Technical and economic analysis of using biomass energy

Abstract

In the first part of the article were presented the technical possibilities of obtaining solid biomass, biogas, landfill gas, a biogas from wastewater treatment plants, bioethanol and biodiesel. Then processes was described, allowing use of energy from biomass. As first was discussed the incineration which includes drying and degassing of the wood materials, wood gas burning at 1200°C, post-combustion gas and heat transfer in the heat exchanger. Then had been described gasification, or thermochemical conversion process, occurring at high temperature. It is two-stage process. In the first chamber at deficiency of air and at relatively low temperatures (450–800°C), the fuel is being degasified, resulting in creating combustible gas and a mineral residue (charcoal). In the second stage, secondary combustion chamber and at a temperature of about 1000–1200°C and in the presence of excess of oxygen resultant gas is burned. A further process is pyrolysis. It consists of the steps of drying fuel to a moisture level below 10%, milling the biomass into very small particles, the pyrolysis reaction, separation of solid products, cooling and collecting bio-oil. Then discusses co-generation, which is combined production of heat and electricity. In this situation where the biomass contains too much water it can be used for energy purposes through biochemical processes. The alcoholic fermentation results in decomposition of carbohydrates taking place under anaerobic conditions, and the product is bioethanol. Another biochemical process used for the production of liquid biofuels is esterification of vegetable oils. Methane fermentation in turn causes a decomposition of macromolecular organic substances with limited oxygen available. As a result, we obtain alcohols, lower organic acids, methane, carbon dioxide and water. There was analysis of economic increasing of solid biomass energy, biogas and liquid biofuels in the following article.