| 摘要 |
<p>#CMT# #/CMT# Preparing and purifying a product gas comprises thermochemical conversion of biomass in a reactor (20), conducting the produced product gas loaded with 100% pollutant load into a main gas treatment step (22), cooling the product gas to condense the unwanted tars as aerosols resulting during the preparation of the product gas, and conducting the purified product gas having 10% of pollutant load, into a filter (24), which is also operated wet and is formed as fibrous deep filters with large depth, i.e. at least 1.5 kg fibers per square of inflow area. #CMT# : #/CMT# Preparing and purifying a product gas comprises thermochemical conversion of biomass in a reactor (20), conducting the produced product gas loaded with 100% pollutant load (dust particles and tars as aerosols) from the thermochemical production and supplying this product gas into a main gas treatment step (22), which works at a wet condition and at least includes an electrostatic precipitator with pre-quench or high performance scrubbers, which can separate at least 95%, preferably at least 98%, of the pollutant load with a diameter of 1mu m, cooling the product gas up to at least its cooling limit temperature of less than 90[deg] C, preferably below 50[deg] C, to condense the unwanted tars as aerosols resulting during the preparation of the product gas; and conducting the purified product gas having 10% of pollutant load, into a filter (24), which is also operated wet and is formed as fibrous deep filters with large depth, i.e. at least 1.5 kg fibers per square of inflow area, and providing in such a way cleaned product gas to a consumer. The product gas is produced by thermochemical conversion of biomass directly or by other methods processed biomass and provides a calorific value sufficient for the further energy conversion. The high performance scrubbers include single or multistage rotation scrubbers, Venturi scrubbers with fixed or adjustable Venturi grooves and/or adjustable groove cross-section, multi Venturi scrubber, disintegrator scrubber and Bayer rider scrubber and further wet scrubbers. An independent claim is also included for the filtering device useful in the above method, where the filter depth with respect to flow velocity is 0.2-20 meters per minute, preferably 2-8 meters per minute, when the filter is wet operated at an operating differential pressure controlled by an additional external fluid or steam, where the filter is operatable with long maintenance intervals. #CMT#USE : #/CMT# The method is useful for preparing and purifying a product gas produced by thermochemical conversion of biomass. #CMT#ADVANTAGE : #/CMT# The cleaning is done only at long intervals (maintenance interval), preferably at an interval of one month, so an uninterrupted operation until the next service or the next maintenance interval is possible. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure shows a schematic representation of the process for the production and purification of a high calorific value product gas, in which the filter is a main wet cleaning step. 20 : Reactor 22 : Main gas purifying unit 24 : Filter #CMT#ENVIRONMENT : #/CMT# Preferred Method: A reheating of the product gas, dependent on the scrubber type used in the main treatment step, over the cooling limit temperature of the product gas is switched between the main treatment step and the purification method, which are used for adjusting the droplet loading of the product gas. The method is operated with additional external humidification with wash liquid, preferably water, crude gas- and/or clean gas side (preferred). The additional external humidification with wash liquid takes place continuously and/or batch wise (preferred). The external humidification takes place with vapor. At least glass wool is used as fibrous deep filter material. At least rock wool and aluminum silicate fibers, sheep wool, felts, hemps, flax or coconut fibers are used as fibrous deep filter material. The glass wool with an average fiber diameter of 2-30 mu m, preferably 3-6 mu m, with a specific bulk density of 12-75 kg/m 3>, preferably 16-25 kg/m 3>and a layer thickness of 20-100 cm in the dry new condition is used as deep filters. The compression of the deep filter materials increases during installation in the clean and dry new condition towards the gas flow. Pressing devices exist at least for wash liquid from the substantial portions of the deep filter material to facilitate disassembly. The humidification of the deep filter materials takes place over an additional external liquid or steam, preferably discontinuously during operation, when the operational pressure loss is dropped below a minimum value. #CMT#INSTRUMENTATION AND TESTING : #/CMT# Preferred Components: The filter material for simple exchange is packed at least partially in the form of cassettes or cartridges. The substantial portions of the deep filter material are connected upstream in relation to the substantial portions of the deep filters thinly configured pre-precipitator layers.</p> |
