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Agricultural residues, such as wheat straw, are feasible substrates for ethanol fermentation provided that pentoses and hexoses can be converted efficiently. Separate hydrolysis and cofermentation (SHCF) constitute a framework for improvement of conversion efficiency, because it permits independent optimization of the enzymatic hydrolysis and cofermentation steps. A drawback is that the high gluco
Wastewater treatment with activated sludge is the most common way of treating wastewater. The process relies on bacteria converting nutrients, BOD and COD into biomass, CO2 and N2. Even though the configuration of activated sludge processes and wastewater treatment plants varies there are common problems which are shared. Filamentous bulking sludge is one problem that is widespread and disturbs th
Diesel engines are one of the most important power generating units these days. Increasing greenhouse gas emissions level and the need for energy security has prompted increasing research into alternative fuels for diesel engines. Biodiesel is the most popular amongst the alternatives for diesel fuel as it is biodegradable, renewable and can be produced domestically from vegetable oils. In recent
Heat integration and industrial symbiosis have been identified as key strategies to foster energy eficient and low carbon manufacturing industries (see e.g. contribution of Working Group III in IPCC's 5th assessment report). As energy efficiency potentials through horizontal and vertical integration are highly specific by site and technology they are often not explicitly reflected in national ener
Germany's current efforts to decarbonize its electricity system are analysed. As nuclear power and fossil power plants equipped with carbon capture and storage were ruled out in 2011, renewable electricity generation (RES) together with electricity savings are the primary focus for achieving decarbonization. Germany aims to have RES account for at least 80% of its electricity by 2050. Achieving re
It is important to minimize transmission heat transfer losses through the building envelope when designing and building energy efficient buildings in heating dominated climates. In such a climate, a large part of the space heating demand is caused by transmission heat transfer losses through the building envelope. Calculations of these losses must be carried out in a correct way to ensure a proper
The purpose of decentralised solar district heating plants is to feed solar heat directly into district heating networks. This decentralised heat supply has to consider two major output conditions: a stable required feed-in supply temperature and a feed-in heat power equal to the heat output from the solar collectors. However, many installations cannot achieve the second output condition, since se
In the construction industry, sustainability and greening is more than just a passing trend. It has become an important agenda since the building sector has immense environmental impacts. It accounts for 42% of final energy consumption and about 35% of all greenhouse gas emissions. In order to meet these challenges, the construction industry needs to change and adopt new working procedures which t
To optimise district heating (DH) systems and simplify the transition towards the fourth generation of district heating, it is important to remove any bottlenecks existing in the DH network. DH bottlenecks are in this study defined as pipes with too high flow relative to the pipe diameter, resulting in difficulties to maintain sufficient differential pressure in the area beyond the pipe. The aim o
This article examines whether there exists any causal relationship between foreign trade and declining pollution in developed countries. In other words, do developed countries outsource their problems to less developed countries rather than solve them? The case study is the Swedish economy and the two environmental indicators employed are energy consumption and CO2 emissions. No causal relationshi
This study seeks to find answers to the question of how much competition is introduced by different types of regulation aimed at promoting electricity generated with renewable energies. For this purpose the partial equilibrium model is applied. Further analysis of the costs of governance for two realised regulations, the German EEG and the Texas RPS, is based on Transaction Cost Economics.
Experiments were conducted to study the energy efficiency of the impulse unit in the pilot-scale research paper machine at the Swedish Pulp and Paper Research Institute (STFI) In Stockholm, Sweden. The paper produced was made of kraft softwood pulp with basis weights of 60-120 g/m(2). The roll surface temperature ranged from ambient temperature to 350 degreesC and the press loads were between 400-
Solar-driven reduction of water to produce hydrogen is one of the most promising ways to develop sustainable cleanenergy for the future. The challenge in photocatalytic hydrogen evolution research is to design inexpensive catalystsand construct efficient hydrogen production systems. In this thesis, different photocatalytic hydrogen productionsystems consisting of catalysts, photosensitizers and sa
Behavioural change is expected to play a significant role in the transformation to a more energy efficient built environment. Despite this, current evaluation practice of interventions often overlook behavioural aspects in their ambition of advancing our knowledge on transformative change. Moreover, little attention is paid to how different research perspectives on human behaviour can complement e
This paper suggests a taxonomy for labeling deviating patterns in district heating (DH) customer data. The taxonomy contains several fault labels intended to register information about faults in the DH systems that cause deviations in customer data. This taxonomy is needed because the DH industry is currently missing a unanimous way to label identified faults. The lack of a taxonomy makes it hard
Plastics are widely used in our daily lives and industry. Unfortunaltely, most plastics are produced from non-renewable fossil resources. The transition toward sustainable resources such as various biomass is critically important for the future of plastic industry and the whole society. Polyesters consitute a major class of plastics, which are widely used in textiles, packaging and other applicati
The UK housing stock will play an important role in achieving the 2050 national carbon reduction targets. Upgrading the energy performance of the existing housing stock is a significant challenge because retrofit activities are shaped by a wide range of fragmented policies, programmes and actors. Existing approaches to housing retrofit focus on regulations, financial incentives and information pro
CO2 is a greenhouse gas that is believed to be one of the main contributors to global warming. Recent studies show that a combination of methanol as a renewable fuel and advanced combustion concepts could be a promising future solution to alleviate this problem. However, high unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions can be stated as the main drawback in low load operations whe
Real-time rendering is increasingly being performed on battery powered devices, such as laptops and mobile phones. As a result, performance in rendering time is not the only important factor, but the energy consumption is also becoming more and more important, as a lower energy usage directly translates to longer battery time. The main topic of this thesis is energy consumption of graphics process
