Pyrolysis and combustion process and system

A process for pyrolysis and combustion of combustible solid material which comprises:

• introducing combustible solid feed material derived from industrail waster and comprises essentially of carbonaceous material including volatile hydrocarbons, through a feed-lock system,
• introducing said solid material exiting said feed-lock system into an upper section of a pyrolysis chamber having a lower section and a bottom,
• moving said solid material downwardly in a plurality of successive vertically disposed stages in said pyrolysis chamber at a controlled rate, said vertically disposed stages being provided by a series of horizontally moveable vertically spaced grates in said pyrolysis chamber,
• depositing carbon char in the lower section of the pyrolysis chamber,
• flowing air into the carbon char in the lower section of said pyrolysis chamber and partially oxidizing said char to form hot gases containing C, H.sub.2 and N.sub.2,
• passing said hot gases upwardly countercurrent to the downward movement of said solid material in said pyrolysis chamber,
• driving off said volatile hydrocarbons from said solid carbonaceous material and pyrolyzing it to form said carbon char, in a multistage equilibrium process,
• the rate of downward movement of the combustible solid material in the pyrolysis chamber in relation to the upward flow of the hot gases being such as to achieve substantial reaction equilibrium in each of said stages in the pyrolysis chamber between the solid combustible feed material and said upwardly passing hot gaseous products,
• removing a mixture of said volatile hydrocarbons and said hot gases as an overhead hot fuel gas from the upper section of said pyrolysis chamber,
• the overhead hot fuel gas being maintained in a predetermined temperature range by controlling the flow rate of air into the carbon char,
• quenching ash and other non-combustible material resulting from the partial oxidation of said char and removing same from the bottom of said pyrolysis chamber,
• introducing said hot overhead fuel gas into a combustion zone for combustion therein with an excess of oxygen,
• subjectng said overhead fuel gas to combustion in said combustion zone, and
• passing the resulting hot combustion gases to a heat load.

A process for pyrolysis and combustion of combustible solid material which comprises:

• introducing combustible solid material containing volatile matter into an upper section of a pyrolysis chamber having a lower section and a bottom,
• moving said material at a controlled rate downwardly through multiple stage zones in said pyrolysis chamber, said multiple stage zones being provided by a series of spaced vertically disposed horizontally moveable grates in said pyrolysis chamber,
• depositing carbon char in the lower section of the pyrolysis chamber,
• introducing air into the lower section of said pyrolysis chamber and partially oxidizing said char to form hot gaseous products,
• passing said hot gaseous products of the partial oxidation of said carbon char upwardly countercurrent to the movement of said solid material in said pyrolysis chamber, and driving off said volatile matter in said solid material in a multistage equilibrium process, wherein substantial reaction equilibrium is achieved in each of said stage zones in the pyrolysis chamber between the solid combustible feed material and said upwardly passing hot gaseous products,
• removing ash and other non-combustible material from the bottom of said chamber, and
• removing a hot overhead fuel gas comprised of said volatile matter from the solid material and the hot gaseous products of the partial oxidation of the carbon char.

A system for pyrolysis and combustion of combustible solid material which comprises:

• a pyrolysis chamber having an upper section, a lower section and a bottom,
• means for introducing a combustible solid feed material containing volatile matter into said upper section of said pyrolysis chamber,
• means comprising a series of spaced vertically disposed horizontally moveable grates forming a plurality of stage zones in said pyrolysis chamber and permitting downward movement of the solid material at a controlled rate through said zones,
• means for introducing air into the lower section of said pyrolysis chamber for contact with carbon char which will be deposited therein from the solid material, for partially oxidizing the carbon char, and forming hot gaseous products passing upwardly countercurrent to the movement of the solid matreial in said pyrolysis chamber and driving off volatile matter in the material by a multistage equilibrium operation, wherein substantial reaction equilibrium is achieved in each of said stage zones in the pyrolysis chamber between the solid combustible feed material and the upwardly passing hot gaseous products,
• means for removing ash and other non-combustible material from the bottom of said chamber,
• means for removing a hot overhead fuel gas from said pyrolysis chamber,
• a combustion chamber,
• means for introducing the overhead fuel gas into said combustion chamber,
• means for introducing air into said combustion chamber for combustion of the fuel gas therein,
• a heat load, and
• means for applying the resulting combustion gases to said heat load.