Skip to main content
European Commission logo print header
Content archived on 2022-12-27

USE OF COAL WATER SLURRY TO POWER STEAM GENERATOR

Objective

To construct and operate a high pressure 8 MW steam generating plant specially designed for the combustion of coal water slurry (CWS) derived from the low grade residue of coal extraction.
In comparison with a conventional fuel-oil burning installation of equivalent performance, this plant will show an estimated 25% lower operational costs for the same annual energy production.

The projected system is based on the Fluocarbelf Process: this enables effective use of coal mining by-products (low grade coal, coal sludge etc. . . ) as the prime thermal energy source, for high pressure steam production.
The planned 8 MW Fluocarbelf Steam Generating Plant will consist of an underground coal sludge storing tank, sludge handling system, a feed hopper, roll mill, a set of slurry pumps, a multifluid burner and combustion chamber with rotating furnace and a boiler equipped with a tubular 'economiser' compartment, and three bottom hoppers for the evacuation of ash. As and when required, coal sludge is picked up, loaded into the feeding hopper which administers the correct quantities to be fed to the roll mill where the coal content is crushed into fine particulate then mixed with water and special additives to enhance mixture pumpability. The CWM flows to a buffer tank when a mixture characteristics can be checked: this buffer tank also serves as a separator betweenthe interruptable upstream operation and the continuous downstream process. At this stage, the proportional characteristics of the product should (by weight) be: - 39. 75% water or liquid waste;
- 60% solid particles of 200 um max. size;
- 0. 25% additives;
- specific weight: 1. 25 g/cm3
The mixture is maintained homogeneously fluid by agitation or recirculation, and pumped from the buffer tank into the multifluid burner and combustion chamber assembly where, with auxiliary fluid, combustion air and pressurised air, it is pulverized.
Burning gases circulate through the boiler tubes at a controlled temperature of between 1200 C to 1300 C. Fine ash particles are exhausted with combustion gases via gas scrubbing and dust filtration systems prior to evacuation into the atmosphere. Instrumentation and control equipment monitors each process stage, measuring installation performance and analysing flue gas and residual emissions.
The plant is designed to deliver 20 000 MKcal of thermal energy annually, equivalent to 23 000 MWh for an operational cost of 0. 12 FF/kWh. An equivalent plant of conventional design and burning fuel-oil, would show an energy production cost of 0. 16 FF/kWh. And with annual production of 23 000 MWh, payback is estimated at 4. 8 years. The five phase project commenced in October 1986 and is scheduled for completion by September 1989, at a total cost of 8 000 000 FF. In order to make up for the lost due to the decreasing of heavy fuel oil cost, it is now foreseen to replace the water in the coal slurry, by wastes (cutting oil, oil-water emulsions . . . ).
This will cause no change in the Fluocarbelf process. Corresponding studies, including wastes supplying problems have been made.

Call for proposal

Data not available

Coordinator

Elf Aquitaine Production
EU contribution
No data
Address
26 avenue des Lilas
64018 Pau
France

See on map

Total cost
No data