| 1. |
- Algehed, Jessica, 1971, et al.
(författare)
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Energieffektiv indunstning i framtidens massabruk
- 2001
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Ingår i: Fiberlinjekonferensen 01, Stockholm 2001. - 1404-7098.
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Konferensbidrag (refereegranskat)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.
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| 2. |
- Algehed, Jessica, 1971, et al.
(författare)
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Energy efficient evaporation in future pulp and paper mills
- 2002
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Ingår i: 7th Conference on New Available Technologies, SPCI 2002, Stockholm 2002. - 1404-7098.
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Konferensbidrag (refereegranskat)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.
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| 3. |
- 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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| 4. |
- Andersson, Eva Ingeborg Elisabeth, 1956, et al.
(författare)
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Energy Efficient upgrading of Biofuel Integrated with a Pulp Mill
- 2003
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Ingår i: Proceedings of ECOS 2003, Copenhagen, Denmark. - 1404-7098.
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Konferensbidrag (refereegranskat)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.
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| 5. |
- Andersson, Viktor, 1983, et al.
(författare)
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Efficient Utilization of Industrial Excess Heat for Post-combustion CO2 Capture: An Oil Refinery Sector Case Study
- 2014
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 63, s. 6548-6556
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Konferensbidrag (refereegranskat)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.
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| 6. |
- Andersson, Viktor, 1983, et al.
(författare)
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Temperature Dependence of Heat Integration Possibilities of an MEA Scrubber Plant at a Refinery
- 2013
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 37, s. 7205-7213
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Konferensbidrag (refereegranskat)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.
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| 7. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(författare)
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A tool for creating energy market scenarios for evaluation of investments in energy intensive industry
- 2007
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Ingår i: Conference ECOS 2007 Padova, Italy, June 25-28, 2007. - 8889884088 ; 2, s. 1587-1594
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Konferensbidrag (refereegranskat)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.
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| 8. |
- Axelsson, Erik Marcus Kristian, 1974, et al.
(författare)
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Opportunities for Process Integrated Evaporation in a Eucalyptus Pulp Mill and Comparison with a Softwood Mill Study
- 2007
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Ingår i: Conference PRES 07, Ischia Island, Italy. ; , s. 727-732
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Konferensbidrag (refereegranskat)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.
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| 9. |
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| 10. |
- Bengtsson, Cecilia, 1974, et al.
(författare)
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Cost-efficient CO2-reduction in the pulp and paper industry - results from a case study
- 2002
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Ingår i: 1st International Conference on Sustainable Energy Technologies 12-14 June 2002, Porto, Portugal. ; :paper EES11, s. 7-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)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.
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