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Kjellström, Björn
Publications (10 of 25) Show all publications
Olwa, J., Öhman, M., Pettersson, E., Boström, D., Okure, M. & Kjellström, B. (2013). Potassium retention in updraft gasification of wood (ed.). Paper presented at . Energy & Fuels, 27(11), 6718−6724
Open this publication in new window or tab >>Potassium retention in updraft gasification of wood
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2013 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 27, no 11, p. 6718−6724-Article in journal (Refereed) Published
Abstract [en]

The release of compounds of K with producer gas during biomass gasification is known to play significant roles in fouling and high-temperature corrosion in boilers and high-temperature heat exchangers as well as blades in gas turbines that use producer gas as fuel. These phenomena are a major setback in the application of biomass fuel in combination with advanced process conditions. Updraft gasification provides gas filtering by the fuel bed with a gas cooling effect, conditions anticipated to create an avenue for K retention in the gasifier. The objective of this study was to determine the K retention potential of such gasifiers during wood gasification. Samples for the determination of the fate of K compounds included in the feedstock were collected from the generated producer gas using Teflon filters and gas wash bottles and also from wall deposits and ash residues. Analyses of samples were carried out using inductively coupled plasma–atomic emission spectrometry/mass spectrometry and X-ray diffraction methods. The finding was that about 99% of K was retained in the gasifier. K was found in the ash samples as a crystalline phase of K2Ca(CO3)2(s) (fairchildite). A possible reaction mechanism leading to the formation of K2Ca(CO3)2 is discussed in the paper. The 1% K understood as released, equivalent to 1200 ppbw content of K entrained in the producer gas stream, exceeds a known limit for application of the gas in conventional gas turbines. This would suggest application of the gas in an externally fired gas turbine system, where some limited K and other depositions in the heat exchanger can be relatively easy to handle.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-15843 (URN)10.1021/ef401179f (DOI)000327557800041 ()2-s2.0-84888360866 (Scopus ID)f672b95c-ecd2-4757-aaaa-cb366d061e18 (Local ID)f672b95c-ecd2-4757-aaaa-cb366d061e18 (Archive number)f672b95c-ecd2-4757-aaaa-cb366d061e18 (OAI)
Note
Validerad; 2013; 20131015 (ohmmar)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Eriksson, G. & Kjellström, B. (2011). Corrigendum to: Assessment of combined heat and power (CHP) integrated with wood-based ethanol production [Applied Energy 87 (12) (2010) 3632-3641] (ed.). Paper presented at . Applied Energy, 88(5), 1997-1998
Open this publication in new window or tab >>Corrigendum to: Assessment of combined heat and power (CHP) integrated with wood-based ethanol production [Applied Energy 87 (12) (2010) 3632-3641]
2011 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 5, p. 1997-1998Article in journal, Editorial material (Other academic) Published
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-6861 (URN)10.1016/j.apenergy.2010.11.014 (DOI)000288360500057 ()2-s2.0-79551549708 (Scopus ID)52e0b360-03b0-11e0-b767-000ea68e967b (Local ID)52e0b360-03b0-11e0-b767-000ea68e967b (Archive number)52e0b360-03b0-11e0-b767-000ea68e967b (OAI)
Note
Godkänd; 2011; 20101209 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Eriksson, G. & Kjellström, B. (2010). Assessment of combined heat and power (CHP) integrated with wood-based ethanol production (ed.). Paper presented at . Applied Energy, 87(12), 3632-3641
Open this publication in new window or tab >>Assessment of combined heat and power (CHP) integrated with wood-based ethanol production
2010 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, no 12, p. 3632-3641Article in journal (Refereed) Published
Abstract [en]

A techno-economic assessment is made of wood-based production of ethanol, where the by-products are used for internal energy needs as well as for generation of electricity, district heat and pelletised fuel in different proportions for external use. Resulting ethanol production costs do not differ much between the options but a process where electricity generation is maximised by use of the solid residues as fuel for a combined cycle is found to give 20% more reduction of green-house gas emissions per liter of ethanol produced than the other options. Maximising electricity generation at the expense of district heat generation also allows more freedom when suitable sites for ethanol plants are looked for. Use of gasified biofuel for a combined cycle power plant is a demonstrated technology, however, the low ash and alkali content of the hydrolysis residue may allow direct combustion in the gas turbine topping cycle. This would reduce the necessary investment considerably. The potential advantages of using a combined cycle for maximising the electric power output from an energy combinate, producing ethanol and electricity from biomass, justifies further exploration of the possibilities for using hydrolysis residue directly as gas turbine fuel.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-2618 (URN)10.1016/j.apenergy.2010.06.012 (DOI)000281657000003 ()2-s2.0-77955658617 (Scopus ID)042844c0-90c1-11df-8806-000ea68e967b (Local ID)042844c0-90c1-11df-8806-000ea68e967b (Archive number)042844c0-90c1-11df-8806-000ea68e967b (OAI)
Note
Validerad; 2010; 20100716 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Ilskog, E. & Kjellström, B. (2008). And then they lived sustainably ever after?: assessment of rural electrification cases by means of indicators (ed.). Paper presented at . Energy Policy, 36(7), 2674-2684
Open this publication in new window or tab >>And then they lived sustainably ever after?: assessment of rural electrification cases by means of indicators
2008 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 36, no 7, p. 2674-2684Article in journal (Refereed) Published
Abstract [en]

Increasing the current low level of access to electricity in developing countries is important for economic development and poverty eradication. Encouraging the involvement of new actors for implementation of rural electrification projects is a relatively new policy. At the same time, it is required that the projects contribute to sustainable development. It is therefore of interest to investigate whether, for instance, private sector involvement can contribute more to some aspects of sustainability than the conventional approach where rural electrification is the responsibility of a government utility. It seems that so far no studies have addressed this issue.This paper presents findings from field trips to seven rural electrification areas in Eastern and Southern Africa and shows how these studies can be used to illustrate different dimensions of sustainability by means of indicators.The field studies generated valuable experiences regarding collection of data for evaluation of the indicators and illustrate some difficulties associated with comparing the different aspects of sustainability.The evaluation indicates that the national utilities perform better from a social/ethical perspective, whereas the private organisations and the community-based organisations manage their client-relation issues in a more sustainable way.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-6300 (URN)10.1016/j.enpol.2008.03.022 (DOI)000257725900037 ()2-s2.0-44649117078 (Scopus ID)48495460-3ba9-11dd-8e42-000ea68e967b (Local ID)48495460-3ba9-11dd-8e42-000ea68e967b (Archive number)48495460-3ba9-11dd-8e42-000ea68e967b (OAI)
Note
Validerad; 2008; 20080616 (keni)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Ilskog, E., Kjellström, B., Gullberg, M., Katyega, M. & Chambala, W. (2005). Electrification co-operatives bring new light to rural Tanzania (ed.). Paper presented at . Energy Policy, 33(10), 1299-1307
Open this publication in new window or tab >>Electrification co-operatives bring new light to rural Tanzania
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2005 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 33, no 10, p. 1299-1307Article in journal (Refereed) Published
Abstract [en]

One possibility to accelerate the progress of rural electrification in developing countries could be to form independent electrification co-operatives that are allowed to generate and distribute electric power and set their own tariffs. This approach has been successfully tried in the village Urambo, located about 80 km west of Tabora in Tanzania. The co-operative was formed in 1993 and started regular operation in 1994 with 67 consumers. The co-operative received initial financial support for rehabilitation of a diesel power plant and some other investments. The national utility TANESCO has provided technical support and training for operators and an accountant. Despite a tariff more than 15 times higher than in the nearby town Tabora that is served by TANESCO, the number of consumers in Urambo has been growing and reached 241 in October 2002. About 70% of the supplied electricity in 2002 was used by households, 15% in businesses, 12% in institutions and public buildings and approximately 3% for street lighting. The reliability of the supply has improved from 80% in 1994, to 97% during 2002. The experiences must be considered as very promising. Several more electrification co-operatives have been formed in Tanzania and are looking for financing for the necessary initial investments.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-6035 (URN)10.1016/j.enpol.2003.12.006 (DOI)000228206800007 ()2-s2.0-11244249793 (Scopus ID)43a8bfd0-cb26-11db-b3ed-000ea68e967b (Local ID)43a8bfd0-cb26-11db-b3ed-000ea68e967b (Archive number)43a8bfd0-cb26-11db-b3ed-000ea68e967b (OAI)
Note
Validerad; 2005; 20070202 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
McKeough, P., Solantausta, Y., Kyllönen, H., Faiij, A., Hamelinck, C., Wagener, M., . . . Kjellström, B. (2005). Techno-economic analysis of biotrade chains: upgraded biofuels from Russia and Canada to the Netherlands (ed.). Paper presented at . Espoo: VTT Building and Transport
Open this publication in new window or tab >>Techno-economic analysis of biotrade chains: upgraded biofuels from Russia and Canada to the Netherlands
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2005 (English)Report (Other academic)
Abstract [en]

This study consisted of in-depth techno-economic analyses of biofuel upgrading processes and of whole biotrade chains. The chains encompassed the production of pyrolysis oil or pellets from biomass residues in the source regions, the transportation of the upgraded fuels internationally over long distances and the final utilisation of the fuels. The techno-economic analysis of the biofuel upgrading processes was undertaken primarily to generate techno-economic data that were needed as input data for the assessment of the biotrade chains. The evaluation of pyrolysis-oil production was deemed to be one of the most reliable assessments made to date. The estimated pyrolysis-oil production costs, e.g. below 25 EUR/MWh for stand-alone production from forestry residues, compare favourably with the current consumer-prices of heavy fuel oil in many European countries. Integration of the pyrolysis process with an industrial combined heat and power (CHP) plant would lower the production costs by more than 20%. The production of pellets was assessed to be somewhat more energy-efficient and more cost-efficient than the production of pyrolysis oil. However, the higher production costs of pyrolysis oil would be counteracted by lower costs in connection with product handling and utilisation. Four international biotrade chains were analysed in detail. The chains cover two source regions, North-Western Russia and Eastern Canada, and two traded commodities, pyrolysis oil and pellets. The chains terminate in the Netherlands where the imported biofuels are co-fired with coal in condensing power stations. The costs of the delivered biofuels were estimated to be in the range 18-30 EUR/MWh, with the costs of pellets about 25% lower than those of pyrolysis oil. The estimated electricity-generation costs displayed little dependence on the type of biofuel - pyrolysis oil or pellets - because the costs associated with the utilisation of the biofuels for co-firing are higher for the pellets. For the Canada-Netherlands chains based on zero-cost sawmilling residues, the costs of the delivered biofuels were estimated to be about 20% lower, and the electricity-generation costs about 10% lower, than those of the Russia-Netherlands chains. With the electricity consumption calculated as the equivalent amount of fuel that would be needed for its generation, the energy consumptions of the biotrade chains, prior to the end-use of the bioftiels, were estimated to be in the range 13-23% of the energy content of the original biomass residues. Local-utilisation alternatives were also evaluated. It was concluded that, particularly when the local reference energy system is carbon intensive, local utilisation can be a more cost-efficient and a more resource-efficient option than international trade and use of biomass resources elsewhere. This type of comparison is, however, very dependent on both the greenhouse-gas emission intensities and the costs of the reference energy systems in the exporting and importing regions. In practice, there are many factors which may limit local utilisation or make utilisation of biomass resources elsewhere more attractive. Obviously, when increased local utilisation is not feasible, exporting surplus biofuel is a highly beneficial and fully justified option. Other drivers for international bio-energy trade, such as improving access to markets, developing biomass production potentials over time and securing stable supply and demand, fuel supply security and other issues were not part of the present work programme. Overall, it was concluded that biotrade will have a definite and important role to play in reducing humankind's dependency on fossil fuels

Place, publisher, year, edition, pages
Espoo: VTT Building and Transport, 2005. p. 40
Series
V T T Tiedotteita, ISSN 1235-0605 ; 2312
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-24074 (URN)995df240-3687-11df-be5c-000ea68e967b (Local ID)951-38-6745-5 (ISBN)995df240-3687-11df-be5c-000ea68e967b (Archive number)995df240-3687-11df-be5c-000ea68e967b (OAI)
Note

Godkänd; 2005; 20100323 (andbra)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Gullberg, M., Ilskog, E., Katyega, M. & Kjellström, B. (2005). Village electrification technologies: an evaluation of photovoltaic cells and compact fluorescent lamps and their applicability in rural villages based on a Tanzanian case study (ed.). Paper presented at . Energy Policy, 33(10), 1287-1298
Open this publication in new window or tab >>Village electrification technologies: an evaluation of photovoltaic cells and compact fluorescent lamps and their applicability in rural villages based on a Tanzanian case study
2005 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 33, no 10, p. 1287-1298Article in journal (Refereed) Published
Abstract [en]

Electrification of remote sites in developing countries is often realised trough diesel generator sets and an electric distribution network. This was also the technology used in the village Urambo, where the first rural electrification co-operative in Tanzania was started in 1994. Climate change however calls for decreased fossil fuel combustion worldwide and new technologies have been further developed since the erection of the diesel generator sets in Urambo. It is therefore not obvious that electrification of other rural areas shall follow the Urambo example. In this article, the situation for 250 electricity consumers in Urambo will be demonstrated and the implications for them of introducing new technologies will be evaluated. Technology options regarded in the study are individual photovoltaic (PV) power systems and either incandescent lamps, tube lights or compact fluorescent lights (CFLs) supplied by diesel generation. The different options have been evaluated with respect to consumer costs and environmental impact. The results of the comparison show that PV generation is able to compete with diesel generation if combined with incandescent lamps, but not when tube lights or CFLs are used in the conventional supply system. It should be noted, however, that while the diesel option offer financially more attractive solutions, individual PV systems do not result in any CO2 emissions. Furthermore, PV systems normally have a higher reliability. However, since the diesel option is not only cheaper but also offers a wider range of energy services and facilitates, future connection to the national electric grid, the conclusion is that this is preferable before individual PV systems for communities similar to Urambo, if the consumers shall pay the full cost of the service.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-3489 (URN)10.1016/j.enpol.2003.12.005 (DOI)000228206800006 ()2-s2.0-11244322015 (Scopus ID)15200f60-cb26-11db-b3ed-000ea68e967b (Local ID)15200f60-cb26-11db-b3ed-000ea68e967b (Archive number)15200f60-cb26-11db-b3ed-000ea68e967b (OAI)
Note
Validerad; 2005; 20070203 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Eriksson, G., Kjellström, B., Lundqvist, B. & Paulrud, S. (2004). Combustion of wood hydrolysis residue in a 150 kW powder burner (ed.). Paper presented at . Fuel, 83(11-12), 1635-1641
Open this publication in new window or tab >>Combustion of wood hydrolysis residue in a 150 kW powder burner
2004 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 83, no 11-12, p. 1635-1641Article in journal (Refereed) Published
Abstract [en]

A combustion test has been made with residues from hydrolysis of wood for fuel ethanol production. A 150 kW powder burner was used. Fuel feeding and combustion were stable. The average concentration of CO in the stack gas was 8 mg/MJ, the average concentration of NOx was 59 mg/MJ and the average total hydrocarbon concentration was below 1 ppm, at an average O2-concentration of 4.6%. The low contents of potassium and sodium in the hydrolysis residue make the material attractive as a gas turbine fuel and the conclusion of this test is that direct combustion may be a feasible approach for gas turbine applications.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-13067 (URN)10.1016/j.fuel.2004.02.012 (DOI)000222231000021 ()2-s2.0-2442425380 (Scopus ID)c39921b0-aa2b-11db-aeba-000ea68e967b (Local ID)c39921b0-aa2b-11db-aeba-000ea68e967b (Archive number)c39921b0-aa2b-11db-aeba-000ea68e967b (OAI)
Note
Validerad; 2004; 20070122 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Nturanabo, F., Okure, M. & Kjellström, B. (2002). The role of non-woody biomass as an energy source in the tropics: the case of Uganda (ed.). In: (Ed.), (Ed.), Proceedings of Energy and Environment 2002: . Paper presented at Energy and the Environment : 23/10/2002 - 25/10/2002 (pp. 135-145). : Hrvatsko Udruzenje za Suncevu Energiju
Open this publication in new window or tab >>The role of non-woody biomass as an energy source in the tropics: the case of Uganda
2002 (English)In: Proceedings of Energy and Environment 2002, Hrvatsko Udruzenje za Suncevu Energiju , 2002, p. 135-145Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Hrvatsko Udruzenje za Suncevu Energiju, 2002
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-31001 (URN)508351e0-b46d-11db-bf94-000ea68e967b (Local ID)953-6886-03-0 (ISBN)508351e0-b46d-11db-bf94-000ea68e967b (Archive number)508351e0-b46d-11db-bf94-000ea68e967b (OAI)
Conference
Energy and the Environment : 23/10/2002 - 25/10/2002
Note
Godkänd; 2002; 20070204 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Gabra, M., Nordin, A., Öhman, M. & Kjellström, B. (2001). Alkali retention/separation during bagasse gasification: a comparison between a fluidised bed and a cyclone gasifier (ed.). Paper presented at . Biomass and Bioenergy, 21(6), 461-476
Open this publication in new window or tab >>Alkali retention/separation during bagasse gasification: a comparison between a fluidised bed and a cyclone gasifier
2001 (English)In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, no 6, p. 461-476Article in journal (Refereed) Published
Abstract [en]

Biomass fuelled integrated gasification/gas turbines (BIG/GTs) have been found to be one of the most promising technologies to maximise electricity output in the sugar industry. However, biomass fuels contain alkali metals (Na and K) which may be released during the gasification processes and cause deleterious effects on the downstream hardware (e.g. the blades of gas turbines). Much research has therefore been focused on different kinds of gas cleaning. Most of these projects are using a fluidised bed gasifier and includes extensive gas cleaning which leads to a high capital investment. Increasing alkali retention/separation during the gasification may lead to improved producer gas quality and reduced costs for gas cleaning. However, very little quantitative information is available about the actual potential of this effect. In the present work, comparative bench-scale tests of bagasse gasification were therefore run in an isothermal fluidised bed gasifier and in a cyclone gasifier to evaluate which gasification process is most attractive as regards alkali retention/separation, and to try to elucidate the mechanisms responsible for the retention. The alkali retention in the fluidised bed gasifier was found to be in the range of 12-4% whereas in the cyclone gasifier the alkali separation was found to be about 70%. No significant coating of the fluidised bed's bed material particles could be observed. The SEM/EDS and the elemental maps of the bed material show that a non-sticky ash matrix consisting of mainly Si, Al and K were distributed in a solid form separated from the particles of bed material. This indicates the formation of a high temperature melting potassium containing silicate phase, which is continuously scavenged and lost from the bed through elutriation.

National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-11334 (URN)10.1016/S0961-9534(01)00042-3 (DOI)000172364500007 ()2-s2.0-0035174727 (Scopus ID)a46e6840-b43f-11db-bf94-000ea68e967b (Local ID)a46e6840-b43f-11db-bf94-000ea68e967b (Archive number)a46e6840-b43f-11db-bf94-000ea68e967b (OAI)
Note
Validerad; 2001; 20070204 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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