Optimal användning av biomassa : En studie av biomassans användning i kraftvärme, biogas och bioplast

Sammanfattning: Humanity has always used energy in different forms; muscle power and heating, for example. The sources of energy undergo constant development, and in the 18th century, fossil fuels were discovered. Today, the awareness of climatic effects and climate problems related to the fossil fuels has increased, and they are not accepted in the same way they were then. One of today’s common sources of energy is biomass. The usage of biomass is nothing new, for example, the burning of wood has been used for cooking and heating for a long time, but today there are additional possible uses, and even more areas of use are under development. Biomass is a renewable source of energy, containing inartificial organic material, living or dead. There are three types of biomass: raw material from the forest, from watercourses and from agriculture. These can, among other things, be used for biofuels, food and animal feed, textiles, plastics and nanocellulose – a very strong material, with attributes similar to Kevlar. The purpose of this bachelor’s degree project was to investigate the areas of use for biomass and to find out which one of them that is optional, with help from a breakdown of cost and energy, in consideration of chosen limitations and formulations of questions. The work was based on the increasing demand for alternatives to the fossil based energy sources. The aim was to find the optimal area of use for those alternatives, in regard to energy usage, climatic effects and economy. The work begun with an information search, where the areas of use for biomass and their pros and cons were investigated. Then, the three most interesting areas were chosen: combined power and heating, biogas and bioplastics. Subcategories were chosen and calculations were made for these with an economic, environmental and ethical perspective, in order to decide the optimal area of use for biomass. The final result was that, among other things discovered, combined heating and power fueled with wooden chips is the most optimal area of use for biomass considering climatic/environmental effects, and that bioplastics is the most optimal area of use for the future, considering chosen limitations. Combined power and heating fueled with waste is the area of use that generates the biggest income in comparison to raw material cost.