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Business and Technology : RICE HUSK FIRING POWER GENERATION BOILER |
We have succeeded in completing the rice husk firing power generation boiler plant at Roi-et Green Co., Ltd. adjacent to the rice milling plant located at Roi-et in the North Western Thailand.
The Project is to sell the generated power 8.8MW to EGAT (Electricity Generating Authority of Thailand) by generating 9.95MW with steam turbine using the steam provided from the boiler firing the rice husk as fuel, collected from adjacent or neighboring rice milling plants.
BOILER SPECIFICATION & OPERATION DATA CHART
BOILER TYPE |
Bi-Drum Natural Circulation type YOSHIMINE H-1600 Type |
COMBUSTION SYSTEM |
Pneumatic spread type Travelling stoker |
FUEL |
Rice husk 12.56 MJ/kg (LHV) |
STEAM GENERATION |
55 ton/hour |
STEAM PRESSURE |
4.0 MPaG |
STEAM TEMPERATURE |
405 ± 10°C |
POWER GENERATION |
9.95 MW |
ITEMS |
UNIT |
DESIGN |
ACTUAL |
BOILER EFFICIENCY |
% |
84.5 |
88.9 |
UNBURNT COMBUSTIBLE CONTENT OF ASH |
% |
5> |
3.17 |
NOx as NO2 |
ppm |
360> |
153.6 |
SOx as SO2 |
ppm |
640> |
25.6 |
PARTICULATE |
g/Nm³ |
0.12> |
0.033 |
Power plant is operated by DCS (Distributed Control System) located at central control room. Rice husk fuel is supplied to conveyor for boiler by loader from indoor and/or outdoor storage area during day time, and rice husk storage silo of 600m3 capacity is used to save labor on night time operation, as a boiler fuel supply system.
The total number of operator for this power plant is only five persons including the operator for electric power facility and fuel handling also. It is quite laborsaving advanced system for biomass fuel firing boiler.
CHARACTERISTIC OF RICE HUSK FUEL
Rice husk fuel is so light that it mostly burns in suspension, leaving the fuel more unburnt than other fuels such as wood or something like that, therefore, we decided to reburn this unburnt ash by reinjecting into the combustion chamber to clear sufficiently Ignition loss 5 % as a result.
The representative characteristics of rice husk which are highly valued as fuel are as follows.
MOISTURE |
9〜12% |
ASH |
13〜18% |
VOLATILITY |
60〜65% |
FIXED CARBON |
13〜19% |
LHV |
12.56〜13.40 MJ/kg |