摘要:
Continuous process for hydroformylation of olefins containing, typically, from 6 to 20 carbon atoms to produce the corresponding aldehydes. The rate of formation of high boiling aldehyde condensation products is minimized by use of a high boiling inert solvent whose boiling point, at the pressure prevailing in the product recovery zone, lies intermediate between that of the highest boiling aldehyde product produced in the hydroformylation reaction and that of the ligand, as well as by maintaining the concentration of product aldehyde at or below a predetermined minor amount. In this way the length of a production run can be significantly extended before it becomes necessary to shut down the plant due to accumulation of high boiling aldehyde condensation products.
摘要:
A process is provided for the recovery of an optionally substituted C.sub.7 to C.sub.17 aldehyde from a liquid hydroformylation product medium obtained by rhodium catalyzed hydroformylation of an optionally substituted C.sub.6 to C.sub.16 olefin which contains (i) a rhodium complex hydroformylation catalyst containing rhodium in complex combination with carbon monoxide and with a ligand, (ii) excess ligand, (iii) at least one optionally substituted C.sub.7 to C.sub.17 aldehyde, and (iv) aldehyde condensation products, which process comprises:(a) degassing said liquid hydroformylation medium;(b) passing the degassed liquid hydroformylation medium through an evaporation zone maintained under temperature and pressure conditions conducive to evaporation of said at least one C.sub.7 to C.sub.17 aldehyde;(c) recovering from the evaporation zone a liquid catalyst-containing stream;(d) cooling the catalyst-containing stream exiting the evaporation zone;(e) recovering a vaporous stream from the evaporation zone containing (i) at least one optionally substituted C.sub.7 to C.sub.17 aldehyde, (ii) ligand and (iii) a minor amount of said aldehyde condensation products;(f) passing said vaporous stream to a fractionation zone;(g) recovering from said fractionation zone (i) a vaporous product stream containing said at least one C.sub.7 to C.sub.17 aldehyde, and (ii) a liquid bottom stream containing said ligand and aldehyde condensation products; and(h) recycling said cooled catalyst-containing stream of step (d) and at least a part of the material of said liquid bottom stream of step (g) to said hydroformylation zone.
摘要:
A process is described for the production of substantially pure gamma-butyrolactone from a feed mixture containing a major amount of gamma-butyrolactone and a minor amount of diethyl succinate which comprises fractionally distilling the mixture in a fractionation zone in the presence of added diethyl maleate and recovering from the fractionation zone an overhead vaporous product comprising gamma-butyrolactone which is substantially free from diethyl succinate and a liquid bottom product comprising diethyl maleate and diethyl succinate in admixture one with another. This procedure can be used to separate a gamma-butyrolactone rich fraction obtained by distillation in one or more stages of a crude reaction product obtained by hydrogenation of a C.sub.4 dicarboxylic acid ester feedstock that contains a major molar amount of diethyl maleate and a minor molar amount of diethyl succinate, using a diethyl maleate feedstock from an esterification plant to provide both diethyl maleate for use in the fractionation zone and also diethyl maleate for use as feedstock for the hydrogenation process.
摘要:
A continuous hydroformylation process for the production of an aldehyde by hydroformylation of an olefin comprises:providing a hydroformylation zone containing a charge of a liquid reaction medium having dissolved therein (a) a complex rhodium hydroformylation catalyst comprising rhodium in complex combination with carbon monoxide and with a cyclic phosphite having a phosphorus atom linked to three oxygen atoms at least two of which form together with the phosphorus atom part of a ring and (b) a ligand stabilizing amount of a tertiary amine;supplying said olefin to the hydroformylation zone;maintaining temperature and pressure conditions in the hydroformylation zone conducive to hydroformylation of the olefin;supplying make-up hydrogen and carbon monoxide to the hydroformylation zone; andrecovering from the liquid hydroformylation medium a hydroformylation product comprising at least one aldehyde.
摘要:
Aldehyde ethers of the general formula ##STR1## wherein R.sub.1 and R.sub.2 each, independently of the other, represent a C.sub.1 to C.sub.4 alkyl radical, and R.sub.3 and R.sub.4 each, independently of the other, represent a hydrogen atom or a C.sub.1 to C.sub.3 alkyl radical, or wherein R.sub.1 represents a C.sub.1 to C.sub.4 alkyl radical, R.sub.2 and R.sub.3 together with the carbon atoms to which they are attached form a 5-membered or 6-membered cycloaliphatic ring, and R.sub.4 represents a hydrogen atom or a C.sub.1 to C.sub.3 alkyl radical, and wherein Y represents --CH.sub.2 --CH.sub.2 --CH.sub.2 or --CH.sub.2 --CH (CH.sub.3)--, are prepared by hydroformylation of a corresponding compound of formula. ##STR2## by reaction with hydrogen and carbon monoxide in the presence of a hydroformylation catalyst, e.g. a rhodium complex catalyst. Preferred compounds include 4-t-butoxybutyraldehyde and 3-t-butoxy-2-methylpropionaldehyde. The compounds are useful chemical intermediates in the production of, for example, butane-1,4-diol, butyrolactone and tetrahydrofuran.
摘要:
Liquid sulphur-containing hydrocarbon feedstock is passed through two or more hydrodesulfurization zones and connected in a series each containing a packed bed of solid sulfurized catalyst. The liquid is passed from the first zone to the next until the final zone. Make up hydrogen is supplied to a hydrodesulfurization zone (i) other than the first hydrodesulfurization zone; hydrogen-containing gas is recovered from each hydrodesulfurization zone. The first hydrodesulfurization zone is supplied with hydrogen-containing gas recovered from a subsequent hydrodesulfurization zone. Hydrogen-containing gas recovered from the first hydrodesulfurization zone is purged. Liquid material recovered from the first hydrodesulfurization zone is recycled to the inlet of the hydrosulfurization zone so as to provide diluent for admixture with liquid feedstock. Any other hydrodesulfurization zone other than the first hydrodesulfurization zone and other than the hydrodesulfurization zone of step (i) is supplied with hydrogen-containing gas recovered from another hydrodesulfurization zone. The sulfur content of the hydrogen-containing gas and of the liquid hydrocarbon feedstock supplied to the first hydrodesulfurization zone is monitored and, if necessary, sulfur-containing material selected from hydrogen sulfide and active sulfur-containing materials is supplied to the first hydrodesulfurization zone so as to maintain the catalyst charge thereof in sulfided form.
摘要:
A liquid phase catalytic hydrogenation process is described in which an organic feedstock, such as an aldehyde containing from 2 to about 20 carbon atoms, is contracted with hydrogen in the presence of a solid hydrogenation catalyst under hydrogenation conditions to produce a hydrogenation product, such as the corresponding alcohol containing from 2 to about 20 carbon atoms, which process comprises passing a feed solution of the organic feedstock in an inert diluent therefor downwardly in co-current with a hydrogen-containing gas through a hydrogenation zone containing a bed of a particulate hydrogenation catalyst whose particles substantially all lie in the range of from about 1.5 mm to about 5 mm, maintaining the bed of catalyst particles under temperature and pressure conditions conducive to hydrogenation, recovering from a bottom part of the bed a liquid phase containing the hydrogenation product, controlling the rate of supply of the feed solution to the bed so as to maintain a superficial liquid velocity of the liquid down the bed in the range of from about 1.5 cm/sec to about 5 cm/sec, and controlling the rate of supply of the hydrogen-containing gas to the bed so as to maintain at the top surface of the bed of catalyst particles a flow of hydrogen-containing gas containing from 1.00 to about 1.15 times the stoichiometric quantity of hydrogen theoretically necessary to convert the organic feedstock completely to the hydrogenation product.
摘要:
Butane-1,4-diol is produced by converting allyl alcohol to an allyl t-alkyl or -cycloalkyl ether of the general formula: ##STR1## wherein R.sub.1 and R.sub.2 each, independently of the other, represent a C.sub.1 to C.sub.4 alkyl radical, and R.sub.3 and R.sub.4 each, independently of the other, represent a hydrogen atom or a C.sub.1 to C.sub.3 alkyl radical, or wherein R.sub.1 represents a C.sub.1 to C.sub.4 alkyl radical, R.sub.2 and R.sub.3 together with the carbon atoms to which they are attached form a 5-membered or 6-membered cycloaliphatic ring, and R.sub.4 represents a hydrogen atom or a C.sub.1 to C.sub.3 alkyl radical, followed by reacting resulting compound of formula (III) under hydroformylation conditions with carbon monoxide and hydrogen in the presence of a hydroformylation catalyst to form a corresponding aldehyde-ether of the general formula: ##STR2## reducing resulting aldehyde-ether of the general formula (II) to form a corresponding hydroxy-ether of the general formula: ##STR3## and cleaving resulting hydroxy-ether of the general formula (II) to give butane-1,4-diol. Typically R.sub.1 and R.sub.2 each represent a methyl group while R.sub.3 and R.sub.4 each represent a hydrogen atom. The alkene of the general formula: ##STR4## released upon cleavage of the hydroxy-ether of formula (II) can be recycled for reaction with further allyl alcohol to form a further quantity of the ether of the general formula (III).
摘要:
A process for the production of an aldehyde by hydroformylation of an olefin comprises:providing a hydroformylation zone containing a charge of a liquid reaction medium having dissolved therein a complex rhodium hydroformylation catalyst comprising rhodium in complex combination with carbon monoxide and with an organic phosphite ligand of the general formula:(RO).sub.3 P (I) in which each R represents an optionally substituted hydrocarbyl radical;supplying said olefin to the hydroformylation zone;maintaining temperature and pressure conditions in the hydroformylation zone conducive to hydroformylation of the olefin;supplying make-up hydrogen and carbon monoxide to the hydroformylation zone;recovering from the liquid hydroformylation medium a hydroformylation product comprising at least one aldehyde; andsupplying make-up phosphite ligand to the hydroformylation zone at a rate sufficient to maintain a predetermined level of free phosphite ligand in the hydroformylation medium.
摘要:
Aldehyde ethers of the general formula ##STR1## wherein R.sub.1 and R.sub.2 each, independently of the other, represent a C.sub.1 to C.sub.4 alkyl radical, and R.sub.3 and R.sub.4 each, independently of the other, represent a hydrogen atom or a C.sub.1 to C.sub.3 alkyl radical, or wherein R.sub.1 represents a C.sub.1 to C.sub.4 alkyl radical, R.sub.2 and R.sub.3 together with the carbon atoms to which they are attached form a 5-membered or 6-membered cycloaliphatic ring, and R.sub.4 represents a hydrogen atom or a C.sub.1 to C.sub.3 alkyl radical, and wherein Y represents --CH.sub.2 --CH.sub.2 --C.sub.2 or --CH.sub.2 --CH (CH.sub.3)--, are prepared by hydroformylation of a corresponding compound of formula: ##STR2## by reaction with hydrogen and carbon monoxide in the presence of a hydroformylation catalyst, e.g. a rhodium complex catalyst. Preferred compounds include 4-t-butoxybutyraldehyde and 3-t-butoxy-2-methylpropionaldehyde. The compounds are useful chemical intermediates in the production of, for example, butane-1,4-diol, butyrolactone and tetrahydrofuran.