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Multi Fuel Operated Integrated Clean Energy Process: Thermal Desorption Recycle-reduce-reuse Technology

Exploitable results

The preventive pre-treatment of low-grade solid fuels is safer, faster, better and less costly versus the “end-of-the-pipe” post treatment solutions. The “3R” Recycle-Reduce-Reuse integrated environment control technology provides preventive pre-treatment of low grade solid fuels, such as brown coal and contaminated solid fuels to achieve high grade cleansed fuels with anthracite and coke comparable quality. The purpose of the 3R technology is to provide cost efficient and environmentally sustainable solutions by preventive pre-treatment means for solid fuel combustion power plants (<300MWe). The 3R technology may be applied as vital component for an integrated strategy towards near zero emission targets to combine technologies for environmentally sustainable and economical solid fuel power generation, including but not limited to the removal of hazardous air pollutants “HAPs” prior burning and decrease of the output green house gases, such as CO2. The 3R advantageously integrated to the oxyfuel - oxy-firing and Foster Wheeler anthracite arch-fired utility type boiler technologies in combination with CO2 capture and storage. For pre-treatment a specific purpose designed, developed and patented pyrolysis technology used, consisting of a horizontally arranged externally heated rotary kiln, where the feed material is carbonised and decomposed in reductive environment (850°C). Specific pyrolysis gas post burner and off-gas treatment scrubber used. The volatile HAPs are safely removed in the reduced volume of gas-vapor stream and burned out in the post burner at 850°C2sec+/-50°C, while the 3R solid end product is utilized as input feed material for conversion of clean coal to clean energy production. “Product like” pilot plant has been built and successfully tested under semi industrial conditions in 2005. Nine different types of feed materials (three types of browncoals with different S/ash content, hard coal, four types of biomass – straw-grain-wood-chip-sawdust), totally 111 tons, have been tested with up to 265 kg/h throughput-capacity under 1779 hrs, incl. 59 hrs continuous run. The technical viability of the 3R technology demonstrated, including EU compatible industrial permitting from ten different Authorities and certification of ISO 9001/14001. Full scale application is pre designed with modular installation up to 560,000 t/year solid fuel throughput. ADVANTAGES: Feedstock Flexibility: application of pre-treated multi fuels from wider fuel selection and availability. Improved burning efficiency. Technology Flexibility: efficient and advantageous interlink to proven boiler technologies. Near Zero Pollutants for HAPs: preventive separation of halogens and heavy metals and separated treatment in small volume streams. Metals will not react with other elements in the feed stream such as Cl and S, which otherwise in oxidative environment may form more volatile toxic compounds than the original species. Comprehensive residual utilization made. 97 % organic Sulphur removal achieved. Cost Reduction: decrease of overall production costs when all real costs are calculated, including the environmental costs as well. For full scale applications from as low as US $25/tons treatment cost calculated between the price gap of low and high grade solid fuels. Safety: application of preventive measures and separated downsized treatment of HAPs. Limitation: high input ash content of the raw feed material. Two patents applied by the Swedish inventor Edward Someus, who made the process modelling, engineered design and construction for the comprehensive technology. The related US patent US 5,707,592 maintained. Dissemination and marketing strategy defined for the USA and the EU. The 3R technology is engineered original solution and opens new technological and economical opportunities for solid fuel power generation with sustainable near zero emission performance, while securing oil/gas independent energy supply.
The 3R Clean Multi Fuel Provides pretreatment of coal and lignite by pyrolysis for preventive removal of hazardous air pollutants (organic S, Cl, Hg) and flexible integration of the renewable biomass energy and fossil fuel feed, for safe and long term clean energy solution at solid fuel power gen up to 300MW. Hazardous air pollutants are removed from the coal prior burning by low temperature carbonization "LTC" and feed is combined with renewable multi fuels. The LTC is an horizontally arranged indirectly heated rotary kiln, for partial gas out of the coal and removal of volatile components in downscaled reductive environment. Gas vapour post burned, heat is recovered and off-gas is cleansed in wet scrubber, whereas clean gypsum is produced and Hg is separately recovered. The solid material Clean Coal is utilized as clean fuel, alternative in combination with waste vegetable oil burning as add-on fuel. Results: Sustainable reuse of solid fuels by pre-treatment: achievement of continued and extended environmental friendly reuse of solid fuels by reductive thermal decomposition pre-treatment of feeding, - for preparation of clean solid fuels and prevention of high toxic element load through the system and at the "end of pipe"-prior introduction to conventional heat and electricity power generation systems. Clean fuel provides clean burning: environmentally clean burning resulting significant emission reduction at the "end of the pipe". By reduced pollution content of fuels and improved efficiency of energy production and meet Kyoto Protocol targets. Multi fuel applications, such as renewable-biomass, carboniferous solid waste and coal, increased feed flexibility. Add-on direct link and integration opportunity to existing and new conventional solid fuel power plants for environmental and burning efficiency upgrade. Improved solid fuel burning efficiency, clean and homogenized fuel provide improved burning characteristics and lower corrosion effects in the boiler. Cost reduction, by providing clean fuel and pretreatment separation of target pollutants, such as sulfur, the total cost efficiency of the operation at the end will be increased.