H2SO4 making

Finally, we determine the amount of sulfuric acid solution containing 90.0% H2SO4 that contains 565 kg of pure H2SO4. We now know that 0.900 kg of pure H2SO4 makes 1 kg of 90.0% solution. Then... 

Fig. 1.4. Double contact sulfuric acid manufacture flowsheet. The three main S02 sources are at the top. Sulfur burning is by far the biggest source. The acid product leaves from two H2SO4 making towers at the bottom. Barren tail gas leaves the final H2S04 making tower, right arrow.

Fig. 9.1. Single contact H2SO4 making flowsheet. SO3 rich gas from catalytic SO2 oxidation is reacted with strong sulfuric acid, Reaction (1.2). The reaction consumes H20(f) and makes H2S04(f), strengthening the acid. Double contact H2SO4 making is described in Fig. 9.6. A few plants lower the SO2 content of their tail gas by scrubbing the gas with basic solution (Hay et al., 2003).

Fig. 9.3. Acid mist removal candle filter being installed atop a stainless steel H2SO4 making tower. It is one of many. Exiting gas passes inward through the candle fabric and out the top of the candle - then out of the tower. The acid mist is caught in the candle fabric by impact, diffusion and Brownian forces (Brink, 2005 Friedman and Friedman, 2004 Lee and Byszewski, 2005 Ziebold and Azwell, 2005). The large total area of the candles gives a low gas velocity through the fabric, which allows 99+% capture of the mist. The captured mist trickles down the fabric and drips back into the tower or into collection pipes (Outokumpu 2005).

After-H2SO4-making % S02 oxidized defined After-intermediate-H2S04-making % S02 oxidized is defined as ... 

Effect of incomplete S03-from-gas removal during intermediate H2SO4 making... 

Catalyst beds before intermediate H2SO4 making + beds after intermediate H2SO4 making. 

The total mass balance for Fig. 23.1 (excluding S02, 02 and N2 in H2SO4 making tower input and output gas) is ... 

The data are for FINAL H2SO4 making in double contact plants. ... 

Chapter 19 s S02 oxidation calculations assume that 100% of the SO3 entering H2SO4 making reacts to form H2S04(f). This appendix s calculations remove that restriction. They also consider C02 in feed gas. 

Since 0.900 kg of pure H2SO4 makes 1 kg of 90.0% solution, then... 

After treatment, the gas contains 1 milligram of dust per Nm of gas. It is ready for drying, catalytic SO2 oxidation and H2SO4 making. 

The gas is now ready for catalytic SO2 oxidation and subsequent H2SO4 making. 

Fig. 5.1. Spent sulfuric acid regeneration flowsheet. H2SO4(0 the contaminated spent acid is decomposed to S02(g), 02(g) and H20(g) in a mildly oxidizing, 1300 K fuel fired furnace. The fiunace offgas (6-14 volume% SO2,2 volume% O2, remainder N2, H2O, CO2) is cooled, cleaned and dried. It is then sent to catalytic SO2 + AO2 SO3 oxidation and H2SO4 making, Eqn. (1.2). Air is added just before dehydration (top right) to provide O2 for catalytic SO2 oxidation. Molten sulfur is often burnt as fuel in the decomposition fiimace. It provides heat for H2SO4 decomposition and SO2 for additional H2SO4 production. Tables 5.2 and 5.3 give details of industrial operations.

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