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Andersson, Jan-Olof
Alternative names
Publications (9 of 9) Show all publications
Andersson, J.-O. (2014). Energy and Resource Efficiency in Convective Drying Systems in the Process Industry (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Energy and Resource Efficiency in Convective Drying Systems in the Process Industry
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Energi- och resurseffektivitet i konvektiva torksystem inom processindustrin
Abstract [en]

Growing concern about environmental problems has increased the public’s interest in energy usage. The subsidies for biomass, together with the rising energy prices have madebiomass a desirable product on the energy market. This has led to higher biomass prices and an increased interest in improving the resource and energy efficiency associated withbiomass production. Biofuel is an interesting substitute for fossil fuels to decrease the greenhouse gas emissions. One challenge with biofuels is to find sufficient amounts of biomass since the foresting is already close to its maximum sustainable capacity. Sawmills are important suppliers to the biomass market, since the sawmill industries produce a significant part of the available biomass. This Doctoral thesis focuses on strategies to decrease biomass usage in order to increase the biomass availability at the market. This is done through mapping and system analysis of energy and material streams for process industries using convective drying techniques. The energy analysis is mainly done through thermodynamics and psychrometry. Available state-of-the-art technologies on the market are studied to determine their potential for decreasing the total energy usage in sawmills. Integration possibilities between biomass consumers are also investigated through process integration with mathematical programming and pinch analysis. Energy efficiency of berry drying in a juice plant is also studied. The main conclusions are as follows. The heat demand of drying lumber in Swedish sawmills is about 4.9 TWh/year. Using available state-of-the-art technologies (heat pumps,heat exchangers and open absorption system) it is possible to reduce the energy usagesubstantially. If the recovered heat is used for heat sinks inside, or close to, the sawmill, the energy efficiency can be improved significantly. Using mechanical heat pumps nationally could save 4.9 TWh/year ofheatandgenerate0.62 TWh/year of surplus heat, at the cost of 1TWh/year of electricity. Using open absorption systems nationally, could save 3.4 TWh/year of heat, at the cost of only 0.05 TWh/year of electricity. Saving this heat means that an even larger amount of biomass will be saved, since there are heat losses during the combustion and distribution. Another way of saving energy is to displacethe starting time between batch kilns, and recycle evacuation air between the kilns. Nationally, this could save 0.44 TWh/year of heat. Industrial site integration between sawmills and the main biomass users (pelleting plants an d CHP plants) can decrease the use of biomass in the industrial site with 43% wt compared to a standalone site with a comparable production. Nationally, this could save up to 7.1 TWh/year of biomass. Despite the significant savings in terms of resources, it is not profitable due to the currentprice ratio between district heating and biomass. Finally, drying and separationof berry press cake in a juice plant is found to be possible using only energy from the exhaust gases of the steam boiler, if the drying air is sufficientlyrecycled. Instead of composting the press cake, the dried and separated skins and seeds could then be sold.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2014. p. 54
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-18230 (URN)783f7a36-5d01-42c6-8918-13cdf2b973c9 (Local ID)978-91-7439-872-4 (ISBN)978-91-7439-873-1 (ISBN)783f7a36-5d01-42c6-8918-13cdf2b973c9 (Archive number)783f7a36-5d01-42c6-8918-13cdf2b973c9 (OAI)
Note
Godkänd; 2014; 20140218 (janand); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Jan-Olof Andersson Ämne: Energiteknik/Energy Engineering Avhandling: Energy and Resource Efficiency in Convective Drying Systems in the Process Industry Opponent: Associate professor Zhifa Sun, Dept of Physics, Otago University, Dunedin, New Zealand Ordförande: Bitr professor Lars Westerlund, Avd för energivetenskap, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Tid: Torsdag den 27 mars 2014, kl 10.00 Plats: E632, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Andersson, J.-O., Elfgren, E. & Westerlund, L. (2014). Improved energy efficiency in juice production through waste heat recycling (ed.). Paper presented at International Conference on Applied Energy : Energy Solution for a Sustainable World 01/07/2013 - 05/07/2013. Applied Energy, 130(S1), 757-763
Open this publication in new window or tab >>Improved energy efficiency in juice production through waste heat recycling
2014 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 130, no S1, p. 757-763Article in journal (Refereed) Published
Abstract [en]

Berry juice concentrate is produced by pressing berries and heating up the juice. The by-products are berry skins and seeds in a press cake. Traditionally, these by-products have been composted, but due to their valuable nutrients, it could be profitable to sell them instead. The skins and seeds need to be separated and dried to a moisture content of less than 10 %wt (on dry basis) in order to avoid fermentation. A berry juice plant in the north of Sweden has been studied in order to increase the energy and resource efficiency, with special focus on the drying system. This was done by means of process integration with mass and energy balance, theory from thermodynamics and psychrometry along with measurements of the juice plant. Our study indicates that the drying system could be operated at full capacity without any external heat supply using waste heat supplied from the juice plant. This would be achieved by increasing the efficiency of the dryer by recirculation of the drying air and by heat supply from the flue gases of the industrial boiler. The recirculation would decrease the need of heat in the dryer with about 52%. The total heat use for the plant could thereby be decreased from 1262 kW to 1145 kW. The improvements could be done without compromising the production quality.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-33065 (URN)10.1016/j.apenergy.2014.01.092 (DOI)000340311500076 ()2-s2.0-84904819243 (Scopus ID)7d43cecf-6d02-4fbb-bb80-e13b44ce5f5d (Local ID)7d43cecf-6d02-4fbb-bb80-e13b44ce5f5d (Archive number)7d43cecf-6d02-4fbb-bb80-e13b44ce5f5d (OAI)
Conference
International Conference on Applied Energy : Energy Solution for a Sustainable World 01/07/2013 - 05/07/2013
Note
Validerad; 2014; 20140310 (andbra); Konferensartikel i tidskriftAvailable from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Andersson, J.-O. & Westerlund, L. (2014). Improved energy efficiency in sawmill drying system (ed.). Paper presented at . Applied Energy, 113, 891-901
Open this publication in new window or tab >>Improved energy efficiency in sawmill drying system
2014 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 113, p. 891-901Article in journal (Refereed) Published
Abstract [en]

The worldwide use of biomass has increased drastically during the last decade. At Swedish sawmills about half of the entering timber becomes lumber, with the remainder considered as by-product (biomass). A significant part of this biomass is used for internal heat production, mainly for forced drying of lumber in drying kilns. Large heat losses in kilns arise due to difficulties in recovering evaporative heat in moist air at low temperatures. This paper addresses the impact of available state-of-the-art technologies of heat recycling on the most common drying schemes used in Swedish sawmills. Simulations of different technologies were performed on an hourly basis to compare the heat and electricity demand with the different technologies. This was executed for a total sawmill and finally to the national level to assess the potential effects upon energy efficiency and biomass consumption. Since some techniques produce a surplus of heat the comparison has to include the whole sawmill. The impact on a national level shows the potential of the different investigated techniques. The results show that if air heat exchangers were introduced across all sawmills in Sweden, the heat demand would decrease by 0.3 TWh/year. The mechanical heat pump technology would decrease the heat demand by 5.6 TWh/year and would also produce a surplus for external heat sinks, though electricity demand would increase by 1 TWh/year. The open absorption system decreases the heat demand by 3.4 TWh/year on a national level, though at the same time there is a moderate increase in electricity demand of 0.05 TWh/year. Introducing actual energy prices in Sweden gives an annual profit (investment cost excluded) on national level for the open absorption system of almost 580 million SEK. For the mechanical heat pump technology the profit is 204 million SEK and for the traditional heat exchanger the profit is significant lower. It has been found that a widespread implementation of available energy recovery technologies across Swedish sawmills would result in substantial savings of biomass for other purposes in the society

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-15547 (URN)10.1016/j.apenergy.2013.08.041 (DOI)000329952500087 ()2-s2.0-84883722827 (Scopus ID)f15453d1-86cf-416d-9585-318e6d239750 (Local ID)f15453d1-86cf-416d-9585-318e6d239750 (Archive number)f15453d1-86cf-416d-9585-318e6d239750 (OAI)
Note
Validerad; 2014; 20130910 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Andersson, J.-O., Elfgren, E. & Grip, C.-E. (2013). Improved energy efficiency in juice production through waste heat recycling (ed.). In: (Ed.), (Ed.), International Conference on Applied Energy, ICAE 2013: . Paper presented at International Conference on Applied Energy : Energy Solution for a Sustainable World 01/07/2013 - 05/07/2013.
Open this publication in new window or tab >>Improved energy efficiency in juice production through waste heat recycling
2013 (Swedish)In: International Conference on Applied Energy, ICAE 2013, 2013Conference paper, Published paper (Refereed)
Abstract [en]

The global demand for Nordic wild berries has increased steadily, partly due to their healthy properties and their good taste. Juice concentrate is produced by pressing berries and heating up the juice. The by-products are berry skins and seeds. Traditionally, the by-products have been composted. Higher competiveness can be achieved by decreasing the production cost and increasing the product values. The berry skins and seeds have a commercial value since they are rich in vitamins and nutrients. To use and sell these by-products, they need to be separated from each other and dried to a moisture content of less than 10 %wt. A berry juice industry in the north of Sweden has been studied in order to increase the energy and resource efficiency and optimize the quality and yield of different berry fractions. This was done by means of process integration with thermodynamics and psychrometry along with measurements of the berry juice production processes. Our calculations show that the drying system could be operated at full without any external heat supply. This could be achieved by increasing the efficiency of the dryer by recirculating 80 % of the drying air and by heating the air with heat from the flue gases from the industrial boiler. This change would decrease the need for heat in the dryer with about 64 %. The total heat use for the plant could thereby be decreased from 1204 kW to 1039 kW. The proposed changes could be done without compromising the production quality or the lead time.

Keywords
Natural sciences - Physics, renewable energy resources, psychrometrics, thermodynamic, drying, pinch analys, Naturvetenskap - Fysik
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-36993 (URN)add3b9bb-6da2-4d22-bfff-e78c64e19b15 (Local ID)add3b9bb-6da2-4d22-bfff-e78c64e19b15 (Archive number)add3b9bb-6da2-4d22-bfff-e78c64e19b15 (OAI)
Conference
International Conference on Applied Energy : Energy Solution for a Sustainable World 01/07/2013 - 05/07/2013
Note
Godkänd; 2013; Bibliografisk uppgift: Konferensbidrag, finns omskrivet till en journal artikel; 20130613 (janand)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-05-02Bibliographically approved
Andersson, J.-O. & Toffolo, A. (2013). Improving energy efficiency of sawmill industrial sites by integration with pellet and CHP plants (ed.). Paper presented at . Applied Energy, 111, 791-800
Open this publication in new window or tab >>Improving energy efficiency of sawmill industrial sites by integration with pellet and CHP plants
2013 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 111, p. 791-800Article in journal (Refereed) Published
Abstract [en]

An essential strategy to lower energy and resources consumption is the development of highly integrated industrial sites including different kind of plants complementing one another. Sawmills are huge biomass suppliers to other industries, such as pulp and paper mills, pellet plants and CHP plants, and part of the biomass is also used for the internal heat requirement. In this paper the integration of a sawmill with a pellet plant and a CHP plant is investigated using advanced process integration techniques, so that the thermal energy and the electricity produced in the CHP plant by burning part of the sawmill biomass output are used for the heat and power requirements of the other two industries. The results show that up to 18% of the biomass by-products from the sawmill can be saved, but from the economic point of view the ratio between prices of the thermal energy sold for district heating and the low quality biomass has to be lower than the present one to make the integrated design solution more attractive than separate plant operation.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-15690 (URN)10.1016/j.apenergy.2013.05.066 (DOI)000325834900073 ()2-s2.0-84879437595 (Scopus ID)f3cb8bf8-0ccb-4d8e-9349-cb60137c906f (Local ID)f3cb8bf8-0ccb-4d8e-9349-cb60137c906f (Archive number)f3cb8bf8-0ccb-4d8e-9349-cb60137c906f (OAI)
Note
Validerad; 2013; 20130613 (janand)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Anderson, J.-O. & Westerlund, L. (2012). Analysis of the heat demand in batch kilns (ed.). Paper presented at International IUFRO Wood Drying Conference : 30/07/2012 - 03/08/2012. Paper presented at International IUFRO Wood Drying Conference : 30/07/2012 - 03/08/2012.
Open this publication in new window or tab >>Analysis of the heat demand in batch kilns
2012 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

During the production of lumber more than half of the entering timber to the sawmill becomes biomass. About 12 %wt of the entering timber is combusted to supply heat for the sawmill. Major part of the heat is supply the kilns. Due to the high evacuation losses the energy efficiency in a traditional drying kiln is only 13 %. This makes the lumber drying to a low and ineffective process in an energy point of view.Forced drying technologies are a compromise between high lumber quality, low lead time and decreased energy use. Often is the quality and lead time prioritised. This paper advises an appropriate method to simulate the energy efficiency when drying lumber in a batch kiln. To ensure real life drying conditions, with sufficient quality and lead time the initial conditions were made from simulated drying schemes, from simulation program called Torksim. By combine thermodynamics and psychrometric relationship, the energy streams and losses during the drying scheme were established. The program can be used to compare several drying conditions and clarify the magnitude of losses. Different types of technologies affecting the kiln energy efficiency and to compare drying conditions to each other. For instance heat exchanger, heat pumps, condense walls, absorption system etc.The used drying conditions are suitable for north European lumber and climate, but the initial conditions can be changed for analyses of other types of drying conditions. The program is a usable tool to analyses different types of technologies effect on the kiln energy efficiency and to compare drying conditions and different drying scheme to each other.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-31903 (URN)639de65f-e53e-461f-ae48-5b73145f5aff (Local ID)639de65f-e53e-461f-ae48-5b73145f5aff (Archive number)639de65f-e53e-461f-ae48-5b73145f5aff (OAI)
Conference
International IUFRO Wood Drying Conference : 30/07/2012 - 03/08/2012
Note
Godkänd; 2012; 20130306 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Andersson, J.-O. (2012). Improving energy use in sawmills: from drying kilns to national impact (ed.). (Licentiate dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Improving energy use in sawmills: from drying kilns to national impact
2012 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Increased concern about environmental problems has amplified the public`s interest inenergy usage. The improved subsidies for biomass, together with the rising energy priceshave made biomass a desirable product on the energy market. Energy intensive industries inthe field of wood and biomass now have nowadays an opportunity to decrease energyconsumption and to sell their biomass surplus on the energy market.This Licentiate thesis focuses on strategies to decrease biomass usage in sawmill industriesin order to increase their surplus biomass and increase their profit. This is done throughsystem analysis of sawmill industries in terms of mass and energy flows. The energyanalysis focuses on the drying kiln using psychrometric and thermodynamic relationships.State-of-the-art technologies, available on the market, have been studied to determine theirpossible effect on the total energy usage in the sawmills.This study was undertaken to determine the national use of energy due to sawmills and thepotential magnitude of improvements. Sawmills are important suppliers to the biomassmarket, since medium to large capacity sawmills contribute with 95% of the Swedish annuallumber (sawn boards) production (17.3 Mm3) with a lumber interchange of only 47%. Therest of the timber (unsawn logs) is transformed into biomass through the lumber productionprocesses. An essential part (12%) of the timber is used for supplying heat to the productionprocesses, mainly to the drying process which is the most time and heat consuming processin the sawmill. The main conclusions are that the heat demand for drying lumber in Swedishsawmills was found to be 4.9 TWh per year and the drying process can be made moreeffective by use of state-of-the-art technologies. Hence the internal use of biomass insawmills can be decreased, thereby increasing the biomass that can be sold to the marketand/or to generate heat and/or electricity, resulting in more profitable sawmills and asignificant increased supply of biomass to the market.It was also found that with available state-of-the-art technologies it is possible to recycle theheat in the evacuated air from the dryer, and if the recovered heat is used for heat sinksinside or close to the sawmill a large decrease of the energy usage can be achieved. If thetechnologies are implemented up to 5.56 TWh of equivalent biomass can be saved,depending on the technology, the specific sawmill conditions, kiln settings and dryingsystem operation. However, some of the considered technologies consume a substantialamount of electricity, so the economic benefit should be carefully evaluated.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2012
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-26713 (URN)fb8d0e75-22fd-4dea-a1bf-d5c52c21c901 (Local ID)978-91-7439-540-2 (ISBN)fb8d0e75-22fd-4dea-a1bf-d5c52c21c901 (Archive number)fb8d0e75-22fd-4dea-a1bf-d5c52c21c901 (OAI)
Note
Godkänd; 2012; 20121203 (andbra); LICENTIATSEMINARIUM Ämne: Energiteknik/Energy Engineering Examinator: Biträdande professor Lars Westerlund, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Diskutant: Universitetslektor Micael Öhman, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet, Skellefteå Tid: Torsdag den 13 december 2012 kl 09.00 Plats: E243, Luleå tekniska universitetAvailable from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-24Bibliographically approved
Andersson, J.-O. & Westerlund, L. (2011). Surplus biomass through energy efficient kilns (ed.). Paper presented at . Applied Energy, 88(12), 4848-4853
Open this publication in new window or tab >>Surplus biomass through energy efficient kilns
2011 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 12, p. 4848-4853Article in journal (Refereed) Published
Abstract [en]

The use of biomass in the European Union has increased since the middle of the 1990s, mostly because of high subsidies and CO2 emission regulation through the Kyoto protocol. The sawmills are huge biomass suppliers to the market; out of the Swedish annual lumber production of 16.4 Mm3, 95% is produced by medium to large-volume sawmills with a lumber quotient of 47%. The remaining part is produced as biomass. An essential part (12%) of the entering timber is used for supply of heat in their production processes, mostly in the substantial drying process. The drying process is the most time and heat consuming process in the sawmill. This study was undertaken to determine the sawmills’ national use of energy and potential magnitude of improvements. If the drying process can be made more effective, sawmills’ own use of biomass can be decreased and allow a considerably larger supply to the biomass market through processed or unprocessed biomass, heat or electricity production. The national electricity and heat usage when drying the lumber have been analysed by theoretical evaluation and experimental validation at a batch kiln. The main conclusion is that the heat consumption for drying lumber among the Swedish sawmills is 4.9 TW h/year, and with available state-of-the-art techniques it is possible to decrease the national heat consumption by approximately 2.9 TW h. This additional amount of energy corresponds to the market’s desire for larger energy supply.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-5786 (URN)10.1016/j.apenergy.2011.06.027 (DOI)000295387200062 ()2-s2.0-80052266676 (Scopus ID)3f809f0a-d477-47b8-9697-db367c1d1c64 (Local ID)3f809f0a-d477-47b8-9697-db367c1d1c64 (Archive number)3f809f0a-d477-47b8-9697-db367c1d1c64 (OAI)
Note
Validerad; 2011; 20110808 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Andersson, J.-O. & Westerlund, L. (2010). MIND based optimisation and energy analysis of a sawmill production line (ed.). In: (Ed.), (Ed.), PRES 2010: 13th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, 28 August - 1 September 2010, Prague, Czech Republic. Paper presented at Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction : 28/08/2010 - 01/09/2010 (pp. 1-5).
Open this publication in new window or tab >>MIND based optimisation and energy analysis of a sawmill production line
2010 (English)In: PRES 2010: 13th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, 28 August - 1 September 2010, Prague, Czech Republic, 2010, p. 1-5Conference paper, Published paper (Refereed)
Abstract [en]

The lumber drying process uses about 80 % of the total heat consumption in sawmills. Efforts to increase energy efficiency in lumber kilns were very restricted due to the low biomass prices between the 80th and 90th. Today with higher production and biomass prices, companies want to decrease their own use of biomass and increase the heating system efficiency. The study proposes alternative ways to reduce the heat consumption at batch kilns by recirculation of the evacuation air and addresses particular problem encountered in sawmills. Which produce their own heat and suffer from bottlenecks in the heating system due to high heat load from the dryers and increased production. The study shows the possibility to recycle the evacuation air from each kiln which reduces the overall heat consumption of the kilns by 12 %. At nationally basis this corresponds to a decrease of heat consumption of 440 GWh annually, among Swedish sawmill. This will decrease the individual heat consumption of the kilns, heat load in the heating system and the bottleneck effect in the drying process. The decreased own use of biomass brings benefits of more available biomass to the market and increased profits for the sawmill.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-40490 (URN)fa583a10-02bf-11e0-803d-000ea68e967b (Local ID)fa583a10-02bf-11e0-803d-000ea68e967b (Archive number)fa583a10-02bf-11e0-803d-000ea68e967b (OAI)
Conference
Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction : 28/08/2010 - 01/09/2010
Note
Godkänd; 2010; 20101208 (janand)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
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