Boilers sulfur burning boiler

Two objectionable air emissions have characterized pulp mills for years the sulfur dioxide of the sulfite pulping mill and the malodorous reduced sulfur compounds (TRS) (mercaptans and hydrogen sulfide) of the kraft mill. Still another less noxious air emission is the particulate matter from steam boilers. Coal-burning boilers also emit sulfur dioxide, as is well known. The treatments for the particulate emissions are shown in Table 28.7. 

A portion of the heat obtained from this reaction is also recovered as steam which, together with that produced by the sulfur-burning boiler, is frequently sufficient to heat the stripper of the associated Girbotol (amine scrubber) plant. The net overall Claus chemistry, thus, involves oxidation of hydrogen sulfide with air to yield sulfur and water (Eq. 9.20). 

In Table II, a former oil burning boiler that was converted to burning low sulfur coal could not meet particulate compliance levels. To continue to operate, the utility was forced to derate from 650 Mw to 440 Mw. The LPA flue gas conditioner, however, allowed operation at 582 Mw, well within particulate compliance levels. (LPA and LAC are product series designations of Apollo Chemical Corp.)... 

Fig. 25.11. Sankey energy flow diagram for a 1000ton/day sulfur-burning double absorption sulfuric acid plant (feed gas 10% S02). A Blower B Sulphur furnace C Waste heat boiler D Catalyst bed 1 E Steam superheater F Catalyst bed 2 G Boiler H Catalyst bed 3 J Intermediate heat exchangers K Intermediate absorber L Converter bed 4 M Economizer N Final absorber O Air dryer P Acid coolers. (Courtsey Lurgi GmbH, Frankfurt, Germany.)...

Fig. 3.4. Entrance to fire tube boiler tubes after Fig. 3.3 s sulfur burning furnace. 1400 K gas ( 11 volume% S02, 10 volume% 02, 79 volume% N2) leaves the furnace and enters the boiler. It turns 90° in the boiler and flows into the tubes. The tubes are surrounded by water. Heat is transferred from the hot gas to the water - cooling the gas and making (useful) steam. The tubes are typically 0.05 m diameter. Table 3.1 gives industrial furnace data. Sulfur furnace boilers are discussed by Roensch (2005).

Sulfur burning furnaces are 2 cm thick cylindrical steel shells lined internally with 30 to 40 cm of insulating refractory, Fig. 3.3. Air and atomized molten sulfur enter at one end. Hot S02, 02, N2 gas departs the other into a boiler and steam superheater (Fig. 3.4). Some furnaces are provided with internal baffles. The baffles create a tortuous path for the sulfur and air, promoting complete sulfur combustion. Complete sulfur combustion is essential to prevent elemental sulfur condensation in downstream equipment. 

Product gas departs the sulfur burning fumace/boiler/superheater into ... 

Decreasing sulfur burning s air/sulfur ratio raises product gas temperature, Fig. 3.6. If carried too far (i.e. to raise % S02-in-gas), this may damage the sulfur burning furnace or boiler. 

Sulfur burning offgas is introduced directly into the hot converter because it leaves the sulfur burning fumace/boiler/superheater at its specified feed gas temperature, 700 K. 

About 2% of (S02 + S03) in sulfur-burning fumace/waste heat boiler offgas is S03. Sulfur burning offgas isn t water quenched/cleaned so its S03 isn t absorbed. It enters the Fig. 10.1 catalyst bed. 

All techniques of steam generation as used in electric power generation with special apparatus such as super-heater, economiser, or steam boiler for sulfur burning. 

Pulverized coal (PC) boilers are the most common large combustion systems for the generation of electricity in the US and the industrialized economies of the world. PC boilers include both wall-fired boilers and tangentially-fired (T-fired) boilers wall-fired boilers include both front wall and opposed wall configurations. Like cyclone boilers, they have the potential to use petroleum coke as a fuel provided that a sulfur dioxide scrubber has been installed on the unit. The vast majority of the petroleum coke fired in the USA is burned in PC boilers due to their dominance of the industry. Again the low volatility in the petroleum coke limits its use in PC boilers the typical cofiring percentage is on the order of 20 - 30 percent (calorific value basis). 

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