| 1. |
- Ahlgren, Erik, 1962, et al.
(author)
-
Produktionsrelaterade systemstudier
- 2006
-
Reports (other academic/artistic)abstract
- I denna rapport, Produktionsrelaterade systemstudier – flexibla el- och värmesystem, har kortfattat ett antal områden som kan tänkas få betydelse för utvecklingen av de svenska el- och värmeförsörjningssystemen analyserats. Målet har varit att ge en bakgrundsbeskrivning av ett antal tekniska och teknisk-ekonomiska områden som kommer att påverkas av och/eller påverka framtida el- och värmeförsörjning. Författarna har utgått från de övergripande frågorna, såsom försörjningstrygghet i en avreglerad marknad och energisektorns miljöpåverkan speciellt med avseende på klimatpåverkan. Systemgränsen runt el- och värmesektorn har avsiktligt dragits mycket brett så att också bebyggelse- och industrisektorerna är inkluderade, eftersom dessa är de klart dominerande sektorerna både med avseende på elanvändning och med total energianvändning. Avsikten med detta har varit att peka på den stora betydelse som ändrade energiefterfrågemönster inom bebyggelsesektorn och än annan syn på industrisektorn, inte bara som energianvändare utan också delvis som energileverantör, kan få för det framtida el- och värmeförsörjningssystemet. Studien behandlar produktionsrelaterade elsystemfrågor, men med ett perspektiv av interaktion mellan tillgång och efterfrågan. Ett stort antal tillförseltekniker och –system har kort berörts. Vissa av dessa dominerar systemet idag, andra kan tänkas få en inte oväsentlig betydelse i framtida system. Genomgående trycks på behovet av en integrerad analys där hänsyn tas till samspel mellan tillförsel och användning, mellan teknik och ekonomi, mellan kort och lång sikt, mellan el och värme och även transporter, för att uppnå en högre verkningsgrad och därmed minskad miljöbelastning. Verkningsgraden har betraktats utgående från ett systemperspektiv snarare än från ett anläggnings-perspektiv. Slutsatsen av analysen är att det fortfarande finns ett antal markanta kunskapsluckor, och att dessa framför allt finns på systemnivå i samspelet, eller det möjliga samspelet, mellan ovan nämnda områden; tillförsel och användning; el, värme och transporter; samt betydelsen för försörjningssystemet av förväntade ändringar med tiden av såväl el- och värmeefterfrågan, som av tillgängliga tekniska lösningar.
|
|
| 2. |
- Albert, Ludvig, et al.
(author)
-
Icke-azeotropa blandningar i värmepumpar - Förstudie för fullskaleprojekt
- 1990
-
Reports (other academic/artistic)abstract
- In cooperation between STAL Refrigeration AB and the Department of Heat and Power Technology, Chalmers University of Technology, an experimental heat pump with a nonazeotropic mixture as working fluid is being prepared. This will be the first full scale plant in Sweden.This report contains the results from a pre-study to thefull scale project. The influence of a non-azeotropic mixture, as compared with a pure fluid on the design of the components in the heat pump, has been analyzed. This study has partly been done with a previously developed computer program, which has been improved. Some supplementary routines have been added to it, and the specific design of the prepared experimental planthas been inserted.The experimental heat pump which is to be used, has a countercurrent evaporator and a crosscurrent condenser. Since the best design for a non-azeotropic mixture is countercurrent, heat exchanger calculations have been done for this type of condenser. Comparisons indicate that a shell and tube heat exchanger with the non-azeotropic mixture on the shell side is highly interesting to investigate practically. The study of the internal heat exchanger shows that the dependence of COP on the degree of superheat before the compressor is slightly larger for a non-azeotropic mixture than for a pure fluid.During this project and also afterwards a dynamic debate onthe environmental effect of "CFCs" has been going on. Theuse of the mixture HCFC22/CFCl14, suggested in this report,will be forbidden in the future. However, it is stillinteresting to study it, since there are more and betterthermodynamic and physical data available for this mixturethan for other non-azeotropic mixtures. The experience andknowledge acquired in this project are possible to apply onother mixtures. Accurate calculations can be done for thesewhen more reliable data are available.
|
|
| 3. |
- Albert, Ludvig, et al.
(author)
-
Provning av icke azeotropiska arbetsmedieblandningar i större värmepumpar
- 1990
-
Reports (other academic/artistic)abstract
- Ett fullskaleprov har genomförts med en ickeazeotrop blandning av HCFC22 och CFC114 i en enstegs värmepump. Mätningar och utvärdering har gjorts i samarbete mellan Institutionen for Värmeteknik och maskinlära och STAL refrigeration AB. Den använda värmepumpen är en av STALs testriggar vid fabriken i Norrköping. STAL har ansvarat for utförande och utvärdering av mätningarna medan Institutionen for Värmeteknik och maskinlära genomfort en jämförelse mellan matresultat och datorsimuleringar.Fullskaleprovet har visat att användning av arbetsmedieblandningar som ersättning av CFC12 i befintliga aggregat, åtminstone av den typ som provats, ar tekniskt mojlig. Betydande insatser återstår dock for att uppnå den säkerhet, servicevanlighet och lönsamhet som stalls på värmepumpar arbetande med rena arbetsmedier. En del registrativa frågor, sa som faststallande av tillåtet drifttryck, dimensionering av säkerhetsventiler, hantering av arbetsmedier etc, for blandningar måste lösas.Utvärdering av referensprov med HCFC22 visade att förångarens kapacitet inte var sa hög som förväntat. Troliga orsaker kan vara kraftig snedfördelning av arbetsmediet mellan tuberna alternativt att kontakten mellan rörväggen och insaten i tuberna varit dalig. Vid fortsatta simuleringar beaktades förångarens laga kapacitet på samma sätt for rena ämnen som for blandningar. Jämförelser mellan simulering och matning for blandningarna antyder att det masstransportmotstånd som förekommer vid förångning av en blandning inte har sa stort inflytande som man tidigare hävdat. Nar masstransportmotståndet försummades fick vi lika god överensstämmelse mellan matning och simulering för blandningarna av HCFC22/CFC114 som för ren HCFC22.
|
|
| 4. |
- Algehed, Jessica, 1971, et al.
(author)
-
Energieffektiv indunstning i framtidens massabruk
- 2001
-
In: Fiberlinjekonferensen 01, Stockholm 2001. - 1404-7098.
-
Conference paper (peer-reviewed)abstract
- Det arbete som presenteras i denna artikel har gjorts inom KAM-programmets energipotentialprojekt. KAM står för Kretsloppsanpassad massafabrik och är ett MISTRA-finansierat forskningsprogram, vars vision är en kretsloppsanpassad massafabrik som tillverkar högkvalitativa produkter och samtidigt utnyttjar vedråvaran så effektivt som möjligt. Förenklat kan man säga att avsikten med energipotentialprojektet är att finna effektiva energisystem för framtidens massa- och pappersbruk, som är tekniskt och ekonomiskt möjliga.För att spara energi i en fabrik måste processerna i sig göras mer effektiva, vilket naturligtvis sker i och med den ständiga teknikutveckling som pågår, men de måste även värmeintegreras bättre med varandra. Exempel på värmeintegration som redan sker är sekundärvärmesystem där värme från olika processdelar återanvänds och integrerade stripprar, som ”lånar” ånga från indunstningsanläggningen istället för att använda färskånga. Pinchtekniken är ett vanligt hjälpmedel för att finna vilka delar i en fabrik som bör värmeintegreras med varandra och vilket minimalt värme- och kylbehov man har när alla delar av fabriken är integrerade på ”rätt” sätt. Flera tidigare pinchstudier har visat att man i ett sulfatmassabruk uppnår störst ångbesparingar när man värmeintegrerar indunstningen med den övriga processen. Anledningen till detta är att indunstningen är en av de största ånganvändarna och samtidigt en av de mest flexibla processerna i ett sulfatmassabruk. I princip kan indunstningen värmeintegreras med den övriga processen på två sätt, antingen genom att indunstningen till viss del utnyttjar spillvärme från den övriga processen vid relativt låga temperaturer, dvs under 100°C, eller att indunstningen drivs vid så hög temperatur att den delvis kan leverera lågtrycksånga till den övriga processen. Dessa båda sätt att värmeintegrera indunstningen på har studerats vid Institutionen för värmeteknik och maskinlära och i denna artikel sammanfattas resultat från två vetenskapliga artiklar , , som handlar just om spillvärmedriven indunstning och indunstning driven med mellantrycksånga.
|
|
| 5. |
- Algehed, Jessica, 1971, et al.
(author)
-
Energy efficient evaporation in future pulp and paper mills
- 2002
-
In: 7th Conference on New Available Technologies, SPCI 2002, Stockholm 2002. - 1404-7098.
-
Conference paper (peer-reviewed)abstract
- In this paper ways to design energy efficientevaporation plants in future pulp and paper mills arediscussed. There is more than 1 GJ/ADMT excessheat in the model mills studied that can be madeavailable for use in other parts of the mill. If thisheat is used for evaporation and/or if the evaporationplant is designed to use MP steam and deliver LPsteam to the steam network, large amounts of steamcan be saved. It is shown that these savings lead toreductions in CO2 emissions; the largest reductionare achieved if assuming that oil can be saved or ifbiomass fuel is exported from the mill and used toreplace oil elsewhere. It is also shown that theeconomic incentive for redesigning the evaporationplant depends on how the saved live steam is usedand the economic conditions assumed. The largestsavings are obtained if the live steam savings lead todecreased oil consumption. If producing condensingpower or excess bark that can be sold, the savingsare smaller, but in most cases still considerable in size.
|
|
| 6. |
|
|
| 7. |
- Algehed, Jessica, 1971, et al.
(author)
-
Evaporation of black liquor and wastewater using medium-pressure steam : Simulation and economic evaluation of novel designs
- 2003
-
In: ScienceDirect. - 1404-7098. ; 23:4, s. 481-495
-
Journal article (peer-reviewed)abstract
- In this paper, novel evaporation plant designs that use medium-pressure steam and deliver low-pressure(LP) steam to the steam network as well as conventionally designed plants are simulated and evaluatedfrom a technical and economic point of view. Both evaporation of black liquor only and combinedevaporation of black liquor and wastewater are analyzed.The results show that the novel designs suggested in this work all have large potential to save live steamand that an additional 8 m3 of wastewater/ADMT (air dry metric ton) can be evaporated without increasingthe mill´s total live steam demand. They also indicate that the demand for LP steam in the rest ofthe process is less important for the savings in live steam. The total cost for the novel designs and the relationship between that cost and the cost for conventional designs depend on the economic conditions assumed. If the investment in a more energy efficient evaporation plant is considered from a strategic point of view using an annuity factor of 0.1 and if the cost of thesaved fuel is rather high in comparison to the electricity price, the total cost for the novel designs will have alower total cost than the traditional designs.
|
|
| 8. |
- Algehed, Jessica, 1971, et al.
(author)
-
Opportunities for process integrated evaporation in kraft pulp mills
- 2000
-
In: TAPPI Engineering Conference. ; , s. 841-849
-
Conference paper (peer-reviewed)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.
|
|
| 9. |
- Andersson, Eva Ingeborg Elisabeth, 1956, et al.
(author)
-
Energy efficient upgrading of biofuel integrated with a pulp mill
- 2006
-
In: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 31:10-11, s. 1384-1394
-
Journal article (peer-reviewed)abstract
- This paper presents and evaluates different energy efficient options for integrating drying and pelletising ofbiofuel with a modern energy efficient pulp mill process. When drying biofuel, a large amount of the heat input canoften be recovered. One option for heat recovery is to cover low-temperature heat demand in the pulping process.Alternatively available excess heat from the pulp mill can be used for drying. Both alternatives will contribute to abetter energy efficiency for the combined pulp mill and biofuel upgrading facility. Pinch analysis tools can be usedto estimate the excess heat potential at different temperature levels in the pulp mill. Three different technologies forpulp mill integrated biofuel drying were chosen for the study, namely steam drying, flue gas drying and vacuumdrying. The different technologies are evaluated on the basis of energy usage, global CO2 emissions and resultingpellets production cost, using stand-alone pellets production as a reference. The pulp mill assumed for thecalculations is the Eco-Cyclic reference pulp mill. The results of the study indicate that the most attractiveintegrated drying technology option is the flue gas dryer, using flue gases from the black liquor boiler. With theavailable flue gas stream at the reference pulp mill, a potential pellets production of 70,000 ton/yr could beachieved at a cost of 24.6 EUR/ton. The associated reduction in CO2 emissions compared to stand-alone pelletsproduction is 3136 kg/MWh-pellets.
|
|
| 10. |
- Andersson, Eva Ingeborg Elisabeth, 1956, et al.
(author)
-
Energy Efficient upgrading of Biofuel Integrated with a Pulp Mill
- 2003
-
In: Proceedings of ECOS 2003, Copenhagen, Denmark. - 1404-7098.
-
Conference paper (peer-reviewed)abstract
- This paper presents and evaluates different energy-efficient options for integrating drying and pelletising of biofuel with a modem energy-efficient pulp mill process. When drying biofuel, a large amount of the heat input can often be recovered. One option for heat recovery is to cover low temperature heat demand in the pulping process. Alternatively available excess heat from the pulp mill can be used for drying. Both alternatives will contribute to a better energy efficiency for the combined pulp mill and biofuel upgrading facility. Pinch analysis tools can be used to estimate the excess heat potential at different temperature levels in the pulp mill. Three different technologies for pulp mill integrated biofuel drying were retained for the study, namely steam drying, flue gas drying and vacuum drying. The different technologies are evaluated on the basis of energy usage, global CO2 emissions and resulting pellets production cost, using stand-alone pellets production as a reference. The pulp mill assumed for the calculations is the Eco-Cyclic reference pulp mill. The results of the study indicate that the most attractive integrated drying technology option is the flue gas dryer, using flue gases from the black liquor boiler. With the available flue gas stream at the reference pulp mill, a potential pellets production of 70 000 tonnes/yr could be achieved at a cost of 24.6 €/tonne. The associated reduction in CO, emissions compared to stand-alone pellets production is 31-36 kg/MWhpellets.
|
|
| 11. |
- Andersson, Eva Ingeborg Elisabeth, 1956, et al.
(author)
-
Pinch analysis at Preem LYR
- 2013
-
Reports (other academic/artistic)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.
|
|
| 12. |
- Andersson, Viktor, 1983, et al.
(author)
-
Algae-based biofuel production as part of an industrial cluster
- 2014
-
In: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 71, s. 113-124
-
Journal article (peer-reviewed)abstract
- This paper presents a study on the production of biofuels from algae cultivated in municipal wastewater in Gothenburg, Sweden. A possible biorefinery concept is studied based on two cases; Case A) combined biodiesel and biogas production, and Case B) only biogas production. The cases are compared in terms of product outputs and impact on global CO2 emissions mitigation. The area efficiency of the algae-based biofuels is also compared with other biofuel production routes. The study investigates the collaboration between an algae cultivation, biofuel production processes, a wastewater treatment plant and an industrial cluster for the purpose of utilizing material flows and industrial excess heat between the actors. This collaboration provides the opportunity to reduce the CO2 emissions from the process compared to a stand-alone operation. The results show that Case A is advantageous to Case B with respect to all studied factors. It is found that the algae-based biofuel production routes investigated in this study has higher area efficiency than other biofuel production routes. The amount of algae-based biofuel possible to produce corresponds to 31 MWfuel for Case A and 26 MWfuel in Case B.
|
|
| 13. |
- Andersson, Viktor, 1983, et al.
(author)
-
Efficient Utilization of Industrial Excess Heat for Post-combustion CO2 Capture: An Oil Refinery Sector Case Study
- 2014
-
In: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 63, s. 6548-6556
-
Conference paper (peer-reviewed)abstract
- A key issue in post-combustion carbon capture is the choice of absorbent. In this paper two different absorbents, monoethanolamine (MEA) and ammonia (NH3), have been modeled in Aspen Plus at different temperatures for possible implementation at an oil refinery. The focus of investigation is the possibilities of heat integration between the oil refinery and the carbon capture process and how these possibilities could change in a future situation where energy efficiency measures have been implemented.The results show that if only using excess heat from the refinery for heating of the carbon capture process, the MEA process can capture more CO2 than the NH3 process. It is shown that the configuration requiring least supplementary heat when applying carbon capture to all flue gases is MEA at 120 °C.The temperature profile of the excess heat from the refinery suits the MEA and NH3 processes differently. The NH3 process would benefit from a flat section above 100 °C to better integrate the heat needed to reduce slip, while the MEA process only needs heat at stripper temperature.
|
|
| 14. |
- Andersson, Viktor, 1983, et al.
(author)
-
Industrial excess heat driven post-combustion CCS: The effect of stripper temperature level
- 2014
-
In: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 21, s. 1-10
-
Journal article (peer-reviewed)abstract
- The implementation of post-combustion CCS provides an opportunity for the oil refining sector to drastically decrease its CO2 emissions. Previous studies have shown that the largest cost is the heat supply to the stripper reboiler. When performing CCS at an oil refinery it could therefore prove economically beneficial to utilize the excess heat from refinery processes to meet this demand for heat. The present study investigates the heat demand in a stripper reboiler at different temperature levels from 120 degrees C down to 90 degrees C. At temperatures lower than 120 degrees C the heat demand increases, but the availability of excess heat also increases. A case study that connects heat demand results with data from an oil refinery shows that if only excess heat is utilized as a heat source, the amount of CO2 that can be separated is largest when the temperature in the stripper reboiler is 90 degrees C. If, however, CCS with a capture rate of 85% were applied to the four largest chimneys at the refinery, the external heat demand would be the lowest for the standard temperature of 120 degrees C. (C) 2013 Elsevier Ltd. All rights reserved.
|
|
| 15. |
- Andersson, Viktor, 1983, et al.
(author)
-
Integration of algae-based biofuel production with an oil refinery: Energy and carbon footprint assessment
- 2020
-
In: International Journal of Energy Research. - : Hindawi Limited. - 1099-114X .- 0363-907X. ; 44:13, s. 10860-10877
-
Journal article (peer-reviewed)abstract
- Biofuel production from algae feedstock has become a topic of interest in the recent decades since algae biomass cultivation is feasible in aquaculture and does therefore not compete with use of arable land. In the present work, hydrothermal liquefaction of both microalgae and macroalgae is evaluated for biofuel production and compared with transesterifying lipids extracted from microalgae as a benchmark process. The focus of the evaluation is on both the energy and carbon footprint performance of the processes. In addition, integration of the processes with an oil refinery has been assessed with regard to heat and material integration. It is shown that there are several potential benefits of co-locating an algae-based biorefinery at an oil refinery site and that the use of macroalgae as feedstock is more beneficial than the use of microalgae from a system energy performance perspective. Macroalgae-based hydrothermal liquefaction achieves the highest system energy efficiency of 38.6%, but has the lowest yield of liquid fuel (22.5 MJ per 100 MJalgae) with a substantial amount of solid biochar produced (28.0 MJ per 100 MJalgae). Microalgae-based hydrothermal liquefaction achieves the highest liquid biofuel yield (54.1 MJ per 100 MJalgae), achieving a system efficiency of 30.6%. Macro-algae-based hydrothermal liquefaction achieves the highest CO2 reduction potential, leading to savings of 24.5 resp 92 kt CO2eq/year for the two future energy market scenarios considered, assuming a constant feedstock supply rate of 100 MW algae, generating 184.5, 177.1 and 229.6 GWhbiochar/year, respectively. Heat integration with the oil refinery is only possible to a limited extent for the hydrothermal liquefaction process routes, whereas the lipid extraction process can benefit to a larger extent from heat integration due to the lower temperature level of the process heat demand.
|
|
| 16. |
- Andersson, Viktor, 1983, et al.
(author)
-
Techno-economic analysis of excess heat driven post-combustion CCS at an oil refinery
- 2016
-
In: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 45, s. 130-138
-
Journal article (peer-reviewed)abstract
- Carbon capture and storage may, as a bridging technology, rapidly decrease CO2 emissions in the industrial sector. In this paper, a techno-economic study of a future MEA carbon capture plant implemented at a case study oil refinery is presented. Costs are calculated for six setups of carbon capture at the refinery. Excess heat from the refinery processes is used in the capture plant for regeneration of the absorption fluid, and the stripper reboiler temperature is varied to increase the extractable of excess heat. Supplementary heating is carried out with a heat pump. The number of chimneys to be included in the capture process is also varied, resulting in different CO2 concentrations and amounts of CO2 at the inlet of the capture plant. Results show that the specific cost for carbon capture increases as the amount of captured carbon increases due to the need for heat pumps. The costs are in the range of 41-57(sic)/t for the low-temperature cases (T-Reb =90 degrees C) and 39-44(sic)/t for the high-temperature cases (T-Reb = 120 degrees C).
|
|
| 17. |
- Andersson, Viktor, 1983, et al.
(author)
-
Temperature Dependence of Heat Integration Possibilities of an MEA Scrubber Plant at a Refinery
- 2013
-
In: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 37, s. 7205-7213
-
Conference paper (peer-reviewed)abstract
- A study has been conducted in order to investigate how the specific heat requirements in the stripper reboiler of a MEA capture plant changes with changing temperature. It was found that the increase in heat demand is dramatic when lowering the temperature, approximately 40% when the temperature changes from 120 to 90° C. Heat integration with a refinery was also studied, and showed that even if the heat demand was larger for the lower temperature the heat integration possibilities were also larger for the base case.
|
|
| 18. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
A tool for creating energy market scenarios for evaluation of investments in energy intensive industry
- 2007
-
In: Conference ECOS 2007 Padova, Italy, June 25-28, 2007. - 8889884088 ; 2, s. 1587-1594
-
Conference paper (peer-reviewed)abstract
- The energy intensive industry can be a major contributor to CO2 emissions reduction, provided that appropriate investments are made. Predictions about future energy market conditions are needed to assess profitability and net CO2 emissions reduction potential of such measures. Energy market scenarios can be used to reflect different possible future energy market conditions. This paper presents a tool for creating consistent energy market scenarios adapted for evaluation of energy related investments in energy intensive industrial processes. Required user inputs include fossil fuel prices and costs associated with policy instruments, and the outputs are energy market prices and CO2 consequences of import/export of different energy streams (e.g. electric power and biofuel) from an industrial process site. The paper also presents four energy market scenarios for 2020 created with the tool.
|
|
| 19. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
A tool for creating energy market scenarios for evaluation of investments in energy intensive industry
- 2009
-
In: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 34:12, s. 2069-2074
-
Journal article (peer-reviewed)abstract
- The energy intensive industry can be a major contributor to CO2 emissions reduction, provided that appropriate investments are made. To assess profitability and net CO2 emissions reduction potential of such investments, predictions about future energy market conditions are needed. Energy market scenarios can be used to reflect different possible future energy market conditions. This paper presents a tool for creating consistent energy market scenarios adapted for evaluation of energy related investments in energy intensive industrial processes. Required user inputs include fossil fuel prices and costsassociated with policy instruments, and the outputs are energy market prices and CO2 consequences of import/export of different energy streams (e.g. electric power and biomass fuel) from an industrial process site. The paper also presents four energy market scenarios for the medium-term future (i.e. around 2020) created using the tool.
|
|
| 20. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
Heat integration opportunities in an average Scandinavian fine paper mill: Model study and comparison with a market pulp mill
- 2008
-
In: Tappi Journal. - 0734-1415. ; 7:2, s. 19-25
-
Journal article (peer-reviewed)abstract
- Within the FRAM programme, two models of average Scandinavian mills producing bleached market pulp have been analysed from an energy perspective. The aim was to explore the opportunities for heat integration in order to create a steam surplus. The steam surplus gives opportunities for increased power generation or lignin extraction. The technical and economic consequences of using the steam surplus in this way are explored in a continuation of this project. Two different approaches for creating a steam surplus have been investigated: 1) conventional measures and 2) processintegrated evaporation (PIvap). The former approach includes improved heat integration and new equipment. The latter approach means that excess heat from the mill is used for evaporation to partly replace live steam.The two model mills created within FRAM both produce 1000 ADt/d softwood pulp. The mills differ in the level of water usage, since it is expected that the amount of excess heat for PIvap will increase with decreasing water usage. By investing 11 M€ in conventional measures it is possible to create a steam surplus of 53 MW (about 26% of the total consumption), independent of the level of water usage. For the PIvap approach, the level of water usage matters, since there is more excess heat for PIvap in the mill with lower water usage. As a result, the total steam surplus with the PIvap approach differs in the two mills: up to 52 and 56 MW, respectively. Hence, the steam savings for the PIvap approach are similar to those in the approach with conventional measures; and so are the investments needed (10-12 M€). Even though the two approaches give approximately the same savings with the same investment, the PIvap approach might be easier to implement in an existing mill.
|
|
| 21. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
Heat integration opportunities in average Scandinavian kraft pulp mills: Pinch analyses of model mills
- 2006
-
In: Nordic Pulp and Paper Research Journal. ; 21:4, s. 466-475
-
Journal article (peer-reviewed)abstract
- Within the FRAM programme, two models of average Scandinavian mills producing bleached market pulp have been analysed from an energy perspective. The aim was to explore the opportunities for heat integration in order to create a steam surplus. The steam surplus gives opportunities for increased power generation or lignin extraction. The technical and economic consequences of using the steam surplus in this way are explored in a continuation of this project.Two different approaches for creating a steam surplus havebeen investigated: 1) conventional measures and 2) processintegrated evaporation (PIvap). The former approach includes improved heat integration and new equipment. The latter approach means that excess heat from the mill is used for evaporation to partly replace live steam.The two model mills created within FRAM both produce 1000 ADt/d softwood pulp. The mills differ in the level of waterusage, since it is expected that the amount of excess heat for PIvap will increase with decreasing water usage.By investing 11 M€ in conventional measures it is possible to create a steam surplus of 53 MW (about 26% of the total consumption), independent of the level of water usage. For the PIvap approach, the level of water usage matters, since there is more excess heat for PIvap in the mill with lower water usage.As a result, the total steam surplus with the PIvap approach differs in the two mills: up to 52 and 56 MW, respectively. Hence, the steam savings for the PIvap approach are similar to those in the approach with conventional measures; and so are the investments needed (10-12 M€). Even though the two approachesgive approximately the same savings with the same investment, the PIvap approach might be easier to implement in an existing mill.
|
|
| 22. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
Increased capacity in kraft pulp mills: Lignin separation and reduced steam demand compared with recovery boiler upgrade
- 2006
-
In: Nordic Pulp and Paper Research Journal. - 2000-0669 .- 0283-2631. ; 21:4, s. 485-492
-
Journal article (peer-reviewed)abstract
- For increased production in pulp mills, the recoveryboiler is often a bottleneck. Two different approaches todebottleneck the recovery boiler have been investigated in twomodel mills that represent typical Scandinavian pulp mills. As areference approach, the recovery boiler was upgraded. Inconnection with this, the turbine system was also upgraded toenable increased electricity production. As an alternative to thisconventional approach, the load of the boiler was kept constantby extracting lignin from the black liquor in proportion to theproduction increase. To keep the steam balance, the specificsteam consumption at the mill was reduced through steamsavingmeasures to such an extent that the amount of steamproduced from burning the lignin-lean black liquor was sufficient.Consequently, the extracted lignin was not needed in-houseand could be sold as a biofuel. The net profit of implementinglignin separation was calculated for different conditions. Theresult was that, depending on the conditions, the lignin pricehad to be 2-17 /MWh for lignin separation to be equallyprofitable as boiler upgrade. With an assumed lignin price ofabout 15 /MWh, the conclusion is that lignin separationshould be an economically attractive alternative for debottleneckingthe recovery boiler. With a high power price and along-term investment strategy, however, upgrading the recoveryboiler and the turbine system can be more profitable.
|
|
| 23. |
|
|
| 24. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
Opportunities for Process Integrated Evaporation in a Eucalyptus Pulp Mill and Comparison with a Softwood Mill Study
- 2007
-
In: Conference PRES 07, Ischia Island, Italy. ; , s. 727-732
-
Conference paper (peer-reviewed)abstract
- Significant energy savings can be made in the pulp and paper industry by implementing process-integrated evaporation (PIvap). The concept of PIvap has been evaluated for a Eucalyptus mill producing bleached kraft market pulp in Portugal and the results were compared to the ones from an earlier model mill study of a soft wood mill. In the eucalyptus mill there were, theoretically, 0.86 GJ/ADt of excess heat suitable for a PIvap besides the 2.6 GJ/ADt of pinch violations. The pinch violations could be transferred to excess heat, but some pinch violations were cost effective to solve. A suggestion where 1.1 GJ/ADt of pinch violations are solved and 1.6 GJ/ADt of excess heat are extracted is presented. If the excess heat is used in a 7 effect PIvap with integrated stripper and increased dry solids content, steam savings of 2.7 GJ/ADt could be made in the evaporation plant. Together with the pinch violations and opportunities for improved soot blowing, the total steam savings from the suggested measures were 4.5 GJ/ADt or 35%. The amount of steam savings and associated costs were similar to the ones in the soft-wood model-mill. Hence, no significant differences could be found for the opportunities to implement PIvap in the hardwood mill compared to in the soft wood mill. The existence of a pre-evaporation plant, however, showed to hinder introduction of PIvap, since a pre-evaporation plant uses excess heat, and uses it ineffectively compared to a PIvap. Hence, the pre-evaporation has been removed in the suggestion for integration presented here.
|
|
| 25. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
Opportunities for process-integrated evaporation in a hardwood pulp mill and comparison with a softwood model mill study
- 2008
-
In: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311. ; 28:16, s. 2100-2107
-
Journal article (peer-reviewed)abstract
- Significant energy savings can be made in the pulp and paper industry by implementing process-integrated evaporation (PIvap). The aim of this paper was to evaluate the concept of PIvap for a existing hardwood mill producing kraft pulp and compare the results with the ones from an earlier study of a softwood model mill. Using pinch tools, we found a solution where 1.3 GJ/ADt of pinch violations are solved and 1.1 GJ/ADt of excess heat is extracted. If the excess heat is used in an efficient PIvap, steam savings of 2.7 GJ/ADt could be made in the evaporation plant. Together with the pinch violations and improved soot blowing, the total steam savings were 4.6 GJ/ADt or 36% for an investment cost of 6.6 M€. Compared with the softwood model mill, the configuration of the hardwood mill offered about the same savings with 2.7 M€ lower investment cost, making PIvap more interesting in the hardwood mill. As an alternative to implementing PIvap, more pinch violations can be solved. The PIvap approach gives more steam savings to approximately the same specific cost.
|
|
| 26. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
Pinch analysis of a model mill: Economic and environmental gains from thermal process-integration in a state-of-the-art magazine paper mill
- 2005
-
In: Nordic Pulp and Paper Research Journal. ; 20:3, s. 308-315
-
Journal article (peer-reviewed)abstract
- A model of a modern magazine paper mill has been investigated from an energy perspective. The mills refining process has a power demand of 100 MW (3050 kWh/ADt pulp), and 86 MW of this is recovered as steam. Since the steam demand of the mill is low, there is a steam surplus of 21.5 MW. The steam surplus could be increased by 41 % through thermal process-integration. Simultaneously the cooling demand decreased by 13.2 MW or 49 %, resulting in reduced cooling costs and decreased thermal pollution. The financial evaluation, for which a grass-root situation was assumed, shows promising economy if the mill can sell the surplus heat (e.g. to a district heating system): the marginal payback period for increasing the steam surplus would be less than a year, even with low energy prices. If the surplus steam has to be used on site, power generation in a condensing steam turbine is an option. The financials for increasing the power generation are very dependent on the power price, but with current Swedish power prices the marginal payback period would be 3 to 4 years. Energy exports, whether heat or power, would presumably replace fossil fuel. Consequently, the greenhouse gas emissions in society would decrease by thousands of tons per year. In the future it might be possible to decrease the power consumption in the refining process, resulting in a decrease of the steam surplus. With process integration, the power input can be decreased by 30 % before there is a steam deficit. This option offers a good opportunity for profit as well as decreased environmental impact.
|
|
| 27. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(author)
-
Profitability and off-site CO2-emission reduction from energy savings in the pulp and paper industry in different future energy markets
- 2012
-
In: International Journal of Energy Research. - : Hindawi Limited. - 1099-114X .- 0363-907X. ; 36:9, s. 975-986
-
Journal article (peer-reviewed)abstract
- Previous studies by the authors have shown that energy savings in pulp and paper mills offer opportunities forincreased electricity production on-site or wood fuel export. The energy export implies reductions in CO2 emissions off-site, where fossil fuel or fossil-fuel-based electricity is replaced. To assess this potential and the related profitability for a future situation, four energy market scenarios were used. For a typical Scandinavian mill, the potential for CO2-emission reductions was 15–140 kton year-1 depending on the scenario and the form of energy export. Extrapolated to all relevant mills in Sweden, the potential was 0.4–3.1 Mton year-1, which is in the order of percent of the Swedish CO2 emissions. Wood fuel export implies larger reduction in CO2 emissions in most scenarios. In contrast, electricity export showed better economy in most of the cases studied; with annual earnings of 5–6Mh, this is an economically robust option. In the market pulp mill investigated, the wood fuel export was in the form of lignin. Lignin could possibly be valued as oil, regarding both price and potential for CO2-emissionreduction, making lignin separation an option with good profitability and large reductions of CO2 emissions.
|
|
| 28. |
|
|
| 29. |
- Axelsson, Helén, 1971, et al.
(author)
-
A New Methodology for Greenhouse Gas Reduction in Industry through Improved Heat Exchanging and/or Integration of Combined Heat and Power
- 1999
-
In: Applied Thermal Engineering. ; 19/1999, Issue 7, s. 707-731
-
Journal article (peer-reviewed)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
|
|
| 30. |
- Axelsson, Helén, 1971, et al.
(author)
-
Potential for Greenhouse Gas Reduction in Industry through Increased Heat Recovery and/or Integration of Combined Heat and Power
- 2003
-
In: Applied Thermal Engineering. - 1404-7098. ; 23:1, s. 65-87
-
Journal article (peer-reviewed)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).
|
|
| 31. |
- Bengtsson, Cecilia, 1974, et al.
(author)
-
Co-ordination of pinch technology and the MIND method : applied to a Swedish board mill
- 2002
-
In: Applied Thermal Engineering. - 1359-4311 .- 1873-5606. ; 22:2, s. 133-144
-
Journal article (peer-reviewed)abstract
- By combining the pinch technology and the MIND method, it is possible to identify beneficial and energy-efficient measures in a complex industrial energy system. By tackling a problem on the two different aggregation levels, the result is thoroughly evaluated and durable measures are achieved. The strength of the combination of methods is elucidated in a case study where a Scandinavian pulp and paper mill is analysed. The studied problem concerns pre-evaporation of effluents in a board mill using excess heat. Different alternatives are evaluated, taking into account economic, technical and practicable constraints. The results show that it is cost-effective to pre-evaporate the effluent using excess heat in the studied mill.
|
|
| 32. |
- Bengtsson, Cecilia, 1974, et al.
(author)
-
Cost-efficient CO2-reduction in the pulp and paper industry - results from a case study
- 2002
-
In: 1st International Conference on Sustainable Energy Technologies 12-14 June 2002, Porto, Portugal. ; :paper EES11, s. 7-
-
Conference paper (other academic/artistic)abstract
- It is generally accepted that human activities have a large influence on global climate. In order to minimize human impact on global warming, regulations and agreements may be introduced for all CO2 generating sectors. Therefore, measures to reduce CO2-emissions will be of importance to the industrial sector. Strategic decisions and long-term thinking are needed to comply with the regulations and to fulfil the agreements.The pulp and paper industry is an energy intensive sector with relatively large potentials to accomplish energy efficiency measures that result in reduction of CO2-emissions. To settle the cost-effectiveness for each measure a number of system parameters have to be considered, such as investment costs, boundary conditions and reference systems.This paper presents two methods, pinch technology and the MIND method. These methods are used for analysis of industrial energy systems considering different parameters and aspects. Pinch technology is used for thermodynamic and economic evaluation of process integration possibilities and the MIND method is used for strategic evaluation of different energy efficiency measures. Foundation for long-term decision-making can be obtained by co-ordinating the results from the two methods. In this paper, cost-effectiveness has been determined for different energy efficiency measures. The measures are non-conventional evaporation and heat pumping. The case studied is from a Swedish board mill. Economic potentials and consequences for these CO2-reducing measures are discussed from both an industrial and a societal perspective.
|
|
| 33. |
- Bengtsson, Cecilia, 1974, et al.
(author)
-
Examples of CO2 reduction opportunities in the pulp and paper industry based on process integration measures
- 2003
-
In: Presented at The Dubrovnik Conference on Sustainable Development of Energy, Water and Enviroment Systems, June 15-20 2003. - 1404-7098.
-
Conference paper (peer-reviewed)abstract
- Industrial opportunities for reduction of CO2 emissions can be of strategic importance in the future due to such policy instruments as green certificates, trading in CO2 emissions licences and long-term agreements between government and industry. The pulp and paper industry is an industry branch with large heat demands. The heat demands are covered by large amounts of bio fuel but also by fossil fuels.Process integration in the pulp and paper industry reduces the fuel demand but at the same time reduces the possibilities for backpressure production. Different measures will influence the fuel demand/electricity production ratio in different ways. Depending on the type of fuel reduced in the system, the CO2 reduction opportunities also differ.The focus in this study is on a wider system aspect for some process integration measures. The measures in question are improved heat exchanging, heat pumping and process integrated evaporation, which all have proven to be economically favourable in previous studies. Evaluation and discussion on how the CO2 reduction opportunities depend on different measures and conditions are performed within the study. The results are discussed from both societies and industry’s perspective and based on a case study.
|
|
| 34. |
- Bengtsson, Cecilia, 1974, et al.
(author)
-
Utilization of excess heat in the pulp and paper industry - a case study of technical and economic opportunities
- 2002
-
In: Applied Thermal Engineering. - 1359-4311. ; 22:9, s. 1069-1081
-
Journal article (peer-reviewed)abstract
- Newly developed methods and tools based on pinch technology are used in a case study to investigate the potential and economy of using excess heat for pre-evaporation of chemo thermo mechanical pulp effluent and heat pumping in an integrated pulp and paper mill. The new tools give information about the system that traditional pinch tools such as the grand composite curve or the composite curves would not reveal. For example, the highest temperature levels possible where excess heat can be released are identified together with the amount of excess heat at each temperature level. The new curves are also able to provide information about where heaters and coolers are placed in an existing system. The matrix method has been used successfully in order to find an economically feasible heat exchanger network retrofit for the release of the excess heat found with the curves.The results of the case study show that a pre-evaporation plant can be integrated with the overall process with just a few modifications in the existing process. There are also opportunities for heat pumping in the system. Both projects have a pay-back period shorter than required for implementation.
|
|
| 35. |
|
|
| 36. |
|
|
| 37. |
|
|
| 38. |
|
|
| 39. |
|
|
| 40. |
|
|
| 41. |
|
|
| 42. |
|
|
| 43. |
- Berglin, Niklas, 1966, et al.
(author)
-
Using process integration to approach the minimum impact pulp mill
- 1997
-
In: Presented at 1997 Environmental Conference and Exhibit May 5-7, 1997,Minneapolis Convention Center, Minneapolis, MN.. - 1103-2952. ; TAPPI Proceedings, s. 515-521
-
Conference paper (peer-reviewed)abstract
- A low level of energy use is an important feature of the minimum impact mill. Process integration is used in the pulp and paper industry and other industries to reduce the use of fuels and cooling water. As the industry is in a state of rapid change, a methodical approach to process integration is useful. Pinch analysis is well established as such a tool. In the present paper, composite curves are used to analyze possibilities for process integration in combination with changes in process design. Several examples, including improved integration of the digester and analyses of the whole mill, show that this is an approach that gives good guidance early in the design process. Substantial utility savings can be identified; these are on the order of 2-4 GJ per tonne of pulp compared with already energy-efficient mills.
|
|
| 44. |
|
|
| 45. |
|
|
| 46. |
- Berntsson, Thore, 1947, et al.
(author)
-
Alternativa medier och processer
- 1989
-
In: Föredrag vid 13. Nordiska Kolemode och 4. Nordiske Varmepumpedager i Loen, Norge, 30/5-3/6 1989.
-
Conference paper (peer-reviewed)
|
|
| 47. |
|
|
| 48. |
- Berntsson, Thore, 1947, et al.
(author)
-
Application of Process Integration to the Synthesis of Heat and Power Utility Systems Including Combined Heat and Power (CHP) and Industrial Heat Pumps
- 2013
-
In: Woodhead Publishing Series in Energy - Handbook of Process Integration (PI). - : Elsevier. - 9780857095930 ; , s. 168-200
-
Book chapter (other academic/artistic)abstract
- This chapter discusses the main aspects of application of Pinch Analysis to the analysis and synthesis of heat and power utility systems for industrial processes. The chapter first reviews the basic concepts for the use of the Process Grand Composite Curve as a targeting tool. The chapter then discusses the application of this tool for synthesis and design of utility systems of main relevance in industrial practice, such as centralised heating systems, Combined Heat and Power (CHP) production system and industrial heat pumps.
|
|
| 49. |
|
|
| 50. |
|
|
