| 1. |
- Karlsson, Magnus, et al.
(författare)
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Regional energy system optimization - Potential for a regional heat market
- 2009
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 86:4, s. 441-451
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Tidskriftsartikel (refereegranskat)abstract
- Energy supply companies and industrial plants are likely to face new situations due to, for example, the introduction of new energy legislation, increased fuel prices and increased environmental awareness. These new prerequisites provide companies with new challenges but also new possibilities from which to benefit. Increased energy efficiency within companies and increased cooperation between different operators are two alternatives to meet the new conditions. A region characterized by a high density of energy-intensive processes is used in this study to find the economic potential of connecting three industrial plants and four energy companies, within three local district heating systems, to a regional heat market, in which different operators provide heat to a joint district heating grid. Also, different investment alternatives are studied. The results show that the economical potential for a heat market amounts to between 5 and 26 million EUR/year with payback times ranging from two to eleven years. However, the investment costs and the net benefit for the total system need to be allotted to the different operators, as they benefit economically to different extents from the introduction of a heat market. It is also shown that the emissions of CO2 from the joint system would decrease compared to separate operation of the systems. However, the valuation of CO2 emissions from electricity production is important as the difference of emitted CO2 between the accounting methods exceeds 650 kton/year for some scenarios.
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| 2. |
- Klugman, Sofia, et al.
(författare)
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A Scandinavian chemical wood-pulp mill : Part 1. Energy audit aiming at efficiency measures
- 2007
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 84:3, s. 326-339
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Tidskriftsartikel (refereegranskat)abstract
- A Swedish wood-pulp mill is surveyed in terms of energy supply and use in order to determine the energy-saving potential. Conservation measures are of increasing interest to Swedish industry, as energy prices have continued to rise in recent years. The electricity price particularly increased after the deregulation of the Scandinavian electricity market in 1996. The deregulation expanded to all of the EU in July 2004, which may increase the Swedish electricity price further until it reaches the generally higher European price level. Furthermore, oil prices have increased and the emissions trading scheme for CO2 adds to the incentive to reduce oil consumption. The energy system at the surveyed pulp mill is described in terms of electricity and process heat production and use. The total energy-saving potential is estimated and some saving points are identified. The heat that today is wasted at the mill has been surveyed in order to find potential for heat integration or heat export. The result shows that the mill probably could become self-sufficient in electricity. Particularly important in that endeavor is updating old pumps.
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| 3. |
- Klugman, Sofia, et al.
(författare)
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A Scandinavian chemical wood-pulp mill : Part 2. International and model mills comparison
- 2007
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 84:3, s. 340-350
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Tidskriftsartikel (refereegranskat)abstract
- The energy use at a Swedish chemical wood-pulp mill is compared internationally and for two model mills that aim to use the most efficient available technology. The international comparison is performed between Canadian and Scandinavian pulp-mills on a general level, and on a closer level among eleven Swedish and Finnish non-integrated sulfate pulp-mills, the type of mill considered in the case study. The two model mills that are used for comparison are one Swedish and one Canadian. The Scandinavian pulp-mills are somewhat more energy efficient than the Canadian mills. Still, the variation in energy use is remarkably large among the Scandinavian mills, which indicates that the energy-saving potential is great. If all Swedish freestanding sulfate pulp-mills became as energy efficient as the most efficient Scandinavian mill, electricity savings corresponding to nearly 1% of the national electricity use would be obtained. In the model mills comparison it was found that large amounts of heat could be saved, particularly in the evaporation plant.
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| 4. |
- Klugman, Sofia, et al.
(författare)
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A Swedish integrated pulp and paper mill - Energy optimisation and local heat cooperation
- 2009
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Ingår i: Energy Policy. - : Elsevier BV. - 0301-4215 .- 1873-6777. ; 37:7, s. 2514-2524
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Tidskriftsartikel (refereegranskat)abstract
- Heat cooperation between industries and district heating companies is often economically and environmentally beneficial. In this paper, energy cooperation between an integrated Swedish pulp and paper mill and two nearby energy companies was analysed through economic optimisations. The synergies of cooperation were evaluated through optimisations with different system perspectives. Three changes of the energy system and combinations of them were analysed. The changes were process integration, extending biofuel boiler and turbine capacity and connection to a local heat market. The results show that the single most promising system change is extending biofuel and turbine capacity. Process integration within the pulp and paper mill would take place through installing evaporation units that yield less excess heat but must in this particular case be combined with extended biofuel combustion capacity in order to be beneficial. Connecting to the local heat market would be beneficial for the pulp and paper mill, while the studied energy company needs to extend its biofuel capacity in order to benefit from the local heat market. Furthermore, the potential of reducing CO2 emissions through the energy cooperation is shown to be extensive; particularly if biofuel and turbine capacity is increased.
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| 5. |
- Klugman, Sofia, et al.
(författare)
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An integrated chemical pulp and paper mill : energy audit and perspectives on regional cooperation
- 2006
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Ingår i: ECOS 2006. - 9608758416 ; , s. 637-644
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Konferensbidrag (populärvet., debatt m.m.)abstract
- As a case study, an energy audit was performed at an integrated pulp and paper mill. A top-down approach was applied to identify and categorize the use of electricity, steam and hot water and the results of the audit are presented in this paper. Also, the connections and cooperation with both the nearby district heating system and a local steam deliverer, partly owned by the mill, are described. Potential ways to save energy are pointed out and changes in the cooperation are discussed. Moreover, a discussion of how the system can benefit from the taxation structure is presented, as the design of the studied system, in combination with the introduction of tradable green certificates, creates possibilities to exploit such benefits. As a result from this design it is shown that the introduction of these certificates promotes the use of oil to produce electricity.
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| 6. |
- Klugman, Sofia, 1975-
(författare)
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Energy systems analysis of Swedish pulp and paper industries from a regional cooperation perspective : Case study modeling and optimization
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The industrial sector uses about one third of the energy end-use in the world. Since energy use in many cases highly affects both the local and global environment negatively, it is of common interest to increase energy efficiency within industries. Furthermore, seen from the industrial perspective, it is also important to reduce dependency on energy resources with unstable prices in order to obtain economic predictability.In this thesis, the energy-saving potential within the chemical pulp and paper sector is analyzed. One market pulp mill and one integrated pulp and paper mill were studied as cases. Energy system changes at the mills were analyzed through cost minimization. The thesis focuses on principal energy issues such as finding the most promising alternatives for use of industrial excess heat, possible investments in electricity generation and choice of fuel. In order to find synergies, the same system was optimized first from the perspective of different operators respectively, and then from a joint regional perspective. Also, the prerequisites for a regional heat market in the region were analyzed.This thesis reveals that the use of excess heat from pulp and paper mills for district heating does not generally conflict with process integration measures. This is partly because of the great availability of industrial excess heat and partly because the different purposes require different temperatures and thereby do not compete. Rather, the results show that they strengthen each other since steam and hot water of higher temperatures are made available for district heating when hot water of lower temperature is used for process integration. However, there are cases when the conditions are complicated by preexisting technical solutions within a system. In these cases, a combination of measures could be necessary.Furthermore, it is concluded that energy cooperation in terms of a heat market between municipalities and industries in the studied region gives opportunity for positive synergies. Switching from expensive fuels such as oil to less expensive biofuel in the region proved to be particularly beneficial. Expanding the capacity for combined heat and power generation is also beneficial for the region as well as increased use of industrial excess heat for district heating. The most financially beneficial scenarios also have the greatest potential for CO2 emission reduction; the emissions would be reduced by about 700 thousand tonnes CO2/year for the region in those scenarios.
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| 7. |
- Klugman, Sofia, et al.
(författare)
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Modeling an industrial energy system : Perspectives on regional heat cooperation
- 2008
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Ingår i: International Journal of Energy Research. - Chichester, West Sussex, United Kingdom : John Wiley & Sons. - 0363-907X .- 1099-114X. ; 32:9, s. 793-807
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Tidskriftsartikel (refereegranskat)abstract
- Through energy efficiency measures, it is possible to reduce heat surplus in the pulp and paper industry. Yet pulp and paper mills situated in countries with a heat demand for residential and commercial buildings for the major part of the year are potential heat suppliers. However, striving to utilize the heat within the mills for efficient energy use could conflict with the delivery of excess heat to a district heating system. As part of a project to optimize a regional energy system, a sulfate pulp mill situated in central Sweden is analyzed, focusing on providing heat and electricity to the mill and its surrounding energy systems. An energy system optimization method based on mixed integer linear programming is used for studying energy system measures on an aggregated level. An extended system, where the mill is integrated in a regional heat market (HM), is evaluated in parallel with the present system. The use of either hot sewage or a heat pump for heat deliveries is analyzed along with process integration measures. The benefits of adding a condensing unit to the back-pressure steam turbine are also investigated. The results show that the use of hot sewage or a heat pump for heat deliveries is beneficial only in combination with extended heat deliveries to an HM. Process integration measures are beneficial and even increase the benefit of selling more heat for district heating. Adding a condensing turbine unit is most beneficial in combination with extended heat deliveries and process integration.
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