Abstract:
The invention describes a process for producing sulfuric acid by catalytic oxidation of SO 2 to SO 3 and subsequent absorption of the SO 3 in sulfuric acid, wherein the SO 3 is introduced into a first absorption stage (primary absorber) and at least partly absorbed there in concentrated sulfuric acid, wherein the SO 3 not absorbed in the first absorption stage is supplied to a second absorption stage (secondary absorber) for the further absorption in concentrated sulfuric acid, and wherein the sulfuric acid is cooled after passing through the two absorption stages. The cooling of the sulfuric acid is effected in at least two heat exchangers connected in parallel, wherein one of the at least two heat exchangers is operated as partial evaporator and is cooled with boiler feed water/steam and the other one is cooled with cooling water and operated as pure acid cooler.
Abstract:
Das Verfahren betrifft die zweistufige Umsetzung von Schwefeldioxid zu Schwefelsäure in einem nasskatalytischen Prozess, wobei der erste Reaktor bei ca. 420 °C mit konventionellen Katalysatoren wie Platin und Vanadiumpentoxid betrieben wird, während der zweite Reaktor mit Aktivkohle bzw. Cobaltkatalysator an der Oberfläche bei ca. 70 °C bereits Schwefelsäure produziert und diese mit Dünnsäure ausgewaschen wird, die im Gesamtverfahren wieder zu konzentrierter Schwefelsäure aufgearbeitet wird.
Abstract:
A process for producing in liquid phase, concentrated sulfuric acid in the liquid phase from a source of sulfur dioxide, is described. The process comprises converting the source of sulfur dioxide to sulfuric acid. The liquid phase comprises: a) nitric acid at a sufficient concentration to commence conversion in the presence of oxygen, of sulfur dioxide into sulfuric acid in the initial absence of sulfuric acid, b) nitric acid at a sufficient concentration to maintain conversion of sulfur dioxide in the presence of sulfuric acid either generated by said conversion or present at commencement of said conversion, and c) combined concentration of nitric acid and sulfuric acid ranging from 5M to 16M where the concentration of nitric acid is at least 5M in the initial absence of sulfuric acid, and a source of oxygen is introduced to the aqueous phase at a concentration sufficient to provide for such catalytic conversion of SO2 to H2SO4.
Abstract:
A condenser for condensing vapours of sulphuric acid contained in a process gas comprising a tube of an acid resistant material, configured for having a process gas inlet proximate to one end, a process gas outlet proximate to the other end and an acid outlet proximate to the bottom end, said tubes configured for extending through a cooling zone and said cooling zone configured for having a cooling medium inlet and a cooling medium outlet, for a gaseous cooling medium being passed counter-currently to the process gas, characterized in that the tube has a length of 7.5 m to 12 m.
Abstract:
A process for the recovery of sulfuric acid from a metal sulfate in solution, including the steps of : a) providing a source of metal sulfate in solution; b) converting the metal sulfate in solution into a crystallised metal sulfate salt; c) calcining the crystallised metal sulfate salt to produce the corresponding metal oxide and sulfur dioxide gas; and d) generating sulfuric acid.
Abstract:
The present invention relates to a process for the removal of sulphur dioxide from waste gases which process comprises contacting a waste gas containing sulphur dioxide with an aqueous solution containing sulphuric acid, hydrogen bromide and bromide to form sulphuric acid and hydrogen bromide; catalytically oxidising in the vapour phase the hydrogen bromide formed to bromine and thereafter recycling the bromine to the first step of the process.
Abstract:
An improved process for the recovery of high grade energy from a contact sulfuric acid manufacturing process. Improvements include: injection of steam between an intermediate catalyst stage and a heat recovery absorption tower and/or a heat exchanger for transfer of heat from conversion gas to high pressure boiler feed water; use of a condensing economizer for recovery of the vapor phase energy of formation of sulfuric acid from a wet conversion gas; and use of heat recovery system absorption acid for preheating air to a sulfur burner, the heat transferred to the combustion air being recovered at high pressure and temperature in a waste heat boiler.