The Swedish pulp and paper industry meets higher demand for energy efficiencyi mprovements with increasing energy prices and changes in the Swedish renewable energy certificate system. One action of energy efficiency improvement is by using secondary heat, that otherwise would have been treated as waste heat, for use in a system with lower temperature demands. The aim of this Master´s thesis is to identify possible secondary heat sources in a typical Swedish pulp and paper mill and to investigate what economic benefits the secondary heat will provide when being used for pre heating of wood chips to a kraft digester. The Master´s thesis focuses on three secondary heat sources; dry warm air, warm water and moisture saturated warm air located inside the pulp or paper mill. Two types of kraft digesters are simulated within this study, a typical Scandinavian digester and a modern twin vessel steam phase digester. Due to quality aspects and low temperature level drying is the drying technology with dry warm air rejected. Using warm water in direct contact with wood chips increases the quantity of water to the evaporation plant and thus reduced pulp or paper production and is therefore also rejected. The thesis nevertheless indicates a goodopportunity for further investigation of using moisture saturated warm air for preheating of wood chips. The humid air, from a drying machine or produced from secondary heat warm water, is used in a theoretical modified belt drier. Conservative assumptions regarding heat transfer and investment cost calculations yield a yearly net saving for a typical Swedish pulp mill at over 5 MSEK with a return on investment at 7years.

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In this study, an energy audit of a cultural-historical building in a Nordic climate was carried out. The study has been carried out by studying old drawings to calculate ar-eas of the building and taking part in compiled data from the property owner. The building's energy supply and energy losses have been calculated in order to be able to identify areas for improvement and ultimately provide action proposals. For the proposed measures, the idea is to reduce energy use. At the same time, the profita-bility is examined using present value calculation to see if the energy efficiency measures are profitable investments. Several different measures have been investi-gated through literature studies where the potential to make older buildings more energy efficient is great. These show that certain problems arise when the building has a cultural-historical value. These buildings have special rules to preserve the cul-tural-historical value and it is often difficult to get measures that change the appear-ance of the building. Measures that have been calculated more carefully include re-placement of windows and replacement of thermostatic valves in the heating system. Window change possibilities are limited by conservation requirements; the price will therefore be higher and profitability calculations show that it is not profitable to invest in new highly insulating ones. Current changes to thermostatic valves show profitability calculations that such an investment is profitable. No comfort measure-ments were made in the study, but measures such as improving the insulating ability of windows and installing thermostats on heating systems are both factors that will affect thermal comfort for the better. The result from the energy mapping shows that the building's specific energy use is 137 kWh/m2, year. / I den här studien genomfördes en energikartläggning av en kulturhistorisk byggnad i nordiskt klimat. Studien har genomförts genom att studera gamla ritningar för att beräkna areor på byggnaden och tagit del av sammanställda data från fastighetsäga-ren. Byggnadens energitillförsel och energiförluster har beräknats för att kunna identifiera förbättringsområden och till slut ge åtgärdsförslag. För de framförda åt-gärdsförslagen är tanken att minska energianvändningen. Samtidigt undersöks lön-samheten med hjälp av nuvärdeskalkyl för att se om energieffektiviseringsåtgärderna är lönsamma investeringar. Flera olika åtgärder har undersökts genom litteraturstu-dier där potentialen till att energieffektivisera äldre byggnader är stor. Dessa visar att vissa problem uppstår när byggnaden har ett kulturhistoriskt värde. Dessa bygg-nader har speciella regler för att bevara det kulturhistoriska värdet och det är ofta svårt att få göra åtgärder som förändrar byggnadens utseende. Åtgärder som har be-räknats mer noggrant innefattar fönsterbyte och byte till termostatventiler i värme-systemet. Fönstren begränsas av bevarandekrav; priset blir därmed högre och lön-samhetsberäkningar visar att det inte är lönsamt att investera i nya högisolerande så-dana. Gällande byte till termostatventiler visar lönsamhetsberäkningar på att sådan investeringen är lönsam. Inga komfortmätningar gjordes i studien men åtgärder så som att förbättra fönsters isoleringsförmåga och installation av termostater på vär-mesystem är båda faktorer som kommer att påverka den termiska komforten till det bättre. Resultatet från energikartläggningen visar att byggnadens specifika energian-vändning är 137 kWh/m2, år.