Objective
Demonstration of a method of using biomass as an additional fuel (up to 10%) 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.
It will be shown that BIOCOCOMB:
- is an efficient and economic process for conversion of biomass into electricity, which is suitable for existing or newly designed boiler units
- is not harmful to the boiler or to SCR-equipment
- is a method for producing a reducing gas for reburning in the furnace, which decreases or avoids NH3-consumption for SCR- or SNCR-systems
- provides important information on the precise costs of co-combustion
- has a positive influence in the Regional economy (jobs and money from biomass supply).
It also leads to a better acceptance of coal fired power plants through using biomass and the reduction of C02-emissions. The selection and combination of the partners guarantees a highly qualified team to achieve these aims and results.
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% 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 deg. 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". Thus no predrying or grinding of biomass and no hot gas cleaning is necessary. The energy of biomass is transported into the coal boiler in three different forms: heat, low calorific gas and fine combustable char particles. Therefore the CFB reactor is not a real gasifier, but an equipment, which prepares biomass to the minimum requirements for co-combustion in a pulverised coal fired system.
The efficient combustion system of the boiler combined with the very efficient flue gas cleaning system of the plant guarantees a minimal impact on the environment. The substitution of a certain part of the coal by biomass also reduces C02-emission from fossil fuels.
The use of biomass instead of imported coal offers economic opportunities for local biomass production. New jobs can be created and employment can be stabilised in the forest industry and saw mills.
Other positive features of the process are listed :
* There is a high potential for this product gas to be used as a reducing gas in the reburning zone of the combustion chamber.
- The efficiency of the conversion of biomass to electricity is close to that of large scale coal fired power plants.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- engineering and technologyenvironmental engineeringenergy and fuelsfossil energycoal
- social scienceseconomics and businessbusiness and managementemployment
- engineering and technologyindustrial biotechnologybiomaterialsbiofuels
- agricultural sciencesagricultural biotechnologybiomass
- agricultural sciencesagriculture, forestry, and fisheriesforestry
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Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
9020 Klagenfurt
Austria