摘要:
A process for recovering valuable components of a residue from a stream of used catalyst, discharged from a plant for the liquid-phase, homogeneously catalyzed oxidation of alkylaromatic compounds under pressure, to produce polycarboxylic aromatic acids. The residue containing mainly cobalt (Co) and manganese (Mn) compounds is injected into a molten metal bath in combination with enough oxygen gas to convert essentially all carbon in the residue mainly to CO. The residue may also be sludge from a pond in which the residue is stored. The Co content of the molten metal is determined by how much of the Mn in the residue is to be rejected from the molten metal. The Mn rejected is distributed between a slag overlying the molten metal and the effluent which leaves the bath. In the slag, the Mn is trapped as manganese oxide (MnO); in the effluent Mn leaves as manganese dibromide (MnBr.sub.2). The alloy recovered is atomized to form a powder metal which is then reacted with acetic acid and hydrogen bromide to form the corresponding salts. Mn and bromine (Br) values from the slag and from the effluent are also recovered. Substantially pure Co may be recovered and exported, particularly if earthy residue from a sludge pond is processed to benefit the environment.
摘要:
A method for working up antimony halide catalysts containing inactivating organic impurities having high boiling points, in which anhydrous antimony trichloride can be isolated in a technically simple manner. The antimony trichloride can be chlorinated to obtain antimony pentachloride which can be re-used as a catalyst in a fluorination process.
摘要:
The invention relates to the stabilization of the activity and/or the reactivation of molybdoheteropoly acid catalysts in vapor-phase oxidations, such as the oxidehydrogenation of isobutyric acid or its lower esters to methacrylic acid or its lower esters, by means of an oxidizing treatment of the catalyst in which compounds of catalyst constituents are added, at temperatures ranging from 200.degree. to 400.degree. C., with an oxygen-containing gas.The inventive activation measures can be carried out either during the catalytic vapor-phase reaction, such as oxihydrogenation in particular, or intermittently to alternate therewith, and optionally also physically separated in part from each other.
摘要:
A process for treating a catalyst useful to promote the conversion of a substantially hydrocarbon feedstock containing at least one first metal at least a portion of which is deposited on the catalyst forming a first metal-containing catalyst, which process comprises:contacting the catalyst with at least one component of at least one second metal selected from the group consisting of antimony, tin, gallium, indium, zinc, tellurium and mixtures thereof to increase the second metal content of the catalyst, anddemetallizing the first metal-containing catalyst to provide a demetallized catalyst having a reduced first metal content.