石炭液化プラントの経済性 (II)

天然ガスの導入

抄録

In the previous study, it was presumed that the coal liquefaction plant was located in the coal production area and the natural gas was not available. Furthermore, the steam reforming of the off-gas produced from the plant, and the gasification of raw coal and residue were selected as the hydrogen production process. The capital cost and production cost were reduced by introducing the steam reforming of off-gas along with the gasification of raw coal and residue, and were minimized at the boiler turbine generator (BTG) in comparison with the integrated coal gasification combined cycle (IGCC).
In this study, natural gas is available and the combined cycle generator (CCG) in the power plant is added for power generation. By using Linear Programming (LP) technique, the production costs of hydrogen and power were minimized in the combination of these production processes for the coal liquefaction plant.
As a result of this LP study, the capital cost and production cost were reduced by introducing the steam reforming of natural gas and off-gas along with the gasification of raw coal and residue. They were minimized at BTG in comparison with IGCC. The production of hydrogen by the steam reforming of natural gas reduced the production cost, in which the residue is used for the power generation. On the other hand, the low consumption and the low capital cost were expected in the case of CCG, but the production costs of steam-power and hydrogen depended on the price of natural gas.