Energy Consumption Of CO2 Capture Research Articles

Analysis of the Mechanism of Energy Consumption for Co2 Capture in a Power System

Analysis of the Mechanism of Energy Consumption for Co2 Capture in a Power System

Performance and sensitivity analysis of packed-column absorption process using multi-amine solvents for post-combustion CO2 capture

Although many novel multi-amine solvents with high CO2 solubility were reported, they have not yet been evaluated for the performance in CO2 absorption processes. In this study, the efficiency and inside profile of the packed-column CO2 absorption process using a novel multi-amine solvent were investigated by using a mathematical model. Three amine solvents were selected: 2-(2-aminoethylamino)-ethanol (AEEA) and diethylenetriamine (DETA) as multi-amine solvents and monoethanolamine (MEA) as a reference. Based on the 90% capture efficiency of flue gas CO2 from a coal-fired power plant, a sensitivity analysis using the liquid-to-gas ratio was conducted to minimize the energy consumption for CO2 capture. Based on the utilization of the same 30 wt% solvent, the lowest reboiler thermal energy achieved by the process using DETA was 3.242 GJ/tonCO2, which was 8.57% lower than that obtained when MEA was employed. In contrast, the process using AEEA required 7.04% higher energy than MEA. In the process modified by rich-solvent split for further enhancing efficiency, the DETA process could achieve 2.962 GJ/tonCO2, which reduced the reboiler duty by 16.8% from the MEA process. The CO2 capture performance of absorbents could not be evaluated not only by the absorption rate and capacity. Owing to the larger molecular weight of multi-amines than MEA, the performance of capture and regeneration was discussed with respect to the amine properties and number of amine moles in the solution. A well-selected multi-amine for a modified process configuration has considerable potential for improving the energy efficiency of CO2 capture.

Sustainable ionic liquid organic solution with efficient recyclability and low regeneration energy consumption for CO2 capture

• A novel AFIL organic solution was proposed for CO 2 capture. • The novel AFIL organic solution has obvious advantage in the recyclability and viscosity. • The regeneration energy was 2.30 GJ·t −1 CO 2 and 39.5% lower than that of MEA/water. • The reaction mechanism of [TEPAH][AICA]/NPA/EG solution was comprehensively elucidated. A novel sustainable amino functionalized ionic liquid (AFIL) organic solution of tetraethylene pentamine 5-amino-4-imidazolecarboxamide/n-propanol/ethylene glycol ([TEPAH][AICA]/NPA/EG) was proposed for CO 2 capture to reduce the regeneration energy consumption. The solution had an efficient absorption loading of 1.78 mol·mol −1 , and it still maintained a good recyclability after 10 cycles (regeneration efficiency > 88%). Under this condition, the regeneration energy consumption was 2.30 GJ·t −1 CO 2 , which was 39.5% lower than that of MEA/water. The absorption and desorption mechanisms were investigated by 13 C NMR. For CO 2 absorption reaction, N atom of [AICA] − combined with CO 2 to form the carbamate directly, while other amino groups followed the zwitterion formation and deprotonation. Then some carbamates combined with alcohol to form the alkyl carbonates. For CO 2 desorption reaction, both the alkyl carbonates and carbamates combined with AFILH + to decompose, but the alkyl carbonates decomposed completely and a small amount of carbamates remained, indicating that carbonate was easier to decompose than carbamate. The novel [TEPAH][AICA]/NPA/EG solution with low energy consumption and good recyclability, which provides a sustainable strategy for advancing carbon capture technologies.

Criterial equation of carbon neutrality for power systems

By the end of 2020, most countries in the world have successively proposed carbon-neutral targets. Among them, the major economies in the world, such as the United States (USA), the European Union, Japan, and Canada, have proposed to achieve carbon-neutral targets by 2050. As the world’s largest carbon emitter, China has a total carbon emissions of more than 11.3 billion tons, accounting for about 30% of global carbon emissions. Therefore, the carbon emission reduction required for China is much higher than that of other economies, and its carbon-neutral tasks are obviously more complex and diversified. On 22 September 2020, the Chinese government announced in the 75th Session of the UN (United Nations) General Assembly (New York, USA) that China aims to achieve carbon neutrality before 2060. The announcement of the carbon-neutral target clearly indicated that China needs to carry out a self-revolution to achieve zero CO2 emissions before 2060. The concept of carbon neutrality is essentially a balance between carbon sources and carbon sinks. The carbon source is the process of releasing CO2 into the atmosphere, and the carbon sink is the process of absorbing CO2 from the atmosphere. Investigating the atmospheric system within a certain period, when the amount of CO2 emitted by all carbon sources into the system is equal to the amount of CO2 absorbed by all carbon sinks from the system, carbon neutrality can be achieved. There are various carbon sources and sinks in nature with complicated relationships. Among them, the most important carbon source related to human activities is energy production. In 2020, China’s power sector emitted about 4 billion tons of CO2 per year, which is close to 40% of the total emissions. Thus, the power sector is one of the key areas in emission reduction to achieve the carbon-neutral goal. Building a carbon-neutral power system is the only way to achieve decarbonization in the energy sector. Based on the carbon balance principle, this paper proposed the critical equation of carbon neutrality for power systems. And the further strategies in establishing a carbon-neutral power system were explored according to the carbon neutrality equation: (1) Improve energy efficiency thus reducing the consumption of carbonaceous energy; (2) adjust the energy structure and reduce the proportion of carbonaceous energy; (3) rebuild the balance of sources and sinks by adopting CO2 capture, utilization and storage (CCUS) technology to achieve low-carbon utilization of carbonaceous energy. Results indicate that, although improving energy efficiency of carbonaceous energy is effective in CO2 mitigation, it is limited by the declining energy saving potential of thermal power plants to be the main technical way in carbon emission reduction. Besides, increasing the proportion of renewable energy can quickly reduce the carbon emission intensity of the power system, which is currently the main technical way to reduce the CO2 emission of the power system. However, although energy conservation and the development of renewable energy can reduce the carbon emission intensity of the power system, the CCUS technology and the negative emission technology will be indispensable to achieve the goal of carbon neutrality. And the large-scale promotion of the CCUS technology must overcome technical obstacles of the rather high energy consumption of CO2 capture. Thus, building a carbon-neutral power system in the future requires a combination of energy efficiency, renewable energy and CCUS technology.

Thermodynamic analysis of fuel-cell-based combined cooling, heating, and power system integrated solar energy and chemical looping hydrogen generation

A novel solid-oxide-fuel-cell-based cooling, heating, and power (CCHP) system integrated chemical looping hydrogen generation is proposed, in which the chemical looping hydrogen generation realizes the high-efficiency CO2 capture and provides hydrogen to fuel cell, avoiding carbon deposition caused by the direct reaction of methane. The high-temperature solar heat collector is integrated to assist the fuel cell subsystem in achieving high-efficiency power generation and energy cascade utilization. The thermodynamic models of components are constructed, and the energy and exergy performances under the design conditions with or without solar energy are compared and analyzed. Through validating the thermodynamic models, the simulation results indicate that the energy and exergy efficiencies in cooling mode are 78.02% and 45.92%, respectively. The energy efficiency in heating mode reduces by 5.08%, while the exergy efficiency increases by 0.67%. The CO2 capture rate of the proposed system reaches 99.96% and the CO2 purity is about 99.59%. The energy consumption of CO2 capture in the proposed system reduces by 69.37% compared to the conventional system. The sensitivity analysis of key parameters such as fuel cell operating temperature and direct normal irradiance on system performances are performed. The results show the total energy and exergy efficiencies can be improved by properly increasing the SOFC operating temperature. Although the energy and exergy efficiencies slowly drop with the increasing direct normal irradiation, the energy output increases by 6.10% and 4.95% in cooling and heating mode from 500 W/m2 to 1000 W/m2, respectively.

CO2 absorption and desorption using phase-separation gel

Phase-separation absorbent has attracted much attention to reduce energy consumption for CO2 capture, storage and utilization. In this work, to improve handling of the absorbents, we have developed a new semi-solid absorbent, phase-separation gel, which became clouded gel by CO2 absorption and returned to transparent by CO2 desorption. We measured amounts of CO2 absorption at 50 ˚C and desorption at 90 ˚C with 10 vol% CO2 gas mixed with N2 gas. A cyclic capacity defined by the CO2 desorption amount of a phase-separation gel with solvent of 2-(ethylamino)ethanol/diethylene glycol diethyl ether was larger than those of the other homogeneous gels with 2-(ethylamino)ethanol/diethylene glycol monoethyl ether or diethylene glycol. Furthermore, the initial desorption flux of the phase-separation gel was larger than that of the absorbent solvent, suggesting that the phase-separation absorbent fixed inside the gels improves the initial desorption flux because of the larger interfacial area between the CO2-rich and CO2-lean phases inside the gel.

A novel coal chemical looping gasification scheme for synthetic natural gas with low energy consumption for CO2 capture: Modelling, parameters optimization, and performance analysis

Natural gas is regarded as a clean energy source, but its global supply is seriously insufficient. An alternative route to synthetic natural gas production from other energy sources is thus urgently needed. There is the conventional coal gasification to synthetic natural gas process, but it suffers from high energy consumption because of air separation and CO2 capture. Coal chemical looping gasification is regarded as a state-of-the-art technology that avoids conventional air separation and reduces energy consumption. A new process of coal chemical looping gasification that creates synthetic natural gas is therefore proposed, where low energy consumption for CO2 capture is achieved simultaneously by increasing the CO2 concentration. The results show that the exergy efficiency of the new process is increased by 21%; the internal rate of return is increased by 9%; the fixed capital investment and production costs are reduced by 36% and 29%; and the CO2 emissions are reduced by 15% in comparison with the conventional coal to synthetic natural gas process. This study provides a promising method for the energy-saving, profitable, and sustainable development of coal into synthetic natural gas.

Comparative Investigation of Different CO2 Capture Technologies for Coal to Ethylene Glycol Process

The coal to ethylene glycol (CTEG) process has drawn much attention due to the serious conflict between supply and demand of ethylene glycol in China. However, it is inevitably accompanied by the problem of high CO2 emissions. Carbon capture is one of the most promising potential effective ways to address this issue. However, the CTEG process, integrated with carbon capture technology, will lead to energy and economic penalties. Thus, a comprehensive evaluation of CTEG process with different CO2 capture technologies is urgently needed. This study analyzed the technoeconomic performance of four CO2 capture alternatives for the CTEG process: Rectisol, mono-ethanol amine (MEA), chilled ammonia process (CAP) and dimethyl carbonate (DMC) technologies. Results show the energy consumption of CO2 capture of the Rectisol process is the lowest, 1.88 GJ/tCO2, followed by the DMC process, 2.10 GJ/tCO2, the CAP process, 3.64 GJ/tCO2, and the MEA process, 5.20 GJ/tCO2. The CO2 capture cost of the Rectisol process is lowest, CNY 169.5/tCO2, followed by the DMC process, CNY 193.2/tCO2, the CAP process CNY 232.6/tCO2, and the MEA process CNY 250.5/tCO2. As the Rectisol technology has the best comprehensive performance, it is the best option for CTEG industry in comparison with the MEA, CAP, and DMC technologies.

System integration optimization for coal-fired power plant with CO2 capture by Na2CO3 dry sorbents

For the post-combustion CO2 capture by the Na2CO3 dry sorbents, system integration of CO2 capture into an existing coal-fired power plant is of great significance, as the huge energy consumption of CO2 capture results in great efficiency penalty. By system integration optimization, nearly 80% of the low temperature energy released from the CO2 capture could be recovered to gain more power output and provide considerable heat supply for users, yielding a respective 0.6% and 34.13% increment of the net electric efficiency and coal utilization coefficient. Besides, combination with the waste heat recovery of flue gas further increases the net electric efficiency by 0.57%. Both the thermodynamic and exergy analysis results show that the optimization measures provide a promising way for system integration of the coal-fired power plant with CO2 capture. Techno-economic analysis results shows that cost of electricity and cost of CO2 avoided are obviously reduced due to the optimization measures proposed in this paper.

Integration of LNG Regasification Process in Natural Gas-Fired Power System with Oxy-Fuel Combustion

Oxy-fuel combustion power systems can utilize the cold energy released during the liquefied natural gas (LNG) regasification to reduce the power consumption of CO2 capture, but the specific LNG cold energy consumption of CO2 capture is still too large. To recover more CO2 with the limited LNG cold energy at a low energy cost, a novel natural gas-fired oxy-fuel power system with the cascade utilization of LNG cold energy is proposed in this work, where the LNG cold energy could be sequentially utilized in the air separation unit and the CO2 recovery process. The new system is evaluated with the Aspen Plus software. The results show that the net electrical efficiency and the specific primary energy consumption for CO2 avoided (SPECCA) of the new system are comparable to those of the chemical looping combustion cycle, and superior to those of the conventional O2/CO2 cycles. Moreover, the specific LNG needed for CO2 avoided (SLNCC) of the new system is more than 67.2% lower than the existing oxy-fuel power systems utilizing the LNG cold energy. Furthermore, it is found that the O2 purity of 97.0 mol.% and the CO2 capture ratio of 97.0% are optimal conditions, because the SPECCA, the specific exergy consumption for CO2 avoided (SECCA) and the SLNCC are at the minimum of 1.87 $${\rm{G}}{{\rm{J}}_{LHV}} \cdot {{\rm{t}}_{{\rm{C}}{{\rm{O}}_2}}}^{- 1},2.60\,\,{\rm{GJ}} \cdot {{\rm{t}}_{{\rm{C}}{{\rm{O}}_2}}}^{- 1}$$ and $$1.88\,\,{{\rm{t}}_{{\rm{LNG}}}} \cdot {{\rm{t}}_{{\rm{C}}{{\rm{O}}_2}}}^{- 1}$$ , respectively. Meanwhile, the net electrical efficiency and the exergy efficiency of the new system reach 51.51% and 49.23%, respectively.

Optimal design, thermodynamic, cost and CO2 emission analyses of coal-to-methanol process integrated with chemical looping air separation and hydrogen technology

In China, coal is the main raw material used for methanol production to relieve the domestic supply and demand. The conventional coal-to-methanol (CTM) process suffers from less energy efficiency since high energy consumption of air separation and CO2 capture. A novel CTM process integrated with chemical looping air separation (CLAS) and chemical looping hydrogen (CLH) is designed and analyzed to reduce energy consumption, CO2 emission, and improve energy efficiency. The integration of CLAS technology can remove air separation unit and decrease energy consumption to a certain extent. The integration of CLH technology can remove water-gas shift unit and increase the CO2 concentration and reduce the energy consumption of CO2 capture. The CLH technology also produces hydrogen used for adjustment of hydrogen to carbon ratio of the syngas. Process modelling results show that the energy consumption of the CLAS and that of the CO2 capture of the CLH are decreased by 41% and 89%, comparing to those of the conventional air separation and CO2 capture of the CTM process. In addition, the energy efficiency of the new process is increased by 18% and CO2 emission reduced by 45% in comparison with the conventional CTM process.

Simulation and energy consumption comparison of gas purification system based on elevated temperature pressure swing adsorption in ammonia synthetic system

Elevated temperature pressure swing adsorption (ET-PSA) is a novel process for hydrogen purification. By operating steam rinse and purge at conditions beyond the dew point will significantly improve the recovery rate of the product gas. Moreover, since cooling and reheating processes are not needed in ET-PSA, the sensible heat of the incoming gas could also be preserved. In this study, a seven-column 5000 Nm3/h ET-PSA pilot scale model was designed for energy consumption analysis. Product H2 purity, recovery rate, product CO2 purity, CO2 capture rate, unit H2 purification energy consumption and unit CO2 capture energy consumption were set as the criteria for assessing the purification performance. Rinse pressure, rinse media, and desorption method were selected as variables during the design and optimisation of the ET-PSA process. Herein, a high process efficiency (99.98% product gas purity and 99.33% recovery) was achieved. These values increased by 5.38% and 4.44%, respectively, compared to the base case. Meanwhile, the CO2 capture energy consumption was reduced by 59.2 MJ/ton(CO2).

New Approach with Universal Applicability for Evaluating the Heat Requirements in the Solvent Regeneration Process for Postcombustion CO2 Capture

Benzylamine (BZA), biodegradable with bacteria, has advantages over monoethanolamine (MEA) in terms of corrosiveness, resistance to oxidative degradation, viscosity, mass transfer, and energy consumption for CO2 capture. The current work examined the CO2 absorption-desorption performances of three BZA-based solvents to improve the amine scrubbing process with significant reduction of the energy consumption especially during the solvent regeneration. The experimental results approved that the BZA-1DMA2P reduces the energy cost, increases the cyclic capacity, and increases CO2 desorption rate by 55.3, 478.8, and 189.2 % compared to MEA, respectively. Based on the discoveries from the designed experiments, an evaluation parameter of energy-operation-window (EOW) was proposed to quantitatively describe the flexibility and capability of CO2 extraction from a CO2 rich solution with a certain amount of energy. A combined desorption parameter (DP) was also developed to evaluate the energy performance of an amine ...

Comparative analysis of thermodynamic theoretical models for energy consumption of CO2 capture

CO2 capture is considered an effective technology to control the CO2 level in the atmosphere, but its development has been restricted due to its high energy requirement during CO2 concentration. Theoretical thermodynamic models have been used not only to predict energy consumption, but also to elucidate the energy conversion mechanism. However, the existing theoretical models have been applied without a clear consideration of boundaries, conditions, and limitations in thermodynamic images. Consequently, the results from such theoretical models can lead to a misunderstanding of the energy conversion mechanism during CO2 capture. A comparative analysis of three theoretical thermodynamic models, namely the mixture gas separation (MGS), carbon pump (CP), and thermodynamic carbon pump (TCP) models, was presented in this paper. The characteristics of these models for determining the energy consumption of CO2 capture were clarified and compared in relation to their practical application. The idealization levels of these models were demonstrated through comparison of theoretical estimates of the energy required for CO2 concentration. The correctness and convenience of the CP model were proved through a comparison between the CP and MGS models. The TCP model proposed in this study was proved to approach the ideal status more closely than the CP model. Finally, an application of the TCP model was presented through a case study on direct capture of CO2 from the air (DAC).

A multiobjective experimental based optimization to the CO2 capture process using hybrid solvents of MEA-MeOH and MEA-water

To achieve the reduction of total energy consumption of CO2 capture without the major drawbacks of conventional amine solvents, the superior performance of a blended physical-chemical solvent, MEA-MeOH, was experimentally compared with that of MEA aqueous absorbent in lab-scale absorption/desorption towers, equipped with stainless steel pall ring packings. Considering the typical industrial requirements, the main operating variables accounted for each solvent were the operating temperature (35–55 °C), amine concentration (15–30 wt%), gas flow rate (50–100 l/min), liquid flow rate (0.75–1.25 l/min), CO2 concentration in the inlet gas (5–15 mol %), and the reboiler heat duty (1.4–2.2 kW). Response surface methodology was applied to give a quadratic mathematical model for obtained empirical volumetric overall mass transfer coefficients (KGaV). Based on the drastic increase of the energy requirement for solvent regeneration, a multiobjective optimization framework has been made to achieve the maximum desirable values for the KGaV, and the absorption percentage (Φ) with the minimum energy consumption (Ω). It was suggested that under the optimum operating condition, adding methanol to an aqueous MEA solution, reduces the regeneration energy consumption by 12%, while augmenting the CO2 absorption percentage (Φ) by 9.1%.

Performance Assessment of Coal Fired Power Plant Integrated with Calcium Looping CO2 Capture Process

ABSTRACT CaL technology is a promising means for post-combustion CO2 capture in already existing power plants, and heat integration is an effective way to lower the efficiency penalty caused by CO2 capture. Three cases with different heat integration degree were investigated in the manuscript to predict the efficiency penalty and the specific energy consumption for CO2 capture, aiming to find the optimum scheme of integrating capture unit into coal-fired power plant. The sensitivity analysis was also conducted to compare the impacts of key parameters. The simulation results show that the Case 3, which employs a variety of measures to improve the internal heat integration within CaL and reclaims the surplus released heat via an additional steam cycle, has the lowest efficiency penalty, 5.75%. It also indicates that heat integration in Case 3 results in a 14.4% of decrease in coal consumption, a 5.8% of reduction in power consumed by CO2 compression process, a 13.6% of drop in power consumption in ASU, and a 31.5% of decrease in specific energy consumption for CO2 capture. The sensitivity analysis shows that the efficiency penalty may be reduced by 0.011 percentage points for each degree decrease in temperature difference of MH-1. As the compression efficiency increases from 70% to 85%, the efficiency penalty decreases from 6.51% to 5.47%, and the specific energy consumption reduces from 2.21 MJ/kg CO2 to 1.80 MJ/kg CO2. Abbreviations: APH: Air Preheater; ASUL: Air Separation Unit; BFPT: Boiler Feedwater Pump Turbine; CaL: Calcium Looping; CCS: Carbon Capture and Sequestration; CFPP: Coal-Fired Power Plant; GSS: Gas-Solid Separator; HPC: High Pressure Column; HPEC: High Pressure Economizer; HPSH: High Pressure Super-Heater; HPST: High Pressure Steam Turbine; HRSG: Heat Recovery Steam Generator; IPEC: Intermediate Pressure Economizer; IPEV: Intermediate Pressure Evaporator; IPSH: Intermediate Pressure Super-Heater; LPST: Low Pressure Steam Turbine; LHV: Low Heat Value; LPC: Low Pressure Column; LPEC: Low Pressure Economizer; LPEV: Low Pressure Evaporator; ORC: Organic Rankine Cycle; RH: Reheater.

Post-combustion CO2 capture with membrane process: Practical membrane performance and appropriate pressure

Membrane separation process is one of the most promising methods for post-combustion CO2 capture from coal-fired power plant. In this paper, a multicomponent gas separation process using spiral-wound membrane modules is explored to optimize its membrane area and energy consumption. Firstly, the parametric analysis is conducted for the single-stage membrane process to study the impact of the feed gas CO2 concentration, feed pressure and selectivity on the permeate gas flow rate, permeate gas CO2 concentration and membrane area. Secondly, a feasible procedure that maintains product purity and recovery is applied to discuss the impact of the membrane selectivity, permeance and the feed pressure on the two-stage membrane process. Based on the analysis and conclusions in the single-stage membrane process, the trade-off between membrane area and energy consumption has been analyzed in detail. By varying the selectivity and the feed pressure, the impact of these two parameters on the membrane area and energy consumption is discussed, finding that the combination of low selectivity in the first stage and high selectivity in the second stage has much smaller membrane area and slightly higher energy consumption than that of high selectivity in both stages. Moderate feed pressure, varying from 0.55 MPa to 0.65 MPa, is found to provide relatively low CO2 capture energy consumption. Techno-economic analysis is conducted to further validate the above strategy. To minimize the CO2 capture cost, high CO2 permeance and moderate selectivity is desirable for the first stage, while high selectivity and moderate CO2 permeance should be maintained for the second stage. The membrane developed for the flue gas CO2 capture do not have to simultaneously enhance the CO2/N2 selectivity and CO2 permeance. Even considering the uncertainties related to economic parameters, the optimum feed pressure that provides the minimum CO2 capture cost only varies from 0.69 MPa to 0.83 MPa.

Nonaqueous amine-based absorbents for energy efficient CO2 capture

High energy consumption for CO2 capture using aqueous amines is still a major drawback limiting its deployment on a global scale. In this work, the absorption-desorption performance of CO2 into several blends of monoethanolamine (MEA) or diethanolamine (DEA) with glycol ethers (2-methoxyethanol (2ME) and 2-ethoxyethanol (2EE)) as nonaqueous solvents has been investigated at ambient pressure. Reaction mechanisms and the relative heat duty for these nonaqueous systems were also explored and compared with those of the aqueous MEA. Results showed that the nonaqueous absorbents with 5.0 M MEA had comparable absorption capacity with aqueous 5.0 M MEA and higher desorption efficiency resulting in a larger cyclic capacity (1.45 mol kg−1). Higher partial pressure ratio of CO2 to solvent vapor under the desorption conditions was also observed for these nonaqueous systems. 13C NMR, FTIR spectra and online conductivity analysis provided evidences that CO2 can react with MEA in nonaqueous solvents forming the ionic couples (i.e. protonated MEA and carbamate) as well as carbamic acid at high CO2 loading. The mixture of MEA and 2ME or 2EE could significantly reduce the energy consumption by about 55% as compared to the benchmark aqueous 5.0 M MEA system.

Catalyst-TiO(OH)2 could drastically reduce the energy consumption of CO2 capture

Implementing Paris Climate Accord is inhibited by the high energy consumption of the state-of-the-art CO2 capture technologies due to the notoriously slow kinetics in CO2 desorption step of CO2 capture. To address the challenge, here we report that nanostructured TiO(OH)2 as a catalyst is capable of drastically increasing the rates of CO2 desorption from spent monoethanolamine (MEA) by over 4500%. This discovery makes CO2 capture successful at much lower temperatures, which not only dramatically reduces energy consumption but also amine losses and prevents emission of carcinogenic amine-decomposition byproducts. The catalytic effect of TiO(OH)2 is observed with Raman characterization. The stabilities of the catalyst and MEA are confirmed with 50 cyclic CO2 sorption and sorption. A possible mechanism is proposed for the TiO(OH)2-catalyzed CO2 capture. TiO(OH)2 could be a key to the future success of Paris Climat e Accord.

Thermodynamic analysis of an integrated solid oxide fuel cell, Organic Rankine Cycle and absorption chiller trigeneration system with CO2 capture

A novel trigeneration system which integrates a SOFC system, an Organic Rankine Cycle (ORC), and an ammonia water absorption chiller with a CO2 capture system is proposed and investigated. The exhaust gas from SOFC anode combusts with pure O2 instead of air and thus the combustion products mainly consist of CO2 and H2O, which the CO2 can be captured easily by the condensation method; in SOFC cathode side, a series-connected ORC and ammonia water absorption chiller heat recovery system which can produce power, heat and cooling is employed to recover the waste heat of SOFC cathode exhaust gas. A mathematical model is developed to study the system performance under steady-state conditions. The calculated results show that the net electrical efficiency and the exergy efficiency of the integrated system can reach 52.83% and 59.96%, respectively. The trigeneration efficiencies of the combined system without and with CO2 capture are 74.28% and 72.23%, respectively. The effects of the SOFC inlet temperature, the current density, the steam-to-carbon ratio, the pinch point temperature difference and the turbine II inlet pressure on the trigeneration system performances are investigated in detail. The research achievement in this paper can provide the useful reference for SOFC based trigeneration system with low energy consumption for CO2 capture.