Seeking advice on sulfur-based acid production
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Regarding the production of sulfuric acid using sulfur, what is generally the quality standard for sulfur supplied to the plant? What is the ratio of air to sulfur fed into the sulfur burning furnace? Using the “3+2” process, from which conversion step of the flue gas is nicotinic acid obtained? A beginner’s question – I hope experts can give some advice. Thank you! This post was last edited by mhcy on 2007-11-30 09:55]
Our factory also uses sulfur, but I haven’t checked exactly what grade it is; I’ll ask again. The ratio of air to sulfur must be calculated based on the concentration of sulfur dioxide produced, as well as the oxygen-sulfur ratio in the flue gas entering the conversion unit. This post was last edited by in the blink of an eye on 2007-12-3 17:19]
The SO2 concentration at the outlet of the first converter ranges from 9% to 10.5%. The sulfuric acid production capacity is 100,000 tons per year, of which 65,000 tons are 98% sulfuric acid and 35,000 tons are 103.4% nicotinic acid. The plant operates for 300 days per year. My calculations show a sulfur output of 4,654 kg/h, with 32,417 Nm3/h of air being supplied. This figure does not take into account the amount of SO3 present in the furnace gas; I am not sure what the difference is compared to the actual amount of air used. I earnestly request guidance from experts. Thank you. This post was last edited by mhcy on 2007-11-30 at 10:34
1. Generally, the purity of sulfur is required to be over 99.5%; the moisture in such sulfur must be removed prior to supply. 2. The outlet design of the sulfur incineration furnace generally specifies a SO2 content of 10% on a volume basis, with some designs using a level of up to 11%. However, the refractory bricks in the sulfur incineration furnace should be lined with high-alumina bricks ； 3. Nicotinic acid is produced at the three-stage outlet; the conversion rate is generally around 94%. After being cooled by a heat exchanger and a economizer, it enters the nicotinic acid tower and then the intermediate absorption tower. A bypass line should be provided from the nicotinic acid tower to the intermediate absorption tower, and control valves should be installed at the inlets of both towers ；
Thank you so much for your advice! :) One more question: what is the ratio of sulfur to air at the inlet of the sulfur combustion furnace used in sulfuric acid production? My calculation shows 4654 kg/h of sulfur combined with 32417 Nm3/h of air; this is the theoretical value. What is the actual value? Thank you! !
:It’s a bit strange to have 300 working days per year; currently, the standard is to design things based on 8,000 working hours per year. :) By considering a total sulfur utilization rate of 98.5%–99%, the amounts of sulfur and air can be calculated. Some margin actually needs to be left; it depends to some extent on what your supervisor decides. The SO3 content is generally around 0.2%, and in such cases it can be ignored, as it is also derived from S and O2.
It is necessary to take into account that there is a certain proportion of O2 in the furnace gas; this depends on the catalyst used for the conversion process. Domestic catalysts generally keep the oxygen-sulfur ratio above 1.
Yes, I made a mistake; it should be 8,000 hours of working time
I work on environmental impact assessments for property owners, and I’m not very familiar with the process of producing sulfuric acid; please forgive my lack of knowledge.:loveliness: It would be great if I could get specific numerical values. Thank you for your help
The manufacturer claims to use imported catalysts, but it doesn’t specify where the liquid comes from or what its model is, :P As you mentioned, the oxygen-sulfur ratio should be greater than 1; my calculation gives 32417*0.21/4654 = 1.46. I’m not sure how much this differs from the actual value Please give me some advice!
My calculation formula comes from a book titled \"Calculations in Inorganic Process Technology,\" which is a translation of a Soviet book by M. E. A book by Bo Ren, published by the Chemical Industry Press
For imported catalysts, the flue gas concentration and oxygen-sulfur ratio also need to be determined based on the catalyst loading scheme. The services provided by domestic catalyst manufacturers are currently limited to catalyst products, and they are unable to offer conditions such as performance guarantee values similar to those provided by foreign catalyst manufacturers.