WASTE GASIFICATION TREATMENT METHOD

摘要

PROBLEM TO BE SOLVED: To recover excess heat of low pressure steam, and furthermore to remove the hydrogen chloride gas generated in the treatment of waste plastics by neutralization to improve the efficiency and economy of the entire system in carrying out a primary gasification by a low temperature gasification furnace and a secondary gasification by a high temperature gasification furnace. SOLUTION: A waste gasification treatment method comprises a low temperature gasification step of feeding organic waste to a low temperature gasification furnace to effect a primary gasification; a high temperature gasification dust removing step of feeding the resulting gaseous substance to a high temperature gasification furnace to effect a secondary gasification at high temperatures and subjecting the resulting synthetic gas to dust removing and washing in a gas washing tower; a gas cooking purification step of cooling and purifying the washed gas; a slag recovery step of recovering the slag to be discharged from the high temperature gasification step; and a waste water treatment step of treating waste water from the slag recovery step. In this case, ammonium chloride recovery facilities are provided in the waste water treatment step and the waste water is evaporated under reduced pressure with the use of low pressure steam as the heat source to concentrate and crystallize ammonium chloride which is then subjected to solid-liquid separation and withdrawn outside the system.