The present invention relates to a catalyst system for oxidation of o-xylene and/or naphthalene to phthalic anhydride (PA) comprising at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active material of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt. %. The present invention further relates to a process for gas phase oxidation in which a gas stream comprising at least one hydrocarbon and molecular oxygen is passed through a catalyst system which comprises at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active materials of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt. %.

The present invention relates to a catalyst system for oxidation of o-xylene and/or naphthalene to phthalic anhydride (PA) comprising at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active material of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt. %. The present invention further relates to a process for gas phase oxidation in which a gas stream comprising at least one hydrocarbon and molecular oxygen is passed through a catalyst system which comprises at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active materials of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt. %.

The present invention pertains to a process for the cross-ketonization (Piria reaction) between an aryl carboxylic acid and an aliphatic carboxylic acid using a metal-based compound and a slight or a moderate excess of aryl carboxylic acid. A good selectivity, up to 99 mol %, can be achieved. The aryl aliphatic ketone can be used for the preparation of surfactants and other downstream products.

The present invention pertains to a process for the cross-ketonization (Piria reaction) between an aryl carboxylic acid and an aliphatic carboxylic acid using a metal-based compound and a slight or a moderate excess of aryl carboxylic acid. A good selectivity, up to 99 mol %, can be achieved. The aryl aliphatic ketone can be used for the preparation of surfactants and other downstream products.

A process for recovering by-products of a substituted aromatic hydrocarbon oxidation reaction, comprising cooling one or more of a vapor stream directed to a high-pressure absorber (380), a solvent-rich scrubbing stream (381) directed to a high-pressure absorber (380), and a water-rich liquid stream (383) directed to a solvent recovery zone, by heat exchange with a cooled spent scrubbing liquid withdrawn from a low-pressure scrubber (430).

A process for recovering by-products of a substituted aromatic hydrocarbon oxidation reaction, comprising cooling one or more of a vapor stream directed to a high-pressure absorber (380), a solvent-rich scrubbing stream (381) directed to a high-pressure absorber (380), and a water-rich liquid stream (383) directed to a solvent recovery zone, by heat exchange with a cooled spent scrubbing liquid withdrawn from a low-pressure scrubber (430).

A process for recovering by-products of a substituted aromatic hydrocarbon oxidation reaction, comprising cooling one or more of a vapor stream directed to a high-pressure absorber (380), a solvent-rich scrubbing stream (381) directed to a high-pressure absorber (380), and a water-rich liquid stream (383) directed to a solvent recovery zone, by heat exchange with a cooled spent scrubbing liquid withdrawn from a low-pressure scrubber (430).

The present invention relates to a method of deoxygenating tall oil pitch, yielding aliphatic and aromatic hydrocarbons. The invention even comprises turning the aliphates into polymerizable olefins by steam cracking, and turning the aromates into polymerizable terephthalic acid by oxygenation and, as necessary, rearrangement. The monomers can be used for the production of polymers of partially or completely biologic origin. According to the invention, tall oil pitch is first heated to turn it into liquid, which is then fed into a catalyst bed and catalytically deoxygenated with hydrogen. The deoxygenation catalyst is preferably a Ni—Mo catalyst and, in addition, a cracking catalyst can be used, such as an acidic zeolite catalyst. The deoxygenated product stream is cooled down so as to obtain a liquid, which is distilled for separation of the aliphatic and aromatic hydrocarbons for use in the production of the respective monomers and finally polymers.

The present invention relates to a method of deoxygenating tall oil pitch, yielding aliphatic and aromatic hydrocarbons. The invention even comprises turning the aliphates into polymerizable olefins by steam cracking, and turning the aromates into polymerizable terephthalic acid by oxygenation and, as necessary, rearrangement. The monomers can be used for the production of polymers of partially or completely biologic origin. According to the invention, tall oil pitch is first heated to turn it into liquid, which is then fed into a catalyst bed and catalytically deoxygenated with hydrogen. The deoxygenation catalyst is preferably a Ni—Mo catalyst and, in addition, a cracking catalyst can be used, such as an acidic zeolite catalyst. The deoxygenated product stream is cooled down so as to obtain a liquid, which is distilled for separation of the aliphatic and aromatic hydrocarbons for use in the production of the respective monomers and finally polymers.

The present invention relates to a method of deoxygenating tall oil pitch, yielding aliphatic and aromatic hydrocarbons. The invention even comprises turning the aliphates into polymerizable olefins by steam cracking, and turning the aromates into polymerizable terephthalic acid by oxygenation and, as necessary, rearrangement. The monomers can be used for the production of polymers of partially or completely biologic origin. According to the invention, tall oil pitch is first heated to turn it into liquid, which is then fed into a catalyst bed and catalytically deoxygenated with hydrogen. The deoxygenation catalyst is preferably a Ni—Mo catalyst and, in addition, a cracking catalyst can be used, such as an acidic zeolite catalyst. The deoxygenated product stream is cooled down so as to obtain a liquid, which is distilled for separation of the aliphatic and aromatic hydrocarbons for use in the production of the respective monomers and finally polymers.