What CoaLCO does
CoaLCO is an expert system for coal-fired powerplant aiming for reduced overall power genration cost. It’s ultimate goal is carbon reduction. The abouve statements may sound suprising(or unbelievably good) because burning coal emits carbon. Indeed CoaLCO does not make any powerplant emit less carbon. Instead, it optimzes the use of dirtier but cheaper opportunity coals so that cost reduction is possible.
Such optimization is important for utility because coal is indispensable in the foreseeable future. The strategy is to gradually increase the weight of renewable in order that coal and other undesirables can be retired. To achieve this quick, coal must help reduce cost so that more investment can be devoted into renewables. Under this broad view, CoaLCO does contribute to carbon reduction – indirectly.
CoaLCO is good for powerplants that burn a feedstock from more than dozens of different coal sources. Single-coal feedstock is relatively rare. This issue of how varied feedstock recipes can be coped with is key to optimized power generation. It’s not trivial to cope considering the complexity.
Key strategy of in-furnace coal mixing
Tehnically, CoaLCO implements a simple yet clever scheme of in-furnace coal mixing to achieve optimization. This is in contrast to the common practice of coal blending.
Typcal generator unit in a coal-fired powerplant has a furnace with an array of multiple burners, of which each blows coal powder into the furnace for combustion. In the furnace of a conventional powerplant, all feedstock coals are blended together per specification and the blend is then pulverized to feed the furnace. The composition of coal powder supplied to all burners is uniform across all burners, a practice known as coal blending.
By contrast, in a CoaLCO-operated powerplant, each level of burner in the furnace is fed with a specific coal powder per CoaLCO’s coal mixing scheme. In general, a lower-level burner gets assigned a coal powder that is relatively more difficult to combust than the one level of burner next above it. Thus the top-level burner gets assigned with a coal that’s most easily combustible.
Such scheme is based on the principle that coal with a more-difficult-to-combust characteristic needs more time for a more thorough combustion. It gets fed to a lower-level burner in the furnace. The reason is obvious: combustion flame moves upward inside the furnace. Thus, a CoaLCO powerplant implementing this scheme of in-furnace coal mixing can ensure better combustion efficiency than conventional coal blending. CoaLCO performs distinguishedly. Compared to coal-fired powerplants in Asian countries, around 5 to 8 percent reduction in feedstock cost is achieved by CoaLCO on the basis of the same generated total power.
It’s coal’s part of the equation to reduce its own cost as much as possible so that more investment can be devoted into the more costly renewable, solar, wind, bio, etc. A clever strategy of in-furnace coal mixing instead of the usual trivial coal blending, CoaLCO delivers optimized coal-fired power generation. CoaLCO thus helps to contribute to carbon reduction for utility power generation.