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The transition to a bioeconomy, in which resources from biowaste could be reclaimed for the production of chemicals, materials or fuels, could contribute to the establishment of a sustainable society by replacing fossil fuels as raw materials. The core of this bioeconomy would be biorefineries, which are similar to petroleum-based refineries, but are facilities where biowaste is processed and refined through different chemical and/or biochemical processes. There are already some commercial-scale biorefineries that utilize edible biomass, such as corn or sugarcane, to produce mainly fuels. However, edible biomass can hardly be considered a biowaste, and there is an ethical conflict between the use of such resources for food and the production of energy. An alternative strategy has been developed to utilize non-edible materials such as forest and agricultural residues in biorefineries, but the relatively high price of these residues has prevented biorefineries from being economically viable.This thesis presents a framework for the redesign of current biorefineries so that they can use low-value waste as feedstock. This shift in feedstock would improve not only the economics of biorefineries, as feedstock cost accounts for almost one third of the total production cost, but also their environmental performance, as it would be possible to valorize residues that are otherwise incinerated or landfilled. The framework was developed based on research on animal bedding, i.e. a mixture of manure and straw, and cotton-based waste textiles.The first step involves the adaptation of analytical methods so that they can be applied to these high-complexity and variable low-value residues. Since low-value waste is usually unsorted, fractionation will be required to separate the different materials so that each fraction can be analyzed separately with conventional methods. An example of such fractionation is presented for the case of animal bedding, where manure and straw were separate

For the year 2020, the European Union has set common goals to aim for regarding the environment. One of them being to reduce the green house gas (GHG) emissions by 20 percent. The world population is increasing, consequently increasing the demand for energy and food. Since the use of fossil sources is neither sustainable nor environmentally friendly, new techniques of meeting the energy demand need to be found, starting with one of the biggest contributors to GHG – the transportation sector. Alternative fuels such as bioethanol need to substitute today’s fossil fuels. Bioethanol in particular can be made from materials such as sugar- or starch-based crops, referred to as first generation (1G) bioethanol. It can also be produced from lignocellulosic substrates, which in this case is referred to as second generation (2G) bioethanol. In case of 2G bioethanol, the sugar components that are necessary for the production of bioethanol are difficult to access. This drawback makes the process of 2G bioethanol production more challenging. However, 2G ethanol does not compete with the food market, per se. The aim of this thesis was to investigate different fermentation configurations using animal bedding as the raw material. Bioethanol from animal bedding, can be referred to as 2G bioethanol. The investigation was conducted experimentally at the Department of Chemical Engineering at LTH. The animal bedding was collected at a farm in Køge, Denmark. It was once washed with water and later soaked in 0.4 wt-% sulfuric acid. The animal bedding was pretreated in a steam explosion reactor at 190°C for 10 minutes. Results showed that it is possible to produce bioethanol from animal bedding. When using simultaneous saccharification and fermentation (SSF), an ethanol yield above 0.47 g ethanol/g glucose can be obtained. A slightly higher yield (0.51 g ethanol/g glucose) was achieved when using fed-batch instead of batch. Since it was desired to utilize as much sugar as possible from the, Från avfall till bioetanol - en undersökning av bioetanolproduktion från djupströ Under de senaste 50 åren har befolkningen på vår planet fördubblats, vilket har lett till att energiförbrukningen har ökat drastiskt. En av de främsta bovarna är transportsektorn, som dessutom medför stora utsläpp av växthusgaser. Ett sätt att minimera dessa utsläpp är att använda sig av miljövänliga transportmedel så som el- och gasbilar. Dock är körsträckan för dessa fordon oftast kortare, eftersom man måste tanka/ladda oftare än fordon som drivs på fossila bränslen. Ett starkt alternativ för att successivt eftersträva att nyttjandet av miljövänliga bränslemedel är fullständig är användning av bioetanol och biodiesel. Intresset för nya bränslemedel är enormt och i Sverige subventioneras konsumenter till miljövänliga motorfordon av staten. I denna studie som utförts vid institutionen för kemiteknik vid Lunds Tekniska Högskola har bioetanolproduktionen från djupströ studerats. Djupströ är en blandning av komposterat halm och gödsel som lagrats. I studien undersöktes två olika jäsningsmetoder med två olika jästsorter för att se vilken process som är mest gynnsam vid olika förutsättningar. Den ena jästen kunde bara fermentera glukos (SSF – Simultaneous Saccharification and Fermentation) och den andra var genmodifierad och kunde fermentera både glukos och xylos (SSCF – Simultaneous Saccharification and Co-Fermentation). Vidare studerades även konfigurationer av hur materialet skulle fördelas under jäsningen (sats och satsvis). Odling av den genmodifierade jästen gjordes under examensarbetet för att uppnå tillräcklig mängd till fermenteringen. Av resultaten framgår det att man kan producera etanol från djupströ. Utbytet är högre vid glukosjäsningen eftersom detta är en mer tålig jäst än den genmodifierade jästen – 0,51 g etanol/g glukos jämfört med 0,09 g etanol/g socker. De bästa resultaten erhölls när satsvis matning användes för både SSF och SSCF. Å andra sidan var utbytet signifikant h