CO capture study in advanced Integrated Gasification Combined Cycle

International audienc

Process engineering method for systematically comparing CO2 capture options

In the context of greenhouse gas emissions mitigation, CO2 capture and storage is regarded as a promising alternative for fossil fuel fed power plants. In order to design and evaluate the competitiveness of such complex integrated energy conversion systems, a systematic comparison including thermodynamic, economic and environmental considerations is necessary. From a process engineering perspective, it is important to evaluate the impact of CO2 capture not only on the efficiency but also on the costs and on the environmental impacts, and to assess the trade-offs. This paper presents the development of a systematic thermo-environomic optimisation strategy for the consistent modelling, comparison and optimisation of fuel decarbonisation options. In particular, it is highlighted how the economic scenario influences the competitiveness and hence the optimal process design

Energy and exergy analysis of chemical looping combustion technology and comparison with pre-combustion and oxy-fuel combustion technologies for CO2 capture

Carbon dioxide (CO2) emitted from conventional coal-based power plants is a growing concern for the environment. Chemical looping combustion (CLC), pre-combustion and oxy-fuel combustion are promising CO2 capture technologies which allow clean electricity generation from coal in an integrated gasification combined cycle (IGCC) power plant. This work compares the characteristics of the above three capture technologies to those of a conventional IGCC plant without CO2 capture. CLC technology is also investigated for two different process configurations—(i) an integrated gasification combined cycle coupled with chemical looping combustion (IGCC–CLC), and (ii) coal direct chemical looping combustion (CDCLC)—using exergy analysis to exploit the complete potential of CLC. Power output, net electrical efficiency and CO2 capture efficiency are the key parameters investigated for the assessment. Flowsheet models of five different types of IGCC power plants, (four with and one without CO2 capture), were developed in the Aspen plus simulation package. The results indicate that with respect to conventional IGCC power plant, IGCC–CLC exhibited an energy penalty of 4.5%, compared with 7.1% and 9.1% for pre-combustion and oxy-fuel combustion technologies, respectively. IGCC–CLC and oxy-fuel combustion technologies achieved an overall CO2 capture rate of ∼100% whereas pre-combustion technology could capture ∼94.8%. Modification of IGCC–CLC into CDCLC tends to increase the net electrical efficiency by 4.7% while maintaining 100% CO2 capture rate. A detailed exergy analysis performed on the two CLC process configurations (IGCC–CLC and CDCLC) and conventional IGCC process demonstrates that CLC technology can be thermodynamically as efficient as a conventional IGCC process

Improving Prediction Accuracy of a Rate-Based Model of an MEA-Based Carbon Capture Process for Large-Scale Commercial Deployment

Carbon capture and storage (CCS) technology will play a critical role in reducing anthropogenic carbon dioxide (CO2) emission from fossil-fired power plants and other energy-intensive processes. However, the increment of energy cost caused by equipping a carbon capture process is the main barrier to its commercial deployment. To reduce the capital and operating costs of carbon capture, great efforts have been made to achieve optimal design and operation through process modeling, simulation, and optimization. Accurate models form an essential foundation for this purpose. This paper presents a study on developing a more accurate rate-based model in Aspen Plus® for the monoethanolamine (MEA)-based carbon capture process by multistage model validations. The modeling framework for this process was established first. The steady-state process model was then developed and validated at three stages, which included a thermodynamic model, physical properties calculations, and a process model at the pilot plant scale, covering a wide range of pressures, temperatures, and CO2 loadings. The calculation correlations of liquid density and interfacial area were updated by coding Fortran subroutines in Aspen Plus®. The validation results show that the correlation combination for the thermodynamic model used in this study has higher accuracy than those of three other key publications and the model prediction of the process model has a good agreement with the pilot plant experimental data. A case study was carried out for carbon capture from a 250 MWe combined cycle gas turbine (CCGT) power plant. Shorter packing height and lower specific duty were achieved using this accurate model

A systematic investigation of the performance of copper-, cobalt-, iron-, manganese-, and nickel-based oxygen carriers for chemical looping combustion technology through simulation studies

The Integrated Gasification Combined Cycle coupled with chemical looping combustion (IGCC-CLC) is one of the most promising technologies that allow generation of cleaner energy from coal by capturing carbon dioxide (CO2). It is essential to compare and evaluate the performances of various oxygen carriers (OC), used in the CLC system; these are crucial for the success of IGCC-CLC technology. Research on OCs has hitherto been restricted to small laboratory and pilot scale experiments. It is therefore necessary to examine the performance of OCs in large-scale systems with more extensive analysis. This study compares the performance of five different OCs – copper, cobalt, iron, manganese and nickel oxides – for large-scale (350–400 MW) IGCC-CLC processes through simulation studies. Further, the effect of three different process configurations: (i) water-cooling, (ii) air-cooling and (iii) air-cooling along with air separation unit (ASU) integration of the CLC air reactor, on the power output of IGCC-CLC processes – are also investigated. The simulation results suggest that iron-based OCs, with 34.3% net electrical efficiency and ~100% CO2 capture rate lead to the most efficient process among all the five studied OCs. A net electrical efficiency penalty of 7.1–8.1% points leads to the IGCC-CLC process being more efficient than amine based post-combustion capture technology and equally efficient to the solvent based pre-combustion capture technology. The net electrical efficiency of the IGCC-CLC process increased by 0.6–2.1% with the use of air-cooling and ASU integration, compared with the water- and air-cooling cases. This work successfully demonstrates a correlation between the reaction enthalpies of different OCs and power output, which suggests that the OCs with higher values of reaction enthalpy for oxidation (ΔHr, oxidation) with air-cooling are more valuable for the IGCC-CLC

Mass transfer analysis of CO2 capture by PVDF membrane contactor and ionic liquid

Post-combustion processes based on ionic liquids (ILs) and membrane contactors are attractive alternatives to traditional systems. Here, a gas stream composed of 15% CO2 and 85% N2 flowed through the lumen side of a hollow-fiber membrane contactor containing poly(vinylidene fluoride)-IL (PVDF-IL) fibers. The IL 1-ethyl-3-methylimidazolium acetate [emim][Ac] served as an absorbent due to its high chemical absorption and CO2 solubility. The overall mass transfer coefficient (Koverall), activation energy (Ea), and resistances of the hollow-fiber membrane were quantified. The Koverall value was one order of magnitude higher than those reported in previous works with conventional solvents, and the Ea was lower than formerly stated values for other solvents. A theoretical simulation was conducted to estimate the operational parameters required for 90% CO2 capture and to quantify intensification effects related to CO2 absorption in a packed column.This research was funded by the Spanish Ministry of Economy and Competitiveness (Projects CTQ2013-48280-C3-1-R and CTQ2016-76231-C2-1-R). The authors thank Dr. J. C. Remigy (Laboratoire de Genie Chimique, UPS, Toulouse, France) for the preparation of 1AQ2-PVDF fibers

C02 Capture study in advanced integrated Gasfication Combined Cycle.

Paper G4.3 [CD-ROM

CO2 capture study in advanced integrated gasification combined cycle.

International audienc