capture cost from € 39.8/tCO2 to €44.3/tCO2. The sensitivity analysis on the effect of 1) different BFG composition and 2) different carbon capture rate (CCR) on the capture unit integrated with WGS performance is performed. The obtained results revealed that BFG with a lower calorific value is less practical from a techno-economic point of view as it increases the specific primary energy consumption for CO2 capture avoidance (SPECCA) from 3.3MJLHV/kgCO2 to 3.8MJLHV/kgCO2. Moreover, the lower CCR increases the thermal energy of the H2-rich gas from the capture unit from 266.8 MW to 269.6 MW. The techno-economic advantages of the based case do not results beneficial for na environment point of view since at lower CCR the specific CO2 emissions increase from 51 kgCO2/GJLHV to 70 kgCO2/GJLHV. The fully integrated power plant to the capture unit reveals that the 37.52% (without WGS) and 24.27% (with WGS) efficiencies are achievable through the combined cycle integration. For the combined cycle, the integration of WGS reactor will reduce the CO2 specific emission to 675.1 kgCO2/MWh in comparison to 1391.5 kgCO2/MWh for the case with no WGS.

Assessment of the pre-combustion carbon capture contribution into sustainable development goals SDGs using novel indicators

The rapid progress in the global population and technical advances have resulted in exponential growth in the use of fossil fuels. These are not only limited in resources but also have a severe environmental impact. The accumulation of greenhouse gases (GHGs), more specifically carbon emissions, in the environment has resulted in severe health issues and climate changes. The Paris Climate Agreement calls for restricting global warming to only 1.5 °C by 2050 relative to the pre-industrial era. This requires reducing global GHGs emissions as soon and as much as possible. Massive efforts are being put into minimizing GHG emissions, such as using renewable energy resources and/or using carbon capture technologies (CCT). In this study, different CCTs were introduced, focusing on the pre-combustion as a promising CCT approach. In this work, the role of CCT in realizing the United Nations Sustainable Development Goals (SDGs) was thoroughly analyzed and discussed. A total of 87 indicators were developed to measure and analyze the contribution of CCT to achieving the different SDGs. The focus given to the role of the pre-combustion CCT in achieving SDGs is being elaborated. The indicators and analysis covered the economic, environmental, and social pillars of sustainable development. It was found that CCT contributes well to all 17 SDGs, with core and substantial contributions to SDG-7 of "Affordable and clean energy", and ultimately SDG-13 of "Climate action". The developed indicators would work as a guideline for the different players to ensure that CCT is fully adhering the SDGs principles. The proposed indicators have nine main benefits, i.e., assist in the achievement of the SDGs, providing information for the decision-makers, enhance and benchmark sustainability performance, improve risk management, enhance data management and reporting practices, improve resource allocation and reduce the expenses, improve environmental performance, reduce social impact, and improve communications with stakeholder. Moreover, the different barriers facing the CCT were presented.

Impact of humidity on gas transport in polybenzimidazole membranes

Polybenzimidazoles (PBIs) are promising materials for high temperature H2/CO2 separation in applications such as steam reforming and pre-combustion carbon capture where significant amounts of water are often present. However, PBIs are hydrophilic, and the impact of humidity on PBI gas separation properties is relatively unexplored. Furthermore, opportunity exists to elucidate the interplay between plasticization, free volume, and gas transport in glassy polymer membranes such as PBIs. This study investigates the effect of humidity on H2, O2, and CO2 permeabilities at 35 °C in a commercial PBI and two sulfone-containing PBIs. Water uptake significantly reduces PBI gas permeabilities at low humidities due to competitive sorption and antiplasticization. At high humidities, plasticization increases the permeabilities of larger gases in more hydrophilic PBIs. Effective fractional free volumes evaluated from gas permeation data and previously reported water sorption and dilation data suggest water plasticizes PBIs by increasing accessible free volume via enhanced molecular dynamics rather than by creating new free volume cavities.

A Highly Selective Supramolecule Array Membrane Made of Zero‐Dimensional Molecules for Gas Separation

AbstractWe orderly assembled zero‐dimensional 2‐methylimidazole (mim) molecules into unprecedented supramolecule array membranes (SAMs) through solvent‐free vapor processing, realizing the intermolecular spacing of mim at ca. 0.30 nm available as size‐sieving channels for distinguishing the tiny difference between H2 (kinetic diameter: 0.289 nm) and CO2 (kinetic diameter: 0.33 nm). The highly oriented and dense membranes yield a separation factor above 3600 for equimolar H2/CO2 mixtures, which is one order of magnitude higher than those of the state‐of‐the‐art membranes defining 2017’s upper bound for H2/CO2 separation. These SAMs define a new benchmark for molecular sieve membranes and are of paramount importance to precombustion carbon capture. Given the range of supramolecules, we anticipate SAMs with variable intermolecular channels could be applied in diversified separations that are prevalent in chemical processes.

A Highly Selective Supramolecule Array Membrane Made of Zero-Dimensional Molecules for Gas Separation.

We orderly assembled zero‐dimensional 2‐methylimidazole (mim) molecules into unprecedented supramolecule array membranes (SAMs) through solvent‐free vapor processing, realizing the intermolecular spacing of mim at ca. 0.30 nm available as size‐sieving channels for distinguishing the tiny difference between H2 (kinetic diameter: 0.289 nm) and CO2 (kinetic diameter: 0.33 nm). The highly oriented and dense membranes yield a separation factor above 3600 for equimolar H2/CO2 mixtures, which is one order of magnitude higher than those of the state‐of‐the‐art membranes defining 2017’s upper bound for H2/CO2 separation. These SAMs define a new benchmark for molecular sieve membranes and are of paramount importance to precombustion carbon capture. Given the range of supramolecules, we anticipate SAMs with variable intermolecular channels could be applied in diversified separations that are prevalent in chemical processes.

Parametric Study on Co-Feeding of Municipal Solid Waste and Coal in an IGCC Power Plant with Pre-Combustion Carbon Capture

Municipal solid waste (MSW) is one of the top contributors in greenhouse gas (i.e. methane) emissions - particularly from landfill disposals. However, it could be a remarkable source of renewable energy. In Bangladesh, generation of municipal solid waste is at least 2.7 million tonne per year in the major cities, implying a heavy environmental burden. On the other hand, there are several coal-based power plants are in the pipeline to meet the increasing energy demand in Bangladesh with the potential of significant CO2 emission. To find a remedy to the above situation, a power plant using Integrated Gasification and Combustion Cycle (IGCC) technology with pre-combustion carbon capture is considered in this study. IGCC has the advantage of producing high quality syngas from a wide variety of feed and assists in the capture of CO2 at a lower cost while providing high electric efficiency. The power plant was simulated by commercial simulation packages (Aspen PLUS™ and Aspen HYSYS™) using MSW and bituminous coal (Indonesian) as a combined feed. With a feed rate of 1800 tonne per day, Syngas produced from an entrained flow type gasifier was then treated for CO2 removal using mono-ethanol amine (MEA) solvent after necessary shift in a high temperature shift reactor. About 91% efficiency was achieved in the shift reactor while the CO2 capture efficiency was varied for this study from 30% to 85%. Further parametric variation was studied by varying the moisture content of MSW and MSW to coal feed ratio. Through combustion of the H2 rich syngas in a gas turbine and subsequent steam cycle with reheat resulted in 125 MW of electricity at an efficiency of 28.95% while capturing 50% of the CO2 generated in the process for an MSW to Coal feed ratio of 1:1. With variation in moisture content especially during monsoon season, the plant efficiency could be affected remarkably. On the other hand, it was observed that the energy requirement varied from 6 to 8 MW for every 10% increase in CO2 capture quantity. Overall, by capturing 50% of the generated CO2, it is possible to reduce the emission of a same size ultra-supercritical coal-based power plant from about 700 kg CO2/MWh to about 360 kg of net CO2/MWh incorporating co-feeding and pre-combustion capture in an IGCC power plant.
 Chemical Engineering Research Bulletin 21(2020) 37-42

Application of HyMethShip Propulsion using On-board Pre-combustion Carbon Capture for Waterborne Transport

The HyMethShip project (Hydrogen-Methanol Ship propulsion using on-board pre-combustion carbon capture) is a cooperative R&D project funded by the European Union’s Horizon 2020 research and innovation program. The project aims to drastically reduce emissions while improving the efficiency of waterborne transport. The HyMethShip system will achieve a reduction in CO2 of up to 97% and practically eliminate SOx and particulate matter emissions. NOx emissions will fall by over 80 %, safely below the IMO Tier III limit. In this study the HyMethShip concept is introduced and various aspects of the concept development are discussed. Additionally, some issues that might accelerate or hinder the concept application for commercial shipping are presented. Doi: 10.28991/HIJ-2021-02-02-01 Full Text: PDF

Large-scale applications and challenges of adsorption-based carbon capture technologies

This paper introduces adsorption processes with scaled sizes for post-combustion carbon capture, pre-combustion carbon capture, and direct air capture (DAC). Technical characteristics, separation performances, and operating energy consumptions of adsorption-based pilot plants for carbon capture are analyzed. Opportunities and challenges of adsorption-based carbon capture processes in future development are illustrated. Adsorption-based post-combustion carbon capture is a relatively mature technology, which can be applied to retrofitted power plants. However, in order to commercialize this technology, quantities of research and development resources are still needed. Researches on adsorption-based post-combustion carbon capture should focus on the following three aspects: (1) Low-temperature adsorbents with excellent CO2 working capacities, kinetics, and stabilities, (2) low energy consumption cycles using steam purge, and (3) contactors with low gas-solid mass transfer resistances. The warm gas clean-up technology based on pressure swing adsorption (PSA) is a research hotspot for pre-combustion carbon capture. At present, many warm gas clean-up pilot plants are being built worldwide, and in the meantime, some bottlenecks appear. First, the CO2 working capacities of elevated temperature adsorbents are still lower than those of low temperature adsorbents. The recently reported molten salt-promoted magnesium oxide achieves a very high working capacity through the bulk phase chemical absorption, but a carbon capture prototype needs to be established to verify its cyclic stability. Achieving both high purity and high recovery of warm gas clean-up consumes a large amount of high temperature steam. Although multi-train PSA configuration can reduce the energy consumption, it also increases the operating complexity and equipment investment. In addition to CO2, the removal of other impurities such as H2S, COS, HCl, and heavy metals in syngas/reforming gas should be considered. The sorption enhanced reforming with oxy-fuel regeneration process based on high temperature adsorbents can achieve CO2 enrichment in the regeneration reactor. However, pilot plants for this technology are currently lacking, and so detailed techno-economic analysis is still needed to assess its capture cost. Although DAC is a relatively new concept and is still in the early stage for large-scale commercial application, the synergy between DAC and conventional carbon capture technologies can mitigate climate change effects in the long run. The development of DAC technologies needs to pay special attention to the pressure drop problems. Novel gas-solid contactors using structural adsorbents can effectively reduce the power consumption of the fan. Steam purge under subatomospheric pressures reduces the regeneration temperature of DAC, and thus makes the utilization of renewable energy and industrial waste heat for regeneration becoming possible. When steam purge is used, the cyclic stability of the adsorbents should be concerned. For instance, polyamine impregnated adsorbents are prone to amine leakage in the presence of steam. Therefore, the development of hydrothermally stable DAC adsorbents is significantly important.

Gas-sieving zeolitic membranes fabricated by condensation of precursor nanosheets.

The synthesis of molecular-sieving zeolitic membranes by the assembly of building blocks, avoiding the hydrothermal treatment, is highly desired to improve reproducibility and scalability. Here we report exfoliation of the sodalite precursor RUB-15 into crystalline 0.8-nm-thick nanosheets, that host hydrogen-sieving six-membered rings (6-MRs) of SiO4 tetrahedra. Thin films, fabricated by the filtration of a suspension of exfoliated nanosheets, possess two transport pathways: 6-MR apertures and intersheet gaps. The latter were found to dominate the gas transport and yielded a molecular cutoff of 3.6 Å with a H2/N2 selectivity above 20. The gaps were successfully removed by the condensation of the terminal silanol groups of RUB-15 to yield H2/CO2 selectivities up to 100. The high selectivity was exclusively from the transport across 6-MR, which was confirmed by a good agreement between the experimentally determined apparent activation energy of H2 and that computed by ab initio calculations. The scalable fabrication and the attractive sieving performance at 250-300 °C make these membranes promising for precombustion carbon capture.

Thermodynamic modeling and rational design of ionic liquids for pre-combustion carbon capture

Although ionic liquids (ILs) have been widely explored as promising solvents for carbon capture, systematic study on the rational selection and design of ILs for carbon capture processes is still scarce. In this contribution, a comprehensive literature survey is first performed to provide an up-to-date database comprising 10,116 CO2 solubility data and 463 H2 solubility data measured in a large number of ILs at various temperatures and pressures. Using this dataset, the UNIFAC-IL model for predicting the vapor–liquid equilibrium of the CO2-H2-IL ternary system is developed, where 42 main groups and 53 subgroups are specified and 220 group interaction parameters are fitted. With this model, an optimization-based computer-aided ionic liquid design problem is finally formulated and solved to identify the best ILs for the pre-combustion carbon capture process. It is found that the hydroxyl-ammonium and hydroxyl-imidazolium bis(trifluoromethylsulfonyl)amide ILs are the most promising solvent candidates.

Research trends in carbon capture and storage: A comparison of China with Canada

In order to effectively address climate change, academia and industry have paid much attention to the development trend of Carbon Capture and Storage (CCS). However, there is no mature CCS research trend monitoring system. China is likely to be the largest market for CCS technology in the future, while Canada is the first country to start the research and development of CCS. Existing studies have discussed the CCS research trends at the global level, in China, Canada, and in other countries. However, few comparative studies have been carried out in key countries. In this study, an integrated method of bibliometrics and S-Curve is proposed with the purpose of comparing CCS research trends between China and Canada. Firstly, the bibliometrics method was used to compare the conceptual structure and research route of CCS research in China and in Canada. Secondly, the key collaborators were indentified through the comparison of collaboration relationships. Finally, the S-Curve model was employed to forecast the CCS research output trend in China and Canada. This study found that China's CCS research had the advantage of pre-combustion carbon capture, while Canada's advantage lied in the ecosystem carbon sequestration. It was also shown that Canada’s CCS cumulative publication may reach saturation 15 years later than that in China. This paper provides insight into the CCS research and development optimization for China, Canada and globally. The CCS research trends comparison tools proposed in this study can benefit to monitor the CCS research by governments and enterprises.

Modeling pre-combustion CO2 capture with tubular membrane contactor using ionic liquids at elevated temperatures

A pre-combustion carbon capture process at high temperatures in membrane contactor setup using ionic liquid 1-Butyl-3-methlyimidazolium tricyanomethanide ([Bmim][TCM]) as an absorbent was studied here by developing a comprehensive mathematical model. A detailed 2D mass transport model based on finite element analysis was presented for this purpose. The model considers molecular diffusion in both axially and radially. The effects of various operational parameters were studied for CO2 absorption flux. A comparative study was carried out among different membrane contactor modules having different number of fibers. The increase in number of fibers has significantly enhanced the CO2 absorption process. An increase of 31% in the CO2 separation efficiency was observed by increasing the number of fibers from 1 to 10. Furthermore, the transient state behavior of CO2 concentration during the absorption process until reaching a steady state was systematically studied for various operating temperatures and gas flow rates.