| 1. |
- Berntsson, Thore, 1947, et al.
(författare)
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Towards Sustainabel Oil Refinery - Pre-study for larger co-operation project
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this report, the Chalmers EnergiCentrum (CEC) presents the results of a pre-study commissioned by Preem relating to the effective production of future vehicle fuels.This pre-study was made up of three studies focusing on energy streamlining, the utilisation of waste heat and carbon-dioxide separation and biorefinement relating to the gasification and hydration of vegetable oils. One of the common starting points for these studies was the current situation at the Preem refineries in Göteborg and Lysekil from where the measurement data were obtained and analysed. The report summarises the knowledge situation based on current research in the individual technical fields. The results present some interesting future opportunities for developing the sustainable production of future vehicle fuels. The sections vary, as the areas that have been examined differ and the sections have been written by different people. The reports ends with some joint conclusions and a number of questions which could be included and answered in a more extensive future main study, as part of a developed research partnership between Preem and the Chalmers University of Technology. The preliminary results of this work were analysed with the client at workshops on 1 October and 29 November 2007. The report is written in English combined with an extensive summary in Swedish including a proposal on a future main study. The study was conducted by the Chalmers EnergiCentrum (CEC), in collaboration with a number of researchers in the CEC’s network. They included Thore Berntsson, Jessica Algehed, Erik Hektor and Lennart Persson Elmeroth, all from Heat and Power Technology, Börje Gevert, Chemical and Biological Engineering, Tobias Richards, Forest Products and Chemical Engineering, Filip Johnsson and Anders Lyngfelt, Energy Technology, and Per-Åke Franck and Anders Åsblad, CIT Industriell Energianalys AB. The client, Preem, was represented by Bengt Ahlén, Sören Eriksson, Johan Jervehed, Bertil Karlsson, Gunnar Olsson, Ulf Kuylenstierna, Stefan Nyström, Martin Sjöberg and Thomas Ögren. Tobias Richards was responsible for compiling the report and Bertil Pettersson was the project manager.
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| 2. |
- Andersson, Eva Ingeborg Elisabeth, 1956, et al.
(författare)
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Pinch analysis at Preem LYR
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This energy inventory and pinch analysis of the Preem, Lysekil refinery is a part of the Preem – Chalmers research cooperation and has been carried out by CIT Industriell Energi AB. The result in this report will be used as a basis for the research work at Chalmers.The aim with the project is to supply the researchers at Chalmers with energy data from the refinery in a form that is suitable for different types of pinch analysis. Furthermore, the aim is to make an analysis to establish the possible energy saving potentials in the refinery at various levels of process integration constraints.To be able to perform a pinch analysis, data for process streams has to be collected. This has been made using material received from Preem. Stream data has been extracted for all streams that have been identified on the process flow diagrams for all units of the refinery. Service areas and tank farm is not included.The stream data extraction is documented in a file. For each stream there is a calculation area with the information gathered to explain the choice of data used as stream data for the individual stream. Calculation of stream load is made by using known data of flow and physical data. If necessary data is not available from the screen dumps, data has been estimated. For the most important data, process engineers at Preem have been involved to give background information and assistance to find the best estimation possible.The refinery has a net heat demand of 409 MW (for the operation case studied) which is supplied by firing fuel gas. Steam is generated in the process by cooling process streams. One part of this steam (167 MW) is used in the process and the remainder(17 MW) is expanded in turbines and used for other purposes.The energy saving potential, i.e. the theoretical savings that are achievable depend on the constraints that are put on the heat exchanging between process streams in the refinery. Three levels have been analysed.A: There are no restrictions on the process streams that may be heat exchanged in the refinery. In this case the minimum heat demand is 199 MW giving a theoretical savings potential of 210 MW.B: All streams within each process unit can be exchanged with each other, but heat exchange between process units is not permitted. In this case the minimum heat demand of each process unit must be calculated. Some of the identified pinch violations are impossible to eliminate, due to process constraints, and the minimum heat demand is thus corrected to reflect this. The total savings potential, 140 MW, is calculated by adding the savings potential for the separate units. However only a part II of the steam generated above the pinch can be eliminated since it is used for heating purposes in other process units. Only the steam surplus can be considered a savings potential and the total potential is reduced to 117 MW.C: Heat exchange between process units is allowed for those streams which are heat exchanged with utility today (e.g., steam, air, cooling water). The heat exchange takes place with the aid of one or more utility system. However, it is not allowed to modify existing process to process heat exchangers to improve heat exchange between process units. The scope of the analysis is limited by only looking at the 5 largest process units. This group of units are using ~90 %, 363 MW, of the added external heat. If heat from the flue gases is recovered at a higher temperature it is possible to reduce the external heat demand with 26 MW to 337 MW.
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| 3. |
- Åsblad, Anders, 1956, et al.
(författare)
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Pinch analysis at Preem LYR II - Modifications
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This energy inventory and pinch analysis of the Preem, Lysekil refinery is a part of the Preem – Chalmers research cooperation and has been carried out by CIT Industriell Energi AB. This report is Part II of the report “Pinch analysis at Preem LYR”. The aim with the first part was to supply the researchers at Chalmers with energy data from the refinery in a form that is suitable for different types of pinch analysis. Furthermore, the aim was to make an analysis to establish the possible energy saving potentials in the refinery at various levels of process integration constraints.In this report, “Pinch analysis at Preem LYR, Part II”, we have applied pinch analysis methods such as the “Matrix Method” and “Advance Composite Curves” to find concrete improvements in the heat recovery network.The process units of the refinery have a net heat demand of 409 MW (for the operation case studied) which is supplied by firing fuel gas. Steam is generated in the process by cooling process streams. Most of the generated steam is used in the process units (167 MW) and the remainder (17 MW) is used for other purposes.The energy saving potential, that is the theoretical savings that are achievable, depends on the constraints put on the heat exchanging between process streams in the refinery. Three levels have been analysed:A: There are no restrictions on the process streams that may be heat exchanged in the refinery. In this case the minimum heat demand is 199 MW giving a theoretical savings potential of 210 MW.B: All streams within each process unit can be exchanged with each other, but direct heat exchange between process units is not permitted. In this case the minimum heat demand of each process unit must be calculated. The total savings potential, 146 MW, is calculated by adding the savings potential for the separate units.C: Heat exchange between process units is allowed for those streams which are heat exchanged with utility today (e.g., steam, air, cooling water). However, it is not allowed to modify existing process to process heat exchangers. The scope of the analysis is limited to only consider the 5 largest process units. This group of units are using ~90 %, 363 MW, of the added external heat. It is possible to reduce the external heat demand with 57 MW to 306 MW.In this report, part II, we give results of possible modifications identified in two process areas, ICR 810 and MHC 240. These areas were selected for further analysis due to their large energy savings potentials. Another area with high potential was CDU+VDU. However, improvements in this area were made during the 2013 turnaround.To reach the savings potential calculated in Part I, a Maximum Energy Recovery (MER)-network must be constructed. This will however involve a large number of new and modified heat exchangers. It is unlikely that a MER design would be economical in a retrofit situation. Therefore, the trade-off between capital costs and energy savings in a retrofit situation must be evaluated. However, this analysis is not yet done.The modifications suggested in this study include different levels of increased heat integration.
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| 4. |
- Algehed, Jessica, 1971, et al.
(författare)
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Opportunities for process integrated evaporation in kraft pulp mills
- 2000
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Ingår i: TAPPI Engineering Conference. ; , s. 841-849
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Konferensbidrag (refereegranskat)abstract
- This paper discusses how medium high temperature excess heat made available through process integration can be used for evaporation of black liquor and different types of wastewater. The amount of medium high temperature excess heat varies considerably in different mills, and apart from a reference mill two other mills are simulated-one that uses a new dryer combined with non-conventional evaporation design and one minimum effluent pulp mill. Several new evaporation plant designs are technically and economically analyzed. The total number of evaporators, amount and temperature of black liquor and wastewater to be evaporated, as well as temperature and amount of excess heat available are varied. The economic value of the total energy savings due to the new evaporation design is shown, and the investment opportunity to make different amounts of excess heat available is stated. This work shows that the total live steam demand for today's and future kraft pulp mills can be reduced by at least 20% with a non-conventional evaporation design. The results also show that there is a relatively large investment opportunity to make excess heat available for evaporation.
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| 5. |
- Axelsson, Helén, 1971, et al.
(författare)
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A New Methodology for Greenhouse Gas Reduction in Industry through Improved Heat Exchanging and/or Integration of Combined Heat and Power
- 1999
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Ingår i: Applied Thermal Engineering. ; 19/1999, Issue 7, s. 707-731
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a method that identi®es economically optimal combinations of enhanced heat recovery, integration of combined heat and power (CHP), and fuel switching, in an existing industrial energy system at various emission levels. Novel types of composite curves based on pinch technology, representing the existing temperature levels for supplying heat and the possible ones that may be attained after retro®tting, are used as tools for estimating the opportunities for CHP and the trade-off between improved heat exchangin
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| 6. |
- Axelsson, Helén, 1971, et al.
(författare)
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Potential for Greenhouse Gas Reduction in Industry through Increased Heat Recovery and/or Integration of Combined Heat and Power
- 2003
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Ingår i: Applied Thermal Engineering. - 1404-7098. ; 23:1, s. 65-87
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Tidskriftsartikel (refereegranskat)abstract
- The potential for greenhouse gas (GHG) reduction in industry through process integration measures depends to a great extent on prevailing technical and economic conditions. A step-wise methodology developed at the author's department based on pinch technology was used to analyse how various parameters influence the cost-optimal configuration for the plant's energy system, and the opportunities for costeffective GHG emissions reduction compared to this solution. The potential for reduction of GHG emissions from a given plant depends primarily on the design of the industrial process and its energy system (internal factors) and on the electricity-to-fuel price ratio and the specific GHG emissions from the national power generation system (external factors).
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| 7. |
- Berntsson, Thore, 1947, et al.
(författare)
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Vad är ett bioraffinaderi?
- 2014
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Ingår i: Perspektiv på förädling av bioråvara 2014. - 9789198097450 ; , s. 8-9
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Berntsson, Thore, 1947, et al.
(författare)
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What is a biorefinery?
- 2012
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Ingår i: Systems Perspectives on Biorefineries 2012. - 9789198030013 ; , s. 16-25
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The term “biorefinery” appeared in the 1990’s in response to a least four industry trends. First, there was an increased awareness in industry of the need to use biomass resources in a more rational way both economically and environmentally. The environmental issue was both policy and consumer driven. Second, therewas a growing interest in upgrading more low-quality lignocellulosic biomass to valuable products. Third, there was an increased attention to the production of starch for energy applications. Finally, there was a perceived need to develop more high-value products and diversify the product mix in order to meet global competi- tion and, in some cases, utilise an excess of biomass (especially in the pulp and paper industry).In a biorefinery, biomass is upgraded to one or more valuable products such as transport fuels, materials, chemicals, electricity and, as byproduct, heat. In principle all types of biomass can be used, e.g. wood, straw, starch, sugars, waste and algae. But there is more to it than that. The aim of this chapter is to explain in some more detail what a biorefinery is or could be.There have been many attempts to determine what should be meant by a “biorefinery” and in the next section we provide some of the definitions and additional meaning that has been attached to the concept. To give a more in-depth understanding of what a biorefinery might be, the following sections describe process technologies that are often considered as key constituent parts of biorefineries and some opportunities for integration in existing processing industry that also can be viewed as biorefining.
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| 9. |
- Fornell, Rickard, 1976, et al.
(författare)
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Process integration study of a kraft pulp mill converted to an ethanol production plant - part B: Techno-economic analysis
- 2012
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Ingår i: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311. ; 42, s. 179-190
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Tidskriftsartikel (refereegranskat)abstract
- In a previous study by the authors, energy efficiency measures in a conceptual kraft pulp mill converted to a lignocellulosic ethanol plant were investigated. The results suggested a number of different process designs which would give a substantial improvement in steam economy in the ethanol plant, compared to the original design. In the present study the different process designs are evaluated from an economic point-of-view, in order to determine if energy efficiency measures and increasing by-product sales decrease the production cost of ethanol from this specific process, or if the increased costs related to the implementation of these measures overshadow the benefits from increased by-product sales. The different energy efficiency measures are compared with less capital demanding alternatives (i.e. including low or no energy efficiency improvements) in order to assess the economic benefits of different strategies when converting a !craft pulp mill to ethanol production. The study indicates the economic importance of considering energy efficiency measures when repurposing a kraft pulp mill to an ethanol plant. It is also shown that, within the context of this study, a larger investment in measures will give better economic results than less capital demanding alternatives (with less improvement in energy efficiency). From an economic and energy efficiency viewpoint many of the suggested process designs will give approximately similar results, therefore the process design should be made based on other criteria (e.g. low complexity, low maintenance).
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| 10. |
- Fornell, Rickard, 1976, et al.
(författare)
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Techno-economic analysis of a kraft pulp-mill-based biorefinery producing both ethanol and dimethyl ether
- 2013
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 50:1, s. 83-92
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Tidskriftsartikel (refereegranskat)abstract
- A conceptual biorefinery, based on repurposing a kraft pulp mill, has been studied. In the process an alkaline pre-treatment unit separates the incoming wood raw-material to a cellulose-rich pulp and a residue liquor containing dissolved lignin. The pulp is sent to an ethanol line, while the liquor is gasified and refined to dimethyl ether. The concept has been designed and assessed from an energy and economic point-of-view. The results of the study indicate that the process can be self-sufficient in terms of hot utility (fresh steam) demand. There will be a deficit of electricity, however. The economic assessment shows that the process can be feasible, but that the economic outcome is highly dependent on the development of biofuel prices, and if the investment in this type of biorefinery is seen as a high risk investment or not. It is also shown that CO2 capture and storage can be interesting in this type of biorefinery due to the low cost of capturing CO2 in the process.
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