US 4,314,945 AGranted

Alkylene carbonate process

AssigneeUnion Carbide Corporation

InventorsCharles H. McMullen, James R. Nelson, Bernard C. Ream, Joseph A. Sims, Jr.

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Abstract

A process for making alkylene carbonate by the reaction of carbon dioxide and an alkylene oxide of the formula ##STR1## wherein R, R.sub.1, R.sub.2 and R.sub.3 are one or more of hydrogen, alkyl, aryl, alkaryl, aralkyl, cycloalkyl, allyloxy, chloroalkyl, and aryloxy to produce the corresponding carbonate, which comprises: (a) providing a homogeneous liquid phase reaction zone in which the predominant material therein is the alkylene carbonate; (b) providing a catalytic amount of an alkylene oxide carbonation catalyst to said liquid phase; (c) having dissolved in said liquid phase sufficient CO.sub.2 to provide a molal amount therein which exceeds the molal amount of the catalyst; (d) providing a CO.sub.2 pressure in the reaction zone of between about 150 psig and about 750 psig; (e) maintaining a sufficient amount of the alkylene oxide in the reaction to maintain the pressure and temperature thereof; (f) maintaining the reaction zone at a temperature at which the alkylene oxide and CO.sub.2 react to form alkylene carbonate, which temperature is not greater than about 200.degree. C.; and (g) correlating the reaction zone temperature and pressure to yield an alkylene carbonate efficiency of at least about 99% and a conversion of at least 99.5%.

A process for producing alkylene carbonate by the reaction of carbon dioxide and an alkylene oxide of the formula ##STR4## wherein R, R.sub.1, R.sub.2, and R.sub.3 are one or more of hydrogen, alkyl, aryl, alkaryl, aralkyl, cycloalkyl, allyloxy, chloroalkyl, and aryloxy to produce the corresponding alkylene carbonate which comprises:

(a) providing a homogeneous liquid phase reaction zone in which the predominant material therein is the alkylene carbonate, said alkylene carbonate employed in an amount of from about 85 to about 99.6 weight percent, based on the weight of material within the reaction zone;
(b) providing a catalytic amount of an alkylene oxide carbonation catalyst to said liquid phase, said catalyst a salt characterized by the following formula:
M.sup.+ A.sup.31
wherein M is potassium or a quaternary ammonium cation of the following formula:
##STR5## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 may each be alkyl, aryl, alkenyl, alkaryl, or aralkyl including substituents thereon in any combination or in which any two or more of the radicals R.sub.1, R.sub.2, R.sub.3 and R.sub.4 may be interconnected to form with the basic nitrogen atom a ring of the pyridine, piperidine, quinuclidine, pyrrolidine, pyrroline, morpholine, or thiomorpholine derivatives and 1,4-diazobicyclo[2.2.2]octane, A is bromine, chlorine, or iodine when M is quaternary ammonium cation and is iodine when M is potassium;
(c) having dissolved in said liquid phase sufficient CO.sub.2 to provide a molal amount therein which exceeds the molal amount of the catalyst;
(d) providing a CO.sub.2 pressure in the reaction zone of between about 150 psig and about 750 psig;
(e) maintaining a sufficient amount of the alkylene oxide in the reaction to maintain the pressure and temperature thereof;
(f) maintaining the reaction zone at a temperature at which the alkylene oxide and CO.sub.2 react to form alkylene carbonate, which temperature is not greater than 200.degree. C.;
and
(g) correlating the reaction zone temperature and pressure to yield an alkylene carbon efficiency of at least about 99% and a conversion of at least about 99.5%.

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Abstract

Claims13