| 1. |
- Gourdon, Mathias, 1980, et al.
(författare)
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Pulp mill biorefineries
- 2013
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Ingår i: International Process Integration Jubilee Conference, Gothenburg, Sweden, March 18-20 2013.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Engdahl, Johan, et al.
(författare)
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Multicentre, national, investigator-initiated, randomised, parallel-group, register-based superiority trial to compare extended ECG monitoring versus standard ECG monitoring in elderly patients with ischaemic stroke or transient ischaemic attack and the effect on stroke, death and intracerebral bleeding : the AF SPICE protocol
- 2023
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Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 13:11
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Atrial fibrillation (AF) is a major risk factor for ischaemic stroke and transient ischaemic attack (TIA), and AF detection can be challenged by asymptomatic and paroxysmal presentation. Long-term ECG monitoring after ischaemic stroke or TIA is recommended by all major societies in cardiology and cerebrovascular medicine as a secondary prophylactic measure. However, data on stroke reduction are lacking, and the recommendations show significant diversity.Methods and analysis: AF SPICE is a multicentre, national, investigator-initiated, randomised, parallel-group, register-based trial comparing extended ECG monitoring versus standard ECG monitoring in patients admitted with ischaemic stroke or TIA, with a composite endpoint of stroke, all-cause-mortality and intracerebral bleeding. Patients aged ≥ 70 years without previous AF will be randomised 1:1 to control (standard ECG monitoring) or intervention (extended ECG monitoring). In the control arm, patients will undergo 48±24 hours (ie, a range of 24-72hours) of continuous ECG monitoring according to national recommendations. In the intervention arm, patients will undergo 14+14 days of continuous ECG monitoring 3months apart using an ECG patch device, which will provide an easy-accessed, well-tolerated 14-day continuous ECG recording. All ECG patch recordings will be read in a core facility. In cases of AF detection, oral anticoagulation will be recommended if not contraindicated. A pilot phase has been concluded in 2022, which will transcend into the main trial during 2023-2026, including approximately 30 stroke units. The sample size was calculated to be 3262 patients. The primary outcome will be collected from register data during a 36-month follow-up.Ethics and dissemination: Ethical approval has been provided by the Swedish Ethical Review Authority, reference 2021-02770. The trial will be conducted according to the ethical principles of the Declaration of Helsinki and national regulatory standards. Positive results from the study have the potential for rapid dissemination in clinical practice. Trial registration number NCT05134454.
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| 3. |
- Grip, Carl-Erik, et al.
(författare)
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Application of Pinch Analysis in an Integrated Steel Plant in Northern Sweden
- 2013
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Ingår i: ISIJ International. - : Iron and Steel Institute of Japan. - 0915-1559 .- 1347-5460. ; 53:7, s. 1202-1210
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Tidskriftsartikel (refereegranskat)abstract
- The energy system in a modern integrated steel plant is a complicated network of units exchangingenergy and matter with each other. System studies using process integration tools are important to avoidsub-optimization. At the steel plant in Luleå such studies have been carried out using a MILP-based mathematicalprogramming tool (reMIND), mainly because of its inherent flexibility for handling combinedflows and reactions of both matter and chemical, thermal and mechanical energy. There are, however,areas where the energy system is dominated by creation, transport and exchange of thermal energy, andwhere pinch analysis can be expected to be a valuable tool. For this reason a pinch targeting study wascarried out for the plant site of the integrated steel plant in Luleå. The coke plant and the iron making/steelmaking plant were both studied with three ambition levels of possible improvements. The study confirmedthat pinch analysis is a powerful tool for targeting energy savings in areas where thermal energyflows dominate the local energy system, e.g., the gas cleaning area at the coke plant. The study also indicatedthat a connection between the energy systems in the coke plant and the iron making/steelmakingwould be valuable. This is not 100% feasible because of distance, but, a common steam net could add adegree of flexibility.
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| 4. |
- Holmberg, Henrik, et al.
(författare)
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Minimization of total drying costs for a continuous packed-bed biomass dryer operating at an integrated chemical pulp and paper mill
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 71, s. 431-442
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a MILP (Mixed Integer Linear Programming) model for a continuous packed-bed biomass dryer. The model minimizes total drying costs, including both capital and operational costs, of the dryer. Heated air, which flows through a biomass bed and perforated conveyor, is used as drying gas by the dryer. We define the dryer size with the help of an experimentally-measured characteristic drying curve. The MILP model is tested in a case study where the dryer is assumed to have been installed at a Scandinavian pulp and paper mill. There are three different heat sources available for the heating of drying air: warm water at 60 °C, warm water at 80 °C and backpressure steam at the pressure of 0.4 MPa. The results indicate that, in practice, the use of only low-temperature warm water flows for heating of drying air is the most economic method when their prices are low (below 1 € MWh-1 in the case study). Warm water flows are usually waste heat from pulp and paper mills and their prices are low compared to the price of back-pressure steam (typically from 10 to 15 € MWh-1). The use of steam for drying may be reasonable if the price of warm water is for some reason clearly higher than the price of a typical waste-heat stream. The MILP model presented in this work can be used for minimizing drying costs of any material (not only biomass) dried in a continuous packed-bed dryer if the characteristic drying curve of the material is available.
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| 5. |
- Isaksson, Johan, 1983
(författare)
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Biomass Gasification-Based Biorefineries in Pulp and Paper Mills – Greenhouse Gas Emission Implications and Economic Performance
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The pulp and paper industry has a great opportunity to take advantage of the experience about forestry and wood handling for production of renewable fuels, chemicals and materials. Residues from forestry, i.e., tops, branches and stubs, have great potential to become a raw material that can replace crude oil or natural gas in many applications. By constructing a gasification-based production facility close to a pulp and paper mill, heat from the gasification process can be utilised in the mill, which replaces fuel for the boiler.The overall aim of this thesis has been to demonstrate how the pulp and paper industry can help cut global greenhouse gas (GHG) emissions and increase revenues by efficient use of biomass via gasification. In this thesis, the impact of different end products and biomass pretreatment measures connected to integrated gasification processes were evaluated regarding efficiency, GHG emissions and economic performance.The selection of end product from a gasification-based process (methanol, Fischer-Tropsch crude, synthetic natural gas or electricity, in this thesis) was demonstrated to significantly influence the required biomass input, if the sizing constraint was to replace heat production in the bark boiler. The size varied between approximately 200 MWbiomass and 600 MWbiomass. The selection of dryer type was shown to significantly impact the economic performance of a process despite its relatively low capital cost in relation to the total capital cost of 100 to 140 million Euros. With the preconditions in this study, thermal pretreatment (torrefaction or pyrolysis) of biomass may be beneficial with biomass-to-biofuel efficiencies reaching 68%.Assumptions regarding the electricity production sector influence whether an integrated gasification process is better than a stand-alone unit and whether onsite co-generation of electricity should be prioritised in favour of increased yield of biofuels. Sequestration of separated CO2 has been shown to improve the climatic performance of a system and increase its competitiveness against, e.g., co-firing biomass in a coal power plant, by increasing the potential from approximately 300 kgCO2,eq./MWhbiomass to 700 kgCO2,eq./MWhbiomass. Global GHG emission consequences are greatly affected by the assumed electricity production sector and selected end product.
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| 6. |
- Isaksson, Johan, 1983, et al.
(författare)
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Comparison between a detailed pinch analysis and the 'Heat Load Model for Pulp and Paper' - Case study for a Swedish thermo-mechanical pulp and paper mill
- 2012
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Ingår i: Chemical Engineering Transactions. - 2283-9216 .- 2283-9216. ; 29, s. 43-48
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Tidskriftsartikel (refereegranskat)abstract
- Pinch analysis has been used for several decades as a tool for making industrial processes more energy efficient by identifying process integration opportunities. Hakala et al. (2008) recognise that pinch analysis is a powerful tool when it comes to improving energy efficiency in mechanical pulp and paper mills, however often very time consuming due to the extensive need for input data. The heat load model for pulp and paper (HLMPP) tool was developed at Aalto University in Finland as a means of providing a flexible tool for a first quick scan of process integration potential. The intention of this study is to evaluate if the model can accurately estimate the data necessary for performing a pinch analysis for a Swedish thermo-mechanical pulp (TMP) and paper mill. Jönsson et al. (2010) used the HLMPP tool to evaluate the potential for steam savings for four Scandinavian TMP mills. It was found that the minimum steam demands were 2-20 % lower than the current consumptions in the mills. In this study, a detailed pinch analysis was carried out for one of the studied mills described by Jönsson (the mill with the lowest energy savings potential according to the HLMPP screening) to identify strengths and shortcomings of the HLMPP tool. An initial comparison shows that the pinch temperature and demand for hot and cold utility predicted by the HLMPP tool, as presented by Jönsson, differs from the detailed pinch analysis. However, further investigation showed that the HLMPP results can be aligned to the detailed data with good accuracy if more time and knowledge about the process is put in to the model.
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| 7. |
- Isaksson, Johan, 1983, et al.
(författare)
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Influence of Different Pretreatment Methods on Biomass Gasification and Production of Fischer-tropsch Crude Integrated with a Pulp and Paper Mill
- 2013
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Ingår i: Chemical Engineering Transactions. - 2283-9216 .- 2283-9216. ; 35, s. 559-564
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the influence on the system performance of different biomass pretreatment methods beforegasification and subsequent production of Fischer-Tropsch crude is considered. Entrained flow gasificationat high pressure is a well proven technology for coal as feedstock with the benefit of producing apractically tar free raw gas with a close to complete carbon conversion. The short residence time in thistype of gasifier requires a fuel, which is relatively dry and has a small particle size, to be pressurized fromambient conditions up to 20-50 bar. The small particle size can be acquired by grinding but this is highlyenergy intensive and feeding is challenging. Torrefaction is a thermal pretreatment method carried out ataround 300 °C which makes the biomass easier to grind, thus requiring less electricity, and makes thematerial less fibrous, while on the other hand requiring heat for the process. Pyrolysis is a process carriedout at around 500 °C which lets the biomass decompose into a gaseous, a liquid and a solid part. Thesolid part can be grinded and fed into the gasifier together with the liquid and gaseous phases. This willfurther facilitate the feeding but with a further increased heat demand compared to torrefaction. Thedifferent pretreatment methods and their impact on the overall biorefinery energy system have beenstudied and evaluated using process integration methodology. The results show that the excess heat froman FT process with a biomass input of 300 MW(HHV) can replace the solid fuel boiler in a large chemical pulpand paper mill. With the preconditions given for this study, thermal pretreatment of the biomass can bebeneficial in terms of system thermal efficiency.
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| 8. |
- Isaksson, Johan, 1983, et al.
(författare)
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Influence of dryer type on the performance of a biomass gasification combined cycle co-located with an integrated pulp and paper mill
- 2013
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 59, s. 336-347
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Tidskriftsartikel (refereegranskat)abstract
- Integration of biomass gasification with a pulp and paper mill is a possible route to create more value-added products. This route facilitates, for example, more advanced electricity generation and production of biomass based transportation fuels or chemical feedstock. Each unit operation in such a process affects overall efficiency as well as possibilities for process integration. In this paper, the impact of different dryer types in a biomass gasification combined cycle (BIGCC) has been evaluated in terms of efficiency and economic performance. The BIGCC was sized so that the excess heat would replace the current steam production from bark and oil. The results show that the dryer type can have a significant impact on economic performance and efficiencies. A BIGCC with an integrated belt dryer, utilizing excess heat to heat the drying air from the mill, can result in electrical efficiencies of up to around 40%, while e.g. a steam dryer can reach 36e37%. Choice of oxidant, air or oxygen, in the gasifier affects both capital and operational cost. Air was proven to be themost cost efficient solution for the cases evaluated in this study. The investment of around 100 to 140 million Euros for a BIGCC facility is profitable for most evaluated cases for an annuity factor of 0.1, while the net annual profit is negative for most cases when the annuity factor was increased to 0.2, even when including financial support for renewable electricity.
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| 9. |
- Isaksson, Johan, 1983, et al.
(författare)
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Integration of biomass gasification with a Scandinavian mechanical pulp and paper mill
- 2011
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Ingår i: Proceedings of the 24th International Conference on Efficiency, Cost, Optimisation, Simulation and Environmental impact of Energy Systems, ECOS 2011, Novi Sad, Serbia, July 4-7, 2011. ; , s. 3668-3679
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Konferensbidrag (refereegranskat)abstract
- The Scandinavian mechanical pulp and paper industry has been facing great challenges during the past decades, mainly because of a declining demand for newsprint, and higher prices on raw material and energy. One way of increasing profitability is to produce more value-addedproducts besides the production of pulp and paper, thus creating a “biorefinery”. Gasification of residues from forestry, falling bark and cutter shavings has been raised as a promising option for utilizing low-value biomass to produce syngas, which can be further synthesized to, forexample, transportation fuels or chemicals. In this paper, the results of a case study on biomass gasification integrated with a Swedish thermo-mechanical pulp and paper mill (TMP mill) are presented. The mill has an annual paperproduction of 760 000 tonnes and is co-located with a large saw mill. The demand for raw material to the saw mill is about twice as large as the product output, on a volume basis, which potentially leaves a substantial raw material base for a gasifier. A simplified pinch analysis usingthe HLMPP (Heat Load Model for Pulp and Paper) tool has earlier been performed for the studied TMP mill. This paper evaluates the integration of biomass gasification, includingproduction of electricity or liquid transportation fuels, with the studied TMP mill. It also presents the impact of such integration on the overall heat and mass balances. Proper pre-treatment of the biomass prior to gasification as well as treatment of the product gas have also beenevaluated with respect to heat integration aspects. The results of this initial study indicate an interesting match between the constituting parts, i.e. the pulp and paper mill, the saw mill and the production of electricity and transportation fuels. This work will therefore be followed by an economic evaluation based on a more technically detailed study.
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| 10. |
- Isaksson, Johan, 1983, et al.
(författare)
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Integration Of Biomass Gasification With A Scandinavian Mechanical Pulp And Paper Mill - Consequences For Mass And Energy Balances And Global CO2 Emissions
- 2012
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 44:1, s. 420-428
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Tidskriftsartikel (refereegranskat)abstract
- The Scandinavian mechanical pulp and paper industry has been facing great challenges during the pastdecades, mainly because of declining demand for newsprint, and higher prices on raw material andenergy. One way of increasing profitability is to produce more value-added products besides theproduction of pulp and paper. In this study, integration potentials of three possible future biomassgasification-based energy mills with an existing thermo-mechanical pulp (TMP) mill, co-located witha sawmill, have been evaluated. The product gas was utilized for electricity production in a gas turbine,for production of methanol or for production of FischereTropsch (FT) liquids. Integration of the energymills showed good potential as the TMP mill constitutes a heat sink for which the excess heat from theenergy mills can be utilized all year round. However, since there is little excess heat from the TMP mill atthe required level to be utilized for biomass drying, for example, heat integration is typically one way. Ithas also been shown that integration of biomass gasification with a TMP mill results in larger CO2emissions reduction than stand-alone operation. Still, compared to co-firing biomass in a coal powerplant, the energy mills all have lower potentials for CO2 emissions reduction.
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