A DRY SCRUBBER FOR PRE-NSPS BOILERS

A NEW METHOD FOR REMOVING ACID RAIN PRECURSORS FROM COAL-FIRED BOILERS HAS BEEN CONCEIVED. THE CONCEPT INVOLVESA TAIL-END SCRUBBER RETROFIT FOR INSTALLATION IN PLANTS WHICH PRE-DATE THE 1970 CLEAN AIR ACT. THE CONCEPT IS HIGHLY INNOVATIVE AND HAS MANY ADVANTAGES OVER OTHER SORBENTINJECTION PROCESSES. HETEROGENEOUS REACTIONS BETWEEN SO2 AND CALCIUM-BASED SORBENTS ARE AFFECTED BY THE MASS TRANSFER BETWEEN THE TWO PHASES AND THE CONTACTING PATTERNS OF THE REACTANTS. FLUIDIZED BED SYSTEMS HAVE BEEN FOUND TO BE WELL SUITED TO THESE REACTIONS BECAUSE OF THEIR TURBULENT MIXING AND ABILITY TO CONTROL GAS AND PARTICLE RESIDENCE TIMES. A UNIQUE TYPE OF CIRCULATING BED REACTOR, CALLED A TWIN SCRUBBER, IS PROPOSED FOR THIS RETROFIT APPLICATION. SOME OF ITS ADVANTAGES INCLUDE VERY LOW SPACE REQUIREMENTS, ENHANCED MASS TRANSFER, ABSENCE OF A DISTRIBUTOR PLATE, FEW SORBENT INJECTION POINTS, AND HIGH TURNDOWN. THE PROPOSED PHASE I PROGRAM INCLUDES A FEASIBILITY ANALYSIS OF THIS CONCEPT. A NEW METHOD FOR REMOVING ACID RAIN PRECURSORS FROM COAL-FIRED BOILERS HAS BEEN CONCEIVED. THE CONCEPT INVOLVESA TAIL-END SCRUBBER RETROFIT FOR INSTALLATION IN PLANTS WHICH PRE-DATE THE 1970 CLEAN AIR ACT. THE CONCEPT IS HIGHLY INNOVATIVE AND HAS MANY ADVANTAGES OVER OTHER SORBENTINJECTION PROCESSES. HETEROGENEOUS REACTIONS BETWEEN SO2 AND CALCIUM-BASED SORBENTS ARE AFFECTED BY THE MASS TRANSFER BETWEEN THE TWO PHASES AND THE CONTACTING PATTERNS OF THE REACTANTS. FLUIDIZED BED SYSTEMS HAVE BEEN FOUND TO BE WELL SUITED TO THESE REACTIONS BECAUSE OF THEIR TURBULENT MIXING AND ABILITY TO CONTROL GAS AND PARTICLE RESIDENCE TIMES. A UNIQUE TYPE OF CIRCULATING BED REACTOR, CALLED A TWIN SCRUBBER, IS PROPOSED FOR THIS RETROFIT APPLICATION. SOME OF ITS ADVANTAGES INCLUDE VERY LOW SPACE REQUIREMENTS, ENHANCED MASS TRANSFER, ABSENCE OF A DISTRIBUTOR PLATE, FEW SORBENT INJECTION POINTS, AND HIGH TURNDOWN. THE PROPOSED PHASE I PROGRAM INCLUDES A FEASIBILITY ANALYSIS OF THIS CONCEPT. A NEW METHOD FOR REMOVING ACID RAIN PRECURSORS FROM COAL-FIRED BOILERS HAS BEEN CONCEIVED. THE CONCEPT INVOLVESA TAIL-END SCRUBBER RETROFIT FOR INSTALLATION IN PLANTS WHICH PRE-DATE THE 1970 CLEAN AIR ACT. THE CONCEPT IS HIGHLY INNOVATIVE AND HAS MANY ADVANTAGES OVER OTHER SORBENTINJECTION PROCESSES. HETEROGENEOUS REACTIONS BETWEEN SO2 AND CALCIUM-BASED SORBENTS ARE AFFECTED BY THE MASS TRANSFER BETWEEN THE TWO PHASES AND THE CONTACTING PATTERNS OF THE REACTANTS. FLUIDIZED BED SYSTEMS HAVE BEEN FOUND TO BE WELL SUITED TO THESE REACTIONS BECAUSE OF THEIR TURBULENT MIXING AND ABILITY TO CONTROL GAS AND PARTICLE RESIDENCE TIMES. A UNIQUE TYPE OF CIRCULATING BED REACTOR, CALLED A TWIN SCRUBBER, IS PROPOSED FOR THIS RETROFIT APPLICATION. SOME OF ITS ADVANTAGES INCLUDE VERY LOW SPACE REQUIREMENTS, ENHANCED MASS TRANSFER, ABSENCE OF A DISTRIBUTOR PLATE, FEW SORBENT INJECTION POINTS, AND HIGH TURNDOWN. THE PROPOSED PHASE I PROGRAM INCLUDES A FEASIBILITY ANALYSIS OF THIS CONCEPT.