6 MWTH KOENIG LUDWIG ATMOSPHERIC FLUIDIZED BED COMBUSTION PLANT

Cel

To refine and improve atmospheric fluidized bed combustion technology such that:
1. coal fines, coal/water slurry, and fuels from conditioned domestic refuse can be used;
2. noxious emissions (especially SO 2, NO X, HF, HCP, and heavy metals) are reduced; and
3. ashes are disposed off without using special waste tips and in an environmentally acceptable manner. Energy substitution equal to +or- 1500 TOE is projected.
PHASE I :
Systems and components for storing, feeding and distributing of granulated and pulverized limestone above the nozzle plate have been developed and installed. Pipe sockets for taking fuel lanzes and sampling points were fitted in the tube walls of the boiler. Secondary and tertiary air injection systems have been installed. Amendments have been made on existing coal conveying facilities and hoppers to improve coal flowability.
PHASE II :
Results obtained with different sorbents show that granulated chalk has roughly twice the desulphurization potential of Devonian limestone. And the retention capacity of pulverized chalk is 30 to 50 % higher than that of granulated chalk. Regarding Halide retention no significant change has been observed. NOx -emission were found to be primarily influenced by excess air.
PHASE III :
Experience gained during operation with different conveying systems eg. dense phase conveyor, screw feeder and belt conveyors, and modified hoppers eg. sainless steel lining, this equipment were bottlenecks. It is anticipated that the problems are connected with the fact of a misbalance between fines < 1 mm and water content.
PHASE IV :
In two test periods more than 1000 t of coal-water-slurry (CWS) have been burned. The composition of CWS was 72% wt coal, 27 wt water and 1% wt additive. Production transport, storage and feeding was without problems. Combustion efficiency was 98% and more. Emissions of SO2, CO and NOx were well below limits of German standards (TA-Luft).
PHASE V :
Combustion of Eco-Briq-Briquettes plus bituminous coal on a 50 : 50 basis by energy input was carried out without major problems. Evaluation of emission measurements, especially chlorine, is under way.
PHASE VI :
The influence of staged air supply on NOx-and CO-emission was demonstrated successfully. By reducing the primary air flow NOx -generation is obstructed although CO-concentration increases.
CO is oxidized by injecting secondary air into the freeboard.Detailed evaluation is under way.
PHASE VII :
Analyzing the eluate from the lysimeter system was continued.
From the results evaluated so far, it is expected that the AFBC ash will meet the conditions specified for Dumping Class 2 (domestic refuse).
PHASE VIII :
Tests carried out in cooperation with a Dutch highway material company show that fine grain fly ash is to Dutch standards suitable as an admix for asphalt pavement systems. Tests are ongoing.
PHASE X :
GCA as an 15% (wt) admix to coal was successfully burned thus providing an alternative to its disposal in critical-waste dumps. The CGAGCA had a sulphur content up to approx. 31% (wf).
Using chalk as sorbent, SO2-emission levels were below 400 mg/m3. Variations in CO- and NO- concentration compared with all-coal operation were not observed. HCL retention was about 50% better than in the case of all-coal operation; HF-retention, at approx. 100%, was unchanged. Detailed evaluation is ongoing.
The project was conducted at the existing 6-Mwth AFBC pilot plant ''Koenig Ludwig'' in Recklinghausen. This plant, operating since 1980, serves as a steam generator for the industrial sector and provides decentralized heat for the public sector.
AFBC technology has operated satisfactorily to date however, numerous technical improvements will be tested in 9 phases :
PHASE I - ADDITIONAL EQUIPMENT
To facilitate testing and measuring during the project, the following were installed: storage facilities, handling equipment and feed systems; improvements to the steam generators including absorbent feed systems and secondary air injection system; and additional sampling points.
PHASE II - MINIMIZATION OF SO2 HF, AND HCL EMISSIONS
Feed devices, which uniformally distribute ultrafine lime powder above the nozzle plate, will be developed. It is expected that minimal additions of limestone will reduce noxious emissions and that ash as well as CaO content in the ash will also be reduced.
PHASE III - COMBUSTION OF WASHED COAL FINES
Prior to the project, the plant could handle only lump-size fuels up to 30mm. A simple and reliable fuel handling and feed system will be developed to handle coal fines.
PHASE IV - COMBUSTION OF COAL/WATER SLURRY
The suitability of coal/water slurry as an AFBC fuel will be tested with regard to mixture stability in transportation and storage, combustion, fuel efficiency and noxious emissions.
PHASE V - COMBUSTION OF ECO-BRIQ BRIQUETTES PLUS BITUMINOUS COAL
Combustion of conditioned domestic refuse combined with bituminous coal will be tested with an emphasis on reducing emissions of inorganic chlorine compounds.
PHASE VI - SECONDARY AIR INJECTION
The plant was equipped with secondary air injectors and the radiation chamber (freeboard) enlarged by using a suitable refractory lining. It was expected that this would improve the burn-up rate and reduce NO X and CO emissions.
PHASE VII/VIII - ASH UTILIZATION AND DISPOSAL
The solubility of trace element compounds in AFBC ashes were analysed. A lysimeter, consisting of a +or-10 m3 open tank exposed to the weather, will be used. Its rain and snow-water contents will be examined for trace element compounds. Potential applications for using AFBC ash was to be developed.
PHASE IX - EVALUATION/REPORT
Combustion of highly sulphur loaded GCA combined with bituminous coal to be tested with emphasis on reducing SO2-emission.

Program(-y)

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

Temat(-y)

7.1 - ATMOSPHERIC FLUIDIZED BED COMBUSTION

Zaproszenie do składania wniosków

Data not available

System finansowania

DEM - Demonstration contracts

Koordynator

RUHRKOHLE AG

Wkład UE

Brak danych

Adres

RELLINGHAUSER STRASSE 1 POSTFACH 10 32 62
4300 ESSEN 1
Niemcy

Koszt całkowity