Method for preparing artificial peat and fulvic acid from livestock and poultry manure in breeding industry through high-pressure hydrothermal method

A method for preparing artificial peat and fulvic acid from livestock and poultry manure in the breeding industry through a high-pressure hydrothermal method, wherein the method comprises the following steps:

• regulating the concentration of the livestock and poultry manure to be 10-40% by using a part of flash condensate, then pressurizing the livestock and poultry manure by using a high-pressure pump (1) and feeding it into an electromagnetic heating tube reactor (4) for carrying out the hydrothermal decomposition reaction, wherein the flow rate inside the tube is within the range of 1-5 m/s, the reaction temperature is within the range of 200-330° C., the pressure is not lower than the saturation pressure of water under the reaction temperature, and the reaction time is within the range of 1-90 seconds;
• then feeding the livestock and poultry manure into a tower type delay reactor (6) to extend the reaction time for 10-50 minutes to further enhance the hydrothermal decomposition reaction;
• subsequently passing the hydrothermal reaction slurry at the bottom of the tower type delay reactor (6) through a depressurization flash tower (7) to perform a gas-solid separation to obtain a gas phase and a solid phase slurry, feeding the gas phase into a preheating heat exchanger (3) and subjected to cooling and liquefying, subsequently circulating a part of flash evaporation condensate back to a livestock and poultry manure concentration adjusting tank (2), separating the solid phase slurry through a pressure filter (8);
• using the filtered solid as an artificial peat product;
• pumping a filtrate into a tubular heater (9) by a high pressure pump, heating to 380° C. or above, then desalting in a supercritical settler (10), separating the salt from a desalination tank (11), recovering waste heat from the filtrate, mixing the desalted and cooled filtrate with the remaining flash condensate to obtain a fulvic acid product.