Materials and Techniques for High Temperature CO2 Capture (original) (raw)
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Energy Procedia, 2013
The IGCC technology (Integrated Gasification Combined Cycle) with pre-combustion CO 2 capture is a promising approach for near-zero CO 2 emission power plants to be realized in the near future. A key challenge within this technology is the separation of the CO 2 /H 2 gas mixture resulting from the water gas shift reaction that follows the gasification of coal. For the CO 2 stream a purity of about 95% is required; additionally a CO 2 capture rate of 90% is desired, which implies that both streams, H 2 and CO 2 , are required at rather high purity (~95%). In contrast to postcombustion capture from power plants, where a large gas stream at low pressure and low CO 2 content has to be treated, in pre-combustion capture a gas mixture at up to 40 bar has to be separated; therefore an adsorption based process, such as pressure swing adsorption (PSA), constitutes a promising method for CO 2 removal from H 2 . In this work, new materials, namely USO-2-Ni MOF, UiO-67/MCM-41 Hybrid and MCM-41, are characterized in terms of equilibrium adsorption isotherms. Excess adsorption isotherms of CO 2 and H 2 on these materials are measured at different temperatures (25°C 140°C) and in a wide pressure range (up to 150 bar). The experimental data are then described with a suitable isotherm model, in our case Langmuir, Sips and Quadratic. In addition, the cyclic working capacity of CO 2 on each material is computed as a further assessment of the suitability of these materials for pre-combustion capture.
International Journal of Greenhouse Gas Control, 2019
Natural gas is one of the fossil fuels with the lowest CO 2 emissions per unit energy produced. The removal of CO 2 from natural gas is therefore extremely important to promote its use. For this purpose, CO2CRC Ltd., the leading CCS R&D organization in Australia, has designed and implemented a carbon capture demonstration skid at the Australian Otway National Research Facility. The skid includes a Pressure Swing Adsorption (PSA) rig designed to remove CO 2 from a high CO 2 content natural gas supply in the Otway basin. Two months of operation had been carried out from May 2017 to June 2017, with the feed natural gas containing CO 2 in a range from 30% to 50% using commercially available adsorbents to obtain benchmarking data. The results of operation showed that the PSA rig can successfully capture CO 2 from high pressure natural gas with a recovery of 66%. However, the purity of the final CH 4 product was not sufficient to meet general natural gas requirement (only achieving 80% instead of 95%). This was attributed to the fact that the operating conditions were not optimal: a final desorption pressure of 1 bar abs was desirable but only 5 bar abs was achieved. Based on our preliminary PSA operating results, process simulation were also conducted to predict the separation performance at lower desorption pressures, and showed that a methane purity of over 98% can be achieved if the desorption pressure can be lowered to 1 bar.
Solar-assisted pressure-temperature swing adsorption for CO2 capture: Effect of adsorbent materials
Solar Energy Materials and Solar Cells, 2018
Because of the ability to utilize the low-grade solar thermal energy for regeneration, a CO 2 capture system characterized by solar-assisted pressure temperature swing adsorption (SOL-PTSA) is studied on the effects of adsorbent materials. A detailed cycle description is firstly presented within the diagram of adsorption isotherm for the energy-efficiency analysis. Typical adsorbent materials, including zeolites and chemical adsorbent, are assessed in terms of sensible heat and latent heat, etc. Then, the energy consumption and the second-law efficiency , which can be considered as lumped indicators from such material parameters, are chosen as performance indicators as well. The influence of separation temperature, desorption temperature, CO 2 concentration and CO 2 adsorption pressure on system performance are finally obtained. For the chosen three adsorbent materials, the energy consumption of SOL-PTSA system is at the range of 25.96–87.76 kJ/mol, and the corresponding second-law efficiencies are at the range of 9.18–26.89%. The effect of adsorbent materials on the energy-efficiency of SOL-PTSA system mainly depends on specific heat, CO 2 working capacity and cycle design. In addition, the integration options of solar energy into PTSA technology are also discussed from the standpoint of the utilization of solar grade heat due to two energy loads required for PTSA's operation.
Applied Energy, 2019
A novel multibed heat-integrated vacuum and temperature swing adsorption process has been designed to capture 85% of the CO 2 emitted by an advanced supercritical coal fired power plant of 820 MW e taken as reference, and to produce a concentrated product with 95% of CO 2 using a microporous carbon obtained from olive stones. The overall performance of the postcombustion CO 2 capture process has been evaluated from the results of the dynamic simulation of the process at cyclic steady state, using a detailed non-isothermal nonequilibrium dynamic fixed-bed adsorption model that takes into consideration competitive adsorption between the main flue gas components: N 2 , CO 2 and H 2 O. The proposed process operates between 30 °C and 1.05 bar and 80 °C and 0.05 bar. The specific heat duty of the process, 2.41 MJ th kg-1 CO 2 , which is lower than the benchmark amine absorption technology, can be satisfied using waste heat. On the other hand, its electricity consumption, 1.15 MJ e kg-1 CO 2 , is higher. Increasing the pressure of the production step reduces significantly the energy demand of the process, but also its capture rate. Substantial improvements in performance can be expected from adsorbent development. Adsorption is an environmentally benign technology with great potential to mitigate CO 2 emissions from industrial processes with unused waste heat sources.
High temperature materials for CO2 capture
Greenhouse Gas Control Technologies 9, 2009
The potential benefits of precombustion carbon dioxide capture are well documented, and adsorption remains a promising separation process in this area. This paper details work to identify and assess the potential of high temperature adsorbents suitable for precombustion capture. The aim of this paper is to schematically identify adsorbents that are suitable for carbon capture in different temperature ranges. A critical aspect of this work is to assess the materials not only in terms of carbon dioxide isotherms and absolute loading, but to consider the wide range of other properties that are required to achieve an industrially feasible adsorbent-selectivity, cycling capacity, stability, kinetics, high pressure loading, fate of other components (including water, H 2 S, NH 3 , CO and N 2). It is only when all these requirements are sufficiently met, that an adsorbent can be consider worthy of industrial consideration. A range of analytic screening tests are described to enable a full characterisation of the merit of a specific adsorbent.
Chemical Engineering and Processing - Process Intensification, 2015
CO 2 capture and storage (CCS) technology has attracted attention for the mitigation of CO 2 emissions. Among the dominant CO 2 capture technologies, pressure swing adsorption (PSA) is a promising alternative to amine-based absorption. However, its capture cost should be further decreased to facilitate its commercial implementation in industry. In this study, a novel low-cost PSA CO 2 capture process based on self-heat recuperation technology is discussed. An energy balance of the conventional process and the proposed process is simulated and compared using a commercial process simulator (PRO/II ver. 9.1, Invensys). In the proposed PSA process, the exothermic heat of adsorption is recuperated using a reaction heat transformer (RHT) and is recirculated for adsorbent regeneration. The waste residual gas pressure can also be recovered by an expander at the top of an adsorption tower. The simulation results indicate that the energy consumption of the proposed PSA process is 40% that of the conventional process.
Chemical Engineering Journal, 2019
Vacuum, temperature and concentration swing adsorption processes, have been designed to capture 85% of the CO 2 emitted by an advanced supercritical coal fired power plant of 800 MW taken as reference, and to produce a concentrated product with 95% of CO 2 (dry basis) using a sustainable carbon adsorbent inside the tubes of a tube-bundle adsorber. Indirect heat transfer is used to increase productivity and to conserve energy within the process. Two different configurations of the cyclic process have been evaluated at cyclic steady state through dynamic process simulation, using a detailed non-isothermal non-equilibrium fixed bed adsorption model that takes into consideration competitive adsorption between the main flue gas components: N 2 , CO 2 and H 2 O. Simulation results indicate that the purity and recovery constraints can be met with a specific heat duty of 2.32 MJ th kg-1 CO 2 and a specific electric consumption of 0.66 MJ e kg-1 CO 2. The main advantage of this process is that the specific heat duty, which is lower than the benchmark amine absorption technology, could be satisfied using waste heat.
Environmental Progress
Using hundreds (640) of simulations obtained from a cyclic adsorption process simulator, two heavy reflux (HR) pressure swing adsorption (PSA) cycles were analyzed at the periodic state for the capture and concentration of CO 2 from flue gas at high temperature (575 K), using a K-promoted hydrotalcite like compound (HTlc). Since the values of the adsorption (k a) and desorption (k d) mass transfer coefficients of CO 2 in the K-promoted HTlc were uncertain, this study focused only on the effects of k a and k d on the process performance. Both, a 5-bed 5-step stripping PSA cycle with light reflux (LR) and HR from LR purge and a 4-bed 4-step stripping PSA cycle with HR from countercurrent depressurization were studied using a vacuum swing cycle with the high pressure fixed at 137.9 kPa and the feed set at 15 vol % CO 2 , 75 vol % N 2 , and 10 vol % H 2 O. For the 5-bed process , increasing both k a (¼ 0.0058 s À1) and k d (¼ 0.0006 s À1) by a factor of five increased both the CO 2 purity and CO 2 recovery, achieving a CO 2 purity of nearly 90% at a CO 2 recovery of 72% and feed throughput () of 57.6 L STP/h/kg. Increasing k a and k d by a factor of ten further increased both the CO 2 purity and CO 2 recovery, achieving for the first time a CO 2 purity greater than 90% at a CO 2 recovery of 85% and of 57.6 L STP/h/kg. Making k d ¼ k a (¼ 0.0058 s À1) resulted in a CO 2 purity of 89% with a CO 2 recovery of 72% at a of 57.6 L STP/h/kg; and increasing that value by a factor of five led to a CO 2 purity of 91% at a high CO 2 recovery of 88% and of 57.6 L STP/h/kg. These results suggested that the performance was desorption limited. For the 4-bed process, when k a and k d were both increased by a factor of five, the CO 2 purity increased to 98% at a of 201.7 L STP/h/kg, but the CO 2 recovery decreased to 5%. Overall, it was proven that mass transfer 2006 American Institute of Chemical Engineers
Advancements in adsorption based carbon dioxide capture technologies- A comprehensive review
Heliyon, 2023
The significant increase in energy consumption has facilitated a rapid increase in offensive greenhouse gas (GHG) and CO2 emissions. The consequences of such emissions are one of the most pivotal concerns of environmental scientists. To protect the environment, they are conducting the necessary research to protect the environment from the greenhouse effect. Among the different sources of CO2 emission, power plants contribute the largest amount of CO2 and as the number of power plants around the world is rising gradually due to increasing energy demand, the amount of CO2 emission is also rising subsequently. Researchers have developed different potential technologies to capture post-combustion CO2 capture from powerplants among which membrane-based, cryogenic, absorption and adsorption-based CO2 processes have gained much attention due to their applicability at the industrial level. In this work, adsorption-based CO2 technologies are comprehensively reviewed and discussed to understand the recent advancements in different adsorption technologies and several adsorbent materials. Researchers and scientists have developed and advanced different adsorption technologies including vacuum swing adsorption, temperature swing adsorption, pressure swing adsorption, and electric swing adsorption, etc. To further improve the CO2 adsorption capacity with a compact CO2 adsorption unit, researchers have integrated different adsorption technologies to investigate their performance, such as temperature vacuum swing adsorption, pressure vacuum swing adsorption, electric temperature pressure swing adsorption, etc. Different adsorbent materials have been tested to evaluate their applicability for CO2 adsorption and among these adsorbents, advanced carbonaceous, non—carbonaceous, polymeric, and nanomaterials have achieved much attention due to their suitable characteristics that are required for adsorbing CO2. Researchers have reported that higher CO2 adsorption capacity can be achieved by integrating different adsorption technologies and employing suitable adsorbent material for that system. This comprehensive review also provides future directions that may assist researchers in developing novel adsorbent materials and gaining a proper understanding of the selection criteria for effective CO2 adsorption processes with suitable adsorbents.