Process for operating a utility boiler and methods therefor

Abstract

A process for operating a utility boiler. The process has the following steps: (a) providing fuel to the boiler; (b) providing one or more additives selected from the group consisting of (i) one or more slag control agents, (ii) one or more oxygen-generating agents, (iii) one or more acid mitigation agents, (iv) one or more fouling prevention agents, (v) one or more oxidizer agents, (vi) one or more heavy metal capturing agents, and (vii) any combination of the foregoing to the boiler or an auxiliary device thereof; (c) providing air to the boiler; (d) burning the fuel in the boiler to generate heat and an exhaust gas; (e) intermittently or continuously monitoring one or more physical and/or chemical parameters of the fuel and/or intermittently or continuously monitoring one or more emissions variables of the exhaust gas to obtain one or more values therefor; and (f) varying or maintaining the rate at which either or both of the fuel and the one or more additives are provided to the boiler based on the one or more values obtained.

1 . A process for operating a utility boiler, comprising:
 a) providing fuel to the boiler;   b) providing one or more additives selected from the group consisting of (i) one or more slag control agents, (ii) one or more oxygen-generating agents, (iii) one or more acid reduction agents, (iv) one or more fouling prevention agents, (v) one or more oxidizer agents, (vi) one or more heavy metal capturing agents and (vii) any combination of the foregoing to the boiler or an auxiliary device thereof;   c) providing air to the boiler;   d) burning the fuel in the boiler to generate heat and an exhaust gas and/or a flue gas; and   e) intermittently or continuously monitoring one or more physical and/or chemical parameters of the fuel and/or intermittently or continuously monitoring one or more emissions variables of the exhaust gas and/or a flue gas to obtain one or more values; and   f) varying or maintaining the rate at which either or both of the fuel and the one or more additives is provided to the boiler based on the one or more values obtained.   
     
     
         2 . The process of  claim 1 , wherein the one or more values are communicated in real time to a controller, and wherein the controller provides instructions based on the one or more values in real time to one or more components of the process to vary the rate at which either or both of the fuel and the one or more additives is provided to the boiler and/or its auxiliary devices. 
     
     
         3 . The process of  claim 1 , wherein the rate at which either or both of the fuel and the one or more additives are intermittently or continuously varied as to substantially maintain one or more emissions variables within pre-determined limits. 
     
     
         4 . The process of  claim 3 , wherein the one or more emissions variables in the exhaust gas are selected from the group consisting of opacity, particulates, NO x , SO 2 , SO 3 , acid level, and Hg. 
     
     
         5 . The process of  claim 1 , wherein the one or more additives is one or more slag control agents selected from the group consisting of magnesium hydroxide, magnesium oxide, magnesium carbonate, magnesium organometallic compounds, magnesium carboxylate, magnesium salicylate, magnesium napthenate, and magnesium sulfonate. 
     
     
         6 . The process of  claim 1 , wherein the one or more additives is one or more oxygen-generating agents selected from the group consisting of calcium hydroxide, calcium oxide, calcium carbonate, calcium carboxylate, calcium organometallic compounds, calcium sulfonate, iron hydroxides, iron oxides, iron carbonates, iron carboxylates, iron organometallic compounds, iron sulfonates, barium hydroxide, barium oxide, barium carbonate, barium carboxylate, barium organometallic compounds, and barium sulfonate. 
     
     
         7 . The process of  claim 1 , wherein the one or more additives is added to the fuel to form a treated fuel, and wherein the treated fuel is then provided to the furnace. 
     
     
         8 . The process of  claim 1 , wherein the one or more additives is provided directly to the furnace. 
     
     
         9 . The process of  claim 1 , wherein the fuel is coal 
     
     
         10 . The process of  claim 1 , wherein the fuel is fuel oil. 
     
     
         11 . The process of  claim 1 , wherein the fuel is biomass. 
     
     
         12 . The process of  claim 2 , wherein the one or more components is selected from the group consisting of a flow limiting/controlling device, a pump, a fan, or a belt speeds. 
     
     
         13 . The process of  claim 1 , wherein the physical and/or chemical parameters of the fuel are monitored by a technique selected from the group consisting of one or more of prompt gamma neutron activation analysis, nuclear magnetic resonance spectroscopy, laser induced breakdown spectroscopy, mass spectroscopy; inductively couple plasma; microwave analyzer for moisture readings; atomic absorption; optical emission spectroscopy; X-ray diffraction; X-ray fluorescence; and pulsed fast and thermal neutron analysis. 
     
     
         14 . The process of  claim 1 , wherein the physical and/or chemical parameters of the fuel is selected from the group consisting of one or more of calorific value; volatile matter; ash; moisture; carbon/free carbon; hydrogen; sulfur; sulfur dioxide; sulfur trioxide; sulfate compounds; nitrogen; oxygen (by difference); reducing and oxidizer ash fusion temperatures; and oxides of any of silica, alumina, iron, calcium, magnesium, potassium, sodium, zinc, copper, titanium, chlorine, bromine, arsenic, mercury, cobalt, nickel, chromium, lead, and cadmium. 
     
     
         15 . The process of  claim 1 , wherein the one or more additives is one or more acid mitigation agents selected from the group consisting of magnesium oxide, magnesium hydroxide, magnesium carbonate, sodium bicarbonate carbonate, and calcium carbonate. 
     
     
         16 . The process of  claim 1 , wherein the one or more additives is one or more fouling prevention agents selected from the group consisting of magnesium oxide, magnesium hydroxide, magnesium carbonate, and sodium borate. 
     
     
         17 . The process of  claim 1 , wherein the one or more additives is one or more oxidizer agents selected from the group consisting of calcium bromide, calcium chloride, and sodium bromide. 
     
     
         18 . The process of  claim 1 , wherein the one or more additives is one or more heavy metal capturing agents, wherein the one or more heavy metal capturing agents is one or more mercury capturing agents. 
     
     
         19 . The process of  claim 18 , wherein the one or more additives is one or more mercury capturing agents is selected from the group consisting of calcium sulfide, calcium polysulfide, and sodium sulfide.