Possibility of waste heat utilization from sulfuric acid plant

Abstract

Sulphuric acid is produced by processing iron disulphide ore, through a set of interconnected technological operations, all the chemical processes, and partly the physical ones, being exothermic, taking place with the release of considerable amounts of heat. A great deal of the reaction heat of iron disulphide combustion (about 48%) is used for obtaining aqueous vapor whereas the larger remaining amount is irreversibly wasted or dissipated. Since the released amount of heat may also have a notable impact on the environment, the objective of the research work has been to study the utilization possibilities of waste heat, whereby a double goal could be achieved: the impact of waste heat on the environment would be eliminated and the waste heat could be used for warming up commercial facilities. It is economically justified to exploit the unused waste heat from drying and absorption processes (approximately 69%). This research project includes the utilization of the reaction heat of SO3 absorption for heating industrial and boiler water and for warming up greenhouses. Investment in projects for the utilization of the waste heat from the sulphuric acid plants is economically right and with regard to energy price rise it will be increasingly cost-effective.

Sumporna kiselina se proizvodi preradom rude pirita kroz niz međusobno povezanih tehnoloških operacija, pri čemu su svi hemijski procesi, a delom i fizički, egzotermni i odvijaju se uz oslobađanje znatnih količina toplote. Veliki deo reakcione toplote sagorevanja pirita (oko 48%) iskorišćen je za dobijanje vodene pare, dok se veći preostali deo nepovratno gubi ili rasipa. Kako oslobađena količina toplote može imati i veliki uticaj na životnu sredinu, cilj rada bio je da se analiziraju mogućnosti iskorišćenja otpadne toplote, čime bi se postigao dvostruki cilj: eliminisao bi se uticaj otpadne toplote na životnu sredinu a otpadna toplota iskoristila bi se za zagrevanje komercijalnih postrojenja. Ekonomski opravdano je iskorišćenje dela neutilizovane otpadne toplote sa sušenja i apsorpcije (oko 69%). Ovim projektom obuhvaćeno je iskorišćenje reakcione toplote apsoropcije SO3 za grejanje industrijske i kotlovske vode i zagrevanje staklenika. Investiranje u projekte iskorišćenja otpadne toplote iz postrojenja sumporne kiseline je ekonomski opravdano a s obzirom na rast cena energije biće sve ekonomičnije.