Method and apparatus for reduction of HCI emission from cement plants using cement raw meal as absorber
View Patent ↗The invention relates to a method for reduction of HCl emission from a cement plant based on a treatment of a preheater ( 1 ) and/or bypass gas stream, characterized in that a cement raw meal, as a HCl absorber, is dispersed in the gas stream(s) from which HCl is to be removed; the cement raw meal is introduced from a raw mill ( 6 ) and/or a silo ( 8 ) into a pipe with a up going gas flow; the pipe being arranged in fluid communication at a point after a gas conditioning tower ( 7 ) and/or before a particle filter unit ( 5 ) and/or in a by-pass line before particle filter ( 4 ).
1. A method for reduction of HCl emission from a gas stream of a cement plant, comprising: dispersing a cement raw meal into said gas stream as an HCL absorber, said cement raw meal being introduced from a raw mill and/or a silo into a pipe with an up going gas flow, said pipe being arranged in fluid communication at a point selected from one of the group consisting of: after a gas conditioning tower; before a particle filter unit; in a by-pass line before a particle filter; a combination thereof, wherein an operating temperature of said raw meal as a sorbent is maintained in a level below 180° C.
2. The method according to claim 1 , wherein said pipe has a vertical up going gas flow.
3. The method according to claim 1 , wherein said reduction of HCl emission is applicable when said raw mill is not in operation.
4. The method according to claim 1 , wherein the method is applicable for a total flue gas stream or at least a fraction of said total flue gas stream.
5. The method according to claim 1 , wherein a gas phase moisture content is maintained above 5% vol.
6. The method according to claim 1 , wherein the cement raw meal is a dispersible solid powder.
7. The method according to claim 6 , wherein a moisture content in said dispersible solid powder is elevated before being dispersed into the gas stream.
8. The method according to claim 1 , wherein the cement raw meal is recollected from the gas stream and used as feed to said preheater.
9. A method for reduction of HCl emission from a gas stream of a cement plant, comprising: dispersing a cement raw meal into said gas stream as an HCL absorber, said cement raw meal being introduced from a raw mill and/or a silo into a pipe with an up going gas flow, said pipe being arranged in fluid communication at a point selected from one of the group consisting of: after a gas conditioning tower; before a particle filter unit; in a by-pass line before a particle filter; a combination thereof; wherein said reduction of HCl emission is applicable when said raw mill is not in operation.