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Journal ArticleDOI

Novel two-stage fluidized bed-plasma gasification integrated with SOFC and chemical looping combustion for the high efficiency power generation from MSW: a thermodynamic investigation

15 May 2021-Energy Conversion and Management (Pergamon)-Vol. 236, pp 114066

Abstract: A novel municipal solid waste (MSW)-based power generation system was proposed in this study, which consists of a bubbling fluidized-bed (BFB)-plasma gasification unit, a high-temperature solid oxide fuel cell (SOFC), a chemical looping combustion (CLC) unit and a heat recovery unit. Process simulation was conducted using Aspen Plus™ and validated by literature data. The energetic and exergetic assessment of the proposed system showed that the net electrical efficiency and exergy efficiency reached 40.9% and 36.1%, respectively with 99.3% of carbon dioxide being captured. It was found that the largest exergy destruction took place in the BFB-Plasma gasification unit (476.5 kW) and accounted for 33.6% of the total exergy destruction, followed by the SOFC (219.1 kW) and then CLC (208.6 kW). Moreover, the effects of key variables, such as steam to fuel ratio (STFR), fuel utilization factor (Uf), current density and air reactor operating temperature, etc., on system performance were carried out and revealed that the system efficiency could be optimized under STFR = 0.5, Uf = 0.8 and air reactor operating temperature of 1000 °C. Furthermore, the proposed process demonstrated more than 14% improvement in net electrical efficiency in comparison with other MSW incineration and/or gasification to power processes.
Topics: Exergy efficiency (63%), Chemical looping combustion (61%), Exergy (55%), Plasma gasification (55%), Solid oxide fuel cell (54%)

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Novel two-stage fluidized bed-plasma gasification
integrated with SOFC and chemical looping
combustion for the high efficiency power
generation from MSW: A thermodynamic
investigation
Peng Jiang a,b, Ashak Mahmud Parvez c, Yang Meng a, Xinyue Dong a,
Mengxia Xu a,d, Xiang Luo a,d, Kaiqi Shi a,d, Tao Wu

University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo,
315100, China
First published 2021
This work is made available under the terms of the Creative Commons
Attribution 4.0 International License:
http://creativecommons.org/licenses/by/4.0
The work is licenced to the University of Nottingham Ningbo China
under the Global University Publication Licence:
https://www.nottingham.edu.cn/en/library/documents/research-
support/global-university-publications-licence.pdf

1
Novel two-stage fluidized bed-plasma gasification integrated with SOFC and
1
chemical looping combustion for the high efficiency power generation from MSW:
2
A thermodynamic investigation
3
Peng Jiang
a,b
, Ashak Mahmud Parvez
c
, Yang Meng
a
, Xinyue Dong
a
, Mengxia Xu
a,d
, Xiang Luo
a,d
, Kaiqi
4
Shi
a,d
, Tao Wu
a, d,*
5
a
Department of Chemical and Environmental Engineering, The University of Nottingham Ningbo China, Ningbo 315100, China
6
b
Shenzhen Gas Corporation Ltd., Shenzhen 518040, China
7
c
Institute of Combustion and Power Plant Technology (IFK), University of Stuttgart, Pfaffenwaldring 23, D-70569 Stuttgart, Germany
8
d
Key Laboratory for Carbonaceous Wastes Processing and Process Intensification Research of Zhejiang Province, The University of
9
Nottingham Ningbo China, Ningbo 315100, China
10
*
Corresponding author: Tao Wu, Tao.Wu@nottingham.edu.cn
11
Abstract
12
A novel municipal solid waste (MSW)-based power generation system was proposed in this study,
13
which consists of a bubbling fluidized-bed (BFB)-plasma gasification unit, a high-temperature solid
14
oxide fuel cell (SOFC), a chemical looping combustion (CLC) unit and a heat recovery unit. Process
15
simulation was conducted using Aspen Plus
TM
and validated by literature data. The energetic and
16
exergetic assessment of the proposed system showed that the net electrical efficiency and exergy
17
efficiency reached 40.9 % and 36.1 %, respectively with 99.3 % of carbon dioxide being captured. It
18
was found that the largest exergy destruction took place in the BFB-Plasma gasification unit (476.5
19
kW) and accounted for 33.6 % of the total exergy destruction, which is followed by the SOFC (219.1
20
kW) and then CLC (208.6 kW). Moreover, the effects of key variables, such as steam to fuel ratio
21
(STFR), fuel utilization factor (U
f
), current density and air reactor operating temperature, etc., on
22
system performance were carried out and revealed that the system efficiency could be optimized
23
under STFR = 0.5, U
f
= 0.8 and air reactor operating temperature of 1000 ºC. Furthermore, the
24

2
proposed process demonstrated more than 14% improvement in net electrical efficiency in
25
comparison with other MSW incineration and/or gasification to power processes.
26
Keywords: MSW; bubbling fluidized-bed-plasma gasification; thermodynamic analysis; solid oxide
27
fuel cell; chemical looping combustion
28
Nomenclature
Power, kW
G
0
Gibbs free energy at
standard pressure and
temperature, J mol
1
A
a
Active surface area, m
2
Air reactor
C
10
H
8
Naphthalene
Air separation unit
C
2
H
6
Ethane
Bubbling fluidized-bed
gasifier
C
3
H
6
Propene
Combined cycle
C
3
H
8
Propane
Chemical looping
combustion
CH
4
Methane
Fuel reactor
CO
Carbon monoxide
Gas turbine
CO
2
Carbon dioxide
Heat exchanger
E
Cell voltage, V
Heat recovery and steam
generation
E
0
Nernst voltage, V
Life cycle analysis
ER
Equivalence ratio
Lower heating value
Ex
Exergy, J mol
1
Municipal solid waste
F
Faraday’s constant, C
mol
1
Refused derived fuel
H
2
Hydrogen
Solid Oxide Electrolyser
Cell
H
2
S
Hydrogen sulfide
Solid oxide fuel cells
I
Current, A
Steam turbine

3
i
Current density, A m
2
Volatile organic
compounds
m
Mass flow rate, kg s
-1
n
Molar flow rate, mol s
-1
Coefficient
Ni
Nickle
Efficiency
NiO
Nickle oxide
NO
Nitric Oxide
Activation polarization
NO
2
Nitrogen dioxide
Concentration
polarization
R
Universal gas constant, J
mol
1
K
1
Power generated by the
SOFC
S
Sulfur
Energy
SO
2
Sulfur dioxide
Exergy
STFR
Steam to fuel mass ratio
Ohmic polarization
T
Temperature,
o
C
Reacted molar flow rate
of the gas species
U
f
Fuel utilization factor
29
1. Introduction
30
The generation of solid wastes along with the economic development has become an
31
environmental challenge in the 21
st
century. In China, the municipal solid waste (MSW) production
32
in the 214 major cities rised from 168.1 million tons in 2014 to 235.6 million tons in 2020 [1]. Although
33
the percentage of MSW being treated has reached 99.7 wt% in 2020 in China, landfill and incineration
34
still account for 45.6 wt% and 50.6 wt% of the treated MSW, respectively [2], which are also
35
associated with environmental issues, such as the emission of uncontrolled greenhouse gases,
36
ground water and soil pollution, and the release of gaseous carcinogens [3]. Besides, the energy
37
efficiency of incineration technology is normally low while the cost is high, which render it less
38

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References
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Mohammad M. Hossain1, Hugo de Lasa1Institutions (1)
Abstract: This review reports recent advances on chemical-looping combustion (CLC). CLC is a promising technology for fossil fuel combustion preventing CO 2 dilution with flue gases, mainly nitrogen. In CLC, the solid oxygen carrier supplies the stoichiometric oxygen needed for CO 2 and water formation, and this leads to a free nitrogen mixture. As a result, the requirement of CO 2 separation from flue gases, a major cost for CO 2 capture, is circumvented. Furthermore, formation of NO x is also reduced. A good oxygen carrier for CLC shall readily react with the fuel gas and shall be reoxidized upon being contacted with oxygen. An oxygen carrier is typically formed by a metal oxide and an inert binder, which provide, respectively, oxygen storage, fluidizability and mechanical strength. Over the last 10 years, several research groups have been researching oxygen carriers which are both active and stable under fluidized bed conditions. While Fe, Ni, Cu, Mn and Co oxides are potential oxygen carrier materials, recent studies show that Ni is best suited for CLC. Few studies have been devoted to the solid-state kinetics of both reduction and oxidation with either a nucleation–nuclei growth or unreacted shrinking core models being considered. In order to implement CLC, two interconnected fluidized bed reactors (the fuel and air reactor) with the oxygen carrier circulated between units have been proposed. While reactor design, modeling and hydrodynamics are matters that have been analyzed by several research groups; these topics still require more attention and investigation. Preliminary economic assessments, have suggested that CLC holds great promise for combustion processes, having the potential for achieving very efficient and low cost CO 2 capture. Even with these favorable prospects, commercial scale-up of CLC still depends nowadays on the availability of highly performing and stable oxygen carriers.

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Umberto Arena1Institutions (1)
TL;DR: The analysis indicates that gasification is a technically viable option for the solid waste conversion, including residual waste from separate collection of municipal solid waste, and can have a remarkable effect on reduction of landfill disposal option.
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Book
19 Oct 2010
Abstract: Preface. 1 Introduction. 1.1 Background. 1.1.1 Renewable Energy. 1.1.2 Fossil Energy Outlook. 1.2 Coal Combustion. 1.2.1 Energy Conversion Efficiency Improvement. 1.2.2 Flue Gas Pollutant Control Methods. 1.3 CO2 Capture. 1.4 CO2 Sequestration. 1.5 Coal Gasification. 1.6 Chemical Looping Concepts. 1.7 Chemical Looping Processes. 1.8 Overview of This Book. References. 2 Chemical Looping Particles. 2.1 Introduction. 2.2 Type I Chemical Looping System. 2.2.1 General Particle Characteristics. 2.2.2 Thermodynamics and Phase Equilibrium of Metals and Metal Oxides. 2.2.3 Particle Regeneration with Steam. 2.2.4 Reaction with Oxygen and Heat of Reaction. 2.2.5 Particle Design Considering Heat of Reaction. 2.2.6 Particle Preparation and Recyclability. 2.2.7 Particle Formulation and Effect of Support. 2.2.8 Effect of Particle Size and Mechanical Strength. 2.2.9 Carbon and Sulfur Formation Resistance. 2.2.10 Particle Reaction Mechanism. 2.2.11 Effect of Reactor Design and Gas-Solid Contact Modes.7 2.2.12 Selection of Primary Metal for Chemical Looping Combustion of Coal. 2.3 Type II Chemical Looping System. 2.3.1 Types of Metal Oxide. 2.3.2 Thermodynamics and Phase Equilibrium of Metal Oxide and Metal Carbonate. 2.3.3 Reaction Characteristics of Ca-Based Sorbents for CO2 Capture. 2.3.4 Synthesis of the High-Reactivity PCC-CaO Sorbent. 2.3.5 Reactivity of Calcium Sorbents. 2.3.6 Recyclability of Calcium Oxides. 2.4 Concluding Remarks. References. 3 Chemical Looping Combustion. 3.1 Introduction. 3.2 CO2 Capture Strategies for Fossil Fuel Combustion Power Plants. 3.2.1 Pulverized Coal Combustion Power Plants. 3.2.2 CO2 Capture Strategies. 3.3 Chemical Looping Combustion. 3.3.1 Particle Reactive Properties and Their Relationship with CLC Operation. 3.3.2 Key Design and Operational Parameters for a CFB-Based CLC System. 3.3.3 CLC Reactor System Design. 3.3.4 Gaseous Fuel CLC Systems and Operational Results. 3.3.5 Solid Fuel CLC Systems and Operational Results. 3.4 Concluding Remarks. References. 4 Chemical Looping Gasification Using Gaseous Fuels. 4.1 Introduction. 4.2 Traditional Coal Gasification Processes. 4.2.1 Electricity Production-Integrated Gasification Combined Cycle (IGCC). 4.2.2 H2 Production. 4.2.3 Liquid Fuel Production. 4.3 Iron-Based Chemical Looping Processes Using Gaseous Fuels. 4.3.1 Lane Process and Messerschmitt Process. 4.3.2 U.S. Bureau of Mines Pressurized Fluidized Bed Steam-Iron Process. 4.3.3 Institute of Gas Technology Process. 4.3.4 Syngas Chemical Looping (SCL) Process. 4.4 Design, Analysis and Optimization of the Syngas Chemical Looping (SCL) Process. 4.4.1 Thermodynamic Analyses of SCL Reactor Behavior. 4.4.2 ASPEN PLUS Simulation of SCL Reactor Systems. 4.4.3 Syngas Chemical Looping (SCL) Process Testing. 4.5 Process Simulation of the Traditional Gasification Process and the Syngas Chemical Looping Process. 4.5.1 Common Assumptions and Model Setup. 4.5.2 Description of Various Systems. 4.5.3 ASPEN PLUS Simulation, Results, and Analyses. 4.6 Example of SCL Applications-A Coal-to-Liquid Confi guration. 4.6.1 Process Overview. 4.6.2 Mass/Energy Balance and Process Evaluation. 4.7 Calcium Looping Process Using Gaseous Fuels. 4.7.1 Description of the Processes. 4.7.2 Reaction Characteristics of the Processes. 4.7.3 Analyses of the Processes. 4.7.4 Enhanced Coal-to-Liquid (CTL) Process with Sulfur and CO2 Capture. 4.8 Concluding Remarks. References. 5 Chemical Looping Gasification Using Solid Fuels. 5.1 Introduction. 5.2 Chemical Looping Gasification Processes Using Calcium-Based Sorbent. 5.2.1 CO2 Acceptor Process. 5.2.2 HyPr-Ring Process. 5.2.3 Zero Emission Coal Alliance Process. 5.2.4 ALSTOM Hybrid Combustion-Gasification Process. 5.2.5 Fuel-Flexible Advanced Gasification-Combustion Process. 5.2.6 General Comments. 5.3 Coal-Direct Chemical Looping (CDCL) Processes Using Iron-Based Oxygen Carriers. 5.3.1 Coal-Direct Chemical Looping Process-Configuration I. 5.3.2 Coal-Direct Chemical Looping Process-Configuration II. 5.3.3 Comments on the Iron-Based Coal-Direct Chemical Looping Process. 5.4 Challenges to the Coal-Direct Chemical Looping Processes and Strategy for Improvements. 5.4.1 Oxygen-Carrier Particle Reactivity and Char Reaction Enhancement. 5.4.2 Configurations and Conversions of the Reducer. 5.4.3 Performance of the Oxidizer and the Combustor. 5.4.4 Fate of Pollutants and Ash. 5.4.5 Energy Management, Heat Integration, and General Comments. 5.5 Process Simulation on the Coal-Direct Chemical Looping Process. 5.5.1 ASPEN Model Setup. 5.5.2 Simulation Results. 5.6 Concluding Remarks. References. 6 Novel Applications of Chemical Looping Technologies. 6.1 Introduction. 6.2 Hydrogen Storage and Onboard Hydrogen Production. 6.2.1 Compressed Hydrogen Gas and Liquefi ed Hydrogen. 6.2.2 Metal Hydrides. 6.2.3 Bridged Metal-Organic Frameworks. 6.2.4 Carbon Nanotubes and Graphite Nanofibers. 6.2.5 Onboard Hydrogen Production via Iron Based Materials. 6.3 Carbonation-Calcination Reaction (CCR) Process for Carbon Dioxide Capture. 6.4 Chemical Looping Gasification Integrated with Fuel Cells. 6.4.1 Chemical Looping Gasification Integrated with Solid-Oxide Fuel Cells. 6.4.2 Direct Solid Fuel Cells. 6.5 Enhanced Steam Methane Reforming. 6.6 Tar Sand Digestion via Steam Generation. 6.7 Liquid Fuel Production from Chemical Looping Gasification. 6.8 Chemical Looping with Oxygen Uncoupling (CLOU). 6.9 Concluding Remarks. References. Subject Index. Author Index.

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Jerry D. Murphy1, Eamon McKeogh2Institutions (2)
Abstract: Four technologies are investigated which produce energy from municipal solid waste (MSW): incineration, gasification, generation of biogas and utilisation in a combined heat and power (CHP) plant, generation of biogas and conversion to transport fuel. Typically the residual component of MSW (non-recyclable, non-organic) is incinerated producing electricity at an efficiency of about 20% and thermal product at an efficiency of about 55%. This is problematic in an Irish context where utilisation of thermal products is not the norm. Gasification produces electricity at an efficiency of about 34%; this would suggest that gasification of the residual component of MSW is more advantageous than incineration where a market for thermal product does not exist. Gasification produces more electricity than incineration, requires a smaller gate fee than incineration and when thermal product is not utilised generates less greenhouse gas per kWh than incineration. Gasification of MSW (a non-homogenous fuel) is, however, not proven at commercial scale. Biogas may be generated by digesting the organic fraction of MSW (OFMSW). The produced biogas may be utilised for CHP production or for transport fuel production as CH4-enriched biogas. When used to produce transport fuel some of the biogas is used in a small CHP unit to meet electricity demand on site. This generates a surplus thermal product. Both biogas technologies require significantly less investment costs than the thermal conversion technologies (incineration and gasification) and have smaller gate fees. Of the four technologies investigated transport fuel production requires the least gate fee. A shortfall of the transport fuel production technology is that only 50% of biogas is available for scrubbing to CH4-enriched biogas.

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