Auto-thermal operation and optimization of coal-fueled separated gasification chemical looping combustion in a pilot-scale unit

Wang, Xudong; Wang, Xiaojia; Kong, Zhiwei; Shao, Yingjuan; Jin, Baosheng

doi:10.1016/j.cej.2019.123159

Cited by 41 publications

(14 citation statements)

References 58 publications

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“…On the basis of the design concept of this SG-CLC system, we have successfully built and operated a pilot-scale 20 kW th unit. , After a series of tests, the continuous and stable operation with favorable fuel conversion, high CO 2 capture concentration, and lower mass loss of the OC has been realized, preliminarily verifying the feasibility of this concept. In this study, we have developed a numerical model of a scale-up MW-level SG-CLC-combined cycle system to further predict the feasibility and thermal economy of this novel system for power production.…”

Section: Introductionmentioning

confidence: 82%

“…Moreover, the RR was designed with a large reactor height to provide sufficient residence time for the syngas to react with the OC. Thus, with the favorable gas–solid contact efficiency and sufficient residence time, the high conversion of syngas has been achieved in our previous pilot-scale tests, in which the CO 2 yield could reach around 97%. , The type of the AR was selected as a counter-flow moving bed, which has the advantages of low pressure drop, stable solid flow, and compact structure, to achieve the reoxidization of the OC by air. In addition, a two-stage separation system, including a first-stage inertial separator and a second-stage cyclone separator, was adopted to separate the reduced OC from the RR to the AR for reoxidation and circulate the unconverted char back to the GR for further conversion.…”

Section: Introductionmentioning

confidence: 99%

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Energy and Exergy Investigations of a Separated-Gasification Chemical Looping Combustion-Combined Cycle System for Power Production

Wang

Jin

2020

Ind. Eng. Chem. Res.

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The concept of a novel separated-gasification chemical looping combustion (SG-CLC) system, which is mainly composed of a bubbling fluidized bed as the gasification reactor, a fast fluidized bed as the reduction reactor (RR), and a counter-flow moving bed as the air reactor (AR), has been proposed and evaluated through our previous subpilot scale unit. Extending from the previous work, the present study aims to further investigate the feasibility and potential of this technique for power production. A comprehensive steady-state model integrating various unit blocks has been developed to simulate the operation process of a megawatt-class SG-CLC-combined cycle system based on the ASPEN PLUS simulator. A Chinese Shenhua bituminous coal is used as the fuel with a Fe-based oxygen carrier. During the simulation, the net power production, energy efficiency and exergy efficiency of the combined cycle system, and the work duties of different components are obtained. In addition, the effects of some important operating variables on the system power production performance are elucidated in-depth. The results have shown that the electricity production performance is closely related to the upstream SG-CLC combustion system. At an input thermal power of 1.1 MW and a water flow rate of 750 kg/h, the energy efficiency and exergy efficiency of this novel SG-CLC-combined cycle system can reach high values at 42.9 and 35.6%, respectively. In addition, higher power generation efficiencies can be achieved by properly decreasing the flow rate of feed water, or increasing the temperatures of the RR and the AR.

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Section: Introductionmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Energy and Exergy Investigations of a Separated-Gasification Chemical Looping Combustion-Combined Cycle System for Power Production

Wang

Jin

2020

Ind. Eng. Chem. Res.

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“…Chemical looping combustion (CLC) is a low-energy penalty technology to achieve an almost pure separation of CO 2 . , A typical CLC system consists of a fuel reactor and an air reactor. A solid oxygen carrier is employed in the fuel reactor, which acts as an oxidizing agent to produce almost pure CO 2 -enriched flue gas stream from the fuel reactor . In our previous study, we had built a CLC system with a high-velocity circulating fluidized bed riser as the fuel reactor and a low-velocity moving bed as the air reactor .…”

Section: Introductionmentioning

confidence: 99%

“…A solid oxygen carrier is employed in the fuel reactor, which acts as an oxidizing agent to produce almost pure CO 2 -enriched flue gas stream from the fuel reactor. 15 In our previous study, we had built a CLC system with a highvelocity circulating fluidized bed riser as the fuel reactor and a low-velocity moving bed as the air reactor. 16 The two reactors were connected by a loop seal and a separator to form a solid circulation loop.…”

Section: Introductionmentioning

confidence: 99%

Computational Fluid Dynamics–Discrete Element Model Simulation of Flow Characteristics and Solids’ Residence Time Distribution in a Moving Bed Air Reactor for Chemical Looping Combustion

Shao

Agarwal

et al. 2020

Ind. Eng. Chem. Res.

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In our previous experimental study, a novel multistage moving bed air reactor was proposed for chemical looping combustion; some operating mechanisms including the gas flow carrying capacity and gas leakage performance were investigated. In this paper, a quasi-2D computational fluid dynamics–discrete element model cold flow model is developed for the experimental air reactor. Effects of the operating parameters, geometric parameters, and internals on solids’ flow characteristics and residence time distributions are studied by using the tracer particles. Results show that with increase in the loop seal gas velocity, the solids’ mass flux increases and the average solids’ residence time decreases. The reactor angle has more influence in solids’ movements in the near-wall region, while the wedge angle has more effect on the solids’ movements in the lower part of the reactor. With decrease of the reactor angle, increase of the wedge angle, or increase of the down-comer diameter, the solids’ flow gets closer to ideal plug flow in the reactor. The internals can accelerate the particles in the near-wall region; internals in triangular arrays are better than those in square arrays to slow down the central particles.

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“…On the other hand, a higher concentration was noticed for IG-CLC. Wang et al 25 performed separated gasification CLC of a coal experiment to achieve an autothermal operation. The autothermal operation was achieved when the temperature in the reactor is higher than the outer surface of the test.…”

Section: Introductionmentioning

confidence: 99%

Process Modelling of Chemical Looping Combustion of Paper, Plastics, Paper/Plastic Blend Waste, and Coal

Yaqub

Oboirien

2020

ACS Omega

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Chemical looping combustion (CLC) is a novel carbon capture and storage technology that can be used in the proper disposal of municipal solid waste when used as a solid fuel. In this study, the results of the CLC of paper, plastics, and paper/plastic blends were compared with CLC of South African coal using Chemcad software. The simulation was done for two different CLC processes, namely, chemical looping oxygen uncoupling (CLOU) and in situ gasification CLC (IG-CLC). The results demonstrated that coal at 66% had a lower CO 2 yield than paper (86%) but a higher yield than all the plastic samples in CLOU (3356%) and an equal CO 2 yield in paper and all plastic samples in IG-CLC. Furthermore, coal had a lower CO 2 gas yield than all the optimum blends (72–85%) for CLOU and an equal yield with the entire paper/plastic blend in IG-CLC. On combustion efficiency, coal has a lower combustion efficiency at 80% than paper and polyvinyl chloride (PVC) at 90 and 96%, respectively, but a higher efficiency than other plastic samples that are between 30 and 70% in CLOU while in IG-CLC, it had a lower efficiency than paper, PVC, and polyethylene terephthalate and higher efficiency than high-density polyethylene, low-density polyethylene, polypropylene, and polystyrene. For paper/plastic blends, coal has higher combustion efficiency than all the paper/plastic blends in both CLOU and IG-CLC processes except for the paper/PVC where the combustion efficiency was higher than coal.

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Auto-thermal operation and optimization of coal-fueled separated gasification chemical looping combustion in a pilot-scale unit

Cited by 41 publications

References 58 publications

Energy and Exergy Investigations of a Separated-Gasification Chemical Looping Combustion-Combined Cycle System for Power Production

Energy and Exergy Investigations of a Separated-Gasification Chemical Looping Combustion-Combined Cycle System for Power Production

Computational Fluid Dynamics–Discrete Element Model Simulation of Flow Characteristics and Solids’ Residence Time Distribution in a Moving Bed Air Reactor for Chemical Looping Combustion

Process Modelling of Chemical Looping Combustion of Paper, Plastics, Paper/Plastic Blend Waste, and Coal

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