Simulations of a Circulating Fluidized Bed Chemical Looping Combustion System Utilizing Gaseous Fuel

Mahalatkar, Kartikeya; Kuhlman, John M.; Huckaby, E. David; O’Brien, Thomas J.

doi:10.2516/ogst/2010021

Cited by 15 publications

(7 citation statements)

References 18 publications

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“…The 7,[187][188][189]193 CO 2 and H 2 O have also been proposed as direct products from CH 4 combustion in the CLC system, especially for Mn-based OCs. 113,194,195 3.5. Efficiency and Exergy Analysis.…”

Section: Process Descriptions and Characteristicsmentioning

confidence: 99%

CO₂ Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

et al. 2017

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The world-wide consumption of natural gas (NG) and other fossil fuels (e.g., coal and crude oil) is ever increasing. However, most CO 2 resulting from either NG combustion or other processes is released into the atmosphere without capture. Chemical looping combustion (CLC) is a two-step combustion technology for power and heat generation with inherent CO 2 capture, using either gaseous fuels or solid and liquid fuels. A previous review focused on CLC of solid fuels or CLC of all types of fuels but did not give an in-depth and specific discussion of gaseous fuel CLC systems. China is one of the largest consumers of NG, coal, and crude oil in the world, and it is essential to develop an alternative technology to take the place of gaseous fuel (e.g., NG) combustion. This Review summarizes recent research and development work on CLC using gaseous fuels, including a technological and economic assessment, types of oxygen carriers (OCs), reactor types, coke formation and OCs poisoning, efficiency and exergy analyses, and model development based on a literature survey. The plant efficiency of NG-CLC can be up to 52−60% (LHV), including CO 2 compression, based on calculations and simulations, which is about 3−5% more efficient than a NG combined cycle with CO 2 capture. Ni-based materials have been widely developed and applied for NG-CLC because of its fast kinetics for methane conversion. CuO−Cu 2 O/Cu, Mn 3 O 4 −MnO, and Fe 2 O 3 −Fe 3 O 4 are typical OCs with high selectivity toward CO 2 and H 2 O. The operating conditions are closely dependent on reactor configurations, hydrodynamics, mass and heat balances, and characteristics of the OCs in the system. CLC and other CO 2 capture technologies are also compared in the present Review, which has rarely been investigated previously. From simulation and process analysis, a conceptual design of a NG-CLC power plant of thermal input 655 MW th is conducted to clarify its technological advantages and economic benefits compared to other power generation processes. The air reactor, fuel reactor, and OCs do not impose significant economic barriers for scale-up and commercialization of CLC.

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Section: Process Descriptions and Characteristicsmentioning

confidence: 99%

CO₂ Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

et al. 2017

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“…CFD models have been used to simulate the performance of small facilities up to 1 kW th [351][352][353] showing a good fit between experimental results and theoretical predictions.…”

Section: Model Validationmentioning

confidence: 99%

“…Most of CFD models have been developed for reactors in batch mode, without solids circulation, or for small scale CLC systems (300-1000 W th ). Important progress has been done validating the CFD models with experimental results obtained in small-scale facilities using gaseous fuels [351][352][353], or coal [354]. Up to date, the more complete modelling of a CLC system using CFD codes is the simulation of a bubbling fluidized bed for the fuel-reactor coupled to a riser for the air-reactor using methane as fuel and Mn-or Ni-based oxygen-carriers [349,350].…”

Section: Fluid Dynamicsmentioning

confidence: 99%

Progress in Chemical-Looping Combustion and Reforming technologies

Adánez

Abad

Garcı́a-Labiano

et al. 2012

Progress in Energy and Combustion Science

1,968

1,614

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This work is a comprehensive review of the Chemical-Looping Combustion (CLC) and Chemical-Looping Reforming (CLR) processes reporting the main advances in these technologies up to 2010. These processes are based on the transfer of the oxygen from air to the fuel by means of a solid oxygen-carrier avoiding direct contact between fuel and air for different final purposes. CLC has arisen during last years as a very promising combustion technology for power plants and industrial applications with inherent CO 2 capture which avoids the energetic penalty present in other competing technologies.CLR uses the chemical looping cycles for H 2 production with additional advantages if CO 2 capture is also considered.The review compiles the main milestones reached during last years in the development of these technologies regarding the use of gaseous or solid fuels, the oxygen-carrier development, the continuous operation experience, and modelling at several scales. Up to 2010, more than 700 different materials based on Ni, Cu, Fe, Mn, Co, as well as other mixed oxides and low cost materials, have been compiled. Especial emphasis has been done in those oxygen-carriers tested under continuous operation in Chemical-Looping 2 prototypes. The total time of operational experience (≈ 3500 h) in different CLC units in the size range 0.3-120 kW th , has allowed to demonstrate the technology and to gain in maturity. To help in the design, optimization, and scale-up of the CLC process, modelling work is also reviewed. Different levels of modelling have been accomplished, including fundamentals of the gas-solid reactions in the oxygen-carriers, modelling of the air-and fuel-reactors, and integration of the CLC systems in the power plant. Considering the great advances reached up to date in a very short period of time, it can be said that CLC and CLR are very promising technologies within the framework of the CO 2 capture options.

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“…Nam et al [41] performed a CFD simulation to predict the effects of different jet/grid air ratio and pressure conditions on the hydrodynamics characteristics of a pilot-scale pressurized fluidized bed gasifier. By far, the simulation studies with CFD method on CLC mainly focus on the gas-fueled CLC [42][43][44][45][46][47][48][49][50][51][52] and fluid dynamics in CLC systems [53][54][55][56], and only a few of them have probed into the field of solid-fuel CLC. Mahalatkar et al [57] pioneered the prediction of solid-fuel CLC performance in the fuel reactor using a two-dimensional model.…”

Section: Of 17mentioning

confidence: 99%

Numerical Investigation of Solid-Fueled Chemical Looping Combustion Process Utilizing Char for Carbon Capture

et al. 2019

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The in-depth understanding of the gas–solid flow and reaction behaviors, and their coupling characteristics during the chemical looping combustion (CLC) process has the guiding significance for the operation and optimization of a chemical looping combustor. A three-dimensional numerical model is applied to investigate the char-fueled CLC characteristics in a fuel reactor for efficient CO2 separation and capture. Simulations are carried out in a bubbling fluidized bed fuel reactor with a height of 2.0 m and a diameter of 0.22 m. The initial bed height is 1.1 m, and hence the height–diameter ratio of the slumped bed is five. The oxygen carrier is prepared with 14 wt% of CuO on 86 wt% of inert Al2O3. In the process of mathematical modeling, a Eulerian-Eulerian two-fluid model is adopted for both of the gas and solid phases. Gas turbulence is modeled on the basis of a k–ε turbulent model. The reaction kinetics parameters are addressed based upon previous experimental investigations from literature. During the simulation, the gas–solid flow patterns, composition distributions, and reaction characteristics are obtained. Moreover, the effects of solids inventory and fluidizing number on the reaction performance are elucidated in-depth. The results have shown that the reaction rates have close relationship with the flow patterns and the distributions of gas concentrations. Compared to the steam-char gasification over sand, the application of char-fueled CLC can effectively promote the conversion of gasification products. In addition, higher CO2 concentration at the outlet can be achieved by increasing the initial solids inventory or decreasing the fluidizing number. Some calculated values are verified by the previous data, indicating that the current three-dimensional models are reasonable to study the process mechanism of char-fueled CLC.

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Simulations of a Circulating Fluidized Bed Chemical Looping Combustion System Utilizing Gaseous Fuel

Cited by 15 publications

References 18 publications

CO₂ Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

CO₂ Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

Progress in Chemical-Looping Combustion and Reforming technologies

Numerical Investigation of Solid-Fueled Chemical Looping Combustion Process Utilizing Char for Carbon Capture

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Simulations of a Circulating Fluidized Bed Chemical Looping Combustion System Utilizing Gaseous Fuel

Cited by 15 publications

References 18 publications

CO2 Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

CO2 Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

Progress in Chemical-Looping Combustion and Reforming technologies

Numerical Investigation of Solid-Fueled Chemical Looping Combustion Process Utilizing Char for Carbon Capture

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Product

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CO₂ Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview

CO₂ Capture with Chemical Looping Combustion of Gaseous Fuels: An Overview