| 1. |
- Andersson, Eva Ingeborg Elisabeth, 1956, et al.
(författare)
-
Pinch analysis at Preem LYR
- 2013
-
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.
|
|
| 2. |
- Åsblad, Anders, 1956, et al.
(författare)
-
Pinch analysis at Preem LYR II - Modifications
- 2014
-
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.
|
|
| 3. |
- Andersson, Eva Ingeborg Elisabeth, 1956, et al.
(författare)
-
TSA II Stenungsund - Investigation of opportunities for implementation of proposed energy efficiency measures
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A Total Site Analysis (TSA) study of the chemical cluster in Stenungsund was conducted during 2010. This previous study is hereafter referred to as the TSA I study. The study was conducted by CIT Industriell Energi and the Division of Heat and Power Technology at Chalmers together with the participating cluster companies (AGA Gas AB, Akzo Nobel Sverige AB, Borealis AB, INEOS Sverige AB and Perstorp Oxo AB).In the TSA I study, measures to increase energy efficiency by increased energy collaboration (i.e. increased heat exchange between the cluster plants) were identified. The measures were classified according to ease of implementation based on consultation with plant staff. In this report, conducted within the framework of the second stage of the TSA research project (hereafter referred to as the TSA II project) practical issues associated with implementation of the identified measures are investigated. The investigation is limited to category A measures, considered by plant staff to be relatively easy to implement from a technical perspective. A conceptual design of a possible hot water system for exchanging heat between the different sites is presented. Since the steam systems of the different plants are at present only partly connected, or not at all, the overall reduction in steam use that would results from introduction of a hot water system would lead to steam surplus at certain sites. Therefore introducing a hot water system is only beneficial if new steam lines are also implemented so that it becomes possible to exchange steam between the individual plant sites. The exchange of steam is only possible if steam demand and steam excess are at the same pressure level. To avoid excess steam at low pressure level, demand of low pressure steam must increase. In order to increase the possibility to use more low pressure steam, the opportunities to decrease utility steam pressure in individual process heaters are analyzed. The implementation of energy efficiency measures in the refrigeration systems is also investigated. In practice this can be achieved by changing steam as heating utility to a fluid that can operate below ambient. In addition to the steam saving, the heat transfer fluid can transport energy from the current cooling systems and decrease the amount of compressor work required to operate the existing refrigeration system units.In order to achieve a reduction of purchased fuel for firing in boilers it is necessary to implement both a common site-wide circulating hot water system and a reduction of utility steam pressure used in several process heaters .The results show that if all measures that are considered by plant energy engineers to be feasible by moderate changes are carried out as suggested, fuel usage in boilers could be reduced by 89 MW (corresponding to 200 MSEK/year if fuel gas is valued at 270 SEK/MWh and year-round operation is assumed).A rough estimate of the total investment costs for the implementation of category A measures is 660 MSEK.
|
|
| 4. |
- Hackl, Roman, 1981, et al.
(författare)
-
Targeting for Energy Efficiency and Improved Energy Collaboration Between Different Companies Using Total Site Analysis (TSA)
- 2010
-
Ingår i: Chemical Engineering Transactions. - 2283-9216. ; 21, s. 301-306
-
Konferensbidrag (refereegranskat)abstract
- Rising fuel prices, the threat of global warming and the start of the 2nd period of the EU Emission Trading System make efficient use of energy more and more important. Industrial clusters have the potential to significantly increase energy efficiency by energy collaboration. In this paper Sweden’s largest chemical cluster is analysed using the Total Site Analysis (TSA) method. The cluster consists of 5 chemical companies producing a variety of products. The overall heating and cooling demands of the site are around 442 MW and 953 MW, respectively. 122 MW of heat is produced from internally generated and purchased fuels and delivered to the processes.TSA is used to stepwise design a site-wide utility system which improves energy efficiency. It is shown that utility savings of up to 122 MW can be achieved, plus a steam excess of 7 MW. The proposed retrofitted utility system involves the introduction of a site-wide hot water circuit, increased recovery of low pressure steam and changes in steam levels in several heat exchangers. Qualitative evaluation of the suggested measures shows that 60 MW of the savings potential can be expected to be achieved with moderate changes to the process utility system.
|
|
| 5. |
- Hackl, Roman, 1981, et al.
(författare)
-
Targeting for energy efficiency and improved energy collaboration between different companies using total site analysis (TSA)
- 2010
-
Ingår i: 19th International Congress of Chemical and Process Engineering, CHISA 2010 and 7th European Congress of Chemical Engineering, ECCE-7; Prague; Czech Republic; 28 August 2010 through 1 September 2010.
-
Konferensbidrag (refereegranskat)abstract
- A chemical cluster located in Stenungsund on the West Coast of Sweden is analyzed to determine the total site level energy efficiency opportunities using the Total Site Analysis (TSA) method. The cluster consists of 5 chemical companies, i.e., AGA Gas AB producing industrial gases, Akzo Nobel Sverige AB producing amines and surfactants, Borealis AB producing ethylene, and PE, INEOS Sverige AB producing PVC and Perstorp Oxo AB producing speciality chemicals. The heart of the cluster is a steam cracker plant run by Borealis, which delivers partly feedstock and fuel to the other plants. The overall heating and cooling demands of the site are ∼ 442 and 953 Mw, respectively. TSA is used to stepwise design a site-wide utility system which improves energy efficiency. Utility savings of ≤ 122 Mw can be achieved, plus a steam excess of 7 Mw. Qualitative evaluation of the suggested measures shows that 60 Mw of the savings potential can be expected to be achieved with moderate changes to the process utility system. This is an abstract of a paper presented at the 19th International Congress of Chemical and Process Engineering and 7th European Congress of Chemical Engineering (Prague, Czech Republic 8/28/2010-9/1/2010).
|
|
| 6. |
- Hackl, Roman, 1981, et al.
(författare)
-
Targeting for energy efficiency and improved energy collaboration between different companies using total site analysis (TSA)
- 2011
-
Ingår i: Energy. - : Elsevier BV. - 0360-5442. ; 36:8, s. 4609-4615
-
Tidskriftsartikel (refereegranskat)abstract
- Rising fuel prices, increasing costs associated with emissions of green house gases and the threat of global warming make efficient use of energy more and more important. Industrial clusters have the potential to significantly increase energy efficiency by energy collaboration. In this paper Sweden’s largest chemical cluster is analysed using the total site analysis (TSA) method. TSA delivers targets for the amount of utility consumed and generated through excess energy recovery by the different processes. The method enables investigation of opportunities to deliver waste heat from one process to another using a common utility system.The cluster consists of 5 chemical companies producing a variety of products, including polyethylene (PE), polyvinyl chloride (PVC), amines, ethylene, oxygen/nitrogen and plasticisers. The companies already work together by exchanging material streams. In this study the potential for energy collaboration is analysed in order to reach an industrial symbiosis. The overall heating and cooling demands of the site are around 442 MW and 953 MW, respectively. 122 MW of heat is produced in boilers and delivered to the processes.TSA is used to stepwise design a site-wide utility system which improves energy efficiency. It is shown that heat recovery in the cluster can be increased by 129 MW, i.e. the current utility demand could be completely eliminated and further 7 MW excess steam can be made available. The proposed retrofitted utility system involves the introduction of a site-wide hot water circuit, increased recovery of low pressure steam and shifting of heating steam pressure to lower levels in a number heat exchangers when possible. Qualitative evaluation of the suggested measures shows that 60 MW of the savings potential could to be achieved with moderate changes to the process utility system corresponding to 50% of the heat produced from purchased fuel in the boilers of the cluster.Further analysis showed that after implementation of the suggested energy efficiency measures there is still a large excess of heat at temperatures of up to 137 °C.
|
|
| 7. |
- Hackl, Roman, 1981, et al.
(författare)
-
Total Site Analysis (TSA) Stenungsund
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This project was carried out in cooperation between the Division of Heat and Power Technology at Chalmers University of Technology, CIT Industriell Energianalys AB, AGA Gas AB, Akzo Nobel Sverige AB, Borealis AB, INEOS Sverige AB and Perstorp Oxo AB.A Total Site Analysis (TSA) was performed in this study which can be used as a basis for future implementations of energy system integration at the chemical cluster in Stenungsund.At first stream data (Tstart, Ttarget, Q) and data on overall utility consumption of all the processes in the cluster was collected. The analysis is based on data collected on process streams heated or cooled with utility exceeding a heat load of 300 kW. Additionally steam from by-product incineration which cannot be utilised in another way is considered as process heat. With this data the current energy system was analysed by determining steam excess and deficit at each steam level and company. After that, the data was represented in curves, the so called total site profiles (TSP) and the total site composite curves (TSC). The curves were used to determine the site pinch (the limiting factor for further integration) and to identify measures to increase heat recovery. The measures found by TSA were assessed qualitatively with respect to feasibility to determine the most attractive measures. Finally the site wide potential for cogeneration and measures for reduction of external cooling demand below ambient temperature was analysed.Main findings are presented in the following:From the stream data collected is can be seen that the total demand of hot and cold utility of the cluster is 442 MW and 953 MW respectively.By-products, which have to be incinerated on-site provide 40 MW of steam. To cover the external heat demand additional 122 MW of heat is supplied by steam/hot oil from boilers or directly by flue gas from added fuels purchased or available on site. The TSP and TSC curves show a site pinch at the 2 bar(g) steam system (132 °C). The site pinch limits the potential for heat integration. To increase energy savings by heat integration it is necessary to change the position of the site pinch. It was shown that theoretically by introducing a site-wide hot water circuit, increased recovery of 2 bar(g) steam and adjustment steam levels in several heat exchangers the pinch point can be moved so that hot utility savings of 122 MW plus excess of 7 MW steam at 85 bar(g) can be realised.Only introducing a hot water circuit can save 51 MW of steam from added fuels, which corresponds to estimated savings of 122 MSEK/year. It is possible to replace more steam by hot water, but the demand for 2 bar(g) steam is limited. Therefore a demand for low pressure steam must be created by adjusting steam levels in order to utilise more waste heat in a hot water circuit. The present delivery of heat to the district heating system is not affected by a site wide hot water circuit.There is potential for increased recovery of 33 MW of 2 bar(g) steam from process heat. This would replace the production of the same amount of steam in the boilers, worth 79 MSEK/year.A qualitative assessment on the implementation of a hot water circuit shows estimated steam savings of 55.2 MW (132 MSEK/year) with moderate changes (83.5 MW including more complex changes, 200 MSEK/year). Technically the introduction of a hot water circuit includes hot water pipes between several plants, as most of the consumers of heat are situated at the cracker site and at Perstorp but the sources are spread out across the cluster. Also piping is necessary to transfer the 2 bar(g) steam replaced by hot water to other plants with steam deficit.The practical potential for increased 2 bar(g) steam recovery is estimated to 4.2 MW (10 MSEK/year) with moderate changes and 26.6 MW including more complex changes (64 MSEK/year). Increased 2 bar(g) recovery implies the construction of steam pipes from Borealis to Perstorp and INEOS, as most of the potential steam sources are located at Borealis but Perstorp and INEOS have a demand for 2 bar(g) steam The theoretical cogeneration potential in the cluster is 19 MWel in addition to the 10 MWel generated today (additional revenue is 40 MSEK/year) assuming that steam demand at all pressure levels remains the same but the steam systems are connected with each other. A practical option to increase cogeneration with the existing equipment is to supply steam below 8.8 bar(g) produced at Borealis to INEOS, Akzo and Perstorp. This would result in additional 8.6 MWel by cogeneration in Borealis turbo-alternator (estimated revenue: 18 MSEK/year).Some process streams below ambient temperature are heated with steam. It has been shown that 6.5 MW steam is used for heating stream well below ambient temperature. This steam can be saved and the cooling energy can be recovered. This decreases the energy usage in the cooling system and also saves heating steam. Savings up to 48 MSEK/year were estimated.It has been shown that by site wide collaboration it is possible to increase heat recovery, cogeneration and utilisation of waste heat. The results from this study are the bases to identify concrete projects which contribute to cost and CO2 emissions savings. The study also shows the advantages of TSA in order to find solutions for process integration by the utility system on a site wide level.
|
|
| 8. |
- Holmgren, Kristina, 1977, et al.
(författare)
-
Evaluating the greenhouse gas impact from biomass gasification systems in industrial clusters – methodology and examples
- 2011
-
Ingår i: Proceedings of World Renewable Energy Congress. - : Linköping University Electronic Press. - 1650-3686. - 9789173930703 ; 12:057, s. 3098-3105
-
Konferensbidrag (refereegranskat)abstract
- Biomass gasification is identified as one of the key technologies for producing biofuels for the transport sector and can also produce many other types of products. Biomass gasification systems are large-scale industrial systems and it is important to evaluate such systems from economic, environmental and synergetic perspectives before implementation. The objective of this study is to define a methodology for evaluating the greenhouse gas (GHG) impact of different biomass gasification systems and to exemplify the methodology. The ultimate purpose of the methodology is to evaluate the GHG performance of different biomass gasification systems integrated in industrial clusters. A life cycle perspective is applied.Most biomass gasification systems are multiproduct systems, simultaneously producing biofuels, heat at different temperatures and pressures and electricity. The value, in economic terms and in terms of GHG emissions, is well defined for some products (e.g. biofuels), whereas for other products (such as heat and electricity) it is more uncertain and in some cases dependent on time and location.
|
|
| 9. |
- Holmgren, Kristina, 1977, et al.
(författare)
-
Gasification-based methanol production from biomass in industrial clusters: Characterisation of energy balances and greenhouse gas emissions
- 2014
-
Ingår i: Energy. - : Elsevier BV. - 0360-5442. ; 69, s. 622-637
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluates the potential for reducing life cycle greenhouse gas (GHG) emissions of biomass gasification-based methanol production systems based on energy balances. Configurations which are process integrated with a chemical cluster have been compared to stand-alone units, i.e. units with no connection to any other industry but with the possibility to district heating connection. Two different uses of methanol are considered: the use as a vehicle fuel and the use for production of olefins via the methanol-to-olefins process. An added value of the integration can be the availability of excess hydrogen. For the studied case, the methanol production could be increased by 10% by using excess hydrogen from the cluster. The results show that the integrated systems have greater potential to reduce GHG emissions than the stand-alone systems. The sensitivity analysis demonstrated that the references for electricity production and district heating production technology have important impacts on the outcomes. Using excess heat for district heating was found to have positive or negative impacts on GHG emissions depending on what heat production technologies it replaces. The investigated olefins production systems resulted in GHG emissions reductions that were similar in magnitude to those of the investigated biofuel production systems.
|
|
| 10. |
- Holmgren, Kristina, 1977, et al.
(författare)
-
System aspects of biomass gasification with methanol synthesis - Process concepts and energy analysis
- 2012
-
Ingår i: Energy. - : Elsevier BV. - 0360-5442. ; 45:1, s. 817-828
-
Tidskriftsartikel (refereegranskat)abstract
- A systematic analysis of interrelations between different process steps in the biomass gasification and methanol synthesis chain was made. The energy performance of the system is assessed by reviewing previous studies and analysing a case study. Implications of technology choices and process integration opportunities are in focus.The case study analyses the impact on the energy balance of process-integrated drying compared to import of dried biomass, effects on electricity production due to heat pump integration or district heating (DH) delivery, effect on methanol yield of hydrogen addition and the impacts of adding an methanol-to-olefins (MTO) process.The biomass drying has significant impact on the overall energy balance, the cooling demand increases by 60% for the case study installation when process-integrated drying is not applied for drying the biomass. There is a trade-off between methanol yield, electricity and DH production potential of the system. Heat pumping can increase the electricity yield of the system. Hydrogen addition replacing the water gas shift can increase the methanol yield, in our case study by ∼35%, but in a stand-alone case the electricity demand makes such a system unrealistic. Adding an MTO unit to the system has limited impact on the energy balance.
|
|
