scholarly journals Thermodynamic Analysis of Chemical Looping Combustion Based Power Plants for Gaseous and Solid Fuels

Author(s):  
Sivaji Seepana ◽  
Aritra Chakraborty ◽  
Kannan Kaliyaperumal ◽  
Guruchandran Pocha Saminathan

Abstract The chemical looping combustion (CLC) process is a promising technology for capturing CO2 at the source due to its inherent separation of flue gas from nitrogen. In this regard, the present study is focused on the development of various Rankine cycle based CLC power plant layouts for gaseous and solid fuels. To evaluate the performance of these CLC based cycles, a detailed thermodynamic analysis has been carried out with natural gas (NG)& synthesis gas as gaseous fuels and lignite as solid fuel. For lignite based power production, in-site gasification CLC (iG-CLC) for syngas generation and CLC based combustion process employed. The Energy analysis showed that NG based power plant has a net efficiency of 40.44% with CO2 capture and compression which is the highest among all cases while the same for syngas based power plant is 38.06%. The difference in net efficiency between NG and syngas power plants is attributed to the variation in CO2 compression cost. For lignite based iG-CLC power plant layout, the net efficiency of 39.64% is observed which is higher than syngas fuelledCLC power plant. This shows the potential of CLC technology for power generation applications with or without CO2 capture.

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Bilal Hassan ◽  
Oghare Victor Ogidiama ◽  
Mohammed N. Khan ◽  
Tariq Shamim

A thermodynamic model and parametric analysis of a natural gas-fired power plant with carbon dioxide (CO2) capture using multistage chemical looping combustion (CLC) are presented. CLC is an innovative concept and an attractive option to capture CO2 with a significantly lower energy penalty than other carbon-capture technologies. The principal idea behind CLC is to split the combustion process into two separate steps (redox reactions) carried out in two separate reactors: an oxidation reaction and a reduction reaction, by introducing a suitable metal oxide which acts as an oxygen carrier (OC) that circulates between the two reactors. In this study, an Aspen Plus model was developed by employing the conservation of mass and energy for all components of the CLC system. In the analysis, equilibrium-based thermodynamic reactions with no OC deactivation were considered. The model was employed to investigate the effect of various key operating parameters such as air, fuel, and OC mass flow rates, operating pressure, and waste heat recovery on the performance of a natural gas-fired power plant with multistage CLC. The results of these parameters on the plant's thermal and exergetic efficiencies are presented. Based on the lower heating value, the analysis shows a thermal efficiency gain of more than 6 percentage points for CLC-integrated natural gas power plants compared to similar power plants with pre- or post-combustion CO2 capture technologies.


Author(s):  
Zheming Zhang ◽  
Ramesh Agarwal

Chemical-looping combustion holds significant promise as one of the next generation combustion technology for high-efficiency low-cost carbon capture from fossil fuel power plants. For thorough understanding of the chemical-looping combustion process and its successful implementation in CLC based industrial scale power plants, the development of high-fidelity modeling and simulation tools becomes essential for analysis and evaluation of efficient and cost effective designs. In this paper, multiphase flow simulations of coal-direct chemical-looping combustion process are performed using ANSYS Fluent CFD code. The details of solid-gas two-phase hydrodynamics in the CLC process are investigated by employing the Lagrangian particle-tracking approach called the discrete element method (DEM) for the movement and interaction of solid coal particles moving inside the gaseous medium created due to the combustion of coal particles with an oxidizer. The CFD/DEM simulations show excellent agreement with the experimental results obtained in a laboratory scale fuel reactor in cold flow conditions. More importantly, simulations provide important insights for making changes in fuel reactor configuration design that have resulted in significantly enhanced performance.


2021 ◽  
Author(s):  
Basavaraja Revappa Jayadevappa

Abstract Operation of power plants in carbon dioxide capture and non-capture modes and energy penalty or energy utilization in such operations are of great significance. This work reports on two gas fired pressurized chemical-looping combustion power plant lay-outs with two inbuilt modes of flue gas exit namely, with carbon dioxide capture mode and second mode is letting flue gas (consists carbon dioxide and water) without capturing carbon dioxide. In the non-CCS mode, higher thermal efficiencies of 54.06% and 52.63% efficiencies are obtained with natural gas and syngas. In carbon capture mode, a net thermal efficiency of 52.13% is obtained with natural gas and 48.78% with syngas. The operating pressure of air reactor is taken to be 13 bar for realistic operational considerations and that of fuel reactor is 11.5 bar. Two power plant lay-outs developed based combined cycle CLC mode for natural gas and syngas fuels. A single lay-out is developed for two fuels with possible retrofit for dual fuel operation. The CLC Power plants can be operated with two modes of flue gas exit options and these operational options makes them higher thermal efficient power plants.


2013 ◽  
Vol 316-317 ◽  
pp. 95-98 ◽  
Author(s):  
Ming Luo ◽  
Shu Zhong Wang ◽  
Long Fei Wang

The chemical-looping combustion process of solid fuels has been investigated using thermogravimetric analysis (TGA). Experimental results showed that CuO showed high reactivity during reduction process with coal. The coal conversion rate increased with the increase of reaction temperature, and the optimum reaction temperature was about 800 °C. When CuO was supported on TiO2, the temperature to initiate the reaction decreased and the coal conversion rate also increased. Candlenut wood ash, which contained high amount of alkali metal, displayed catalytic activity in mixtures with coal during the CLC process. A key issue is to find the ways for increasing the gasification rates during the CLC process in an industrial process.


2017 ◽  
Vol 114 ◽  
pp. 334-343 ◽  
Author(s):  
T.R. Costa ◽  
P. Gayán ◽  
A. Abad ◽  
F. García-Labiano ◽  
L.F. de Diego ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document