16 完全無灰炭(ハイパーコール)連続製造技術の開発(3) : 連続脱灰性能とその改善策(改質・処理・クリーン化(3))

抄録

Hyper-coal (HPC) is an ash-free coal produced by the solvent de-ashing technology. Coal is thermally (360-400℃) extracted into the coal-derived solvent (two ring aromatics). The extracted slurry was introduced into the settler. The solid phase (insoluble slurry) was gravitationally concentrated at the settler bottom and withdrawn as the under flow (UF). Though the liquid phase (solution) is clarified and withdrawn as the over flow (OF), and the OF is further filtrated through the stainless mesh filter (0.5 micro-meter pore). Ash concentrations in HPCs after filtration were 400-800ppm as the actual results. On the other hand, the target spec of ash concentration was 200ppm for the direct combustion fuel for gas-turbine. We tried some way to growth cohesion of the sub-micron insoluble particles which passed through the filter. One way was to mix a coal which gave a sticky insoluble to take in the surrounding sub-micron particles. Other way was to set down the filtration temperature to solidify a small amount of the extracted fraction. The precipitate might also affect to take in the sub-micron particles. We finally succeed to make the HPC continuously which had less than 200ppm of ash content.