Process for decreasing N2 O emissions from a fluidized bed reactor

Claim 1

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section having a bed of particulate material comprising nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture; (b) introducing a primary, oxygen-containing gas into said lower region at a fluidizing velocity sufficient to fluidize said particulate material; (c) operating a lower region of said furnace section under substoichiometric conditions such that combustion of said fuel particles is incomplete; (d) operating an upper region of said furnace section above said lower region under oxidizing conditions to complete combustion of said fuel particles in said upper region; and (e) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; and (f) controlling said fluidizing velocity to control passage of said particulate material from said lower region to said upper region to maintain a temperature substantially within a range of 1650° to 1800° F. in said upper region for lowering emissions of N 2 O formed during combustion while permitting efficient sulfur capture to lower emissions of SOx.

Claim 2

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section having a bed of particulate material comprising nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture; (b) introducing a primary, oxygen-containing gas into said lower region at a fluidizing velocity sufficient to fluidize said particulate material; (c) operating a lower region of said furnace section under substoichiometric conditions such that combustion of said fuel particles is incomplete; (d) operating an upper region of said furnace section above said lower region under oxidizing conditions to complete combustion of said fuel particles in said upper region; and (e) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; and (f) controlling said fluidizing velocity to control passage of said particulate material from said lower region to said upper region to maintain a temperature substantially within a range of 1650° to 1800° F. in said upper region for lowering emissions of N 2 O formed during combustion while permitting efficient sulfur capture to lower emissions of SOx.

Claim 5

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section having a bed of particulate material comprising nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture; (b) introducing a primary, oxygen-containing gas into said lower region at a fluidizing velocity sufficient to fluidize said particulate material; (c) operating a lower region of said furnace section under substoichiometric conditions such that combustion of said fuel particles is incomplete; (d) operating an upper region of said furnace section above said lower region under oxidizing conditions to complete combustion of said fuel particles in said upper region; and (e) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; and (f) passing said particulate material from said lower region to said upper region; and (g) controlling the ratio of relatively five particulate material to relatively coarse particulate material passed from said lower region to said upper region to maintain a temperature substantially within a range of 1650° to 1800° F. in said upper region for lowering emissions of N 2 O formed during combustion while permitting efficient sulfur capture to lower emissions of SOx.

Claim 6

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section having a bed of particulate material comprising nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture; (b) introducing a primary, oxygen-containing gas into said lower region at a fluidizing velocity sufficient to fluidize said particulate material; (c) operating a lower region of said furnace section under substoichiometric conditions such that combustion of said fuel particles is incomplete; (d) operating an upper region of said furnace section above said lower region under oxidizing conditions to complete combustion of said fuel particles in said upper region; and (e) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; and (f) passing said particulate material from said lower region to said upper region; and (g) controlling the ratio of relatively five particulate material to relatively coarse particulate material passed from said lower region to said upper region to maintain a temperature substantially within a range of 1650° to 1800° F. in said upper region for lowering emissions of N 2 O formed during combustion while permitting efficient sulfur capture to lower emissions of SOx.

Claim 11

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section; (b) introducing nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture into said furnace section; (c) combusting said fuel particles to form gaseous and solid products of combustion, said solid products of combustion mixing with said fuel particles and said sorbent particles to form particulate material; (d) introducing a primary oxygen-containing gas into a lower region of said furnace section at a first level to support combustion of said fuel particles and to fluidize said particulate material to form a lower dense bed of said particulate material and an upper dispersed bed of said particulate material above said dense bed; (e) operating said lower region at substoichiometric conditions so that said combustion of said fuel particles is incomplete; (f) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; (g) introducing a secondary oxygen-containing gas into said furnace section at a second level above said first level to create oxidizing conditions in said upper region of said furnace section; (h) passing said particulate material from said lower region to said upper region; and (i) controlling the ratio of relatively fine to relatively coarse particulate material passed from said lower region to said upper region to maintain a temperature substantially within a range of 1650° F. to 1800° F. in said upper region for destroying N 2 O while permitting efficient sulfur capture to lower emissions of SOx.

Claim 12

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section; (b) introducing nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture into said furnace section; (c) combusting said fuel particles to form gaseous and solid products of combustion, said solid products of combustion mixing with said fuel particles and said sorbent particles to form particulate material; (d) introducing a primary oxygen-containing gas into a lower region of said furnace section at a first level to support combustion of said fuel particles and to fluidize said particulate material to form a lower dense bed of said particulate material and an upper dispersed bed of said particulate material above said dense bed; (e) operating said lower region at substoichiometric conditions so that said combustion of said fuel particles is incomplete; (f) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; (g) introducing a secondary oxygen-containing gas into said furnace section at a second level above said first level to create oxidizing conditions in said upper region of said furnace section; (h) passing said particulate material from said lower region to said upper region; and (i) controlling the ratio of relatively fine to relatively coarse particulate material passed from said lower region to said upper region to maintain a temperature substantially within a range of 1650° F. to 1800° F. in said upper region for destroying N 2 O while permitting efficient sulfur capture to lower emissions of SOx.

Claim 24

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section having a bed of particulate material in a lower region which contains nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture; (b) introducing a primary, oxygen-containing gas into said lower region of said furnace to fluidized said bed of particulate material, a portion of said particulate material passing from said lower region of said furnace to an upper region thereof; (c) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; and (d) controlling the ratio of relatively fine to relatively coarse particulate material passed from said lower region to said upper region to maintain a predetermined temperature in said upper region for reducing emissions of N 2 O formed during combustion while permitting efficient sulfur capture to lower SOx emissions.

Claim 25

A method of operating a fluidized bed reactor to simultaneously lower emissions of N 2 O, NOx and SOx comprising: (a) providing a furnace section having a bed of particulate material in a lower region which contains nitrogen-containing fuel particles for combustion and sorbent particles for sulfur capture; (b) introducing a primary, oxygen-containing gas into said lower region of said furnace to fluidized said bed of particulate material, a portion of said particulate material passing from said lower region of said furnace to an upper region thereof; (c) maintaining said lower region at a temperature below approximately 1600° F. to lower emissions of NOx; and (d) controlling the ratio of relatively fine to relatively coarse particulate material passed from said lower region to said upper region to maintain a predetermined temperature in said upper region for reducing emissions of N 2 O formed during combustion while permitting efficient sulfur capture to lower SOx emissions.