TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Conditions: The process of providing impact involves providing vibration to the inner surface or spraying a gas on the inner surface. Impact is provided to the inner surface when the pressure in the heater is 26 MPa or more. A liquid mixture containing ash content, catalyst, and water is reacted with hydrochloric acid. Reaction with sodium-hydroxide aqueous solution is carried out such that the pH of filtrate is 6-9. Biomass containing phosphorus is heated using the heat of waste gas obtained by burning production gas with exhaust heat of electric-power generator or the heater. Preferred Arrangement: The peeling apparatus is an oscillation apparatus or a gas injection apparatus. A gas-liquid separator separates the production gas, ash content, catalyst, and water discharged from the reactor into production gas, and liquid mixture containing ash content, catalyst, and water. The preprocessor is equipped with a heater for heating biomass using heat of waste gas. A heat exchanger is provided for preheating the slurry hydrothermally-treated by using heat of produced gas discharged from the reactor, or for preheating the biomass hydrothermally-processed by using heat of hydrothermally-treated slurry, or for preheating biomass hydrothermally-processed with the preprocessor using heat of produced gas. A slurry supply apparatus receives slurry from the preprocessor and supplies to the reactor. Accumulator (I) is arranged between the preprocessor and slurry supply apparatus for accumulating pressure of slurry received in the slurry supply apparatus. Accumulator (II) is arranged between the slurry supply apparatus and reactor for accumulating pressure of slurry supplied from the slurry supply apparatus. A water injection apparatus is provided with an injection hole for water and a discharge port for discharging the injected water. The slurry supply apparatus consists of two cylinders provided with a receiving opening in which the slurry is received from the preprocessor, and a supply port which supplies the received slurry to the reactor. A piston is arranged such that water and slurry in each cylinder may be partitioned off, and a stirrer is provided for stirring the slurry in each cylinder. A shaft is equipped with both ends with piston. The water injection apparatus switches between processes (I,II). Process (I) involves injecting water into cylinder (II) such that the slurry received in cylinder (II) from the preprocessor is supplied to the reactor, while receiving slurry in cylinder (I) from the preprocessor. Process (II) involves injecting water into cylinder (I) such that slurry is received in cylinder (II) from the preprocessor, while supplying slurry received in cylinder (I) to the reactor. The shaft is further equipped with a contact prevention unit which prevents contact with piston and stirrer. The water injection apparatus injects water at constant flow with respect to each cylinder. The reactor is provided with an inlet which introduces the slurry into the reactor from downward direction, a discharge port which discharges produced gas, ash content, catalyst, and water out of the reactor from the upper direction, a flow medium which forms a fluidized bed in the reactor by introducing the slurry, and a dispersion portion in which the slurry introduced from the inlet is dispersed in downward direction of the fluidized bed. The flow medium has a shape such that it is not discharged with introductory speed of the slurry. The dispersion portion is formed by stacking alumina balls. The system is further provided with a unit for recovering catalyst from the liquid mixture, and a crusher for crushing biomass before hydrothermal processing in the preprocessor.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The deposits are monetite and/or hydroxyapatite. The flow medium comprises alumina balls.