Processes for producing olefins include integration of steam cracking with a dual catalyst metathesis process. The processes include steam cracking a hydrocarbon feed to form a cracking reaction effluent containing butenes, separating the cracking reaction effluent to produce a cracking C4 effluent including normal butenes, isobutene, and 1,3-butadiene, subjecting the cracking C4 effluent to selective hydrogenation to convert 1,3-butadiene in the cracking C4 effluent to normal butenes, removing isobutene from a hydrogenation effluent to produce a metathesis feed containing normal butenes, and contacting the metathesis feed with a metathesis catalyst and a cracking catalyst directly downstream of the metathesis catalyst to produce a metathesis reaction effluent. Contacting with the metathesis catalyst causes metathesis of normal butenes to produce ethylene, propene, and C5+ olefins, and contacting with the cracking catalyst causes C5+ olefins produced through metathesis to undergo cracking reactions to produce additional propene, ethylene, or both.

Processes for producing olefins include integration of steam cracking with a dual catalyst metathesis process. The processes include steam cracking a hydrocarbon feed to form a cracking reaction effluent containing butenes, separating the cracking reaction effluent to produce a cracking C4 effluent including normal butenes, isobutene, and 1,3-butadiene, subjecting the cracking C4 effluent to selective hydrogenation to convert 1,3-butadiene in the cracking C4 effluent to normal butenes, removing isobutene from a hydrogenation effluent to produce a metathesis feed containing normal butenes, and contacting the metathesis feed with a metathesis catalyst and a cracking catalyst directly downstream of the metathesis catalyst to produce a metathesis reaction effluent. Contacting with the metathesis catalyst causes metathesis of normal butenes to produce ethylene, propene, and C5+ olefins, and contacting with the cracking catalyst causes C5+ olefins produced through metathesis to undergo cracking reactions to produce additional propene, ethylene, or both.

The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture (1) in a plant comprising an etherification unit (3), a first distillation unit (5), an ether cleavage unit (8) and a second distillation unit (10), the process comprising: (a) contacting the C4-hydrocarbon mixture (1) with a primary alcohol (2) and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether as an intermediate product and diisobutene as a by-product in the etherification unit (3); (b) distilling the reaction mixture (4) from the etherification unit (3) in the first distillation unit (5), a C4-hydrocarbon raffinate being withdrawn as the overhead product (6), the alkyl tert-butyl ether and diisobutene being withdrawn as the liquid or vaporous bottom product (7), and vaporizing the bottom product (7) if it is withdrawn as a liquid; (c) reacting the vaporous bottom product (7) in the presence of an acidic catalyst obtaining isobutene and the primary alcohol as reaction products in the ether cleavage unit (8); (d) distilling the reaction mixture (9) from the ether cleavage unit (8) in the second distillation unit (10), isobutene being withdrawn as the overhead product (11), the primary alcohol and diisobutene being withdrawn as the bottom product (12) and being recycled to the etherification unit (3); the plant further comprising a byproduct separation unit (15) being fed by a bottom purge stream (13) of the first distillation unit (5) and/or by a part of the bottom product of the second distillation unit (10), this feed stream (14) being split up in at least three byproduct streams wherein a first byproduct stream (16) is rich in diisobutene, a second byproduct stream (17) is rich in the primary alcohol, and a third byproduct stream (18) is rich in components with a normal boiling point higher than 110? C.

A method for manufacturing 1,4-bis(4-phenoxybenzoylbenzene), including: reacting terephthaloyl chloride with diphenyl ether in a reaction solvent and in the presence of a Lewis acid, so as to obtain a product mixture including a 1,4-bis(4-phenoxybenzoylbenzene)-Lewis acid complex; contacting the product mixture with a protic solvent, so as to obtain a first phase containing the Lewis acid and a second phase containing 1,4-bis(4-phenoxybenzoylbenzene); subjecting at least the second phase to a solid/liquid separation step by centrifugal filtration, so as to recover solid 1,4-bis(4-phenoxybenzoylbenzene).

Provided are an industrially advantageous method for separating and purifying isobutylene, the method enabling high-purity isobutylene to be efficiently obtained by a simple process, and a method for producing isobutylene. A method for separating and purifying isobutylene from a reaction gas containing the isobutylene and unreacted isobutanol, comprising: a step (1) of contacting the reaction gas containing the isobutylene and unreacted isobutanol with a first solvent to obtain a first gas containing the isobutylene and a recovered solution containing the unreacted isobutanol; a step (2) of contacting the first gas with a specific second solvent to allow the second solvent to absorb the isobutylene contained in the first gas to obtain an absorption solution containing the isobutylene; and a step (3) of distilling the absorption solution to obtain separated and purified isobutylene. A method for producing isobutylene using the separation and purification method.

A method for manufacturing 1,4-bis(4-phenoxybenzoylbenzene), including: reacting terephthaloyl chloride with diphenyl ether in a reaction solvent and in the presence of a Lewis acid, so as to obtain a product mixture including a 1,4-bis(4-phenoxybenzoylbenzene)-Lewis acid complex; contacting the product mixture with a protic solvent, so as to obtain a first phase containing the Lewis acid and a second phase containing 1,4-bis(4-phenoxybenzoylbenzene); subjecting at least the second phase to a solid/liquid separation step by centrifugal filtration, so as to recover solid 1,4-bis(4-phenoxybenzoylbenzene).

The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture (1) in a plant comprising an etherification unit (3), a first distillation unit (5), an ether cleavage unit (8) and a second distillation unit (10), the process comprising: (a) contacting the C4-hydrocarbon mixture (1) with a primary alcohol (2) and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether as an intermediate product and diisobutene as a by-product in the etherification unit (3): (b) distilling the reaction mixture (4) from the etherification unit (3) in the first distillation unit (5), a C4-hydrocarbon raffinate being withdrawn as the overhead product (6), the alkyl tert-butyl ether and diisobutene being withdrawn as the liquid or vaporous bottom product (7), and vaporizing the bottom product (7) if it is withdrawn as a liquid: (c) reacting the vaporous bottom product (7) in the presence of an acidic catalyst obtaining isobutene and the primary alcohol as reaction products in the ether cleavage unit (8): (d) distilling the reaction mixture (9) from the ether cleavage unit (8) in the second distillation unit (10), isobutene being withdrawn as the overhead product (11), the primary alcohol and diisobutene being withdrawn as the bottom product (12) and being recycled to the etherification unit (3); the plant further comprising a byproduct separation unit (15) being fed by a bottom purge stream (13) of the first distillation unit (5) and/or by a part of the bottom product of the second distillation unit (10), wherein a diisobutene product stream rich in diisobutene is separated from this feed stream (13, 14).

The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture (1) in a plant comprising an etherification unit (3), a first distillation unit (5), an ether cleavage unit (8) and a second distillation unit (10), the process comprising: (a) contacting the C4-hydrocarbon mixture (1) with a primary alcohol (2) and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether as an intermediate product and diisobutene as a by-product in the etherification unit (3): (b) distilling the reaction mixture (4) from the etherification unit (3) in the first distillation unit (5), a C4-hydrocarbon raffinate being withdrawn as the overhead product (6), the alkyl tert-butyl ether and diisobutene being withdrawn as the liquid or vaporous bottom product (7), and vaporizing the bottom product (7) if it is withdrawn as a liquid: (c) reacting the vaporous bottom product (7) in the presence of an acidic catalyst obtaining isobutene and the primary alcohol as reaction products in the ether cleavage unit (8): (d) distilling the reaction mixture (9) from the ether cleavage unit (8) in the second distillation unit (10), isobutene being withdrawn as the overhead product (11), the primary alcohol and diisobutene being withdrawn as the bottom product (12) and being recycled to the etherification unit (3); the plant further comprising a byproduct separation unit (15) being fed by a bottom purge stream (13) of the first distillation unit (5) and/or by a part of the bottom product of the second distillation unit (10), wherein a diisobutene product stream rich in diisobutene is separated from this feed stream (13, 14).

A method and a system for converting ethane to ethylene are provided. An exemplary method includes providing a feed stream including the ethane and oxygen to an oxidative dehydrogenation reactor and converting at least a portion of the ethane to ethylene in the oxidative dehydrogenation reactor to provide a reactor effluent stream including ethane, ethylene, and oxygen, acetylene, or both. The method includes cooling the reactor effluent stream to form a cooled effluent stream and providing the cooled effluent stream to an oxygen removal reactor including an ODH catalyst bed. A deoxygenation stream including water and an alcohol is provided to the oxygen removal reactor to form a deoxygenated effluent.

A method and a system for converting ethane to ethylene are provided. An exemplary method includes providing a feed stream including the ethane and oxygen to an oxidative dehydrogenation reactor and converting at least a portion of the ethane to ethylene in the oxidative dehydrogenation reactor to provide a reactor effluent stream including ethane, ethylene, and oxygen, acetylene, or both. The method includes cooling the reactor effluent stream to form a cooled effluent stream and providing the cooled effluent stream to an oxygen removal reactor including an ODH catalyst bed. A deoxygenation stream including water and an alcohol is provided to the oxygen removal reactor to form a deoxygenated effluent.