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- Mattisson, Tobias, 1970, et al.
(författare)
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Chemical-Looping Technologies using Circulating Fluidized Bed Systems: Status of Development
- 2017
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Ingår i: 12th International Conference on Fluidized Bed Technology, CFB 2017. ; , s. 11-22
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Konferensbidrag (refereegranskat)abstract
- In chemical-looping combustion (CLC), an oxygen carrier provides lattice oxygen for complete combustion of a fuel for heat and power production. The reduced metal oxide is then oxidized in a separate reactor. The combustion products CO2 and H2O are obtained in pure form, without any nitrogen in the gas. As no gas separation work is needed, this could be a breakthrough technology for carbon capture (CCS). Normally, the fuel- and air-reactor are designed utilizing inter-connected fluidized beds. The same underlying reversible redox reactions of CLC can be used for other fuel conversion technologies. These include fluidized bed processes for gas, solid and liquid fuels for heat, power, syngas or hydrogen production. Some of these concepts were suggested as far back as the 1950’s, while others have just recently been proposed. Chalmers University of Technology has been involved in CLC research for over 18 years, and this paper will provide a review of some recent developments with respect to CLC with gaseous, liquid and solid fuels. Further, the paper will provide an overview some related technologies where Chalmers is conducting research: i) Chemical-looping gasification (CLG), ii) Chemical-looping reforming (CLR) and iii) Chemical-looping tar reforming (CLTR). In these processes, a pure syngas/hydrogen can be produced effectively, which could be utilized for chemical or fuel production.
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| 218. |
- Mattisson, Tobias, 1970, et al.
(författare)
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Chemical-looping technologies using circulating fluidized bed systems: Status of development
- 2018
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Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820. ; 172, s. 1-12
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Forskningsöversikt (refereegranskat)abstract
- In chemical-looping combustion (CLC), an oxygen carrier provides lattice oxygen for complete combustion of a fuel for heat and power production. The reduced metal oxide is then oxidized in a separate reactor. The combustion products CO 2 and H 2 O are obtained in pure form, without any nitrogen in the gas. As no gas separation work is needed, this could be a breakthrough technology for carbon capture (CCS). Normally, the fuel- and air-reactor are designed utilizing inter-connected fluidized beds. The same underlying reversible redox reactions of CLC can be used for other fuel conversion technologies. These include fluidized bed processes for gas, solid and liquid fuels for heat, power, syngas or hydrogen production. Some of these concepts were suggested as far back as the 1950's, while others have just recently been proposed. This paper will provide a review of some recent developments with respect to CLC with gaseous, liquid and solid fuels, with focus on operational experience. Today, more than 35 continuous units have been used worldwide, with over 9000 h of operational time. Although most experience has been reported for methane and natural gas, significant testing has now also been performed with various solid fuels. Some recent developments include i) shift from Ni-based materials to more benign metal oxide oxygen carriers, ii) use of different types of biomass and iii) operation at semi-commercial scale. Furthermore, this paper will also provide an overview some related technologies which also utilize oxygen carriers in interconnected fluidized beds: i) Chemical-looping gasification (CLG), ii) Chemical-looping reforming (CLR) and iii) Chemical-looping tar reforming (CLTR). In these processes, a pure syngas/hydrogen can be produced effectively, which could be utilized for chemical or fuel production.
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- Mattisson, Tobias, 1970, et al.
(författare)
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Chemical-looping with oxygen uncoupling for combustion of solid fuels
- 2009
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Ingår i: International Journal of Greenhouse Gas Control. - 1750-5836. ; 3:1, s. 11-19
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Tidskriftsartikel (refereegranskat)abstract
- Chemical-looping with oxygen uncoupling (CLOU) is a novel method to burn solid fuels ingas-phase oxygen without the need for an energy intensive air separation unit. The carbondioxide from the combustion is inherently separated from the rest of the flue gases. CLOU isbased on chemical-looping combustion (CLC) and involves three steps in two reactors, oneair reactor where a metal oxide captures oxygen from the combustion air (step 1), and a fuelreactor where the metal oxide releases oxygen in the gas-phase (step 2) and where this gasphaseoxygen reacts with a fuel (step 3). In other proposed schemes for using chemicalloopingcombustion of solid fuels there is a need for an intermediate gasification step of thechar with steam or carbon dioxide to form reactive gaseous compounds which then reactwith the oxygen carrier particles. The gasification of char with H2O and CO2 is inherentlyslow, resulting in slow overall rates of reaction. This slow gasification is avoided in theproposed process, since there is no intermediate gasification step needed and the charreacts directly with gas-phase oxygen. The process demands an oxygen carrier which hasthe ability to react with the oxygen in the combustion air in the air reactor but whichdecomposes to a reduced metal oxide and gas-phase oxygen in the fuel reactor. Three metaloxide systems with suitable thermodynamic properties have been identified, and a thermalanalysis has shown thatMn2O3/Mn3O4 and CuO/Cu2Ohave suitable thermodynamic properties,although Co3O4/CoO may also be a possibility. However, the latter system has thedisadvantage of an overall endothermic reaction in the fuel reactor. Results from batchlaboratory fluidized bed tests with CuO and a gaseous and solid fuel are presented. Thereaction rate of petroleum coke is approximately a factor 50 higher using CLOU in comparisonto the reaction rate of the same fuel with an iron-based oxygen carrier in normal CLC.
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| 220. |
- Mattisson, Tobias, 1970, et al.
(författare)
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Chemical-looping with oxygen uncoupling using CuO/ZrO2 with petroleum coke
- 2009
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 88:4, s. 683-690
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen carrier particles of CuO/ZrO2 were reacted with petroleum coke using chemical-looping with oxy- 24gen uncoupling (CLOU). The fuel was burnt in gas-phase oxygen released from the oxygen carrier parti- 25cles during the fuel oxidation. The particles were then regenerated in 5–21% oxygen. In this process, the 26carbon dioxide from the combustion is inherently separated from the rest of the flue gases without the 27need for an energy intensive air separation unit. Copper oxide has thermodynamic characteristics that 28make it suitable as an oxygen carrier in CLOU. Particles were prepared by freeze granulation and were 29exposed cyclically with petroleum coke and oxygen in a laboratory fluidized bed reactor of quartz. The 30reaction temperature and oxygen concentration during the oxidation were varied. The average conver- 31sion rate of petroleum coke was a function of temperature and varied between 0.5%/s and 5%/s in the 32set-point temperature interval 885–985°C. The conversion rate is considerably higher than rates 33obtained with the same fuel using iron-based oxygen-carrier in chemical-looping combustion. As for 34the regeneration with oxygen, the reduced particles reacted at low oxygen concentrations, with a consid- 35erable part of the reaction occurring near the thermodynamic equilibrium.
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