CIRCULATING FLUIDIZED BED BOILER BURNING A MIXTURE OF MINING WASTES WITH 65% ASH [CONSTRUCTION]

Cel

The general project refers to the installation of a thermoelectric power plant with 50 MWe rated power in the Central Basin of Asturias.
The plant will be equipped with circulating atmospheric fluidized bed-boiler and will use a combustible mixture consisting of "waste" from dumps, wood waste and raw coals from HUNOSA's mine workings.
The expected energy saving in the operation of the plant amounts to 49,000 TEC/yr. The exploitation of fuels such as dump "waste" and wood waste, at present abandoned, means saving 33,000 and 8,000 TEC/yr. Respectively, while the elimination of the washing process of raw coals composing the combustible mixture involves saving 8,000 TEC/yr.
The expected simple payback is of 7,9 years.
This contract follows on from CS/160/88 and covers the project to the start of the construction phase.
Construction of the plant has continued under the support of SF0000/6/90.
It is estimated that the investment cost of the project was first formulated.
Combustion in circulating atmospheric fluidized bed is an emergent technology which we can consider as being on the market for good quality coals and medium power plants.
However, the special features distinguishing the design fuel of this project, i.e. its heterogeneity, very high ash content and very low heat value, represent an innovation.
The basic features of each of the components constituting the combustible mixture are described hereafter:
a) Dump waste:
Ash (%/ dry matter) = 80 H.H.V. = 950 kcal/kg.
b) Wood waste:
Ash (%/ dry matter) = 3 H.H.V. = 2,925 kcal/kg.
c) Raw coal
Ash (%/ dry matter) = 47 H.H.V. = 3,900 kcal/kg.
The percentage of each of these components in the combustion mixture is:
- Dump waste = 59.8%
- Raw coal = 35.3%
- Wood waste = 4.9%
The features of the combustible mixture can be defined as follows:
- Ash (%/dry matter) = 65.5
- H.H.V. = 2,088 kcal/kg.
- Moisture = 6.5%
- Volatile matter (%/dry matter) = 16.5
The expected consumption for a basic operation involving 6,500 h use/year reaches 405,000 t. Combustion in circulating fluidized bed enables thermoelectric exploitation of coals with excellent results as for polluting discharges to the atmosphere.
Consequently, in our case:
- By adding limestone into the furnace with a molar ratio lower than 3/1, over 90% of sulphur is retained resulting a SO2 discharge lower than 600 mg/m3N, i.e. a very lower value than the 1800 mg/m3N value determined in the EEC Regulation 88/699 EEC.
- Discharges of NOx will reach 250 ppm, equivalent to 450 mg/m3N approximately, whereas the aforementioned EEC Regulation allows up to 650 mg/m3N.
Following the adjustments and modifications that where undertaken as a result of the combustion tests and basic engineering calculi, the thermoelectric power plant most significant operation data : - Steam production 185 t/h
- Steam pressure 115 kg/cm2
- Steam temperature 530 deg. C
- Cycle efficiency 2,137 kcal/gkWh
- Boiler efficiency - Auxiliary consumption 9.3% - Net efficiency 2,853 kcal/nkWh The technology of this project is interesting for HUNOSA both from environmental and economic points of view. From environmental point of view, it enables an integrated operation in procedures, i.e. change in coal processing methods greatly reduncing the impact caused by discharges into rivers; use of waste from old dumps thus allowing a remodeling and subsequent use of that soil; clean combustion of the combustible mixture thus greatly improving gaseous discharges from conventional plants by keeping them within the limits determined by the latest EEC Regulations. From the economic point of view, this project enables HUNOSA to start a process of self-generated electric power so that the Company will produce 72% approximately of its own consumption and will deliver to the electric power system a total of 40 GWh which will produce additional revenues.

Program(-y)

ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989

Temat(-y)

8.1 - ATMOSPHERIC FLUIDIZED BED COMBUSTION

Zaproszenie do składania wniosków

Data not available

System finansowania

DEM - Demonstration contracts

Koordynator

E. N. HULLERAS DEL NORTE SA

Wkład UE

Brak danych

Adres

AVDA. DE GALICIA 44
33005 Oviedo
Hiszpania

Koszt całkowity