Description: Das Projekt "Preparation of biofuel for co-combustion" wird vom Umweltbundesamt gefördert und von Österreichische Draukraftwerke durchgeführt. Objective: Demonstration of a method of using biomass as an additional fuel (up to 10 percent) in pulverised coal fired units. The process is an efficient method of preparing biofuel in a CFB-reactor to the minimum requirements for pulverised coal fired systems. The physical principal is partial gasification and grinding by attrition and thermal stress ('Thermal Mill') in a separate CFB gasifier. CO2-reduction by using renewables replacing fossil fuels. Monitoring and evaluation of - long-term influence of biomass co-combustion on boiler performance; - additional useful effects of the product gas (i.e. NOX reduction). Innovation: Conversion of biomass into electricity with the same high efficiency as large coal fired unit. - Much smaller design of the reactor compared to biomass gasification for the use in gas turbines, mainly because partial gasification is sufficient. - The use of the product gas from the CFB-reactor for NOx-reduction in the furnace of the coal boiler by reburning is also innovative. General Information: The BIOCOCOMB process is designed for preparation of biofuel for co-combustion by partial gasification and attrition through mechanical and thermal stress in a circulating fluidized bed reactor. The product gas is fired in the furnace of a coal fired power plant. The proportion of biofuel reaches approximately 3-5 percent of the total thermal input. Biomass is defined as non-contaminated wood, bark and forest residues. Close to the furnace of the boiler a CFB rector will be built, in which the biomass, shredded to chips of a maximum size of 5 cm, will be fed by conventional means. The fluidizing medium of the CFB is hot air, which is taken from the air preheater of the power plant. In the CFB-reactor the biofuel is dried, pyrolysed, partially gasified. The char particles are very fine due to attrition. Part of the volatiles, driven off during pyrolysis will be burned with the air in order to generate the heat for the endothermic gasification process. The temperature of the gas will be between 750-850 degree C. The char is ground by mechanical attrition and thermal stress to a fine powder. The attrition is maximised by the way of operating the CFB, because the air entry is designed as a 'spouted bed' with a relatively high air entry velocity. Wood char particles, which are small enough to burn completely in the coal furnace can pass the cyclone of the CFB and are carried into the furnace together with the hot gas. Larger char particles will remain together with the bed material in the bed only as long as they are reduced in size by thermal and mechanical stress. This permits a shorter residence time in the CFB than in case of complete gasification. The size of the CFB-reactor is therefore reduced compared to complete gasification. Co-combustion with coal in the boiler does not require a high quality of the 'biogas'. ... Prime Contractor: Österreichische Draukraftwerke (Draukraft AG); Klagenfurt; Austria.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Biogas ? Biokraftstoff ? Fossiler Brennstoff ? Zyklon ? Klagenfurt ? Holzgas ? Brennstoff ? Abfallverbrennung ? Pflanzensamen ? Wärmebelastung ? Mitverbrennung ? Österreich ? NOx-Minderung ? Biomassevergasung ? Holzfeuerungsanlage ? Primärenergie ? Pyrolyse ? Bioreaktor ? Stress ? Verbrennung ? Vergasung ? Brand ? Wirbelschicht ? Stromerzeugung ? Altholz ? Gasförmiger Stoff ? Gasturbine ? Kohle ? Kohlekraftwerk ? Warmwasserbereiter ? Mühle ? Reaktor ? Kraftwerk ? Thermisches Verfahren ? Produktbewertung ? Energiegewinnung ? Energietechnik ? Erneuerbare Ressource ? Holzfeuerung ? Vergasungsanlage ? Ofen ? Biomasse ? Brenner ? Kessel ? Partikel ? Brennstoffeinsparung ? Anlagenbeschreibung ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1996-09-01 - 2000-03-31
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