Sulphuric acid plant design

Friedman, L.J., Friedman, S.J., 2007. The metallurgical sulphuric acid plant design, operating materials considerations 2007 update. In Warner, A.E.M., Newman, C.J., Vahed, A., George, D.B., Mackey, P.J., Warczok, A. (Eds.), Cu2007—Volume in (Book 2), The Carlos Diaz Symposium on Pyrometallurgy, Toronto, Canadapp. 545-566. 

VK69 was introduced in the market by Haldor Topsoe in 1996 and has subsequently been installed in the final passes of more than 50 double absorption sulphuric acid plants worldwide. Due to the superior activity of VK69, the S02 emissions can typically be reduced by a factor 2 and new double absorption plants can be designed with less than 40 ppm S02 emission [17], The industrial experience also confirms low deactivation rate and low screening loss as expected from the results obtained in the development phase. 

In a contact sulphuric acid plant, the gases leaving the first convertor are to be cooled from 845 to 675 K by means of the air required for the combustion of the sulphur. The air enters the heat exchanger at 495 K. If the flow of each of the streams is 2 m3/s at NTP, suggest a suitable design for a shell-and-tube type of heat exchanger employing tubes of 25 mm internal diameter. 

The sulphuric acid plant has a nominal capacity for 900 toime of monohydrate per day and it has been designed to comply with a maximum stack emission of300 mg/Nm of SO2. 

A full design of a process plant, be it a sulphuric acid plant or a food processing plant, is not within the competence of any one... 

Process engineers are thus seen to have been able to provide practical solutions to the problems of reducing atmospheric emissions in sulphuric acid plants. They have also achieved a further halving of both wastage and pollution by designing plants that operate at pressure. Increased pressure favours increased conversion because there is a volume contraction on reaction. In France a double absorption plant has been operated at 4 bar for over ten years. 

During my undergraduate studies at Banaras Hindu University (1950-54), the class was asked to design a 50 TPD Sulphuric Acid Plant... 

Louie, D., 2010b. Design considerations for sulphuric acid plants. In Paper in Short Course Sulphuric Acid Production Technologies Given at Cobre-Copper 2010, Hamburg, June 6-10, 2010. 

The silica carrier of a sulphuric acid catalyst, which has a relatively low surface area, serves as an inert support for the melt. It must be chemically resistant to the very corrosive pyrosulphate melt and the pore structure of the carrier should be designed for optimum melt distribution and minimum pore diffusion restriction. Diatomaceous earth or synthetic silica may be used as the silica raw material for carrier production. The diatomaceous earth, which is also referred to as diatomite or kieselguhr, is a siliceous, sedimentary rock consisting principally of the fossilised skeletal remains of the diatom, which is a unicellular aquatic plant related to the algae. The supports made from diatomaceous earth, which may be pretreated by calcination or flux-calcination, exhibit bimodal pore size distributions due to the microstructure of the skeletons, cf. Fig. 5. 

For the unique and high-technology equipment in the systems - the sulphuric acid decomposer in S-I and HyS and the two different electrolysers in HyS and HTSE - costs of equipment in the eventual commercial plant are based on development targets and only weakly derived from examination of fabrication technologies and manufacturing details. This is a manifestation of the immaturity of the designs, which require further iteration and refinement within the current development and demonstration phase. 

Use of PSA for design of emergency mitigation systems in a hydrogen production plant using General Atomics SI cycle technology. Section II Sulphuric acid decomposition... 

In the preparation of nitre from seaweed or wrack (French varech) the dried plants were burned and the ashes leached for the sodium and potassium salts. Upon concentration sodium chloride separated first, followed by potassium chloride and sulphate, other salts of these metals, such as sulphites and carbonates, being left in solution. These were destroyed by addition of sulphuric acid. On one occasion the acid was probably more concentrated or in larger quantity than usual and a violet vapour arose with an irritating odour not unlike that of chlorine. This condensed to a solid crystalline deposit on cold objects without formation of liquid. For a time this new substance was referred to as X, an appellation used many years later to designate the unknown rays discovered by Rfintgen in 1895 anc nowadays often employed in cases of blackmail. As Courtois had insufficient laboratory facilities he... 

Minimise the escape of unreacted inputs from the plant by better process. A good example is the modified 3 + 2 DCDA process for the production of sulphuric acid wherein five catalyst beds are used instead of four. Three beds are used before the interpass absorption tower and two are after it. This results in the conversion of up to 99.85 % of SO2 to SO3. By providing separate acid circuit for the final absorption tower, the emission of SO2 in exit gases can also be brought down further as compared to the earlier design where aU acid towers had a common circulation tank. 

The old design of cell is based on a lead-lined tank filled with aqueous sulphuric acid, and the spent chromic acid solution in porous ceramic pots was placed in the tank. The anodes were lead rods dipped into the ceramic pots and the cathode was the lining to the tank. The plant was obviously operated totally as a batch process. More modern and economic cells are now available they are based on a bipolar filter press concept with lead alloy anodes, steel cathodes and a Nafion protonconducting membrane. The energy consumption and space time yields with such... 

This system is used when the sulphuric acid produced can be utilised locally or easily sold to third parties. The sulphuric acid produced is of an excellent technical grade. The SO3 absorber tower is also used in emergency situations so that the S03/air flow can be diverted immediately to the absorber tower, preventing a complete plant shut-down procedure. The SO2 in the partially converted mixture will be absorbed in the caustic scrubber, which is part of the exhaust gas cleaning system. The design of the SO2 absorber should be adequate to absorb SO2 effectively during the start-up stage. 

Hence, the industrial preference for manufacturing for fuming Sulphuric Acid was in the range of 20-25 % free SO3. This needs removal of exothermic heat of dilution together with heat of absorption of SO3 by specially designed coolers. Some plants have a gas heated oleum boiler for boiling the 25 % oleum to produce pure SO3 vapour. 

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