6 MWTH KOENIG LUDWIG ATMOSPHERIC FLUIDIZED BED COMBUSTION PLANT

Ziel

The objective of this Atmospheric Fluidized Bed Combustor (AFBC) project is fivefold :
1. To further develop and refine the AFBC technology for heat generation and system components
2. Expand the range of possible fuels used in AFBC to include residues from the 200 T/d coal liquefaction plant Bothrop and waste from refineries, petrochemical plants, tar and pitch processing and liquefaction plants.
3. Eliminate existing technical problems which diminish AFBC marketability.
4. Demonstrate the overall technical feasibility of AFBC's especially with regards to fuel flexibility (coke, low volatile, and raw coal).
5. Demonstrate the economic advantages of AFBC for heat generation.
Assuming the demonstration plant replaces an oil fired heating scheme, it is estimated that energy savings will be 1,550 TOE/y.
Phase 1 : Hard Coal Grades
* Combustion efficiency was not significantly affected by coal grade at feed point location. In all cases, the carbon burn-up rate averaged 84-89%, with peaks of +- 93%.
* Optimum SO2 emission was obtained with nr 2 middlings, with a desulphurization level of +- 95% (CA/S = 4. 7 - 7. 9) at +- 810 deg. C.
At an average NOx emission of +- 600 mg/m3 in the main generating range, there are no significant differences between fuels.
* Low volatile fuels were not found to be superior with respect to carbon monoxide emissions.
* Retention of hydrogen fluoride was almost 100 %.
* Dust emissions were well below the limit of 150 mg/m3 (standard, dry) specified by licensing authorities.
* Desulphurization levels more favourable when nr 2 middlings are charged from below, and nr 3 middlings are charged from above.
* Fuel feed point location had no significant effect on nitrogen oxide emissions, carbon monoxide concentration in the flue gas, hydrogen chloride retention, and hydrogen fluoride emissions.
Phase 2: Alternative Fuels
* Liquefaction residue was used successfully with no problems in handling combustion, or plant operation.
* Hard pitch was easily conveyed via the pneumatic system. However after several hours, combustion caused coking residues to be deposited on the boiler walls and feed chute.
* Coke combustion was also problematic. Handling caused problems with the chain conveyors and feed screws. The pneumatic system could be used to convey the coke to the hopper at the boiler but then the rotary valve, used as a metering device, was damaged.
* Plant start-up was not possible using coke alone: the gas was unable to attain ignition temperature of 700 deg. C. Coal was needed to reach the operating temperature of 850 deg. C. before changeover to coke could be made.
In addition, temperature control and steady operating conditions were impossible given the reaction kinetics of coke combustion.
* Emission control and environmental compatability were successfully demonstrated. Emissions of nitrogen oxide, hydrogen fluoride, hydrogen chloride, benzo(a) - pyrene, dibenzo (a,h) anthracene, and all hydrocarbons were below limit values.
The Koenig Ludwig AFBC demonstration plant is a natural-circulation steam boiler with integrated fluidized bed combustion. The thermal capacity is 6 MW saturated steam at 17 Bar and 8. 85 T/h is generated to heat the recirculated district-heating water in a heat exchanger plant. Two completely separate conveyor systems are installed to charge fuel and limestone. One mechanical system feeds the fuel via screw conveyors from below into the fluidized bed; the other is a pneumatic system which charges the test fuels hard pitch and liquefaction residue, due to their low softening points, from above into the bed. Boiler ancillaries consist of a feedwater treatment plant, flue gas cleanup plant (bag filters), and ash removal and disposal facilities.
The demonstration was in four phases. The first two carried out under this contract being :
Phase 1 : Combustion tests were performed on various coal grades; primarily moisture-free middlings with volatile contents either in excess of 20% orless than 10%. A total of 103 single measurement series were done to examine coal grades with respect to burn-up rate, emissions, retention of noxious substances and the effect of fuel feed points.
Phase 2: Combustion tests were performed on coke, hard pitch, and coal liquefaction residue to evaluate suitability for fluidized bed combustion and if emissions of hydrogen halides, sulphur dioxide, nitrogen oxides, polycyclic aromatic hydrocarbons, and trace elements were controllable.
The project will cost an estimated DM 5,951 million.

Programm/Programme

ENG-ENALT 2C - Programme (EEC) of demonstration projects relating to the exploitation of alternative energy sources and to energy saving and the substitution of hydrocarbons, 1983-1985

Thema/Themen

7.1 - ATMOSPHERIC FLUIDIZED BED COMBUSTION

Aufforderung zur Vorschlagseinreichung

Data not available

Finanzierungsplan

DEM - Demonstration contracts

Koordinator

RUHRKOHLE AG

EU-Beitrag

Keine Daten

Adresse

RELLINGHAUSER STRASSE 1 POSTFACH 10 32 62
4300 ESSEN 1
Deutschland

Gesamtkosten