To facilitate pH adjustment for preventing rotting of circulating water used for crushing in water, reduce the amt. of an alkali added in hydrothermal reaction, and avoid the accumulation in the pretreatment step of minute substances contained in water separated after the hydrothermal reaction.
This method converts a waste contg. org. solids into a fuel by slurrying and dehydrating the waste, adding an alkaline substance to the dehydrated slurry, subjecting the resultant alkaline slurry to hydrothermal reaction in a reactor 26, and cooling and dehydrating the reaction product. The dehydration of the slurry is performed so that the solid content after dehydration is equivalent to that of the waste, i.e., 40-60wt.%. A scum contg. org. components is separated and recovered from water obtd. as the filtrate in the dehydration step while keeping the pH of circulating water alkaline by adding an alkali to the filtrate. The scum is mixed into the highly dehydrated slurry. and simultaneously the filtrate is returned to a slurrying vessel. The highly dehydrated, mixed slurry is reslurried to a solid content of 10-20wt.% by using water separated after the hydrothermal reaction in the reactor 26 and is supplied to the reactor to undergo hydrothermal reaction.
OMIYA YOSHIHIRO
HIGO TSUTOMU
SERIKAWA ROBERUTO MASAHIRO
EBARA CORP
Next Patent: LUBRICATING OIL COMPOSITION EXCELLENT IN HYDROLYTIC STABILITY