Davy Mckee (Oil & Chemicals) Limited

Davy Mckee (London) Limited

Davy Process Technology Limited

Davy Mckee Corporation

Davy International (Oil & Chemicals) Limited

Norman Harris

George E Harrison

Alan J Dennis

Colin Rathmell

Keith Turner

Thomas F Shevels

John Scarlett

John W Kippax

Stephen William Colley

Mohammad Sharif

Arthur James Reason

Anthony B Carter

Michael W Bradley

John F Flintoff

A process for the recovery of substantially pure alkyl alkanoate, such as ethyl acetate, from an impure feedstock. The impure feedstock is contacted with a selective hydrogenation catalyst in the presence of hydrogen in a selective hydrogenation zone maintained under selective hydrogenation conditions effective for selective hydrogenation of impurities containing reactive carbonyl groups thereby to hydrogenate the impurities to the corresponding alcohols. After recovery from the selective hydrogenation zone of a selectively hydrogenated reaction product mixture including the alkyl alkanoate and the corresponding alcohols, this is distilled in one or more distillation zones so as to produce substantially pure alkyl alkanoate therefrom which is recovered.

Process for purification of alkyl alkanoate

Aliphatic aldehydes are hydrogenated to alcohols containing by product ester which ester is removed and separately hydrogenated to provide additional product.

Hydrogenation of aldehydes

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.

Process for the production of gamma-butyrolactone

A continuous process is described for the production of a substantially acid free dialkyl maleate, for example diethyl maleate, from a feed stream containing a major amount of dialkyl maleate and a minor amount of the corresponding monoalkyl maleate. This comprises continuously distilling the feed stream in a primary distillation zone, which can comprise a single distillation column or a series of distillation columns connected in series, so as to give (i) a bottom fraction containing monoalkyl maleate and dialkyl maleate in admixture, (ii) a vaporous fraction comprising alkanol, and (iii) an intermediate fraction that is substantially free from alkanol and comprises a major proportion of diethyl maleate and a minor proportion of maleic anhydride. The intermediate fraction (iii) is redistilled in a secondary distillation zone to yield (i) an overhead fraction containing maleic anhydride and (ii) a bottom fraction containing substantially acid free dialkyl maleate. The vaporous stream can be condensed to recover alkanol for recycle to a dialkyl maleate production facility.

Process for the production of a dialkyl maleate

Process for the production of butane-1,4-diol

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).

Production of butane-1,4-diol

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.

Aldehyde-ethers

A process is disclosed for producing a substantially sulphur-free, butene-1 rich stream from a butene-containing C.sub.4 hydrocarbon feed stream by passage through a desulphurization zone, e.g. successive beds of active alumina and zinc oxide, and then distilling it. The desulphurization zone adsorbs, absorbs or converts to higher boiling sulphurous compounds low boiling sulphurous impurities such as H.sub.2 S, COS and CH.sub.3 SH. A sulphur-free butene-1 rich stream is recovered overhead from the distillation zone, while a butene-2 rich stream containing higher boiling sulphurous impurities originally present or produced in the desulphurization zone is recovered as a bottom product. A dechlorination zone (containing, for example, a charge of copper impregnated active carbon) can be provided upstream or downstream from the desulphurization zone but upstream from the distillation zone or can be provided in the path of the butene-1 rich stream from the distillation zone. The butene-1 rich product is suitable for use as a hydroformylation feedstock.

Process for producing substantially sulphur-free butene-1

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.

A rhodium-catalyzed hydroformylation process in disclosed in which an overhead vapor stream is recovered from the hydroformylation zone containing reactant alkene, hydrogen, carbon monoxide, alkene hydrogenation product(s), aldehyde product and aldehyde condensation products. This vapor stream is subjected to condensation conditions in one or two stages to condense therefrom condensible components comprising unreacted alkene, aldehyde product, and aldehyde condensation products. Non-condensed components of the vapor stream (e.g. H.sub.2 and CO) are recycled to the hydroformylation zone. Unreacted alkene is also recycled in liquid form to the hydroformylation zone.

Hydroformylation of alkenes to aldehydes

n-Valeraldehyde is produced by hydroformylation of butene-1 in the presence of one or more of cis- and trans-butene-2 and iso-butylene using a rhodium complex catalyst such as HRh(CO)PPh.sub.3).sub.3. Reaction conditions include use of at least about 100 moles of free triorganophosphine per gram atom of rhodium, a temperature of about 80.degree. C. to about 130.degree. C., a total pressure of not more than about 50 kg/cm.sup.2 absolute, a partial pressure of carbon monoxide of not more than about 1.5 kg/cm.sup.2 absolute, and a partial pressure of hydrogen of from about 1.0 to about 7.5 kg/cm.sup.2 absolute. An n-/iso-ratio of 20:1 and a conversion efficiency of butene-1 to n-valeraldehyde of over 85% are possible under these conditions with essentially no resin formation despite the presence of iso-butylene. The n-/iso-valeraldehyde mixture can be aldolized and reduced without intermediate purification to give a commercially acceptable C.sub.10 -plasticizer alcohol.

Hydroformylation process for the production of n-valeraldehyde

Tetrahydrofuran 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 (I) a corresponding hydroxy-ether of the general formula: ##STR3## and cleaving resulting hydroxy-ether of the general formula (II) under dehydrating conditions to produce tetrahydrofuran. 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).

Production of tetrahydrofuran

A hydroformylation process is disclosed utilizing a rhodium complex catalyst and an excess of a triorganophosphine wherein active rhodium catalyst and triorganophosphine can be separated from inactive rhodium, 'heavies' and triorganophosphine oxide in partially deactivated reaction medium by extraction into concentrated phosphoric acid or aqueous solutions containing at least 40% by weight phosphoric acid. By neutralization of the phosphoric acid extract in the presence of organic solvent, e.g. aldehyde trimers, a solution of active rhodium catalyst and triorganophosphine can be produced that is suitable for re-use in the hydroformylation reaction.

Growing community of inventors

Stockton-on-Tees, United Kingdom

Norman Harris