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 oxidizing in the vapor phase the hydrogen bromide formed to bromine and thereafter recycling the bromine to the first step of the process.

Abstract: A process and device are disclosed for preparing hydroxylamine from NO.sub.x -containing flue gases. Nitrogen removal from the NO.sub.x -containing flue gases by absorption in an aqueous solution of FeII-EDTA and by desorption through vapor stripping of the NA from the thus obtained FeII(NO)-EDTA solution, with admixture of hydrogen, leading to the recovery of an NO/H.sub.2 gaseous mixture, is combined with hydroxylamine synthesis by catalytic reduction of NO with hydrogen.

Abstract: The invention relates to a process for removing hydrogen sulfide (H.sub.2 S) and/or carbon disulfide (CS.sub.2) from exhaust gases. These exhaust gases are brought into contact with water and bromine so that H.sub.2 SO.sub.4 and HBr in aqueous solution and possible CO.sub.2 are formed. Bromine is regenerated from the hydrobromic acid in an electrolysis cell. In addition, marketable hydrogen is produced.

Abstract: The invention concerns a device and a method for removing nitrogen compounds from an aqueous liquid containing nitrogen oxides (NO.sub.x) and/or nitrates (NO.sub.3.sup.-). It comprises an electrochemical cell (10) with a cathode and an anode and a current source applied thereto. According to the invention, the cell is divided by a cation selective membrane into a cathode compartment (2) to be filled with said liquid, and an anode compartment (3) to be filled with an anolyte containing an aqueous solution of an alkali or hydrogen halide such as sodium bromide or sodium chloride, and the membrane (1) is constituted by a microporous fabric of PTFE.

Abstract: The invention relates to a process and a device for flue gas desulphurization using the following reaction:SO.sub.2 +Br.sub.2 +2 H.sub.2 O.fwdarw.H.sub.2 SO.sub.4 +2 HBrThe hydrobromic acid thus formed is split up by electrolysis into hydrogen and bromine. The sulphuric acid thus produced is brought to a saleable concentration rate of at least 90% in two successive concentrators (1, 2), the post-concentrator being fed with high temperature flue gases which are withdrawn immediately behind the economizer of the power plant.A partial flow of the flue gases to be cleaned traverses a heat exchanger (6), in which the cleaned flue gases are reheated to a temperature level which is compatible with the chimney requirements.