| 71. |
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| 72. |
- Mata Las Heras, Erika, 1980, et al.
(författare)
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Cost-Effectiveness of Retrofitting Swedish Buildings
- 2017
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Ingår i: Cost-Effective Energy Efficient Building Retrofitting: Materials, Technologies, Optimization and Case Studies. - 9780081011287 ; , s. 343-362
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter presents potentials for energy conservation through energy retrofitting of existing Swedish buildings, including residential and nonresidential buildings. The Swedish building stock is described with 1800 representative buildings, in a combination of sample and archetype buildings, and is modeled with a dynamic and detailed building-stock model. Ten individual energy conservation measures and 6 packages of measures are considered. The chapter also presents how the cost-effectiveness of the measures depends on energy prices, discount rates, and the assumed investment costs for the different measures. The results are presented and discussed separately for residential buildings, divided into single-family dwellings and multifamily dwellings, and nonresidential buildings.
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| 73. |
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| 74. |
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| 75. |
- Mocholí Montañés, Rubén, 1990, et al.
(författare)
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Large-scale Torrefaction of waste wood for pulverized-coal substitution in blast furnaces: Torero project
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of the Torero project is to be the world-first large scale implementation of the waste wood torrefaction for substitution of pulverized coal in blast furnaces. Steel making is highly dependent on coal for reduction of the iron ore in the blast furnace and for energy supply. Substitution of coal with biomass could effectively reduce CO2 emission in steelmaking. However, the steel making process has strict constrains on the properties of the fuel, making it difficult to use a heterogeneous fuel like biomass. In addition, the price of biomass, especially in a carbon constrained energy system, is higher than for coal. The Torero-project considers substitution of the pulverized coal used in the blast furnace with torrefied waste wood. The torrefaction process produces a bio-coal that is possible to mill and use in the present blast burners. Although waste wood is considered as a difficult, due to the high content of contaminants, which limits the alternative uses and, thus, makes it cost-effective in processes where it can be used. The process will be implemented at the ArcelorMittal site in Gent (Belgium), together with the sister project Steelanol, for microbiological fermentation of the carbon monoxide in blast furnace exhaust fumes to bioethanol. The combination of the two projects aims to convert waste wood to produce 80 million litres per year of bioethanol. This work is a first assessment of the Torero project concept. Process simulations are performed in Aspen Plus to evaluate the heat and mass balances of the integrated torrefaction process. The reaction mechanism of the torrefication process of the waste wood are based on small scale experiments and implemented into the reactor model. The ArcelorMittal plant in Ghent is used as a reference in the evaluation. The results of this investigation highlight performance, emissions and technical barriers including the effects of fuel properties and presence of trace species in the fuel.
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| 76. |
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| 77. |
- Nizzola, Giovanni, et al.
(författare)
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In-flame reduction of NOx in oxy-propane combustion at high inlet oxygen concentrations: the importance of soot-NOx interactions
- 2014
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Ingår i: Proceedings of the 38th International Technical Conference on Clean Coal & Fuel Systems, June 1-5 2014, Clearwater, Florida, USA..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Previous oxy-fuel combustion of propane performed at Chalmers University of Technology has shown possi-bilities for high NOx reduction during inlet oxygen concentrations above 35%. Such enhanced reduction has not been possible to acknowledge to only homogenous reburning effects. In this work it is investigated to what ex-tent this can be an effect of soot-NOx interactions. Soot formation has been studied by using an existing soot model. By comparing modeling results with recently published experimental data it is shown that the model is capable to predict soot formation during relevant conditions. In addition, a model for homogenous nitrogen chemistry has been used in the evaluation and sensitivity to key combustion parameters. The increased amount of soot found at high oxygen concentrations, together with higher reaction activity for gas phase species, known to be of importance for both NOx formation and soot production, support the theory that the high NOx reduction found at high oxygen concentration is a result of soot-NOx interactions.
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| 78. |
- Normann, Fredrik, 1982, et al.
(författare)
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Carbon Monoxide Formation in Oxy-Fuel Combustion
- 2013
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Ingår i: The Proceedings of the 38th International Technical Conference on Clean Coal & Fuel Systems, June 2-6 2013, Clearwater, Florida, USA.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Compared to air-fired flames, an increased in-flame CO concentration has been observed in oxy-fuel combustion. This work analyses the possible explanations for this increase in CO formation. A combustion model is used to investigate the impact of critical combustion parameters on the CO formation routes within a gaseous and lignite fired oxy-fuel flame. In gas-fired oxy-fuel flames the CO formation is promoted by a homogenous reaction between hydrogen radicals and CO2. However, in lignite-fired oxy-fuel combustion, the gaseous reaction route is of less importance to inflame CO formation. Instead CO2 gasification is the largest contributor to the increased CO formation compared to air firing. The substitution of CO2 with steam in the oxidizer during wet oxy-fuel combustion has moderate influence on the CO2 gasification whereas the homogenous CO formation is strongly reduced.
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| 79. |
- Normann, Fredrik, 1982, et al.
(författare)
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CO-COMBUSTION IN AN OXYFUEL POWER PLANT WITH SYNTHESIS GAS PRODUCTION
- 2007
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Ingår i: Proceedings of the 15th European Biomass Conference & Exhibition - From research to market Deployment, Berlin, Germany, 7-11 May 2007.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper investigates new possibilities and synergy effects for co-firing of biomass and coal in an energy system with carbon capture. A new way to make the oxyfuel process more effective through a sub stoichiometric combustion is enabled due to the co-combustion of biomass in the process, which keeps the process CO2 neutral. The sub stoichiometric combustion leads to a production of synthesis gas in the process, which is converted to DME in an integrated process. An available study on an oxyfuel power plant is combined with a process for DME production in a computer model to simulate the suggested process. The degree of sub stoichiometric combustion, or amount of synthesis gas produced, is optimized with respect to the overall efficiency. The maximal efficiency were found at a stoichiometric ratio of 0.6 were the efficiency for the electricity producing oxyfuel process is 0.35 and the efficiency for the DME process is 0.65. The results show how biomass can improve carbon capture processes and on a possibility for an expansion and an efficient use of biomass.
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| 80. |
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