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Göteborg, Sweden

Eriksson K.,CIT Industriell Energi | Karlstrom A.,Chalmers University of Technology
International Mechanical Pulping Conference, IMPC 2014, part of PulPaper 2014 Conference | Year: 2014

The objective of this research project was to develop measurement techniques to strengthen the knowledge about fiber distribution inside refining zones. A method where light extinction, dynamic pressure and temperature are simultaneously measured at high sampling rates were developed and evaluated on a pilot refiner. The characteristics of the sampled signals were clearly affected by the changes process conditions like changes in production rate, changes in dilution water feed rate and changes in plate gap. It was verified that measurement techniques like this can be used for qualitative studies on fiber distribution inside the refining zones and the results obtained strengthen several earlier hypotheses in the area.

Andersson V.,Chalmers University of Technology | Franck P.-A.,CIT Industriell Energi | Berntsson T.,Chalmers University of Technology
International Journal of Greenhouse Gas Control | Year: 2014

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°C down to 90°C. At temperatures lower than 120°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°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°C. © 2013 Elsevier Ltd.

Isaksson J.,Chalmers University of Technology | Asblad A.,CIT Industriell Energi | Berntsson T.,Chalmers University of Technology
Chemical Engineering Transactions | Year: 2012

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. Copyright © 2012, AIDIC Servizi S.r.l.

Hackl R.,Chalmers University of Technology | Andersson E.,CIT Industriell Energi | Harvey S.,Chalmers University of Technology
Energy | Year: 2011

Rising fuel prices, increasing costs associated with emissions of green house gases and the threat of global warming make efficient use of energy more and more important. Industrial clusters have the potential to significantly increase energy efficiency by energy collaboration. In this paper Sweden's largest chemical cluster is analysed using the total site analysis (TSA) method. TSA delivers targets for the amount of utility consumed and generated through excess energy recovery by the different processes. The method enables investigation of opportunities to deliver waste heat from one process to another using a common utility system.The cluster consists of 5 chemical companies producing a variety of products, including polyethylene (PE), polyvinyl chloride (PVC), amines, ethylene, oxygen/nitrogen and plasticisers. The companies already work together by exchanging material streams. In this study the potential for energy collaboration is analysed in order to reach an industrial symbiosis. The overall heating and cooling demands of the site are around 442. MW and 953. MW, respectively. 122. MW of heat is produced in boilers and delivered to the processes.TSA is used to stepwise design a site-wide utility system which improves energy efficiency. It is shown that heat recovery in the cluster can be increased by 129. MW, i.e. the current utility demand could be completely eliminated and further 7. MW excess steam can be made available. The proposed retrofitted utility system involves the introduction of a site-wide hot water circuit, increased recovery of low pressure steam and shifting of heating steam pressure to lower levels in a number heat exchangers when possible. Qualitative evaluation of the suggested measures shows that 60. MW of the savings potential could to be achieved with moderate changes to the process utility system corresponding to 50% of the heat produced from purchased fuel in the boilers of the cluster.Further analysis showed that after implementation of the suggested energy efficiency measures there is still a large excess of heat at temperatures of up to 137 °C. © 2011 Elsevier Ltd.

Andersson V.,Chalmers University of Technology | Franck P.-A.,CIT Industriell Energi | Berntsson T.,Chalmers University of Technology
International Journal of Greenhouse Gas Control | Year: 2016

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€/t for the low-temperature cases (TReb=90°C) and 39-44€/t for the high-temperature cases (TReb=120°C). © 2015 Elsevier Ltd.

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