Improvements in the oxidation of hydrogen sulphide

    公开(公告)号:GB895539A

    公开(公告)日:1962-05-02

    申请号:GB2043260

    申请日:1960-06-10

    Applicant: BASF AG

    Inventor: FUCHS WERNER

    Abstract: Oxidation of hydrogen sulphide to sulphur with oxygen or sulphur dioxide or gases containing them at a temperature between -20 DEG C. and +150 DEG C. and a pressure of 0,5-50 atmospheres is effected in the presence of at least one compound which is liquid under reaction conditions and has the general formula in which R1, R2 and R3 represent hydrogen atoms or alkyl, cycloalkyl, hydroxyalkyl, aminoalkyl or phenyl radicals which may be substituted by alkyl groups, at least one of the radicals R2 or R3 being an organic radical, or in which any two of R1, R2 and R3 may together represent or polymethylene radicals (CH2)n, possibly substituted, which form common members of a heterocyclic ring containing the amide nitrogen atom, which ring may also contain a further nitrogen, or an oxygen or sulphur atom. The compound of the general formula above may be used in the presence of a miscible liquid. Compounds of this formula include N-alkyl substituted amides of open-chain saturated carboxylic acids with 1-4 carbon atoms, e.g. N-methylformamide, N:N-dimethylformamide, N:N-diethylformamide, N:N-dibutylformamide, N-methylacetamide, N:N-dimethylacetamide, N:N-diethylacetamide, N-methyl-butyric acid amide and N-butylacetamide. Other compounds of the given general formula mentioned are those in which the polymethylene radicals (CH2)n may be interrupted by an oxygen or sulphur atom and n has the value 3-5, which with the nitrogen atom of the -CO.N- group form a heterocyclic ring, and which may also contain a further hetero atom, e.g. 0 or 5. Specified examples of such compounds are N-formyl piperidine, N-acetyl piperidine, N-butyl piperidine and the morpholines, thiomorpholines and pyrrolidines N-substituted by the formyl, acetyl, propionyl or butyryl radical. The compounds of the general formula may be used in admixture with each other or admixed with miscible liquids such as water or saturated monohydric and polyhydric aliphatic alcohols, e.g. alkanols with 1-4 carbon atoms, and also diethylene glycol, triethylene glycol and glycol monomethyl ether. The hydrogen sulphide to be oxidized may be contained in Claus contact furnace waste, natural gas, cracking gas, water gas, converter or producer gas, brown coal low temperature carbonisation gas, shale oil low temperature carbonisation gas and waste gases from viscoserayon factories. Apparatus suitable for effecting the oxidation includes the packed tower or bubble cap column arrangements known per se to ensure intimate contact between gases and liquids. Alternatively carrier substances such as active carbon, pumice or kieselguhr may be impregnated with the liquid of the given general formula and gases containing hydrogen sulphide and oxygen and/or sulphur dioxide may be passed thereover. The oxidation may be carried out continuously or intermittently. Examples are given.

    Improvements in the continuous production of phthalodinitriles

    公开(公告)号:GB827355A

    公开(公告)日:1960-02-03

    申请号:GB1317558

    申请日:1958-04-25

    Applicant: BASF AG

    Abstract: The invention comprises a process for the continuous production of a phthalodinitrile, wherein a solid phthalic acid is fluidized by means of an inert gas current, with a dehydration catalyst, having a grain size of 0.1-1.0 mm. diameter, and the resultant fluidizable mixture is then conveyed by means of ammonia into a reaction zone, in which it is reacted at 250-500 DEG C. in a fluidized layer. Any of the isomeric phthalic acids may be used as starting materials. Examples of catalysts which may be used are aluminium oxide, boron phosphate, aluminium phosphate, silica gel, molybdic acid, titanium dioxide, mixtures thereof, or a silica gel impregnated with phosphoric acid. The ratio of the initial material to the catalyst is preferably 1 : 20 to 1 : 3. This mixture is fluidized by means of an inert gas stream in a preliminary vessel. Air or nitrogen may be used as the inert gas. The mixing vessel is preferably kept between room temperature and the melting-point of the initial material, e.g. 50-150 DEG C., and the fluidization may be carried out at normal or increased, e.g. 1-2 atmospheres, pressure. The fluidizable and flowable mixture obtained is then conveyed by a stream of ammonia into the actual reaction zone in such a way that the amount of catalyst in the reaction zone remains constant. The mol. ratio of initial material to ammonia during the reaction in the fluidized layer may be 1 : 3 to 1 : 20. Ammonia may also be additionally introduced directly into the fluidized layer. It is preferable to withdraw a part of the catalyst continuously from the reaction chamber and return it into the mixing vessel, where the substance to be reacted is mixed therewith by fluidization with an inert gas stream. A circulatory system for the unreacted ammonia is also preferably present. The end products are obtained, for example, by cooling from the gases leaving the reaction chamber. Examples are given of the preparation of terephthalonitrile and isophthalonitrile.

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