scholarly journals Oxygen Carrier Aided Combustion in Fluidized Bed Boilers in Sweden—Review and Future Outlook with Respect to Affordable Bed Materials

2021 ◽  
Vol 11 (17) ◽  
pp. 7935
Author(s):  
Felicia Störner ◽  
Fredrik Lind ◽  
Magnus Rydén
Keyword(s):  
Metal Oxide ◽  
Fluidized Bed ◽  
Large Scale ◽  
Low Cost ◽  
Oxygen Carrier ◽  
Low Grade ◽  
Oxygen Carriers ◽  
Fluidized Bed Combustion ◽  
Oxide Particles ◽  
Fluidized Bed Boilers

Oxygen carriers are metal oxide particles that could potentially enhance both fuel conversion and heat distribution in fluidized bed combustion, resulting in e.g., lowered emissions of unconverted species and better possibilities to utilize low-grade fuels. A related technology based on fluidized beds with oxygen carriers can separate CO2 without large energy penalties. These technologies are called oxygen carrier aided combustion (OCAC) and chemical-looping combustion (CLC), respectively. In the past few years, a large number of oxygen carriers have been suggested and evaluated for these purposes, many of which require complex production processes making them costly. Affordable metal oxide particles are, however, produced in large quantities as products and by-products in the metallurgical industries. Some of these materials have properties making them potentially suitable to use as oxygen carriers. Uniquely for Sweden, the use of oxygen carriers in combustion have been subject to commercialization. This paper reviews results from utilizing low-cost materials emerging from metallurgical industries for conversion of biomass and waste in semi-commercial and commercial fluidized bed boilers in Sweden. The paper further goes on to discuss practical aspect of utilizing oxygen carriers, such as production and transport within the unique conditions in Sweden, where biomass and waste combustion as well as metallurgical industries are of large scale. This study concludes that utilizing metal oxides in this way could be technically feasible and beneficial to both the boiler owners and the metallurgical industries.

scholarly journals Advancements in Development of Chemical-Looping Combustion: A Review

2009 ◽  
Vol 2009 ◽  
pp. 1-16 ◽  
Author(s):  
He Fang ◽  
Li Haibin ◽  
Zhao Zengli
Keyword(s):  
Fluidized Bed ◽  
Large Scale ◽  
Oxygen Carrier ◽  
Reactor Design ◽  
Design System ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Design Development ◽  
Conversion Rates

Chemical-looping combustion (CLC) is a novel combustion technology with inherent separation of greenhouseCO2. Extensive research has been performed on CLC in the last decade with respect to oxygen carrier development, reaction kinetics, reactor design, system efficiencies, and prototype testing. Transition metal oxides, such as Ni, Fe, Cu, and Mn oxides, were reported as reactive species in the oxygen carrier particles. Ni-based oxygen carriers exhibited the best reactivity and stability during multiredox cycles. The performance of the oxygen carriers can be improved by changing preparation method or by making mixedoxides. The CLC has been demonstrated successfully in continuously operated prototype reactors based on interconnected fluidized-bed system in the size range of 0.3–50 kW. High fuel conversion rates and almost 100%  CO2capture efficiencies were obtained. The CLC system with two interconnected fluidized-bed reactors was considered the most suitable reactor design. Development of oxygen carriers with excellent reactivity and stability is still one of the challenges for CLC in the near future. Experiences of building and operating the large-scale CLC systems are needed before this technology is used commercially. Chemical-looping reforming (CLR) and chemical-looping hydrogen (CLH) are novel chemical-looping techniques to produce synthesis gas and hydrogen deserving more attention and research.

1-D Model Analysis of Tesla Turbine for Small Scale Organic Rankine Cycle (ORC) System

2017 ◽  
Author(s):  
Jian Song ◽  
Chun-wei Gu
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Organic Rankine Cycle ◽  
Axial Flow ◽  
Rankine Cycle ◽  
Expansion Ratio ◽  
Working Fluid ◽  
Small Scale ◽  
Low Grade ◽  
D Model

Energy shortage and environmental deterioration are two crucial issues that the developing world has to face. In order to solve these problems, conversion of low grade energy is attracting broad attention. Among all of the existing technologies, Organic Rankine Cycle (ORC) has been proven to be one of the most effective methods for the utilization of low grade heat sources. Turbine is a key component in ORC system and it plays an important role in system performance. Traditional turbine expanders, the axial flow turbine and the radial inflow turbine are typically selected in large scale ORC systems. However, in small and micro scale systems, traditional turbine expanders are not suitable due to large flow loss and high rotation speed. In this case, Tesla turbine allows a low-cost and reliable design for the organic expander that could be an attractive option for small scale ORC systems. A 1-D model of Tesla turbine is presented in this paper, which mainly focuses on the flow characteristics and the momentum transfer. This study improves the 1-D model, taking the nozzle limit expansion ratio into consideration, which is related to the installation angle of the nozzle and the specific heat ratio of the working fluid. The improved model is used to analyze Tesla turbine performance and predict turbine efficiency. Thermodynamic analysis is conducted for a small scale ORC system. The simulation results reveal that the ORC system can generate a considerable net power output. Therefore, Tesla turbine can be regarded as a potential choice to be applied in small scale ORC systems.

A Simulation Study for Fluidized Bed Combustion of Petroleum Coke With CO2 Capture

2003 ◽  
Author(s):  
Jinsheng Wang ◽  
Edward J. Anthony ◽  
J. Carlos Abanades
Keyword(s):  
Power Generation ◽  
Fluidized Bed ◽  
Petroleum Coke ◽  
Co2 Capture ◽  
Low Cost ◽  
Volatile Content ◽  
Fluidized Bed Combustion ◽  
High Carbon ◽  
Overall Efficiency ◽  
Fluidized Bed Combustor

Petroleum coke is regarded as a difficult fuel because of its high sulphur content and low volatile content. However, its low price and increased production, means that there is a powerful economic stimulus to use it for power generation. In this work, a process simulation has been performed as part of a feasibility study on the utilization of petroleum coke for power generation with low-cost CO2 capture. The proposed system employs a pressurized fluidized bed combustor and a calciner. In the combustor itself, the petroleum coke is burned and most of the CO2 generated is captured by a CaO sorbent under pressurized condition to form CaCO3. The CaCO3 is transported into the calciner where limited proportion of the petroleum coke is burned with pure O2, and calcines the spent sorbent back into CaO and CO2. A nearly pure CO2 stream is obtained from the calciner for subsequent disposal or utilization. The predicted overall efficiency of the combustion is near 40%. The proposed system would also be suitable for firing other high carbon and low ash fuel, such as anthracite.

Temperature evolution of an experimental salt-gradient solar pond

2010 ◽  
Vol 1 (4) ◽  
pp. 246-250 ◽  
Author(s):  
F. Suárez ◽  
A. E. Childress ◽  
S. W. Tyler
Keyword(s):  
High Resolution ◽  
Large Scale ◽  
Thermal Evolution ◽  
Low Cost ◽  
Heat Extraction ◽  
Low Grade ◽  
Distributed Temperature Sensing ◽  
Solar Pond ◽  
Thermal Desalination ◽  
Salt Gradient

A salt-gradient solar pond is a low-cost, large-scale solar collector with integrated storage that can be used as a source of energy in low-grade-heat thermal desalination systems. This work presents the thermal evolution of an experimental solar pond for both the maturation and heat extraction time periods. The temperature profile was measured every 1.1 cm using a vertical high-resolution distributed temperature sensing (DTS) system, with a temperature resolution of 0.04ºC. Temperatures of 34 and 45ºC were achieved in the bottom of the pond when the lights were on for 12 and 24 hours per day, respectively. Heat was extracted at a rate of 139 W from the solar pond, which corresponded to an efficiency of 29%. Stratification and mixing were clearly observed inside the solar pond using the vertical high-resolution DTS system.

scholarly journals Reverse Water–Gas Shift Chemical Looping Using a Core–Shell Structured Perovskite Oxygen Carrier

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5324
Author(s):  
Minbeom Lee ◽  
Yikyeom Kim ◽  
Hyun Suk Lim ◽  
Ayeong Jo ◽  
Dohyung Kang ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxygen Carrier ◽  
Dark Field ◽  
Water Gas Shift ◽  
Unit Weight ◽  
Core Shell ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Reverse Water Gas Shift ◽  
Water Gas

Reverse water–gas shift chemical looping (RWGS-CL) offers a promising means of converting the greenhouse gas of CO2 to CO because of its relatively low operating temperatures and high CO selectivity without any side product. This paper introduces a core–shell structured oxygen carrier for RWGS-CL. The prepared oxygen carrier consists of a metal oxide core and perovskite shell, which was confirmed by inductively coupled plasma mass spectroscopy (ICP-MS), XPS, and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) measurements. The perovskite-structured shell of the prepared oxygen carrier facilitates the formation and consumption of oxygen defects in the metal oxide core during H2-CO2 redox looping cycles. As a result, amounts of CO produced per unit weight of the core–shell structured oxygen carriers were higher than that of a simple perovskite oxygen carrier. Of the metal oxide cores tested, CeO2, NiO, Co3O4, and Co3O4-NiO, La0.75Sr0.25FeO3-encapsulated Co3O4-NiO was found to be the most promising oxygen carrier for RWGS-CL, because it was most productive in terms of CO production and exhibited long-term stability.

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