| 1. |
- Broberg, Sarah, et al.
(författare)
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Biogas production supported by excess heat - A systems analysis within the food industry
- 2015
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Ingår i: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 91, s. 249-258
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper was to study the effects on greenhouse gases and economics when a change is made in the use of industrial organic waste from external production and use of biogas (A) to internal production and use (B). The two different system solutions are studied through a systems analysis based on an industrial case. The baseline system (A) and a modified system (B) were compared and analysed. Studies show that industrial processes considered as integrated systems, including the exchange of resources between industries, can result in competitive advantages. This study focuses on the integration of internally produced biogas from food industry waste produced by a food company and the use of excess heat. Two alternative scenarios were studied: (1) the use of available excess heat to heat the biogas digester and (2) the use of a part of the biogas produced to heat the biogas digester. This study showed that the system solution, whereby excess heat rather than biogas is used to heat the biogas digester, was both environmentally and economically advantageous. However, the valuation of biomass affects the magnitude of the emissions reduction. Implementing this synergistic concept will contribute to the reaching of European Union climate targets. (C) 2014 Elsevier Ltd. All rights reserved.
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| 2. |
- Broberg, Sarah
(författare)
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Energy efficiency through industrial excess heat recovery-policy impacts
- 2015
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Ingår i: Energy Efficiency. - : Springer Verlag (Germany). - 1570-646X .- 1570-6478. ; 8:1, s. 19-35
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Tidskriftsartikel (refereegranskat)abstract
- The EU target on energy efficiency implies a 20 % reduction in the use of primary energy by implementation of energy efficiency measures. Not all potential cost-effective measures for improved energy efficiency are implemented. This energy efficiency gap is explained by market barriers. Policy instruments can be used to overcome these barriers. The target could, for example, be obtained through industrial excess heat recovery; but there is a knowledge gap on factors affecting excess heat utilization. In this study, interviews were carried out with energy managers in order to study excess heat utilization from industrys perspective. The study seeks to present how excess heat recovery can be promoted or discouraged through policy instruments, and several factors are raised in the paper. The interviews revealed that excess heat recovery is generally referred to in terms of heat deliveries to the district heating network. One may need to look for innovative recovery solutions, and policies are needed to bring these solutions into action. Due to inefficient conversion for heat-driven electricity generation, a system favoring this implementation could favor an inefficient system. Beyond external instruments, internal goals, visions, and the importance of energy as a priority were shown to be important in the work with improved energy management.
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| 3. |
- Broberg Viklund, Sarah, et al.
(författare)
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Industrial excess heat use: Systems analysis and CO2 emissions reduction
- 2015
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 152, s. 189-197
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Tidskriftsartikel (refereegranskat)abstract
- The adopted energy efficiency directive stresses the use of excess heat as a way to reach the EU target of primary energy use. Use of industrial excess heat may result in decreased energy demand, CO2 emissions reduction, and economic gains. In this study, an energy systems analysis is performed with the aim of investigating how excess heat should be used, and the impact on CO2 emissions. The manner in which the heat is recovered will affect the system. The influence of excess heat recovery and the trade-off between heat recovery for heating or cooling applications and electricity production has been investigated using the energy systems modeling tool reMIND. The model has been optimized by minimizing the system cost. The results show that it is favorable to recover the available excess heat in all the investigated energy market scenarios, and that heat driven electricity production is not a part of the optimal solution. The trade-off between use of recovered excess heat in the heating or cooling system depends on the energy market prices and the type of heat production. The introduction of excess heat reduces the CO2 emissions in the system for all the studied energy market scenarios. (C) 2014 Elsevier Ltd. All rights reserved.
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| 4. |
- Broberg Viklund, Sarah, 1983-
(författare)
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System studies of the use of industrial excess heat
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Energy, materials, and by-products, can be exchanged between companies, having positive effects in the form of improved resource efficiency, environmental benefits, and economic gains. One such energy stream that can be exchanged is excess heat, that is, heat generated as a by-product during, for example, industrial production. Excess heat will continue to play an important role in efforts to reduce greenhouse gas (GHG) emissions and improve energy efficiency. Using excess heat is therefore currently emphasized in EU policy as a way to reach EU climate targets.This thesis examines the opportunities of manufacturing industries to use industrial excess heat, and how doing so can positively affect industry, society, and the climate. Since different parts of the energy system are entangled, there is an inherent complexity in studying these systems and introducing excess heat in one part of the energy system may influence other parts of the system. This analysis has accordingly been conducted by combining studies from various perspectives, by applying both quantitative and qualitative methods and covering a broad range of aspects, such as technical possibilities as well as climate, policy, economics, and resource aspects.The results identify several opportunities and benefits accruing from excess heat use. Although excess heat is currently partly used as a thermal resource in district heating in Sweden, this thesis demonstrates that significant untapped excess heat is still available. The mapping conducted in the appended studies identifies excess heat in different energy carriers, mainly low-temperature water. Analysis of excess heat use in different recovery options demonstrated greater output when using excess heat in district heating than electricity production. Optimizing the trade-offs in excess heat used in a district heating network, heat-driven cooling, and electricity production under different energy market conditions while minimizing the system cost, however, indicated that the attractiveness of excess heat in district heating depends on the type of heat production in the system. Viewing excess heat as a low-cost energy source also makes it economically interesting, and creates opportunities to invest in excess heat-recovery solutions. Excess heat is often viewed as CO2 neutral since unused excess heat may be regarded as wasted energy. The GHG mitigation potential of using excess heat, however, was found to be ambiguous. The appended studies demonstrate that using excess heat for electricity production or for applications that reduce the use of electricity reduces GHG emissions. The effects of using excess heat in district heating, on the other hand, depend on the energy market development, for example, the marginal electricity production and marginal use of biomass, and on the type of district heating system replaced. The interviews performed reveal that energy policy does influence excess heat use, being demonstrated both to promote and discourage excess heat use. Beyond national energy policies, internal goals and core values were identified as important for improved energy efficiency and increased excess heat use.
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| 5. |
- Ivner, Jenny, et al.
(författare)
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Effect of the use of industrial excess heat in district heating on greenhouse gas emissions: A systems perspective
- 2015
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Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 100, s. 81-87
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Tidskriftsartikel (refereegranskat)abstract
- European policy promotes increased use of excess heat as a means to increase the efficiency of resourceuse. By studying possible effects on greenhouse gases, this article aims to analyze and discuss systemaspects of the use of industrial excess heat in district heating. Effects on greenhouse gas emissions arestudied by applying different energy market conditions with different system boundaries in time andspace. First, life cycle assessment is used to assess the introduction of excess heat in district heating in acontemporary system with different geographical system boundaries. Thereafter, future energy marketscenarios for Europe are investigated to explore possible future outcomes. This study concludes that boththe heat production system and the energy market conditions affect the system emission effects of usingexcess heat in district heating. Industrial excess heat in district heating can be beneficial even if it leadsto reduced local electricity production when unused biomass can be used to replace fossil fuels. It isrecommended that a strengthened EU policy should encourage the use of biomass where it has the mostfavorable effects from a systems perspective to ensure emission reductions when industrial excess heatis used in district heating.
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