Process for improving olefin etherification catalyst life

A process for the production of .sub.C5 + gasoline boiling range hydrocarbons rich in alkyl tertiary alkyl ethers from a C.sub.5 + olefinic hydrocarbon feedstream rich in isoolefins and containing catalyst deactivating amounts of dienes, said process comprising:

• contacting said .sub.C5 + feedstream with at least one dienophile under reaction conditions sufficient to form the adduct of said diene and said dienophile whereby a reaction product is produced comprising said olefinic hydrocarbon feedstream containing a substantially lower amount of said diene;
• and
• contacting at least a portion of said reaction product and an alkanol feedstream with acidic etherification catalyst under isoolefin etherification conditions whereby an effluent stream is produced comprising unconverted .sub.C5 + hydrocarbons, unconverted alkanol, said adduct and said alkyl tertiary alkyl ether.

A composition comprising high octane value gasoline having an enhanced oxygen content, said composition comprising C.sub.5 + gasoline boiling range hydrocarbons containing alkyl substituted tetrahydrophthalic anhydride or C.sub.1 -C.sub.4 esters thereof.

A composition comprising an etherificastion effluent which contains high octane value gasoline having an enhanced oxygen content, said composition comprising the reaction product of a process comprising:

• contacting a C.sub.5 + feedstream comprising C.sub.5 + gasoline boiling range hydrocarbons containing at least one diene hydrocarbon with a dienophile comprising maleic anhydride under reaction conditions sufficient to form the adduct of said diene and said dienophile, said adduct comprising alkyl substituted tetrahydrophthalic anhydride, whereby a reaction product is produced comprising said olefinic hydrocarbon feedstream containing a substantially lower amount of said diene;
• and
• contacting said reaction product and an alkanol feedstream with acidic etherification catalyst under isoolefin etherification conditions whereby the effluent stream is produced comprising unconverted C.sub.5 + hydrocarbons, unconverted alkanol, said adduct and said alkyl tertiary alkyl ether.

In the process for the production of C.sub.5 + gasoline boiling range hydrocarbons rich in alkyl tertiary alkyl ethers comprising contacting a hydrocarbon feedstream and C.sub.1 -C.sub.4 alkanol with acidic etherification catalyst under etherification conditions whereby said hydrocarbons rich in alkyl tertiary alkyl ethers are produced, said hydrocarbon feedstream comprising C.sub.5 + olefinic hydrocarbons rich in isoolefins and containing catalyst deactivating amounts of dienes and basic nitrogen compounds, the improvement comprising:

• pretreating said feedstream with maleic anhydride under reaction conditions sufficient to form the adduct of said diene and said maleic anhydride, said adduct comprising alkyl substituted tetrahydrophthalic anhydride, whereby a reaction product is produced comprising said olefinic hydrocarbon feedstream containing a substantially lower amount of said catalyst deactivating diene and a substantially lower amount of said basic nitrogen.

A high octane fuel composition for motor gasoline use comprising:

• a major amount of C.sub.5 + gasoline boiling range hydrocarbons;
• an octane-enhancing amount of lower alkyl tert-alkyl ether, and alkyl-substituted tetrahydrophthalic anhydride or C.sub.1 -C.sub.4 esters of said anhydride.

A high octane fuel composition comprising:

• C.sub.5 + gasoline boiling range hydrocarbon, an octane-enhancing amount of lower alkyl ether, and an adduct reaction product of at least one dienophile and conjugated diene, said fuel composition being substantially free of unreacted diene.