A method for preparing alpha-methylstyrene according to one embodiment of the present disclosure includes dehydrating a dimethylbenzyl alcohol solution in a reactor under an acid catalyst to prepare alpha-methylstyrene, where a reaction product after the dehydration reaction comprises a first reaction product including a first alpha-methylstyrene; and a second reaction product including vapor (H.sub.2O), a second alpha-methylstyrene and unreacted materials; and separating the second alpha-methylstyrene and the unreacted materials comprised in the second reaction product and recirculating the second alpha-methylstyrene and the unreacted materials to the reactor, a temperature inside the reactor during the dehydration reaction is 135° C. or higher, and a content of the acid catalyst is from 100 ppm to 1,500 ppm based on a total weight of dimethylbenzyl alcohol of the dimethylbenzyl alcohol solution.

A method for preparing alpha-methylstyrene according to one embodiment of the present disclosure includes dehydrating a dimethylbenzyl alcohol solution in a reactor under an acid catalyst to prepare alpha-methylstyrene, where a reaction product after the dehydration reaction comprises a first reaction product including a first alpha-methylstyrene; and a second reaction product including vapor (H.sub.2O), a second alpha-methylstyrene and unreacted materials; and separating the second alpha-methylstyrene and the unreacted materials comprised in the second reaction product and recirculating the second alpha-methylstyrene and the unreacted materials to the reactor, a temperature inside the reactor during the dehydration reaction is 135° C. or higher, and a content of the acid catalyst is from 100 ppm to 1,500 ppm based on a total weight of dimethylbenzyl alcohol of the dimethylbenzyl alcohol solution.

By this invention processes are provided for the conversion of carbohydrate to ethylene glycol by retro-aldol catalysis and sequential hydrogenation using control methods having at least one of acetol (hydroxyacetone) and a tracer as inputs.

By this invention processes are provided for the conversion of carbohydrate to ethylene glycol by retro-aldol catalysis and sequential hydrogenation using control methods having at least one of acetol (hydroxyacetone) and a tracer as inputs.

The present disclosure relates to the formation of dimethyl terephthalate (DMT). The present invention also relates to the depolymerization of polyethylene terephthalate (PET) and the recovery of dimethyl terephthalate (DMT).

The present disclosure provides methods for producing a regenerated hydrogenation catalyst from a fouled hydrogenation catalyst having a total surface area and at least one associated impurity. The method can include maintaining contact between the fouled hydrogenation catalyst and a flushing medium that comprises water, oxygen, and an inert or diluent gas at a regeneration temperature and a regeneration pressure sufficient to remove at least a portion of the at least one impurity from the hydrogenation catalyst to produce the regenerated hydrogenation catalyst, where the regenerated hydrogenation catalyst is characterized as retaining at least 70% of the activity of the hydrogenation catalyst.

The present disclosure provides methods for producing a regenerated hydrogenation catalyst from a fouled hydrogenation catalyst having a total surface area and at least one associated impurity. The method can include maintaining contact between the fouled hydrogenation catalyst and a flushing medium that comprises water, oxygen, and an inert or diluent gas at a regeneration temperature and a regeneration pressure sufficient to remove at least a portion of the at least one impurity from the hydrogenation catalyst to produce the regenerated hydrogenation catalyst, where the regenerated hydrogenation catalyst is characterized as retaining at least 70% of the activity of the hydrogenation catalyst.

Proposed is a high-yield simultaneous conversion method for a hydrogen source and a carbon dioxide source. The method significantly increases a yield of a formate through conversion of carbon dioxide. To this end, a carbon dioxide source and a hydrocarbon containing one or more hydroxy groups undergo a simultaneous conversion reaction in the presence of a solvent containing one or more alcohols and having a pH of 10 to 14.

Proposed is a high-yield simultaneous conversion method for a hydrogen source and a carbon dioxide source. The method significantly increases a yield of a formate through conversion of carbon dioxide. To this end, a carbon dioxide source and a hydrocarbon containing one or more hydroxy groups undergo a simultaneous conversion reaction in the presence of a solvent containing one or more alcohols and having a pH of 10 to 14.

The present invention discloses a nickel/titanium oxide-silicon oxide catalyst for synthesizing terpinene-4-ol as well as a preparation method and method of synthesizing terpinene-4-ol using the same. The preparation method includes the steps of catalyst preparation, terpinene-4-ol synthesis and the like are disclosed in the present invention. The preparation method includes the following steps: firstly, preparing a mixed colloid of TiO.sub.2 and SiO.sub.2 by using a sol-gel method, and then centrifuging, washing, drying and roasting is performed to prepare a TiO.sub.2—SiO.sub.2 binary oxide; then, preparing Ni/TiO2-SiO2 by dipping in a nickel nitrate solution, and preparing a supported catalyst by drying and roasting; and finally, adopting a terpinolene-4, 8-epoxide a raw material, carrying out isomerization under the dual catalytic action of TiO2-SiO2 and Ni of the supported catalyst, and carrying out hydrogenation to prepare terpinene-4-ol. The preparation method can combine isomerization and hydrogenation reaction on the same catalyst, has good selectivity on terpinene-4-ol, and is simple to operate and high in product yield.