Abstract: The invention relates to a process for eliminating nitrogen oxides and sulphur oxides from a stream of flue gas containing nitrogen oxides and sulphur oxides comprising the steps of(a) adding ammonia to the stream of flue gas and contacting the resulting stream, at a temperature of 250.degree.-450.degree. C., with a reduction catalyst for selective reduction of nitrogen oxides into nitrogen and water, the molar ratio of ammonia to nitrogen oxides being in the range of 0.6-1.8,(b) contacting the stream from step (a), at a temperature of 300.degree.-470.degree. C., with an oxidation catalyst for oxidation of unreacted ammonia into nitrogen and water and simultaneous oxidation of sulphur dioxide into sulphur trioxide, and(c) cooling the stream from step (b) for condensation of sulphur trioxide in the form of sulphuric acid.The products of the process of the invention are steam, nitrogen, and concentrated sulphuric acid of commercial quality giving no waste disposal problems.

Abstract: A process for preparing urethanes by reacting a solution of a nitrogen-containing organic compound and a hydroxyl-containing organic compound with carbon monoxide in the presence of a catalyst comprising rhodium, as a metal or compound, is disclosed. In the process of this invention, the rate of conversion and selectivity to urethane is increased by providing a rhodium catalyst comprising a polyamino ligand having at least two tertiary amino groups capable of coordinating with rhodium.

Abstract: The invention relates to a process for the preparation of a reducing gas having a high reduction potential by catalytic conversion in two steps of a sulphur-free gas mixture of hydrocarbons having a high content of hydrocarbons with two or more carbon atoms. In the first step an inlet stream of at least a part of the gas mixture together with added steam is passed through an adiabatic reactor containing a steam reforming catalyst at an inlet temperature of 440.degree.-510.degree. C. and an outlet temperature of 400.degree.-500.degree. C. and at a pressure of 1-30 kg/cm.sup.2 g the amount of steam added being calculated for obtaining in the inlet stream an H/C ratio of at least 4.8 and an O/C ratio of between 0.5 and 1. The outlet stream from the first step is combined with the top-gas from a reduction furnace, and the combined stream is then further converted in the second step by steam reforming into a reducing gas.

Abstract: This invention relates to a process for preparing urethanes by reacting a solution of a nitrogen-containing organic compound and a hydroxyl-containing organic compound with carbon monoxide in the presence of a ruthenium catalyst comprising a bis phosphine ligand.

Abstract: A process for preparing urethanes by reacting a solution of a nitrogen-containing organic compound and a hydroxyl-containing organic compound with carbon monoxide in the presence of a halide-free ruthenium catalyst is disclosed. In the process of this invention, the rate of conversion and selectivity to urethane is increased by providing a primary amine in the reaction solution.

Abstract: An aluminosilicate catalyst for catalytic dehydration of alcohols into ether is prepared by the steps of (a) contacting a crystalline aluminosilicate at below 800.degree. C., preferably 320.degree.-800.degree. C., with a nitrogen-containing base, preferably ammonia or a lower alkyl amine such as n-butyl amine, to absorb as much as possible of the base; and (b) desorbing part of the absorbed base by passing a stream of an inert gas over the thus-treated aluminosilicate at a temperature of 320.degree.-800.degree. C., preferably 400.degree.-600.degree. C. In step (a) the aluminosilicate catalyst is deactivated and in step (b) it is selectively reactivated so that the catalyst catalyses the ether formation reaction almost as well as the untreated catalyst, whereas the catalytic activity for other reactions such as formation of hydrocarbons and formation of "coke" consisting of polymerizates and/or carbon is eliminated.

Abstract: A gas mixture rich in ethan and/or ethylene is prepared by the conversion of a synthesis gas mixture containing hydrogen, carbon oxides and, optionally, other gases in the presence of one or more gaseous sulphur compounds, in an amount of at least 10 ppm by volume, preferably at least 200 ppm, calculated as H.sub.2 S, utilizing a catalyst consisting of one or more metals of group V-B and/or VI-B of the Periodic Table of Elements, preferably molybdenum and/or vanadium, together with one or more iron group metals each metal being in the form of free metal, oxide, or sulphide, the catalyst being supported on a porous, refractory oxidic support containing titanium dioxide.There is achieved a high activity and notably a high selectivity for the formation of ethane/ethylene, small amounts of propane, not insignificant amounts of methane and almost full suppression of the formation of higher hydrocarbons.The invention also relates to the catalyst prepared by impregnation or coprecipitation techniques.

Abstract: Hydrocarbons and especially as gasoline are prepared by the catalytic conversion in two subsequent reactors of a synthesis gas containing hydrogen and carbon oxides and having a mole ratio CO/H.sub.2 above 1 and when the conversion commences a mole ratio CO/CO.sub.2 of 5 to 20. In the first reactor, which is preferably a cooled reactor, the synthesis gas is converted into a methane-containing first intermediate and this at least partly further into a second intermediate containing dimethyl ether, at 5-100 bar and 150.degree.-400.degree. C., in the presence of catalyst(s), the effluent from this reactor is combined with a recycle stream containing low boiling components of the effluent from the second reactor, and then passed to the second reactor, which is adiabatic, where the conversion of the second intermediate is carried out at substantially the same pressure as in the first reactor and 150.degree.-600.degree. C.

Abstract: The invention relates to a process for preparing concentrated sulfuric acid by conducting a gas stream containing SO.sub.3 and H.sub.2 SO.sub.4 -vapor in a sulfuric acid tower in countercurrent to liquid sulfuric acid formed through a concentrating zone containing filler bodies trickled with sulfuric acid and an absorption zone where sulfuric acid vapor is absorbed in recycled sulfuric acid on filler bodies trickled therewith. A very substantial reduction in the amount of acid mist formed in conventional processes of this type is obtained by maintaining such temperature conditions in the tower that the recycle acid is withdrawn from the tower at a temperature T.sub.4 determined by the formulaT.sub.4 >140+6.alpha.+.beta.+0.2(T.sub.1 -T.sub.d)where .alpha. is the concentration of SO.sub.3 +H.sub.2 SO.sub.4 vapor in the inlet gas to the tower, .beta. the concentration of water vapor in the same inlet gas, T.sub.1 the temperature in .degree. C. of the same inlet gas and T.sub.

Abstract: The invention relates to an improved catalytic methanation process wherein a feed gas containing predominantly hydrogen and being rich in carbon oxides (CO and/or CO.sub.2) is divided into two part streams of which the first is methanated partially in an adiabatic methanation reactor by a methanation catalyst whereafter the effluent from the adiabatic methanation reactor is united after cooling with the second feed gas part stream and the thus-combined stream is methanated in a cooled methanation reactor by a methanation catalyst, preferably the same as that used in the adiabatic methanation reactor. It is possible, but not always necessary, to recycle part of the recycle gas to the adiabatic methanation reactor to keep the temperature therein at a moderate level. The process is useful in connection with transport of energy from a nuclear reactor. It is advantageous because it can be operated to produce superheated steam, for use, e.g.

Abstract: Ammonia converter for radial flow through two catalyst beds has a central heat exchanger mounted centrally in one of the beds. The process stream of synthesis gas is obtained by combining inside the converter separate feed streams: a shell stream serving to cool the converter shell, an exchange stream serving to cool the central heat exchanger, and a by-pass stream for final adjustment of the temperature of the process stream. The process stream passes in succession radially through the first catalyst bed in inwards direction through the central heat exchanger for being cooled, and radially through the second catalyst bed.

Abstract: Hydrogen and carbon oxides are reacted to form methane by passing an inlet stream of preheated methanation synthesis gas together with a recycle stream of product gas through a catalyst bed in an adiabatic methanation reactor. The inlet temperature is between 250.degree. and 350.degree. C, the outlet temperature between 500.degree. and 700.degree. C. The recycle stream is withdrawn from the outlet stream after the latter has been cooled to a temperature between 250.degree. and 350.degree. C and being, however, at least 50.degree. C above the dew point. A preferred means for withdrawing the recycle stream is an ejector driven by the inlet stream or by added steam.

Abstract: The invention concerns a methanation catalyst essentially consisting of nickel on a porous support containing alumina and zirconia in a weight ratio of from 1:2.0 to 1:0.05. This catalyst has good activity at low temperatures and good stability at high temperatures and allows to limit the temperature of the catalyst bed.

Abstract: An apparatus for heat exchange between two fluid streams comprising a pressure shell, tube sheets, and a bundle of exchange tubes. At least one of the tube sheets is connected to the pressure shell by a flexible joint capable of absorbing thermal expansions and of carrying the load of the tube bundle, the flexible joint comprising a substantially cylindrical skirt element and an annular sheet connected with simple joints and connected to the tube sheet and the pressure shell, respectively.