82 results about "Vinyl acetate synthesis" patented technology

The invention relates to a vinyl acetate catalyst, a preparation method and a vinyl acetate synthesis method which are mainly used for solving the problem of low catalyst activity in the prior art. In order to better solve the problem, the technical scheme adopted by the invention is as follows: the vinyl acetate catalyst provided by the invention comprises a carrier, 50-200 g/L zinc acetate and 0-10 g/L potassium acetate; the preparation method comprises the following steps: (a) performing microwave treating on activated carbon under a non-oxidizing atmosphere relative to the activated carbon to obtain the carrier; (b) loading the necessary dosage of zinc acetate and a cocatalyst by an impregnation method; (c) drying to obtain the catalyst. The vinyl acetate catalyst can be used in the industrial production of acetylene method vinyl acetate synthesis.

The present invention relates to a vinyl acetate production method. The present invention provides a method for producing vinyl acetate through ethylene vapor-phase oxidation, wherein the method comprises an optionally ethylene preparation process, a vinyl acetate synthesis process and a vinyl acetate refinement process, and at least one process of the ethylene preparation process, the vinyl acetate synthesis process and the vinyl acetate refinement process adopts at least one selected from a steam mechanical recompression technology, an air cooler, a plate heat exchanger and a double shell side shell and tube heat exchanger.

In one embodiment, the invention is to a process for forming an ethanol mixture by hydrogenating an acetaldehyde feed stream in the presence of a catalyst. The acetaldehyde feed stream comprises acetaldehyde and at least one of acetic acid and ethanol. Preferably the acetaldehyde feed stream is a by-product stream from a vinyl acetate synthesis process.

The invention relates to a novel shell side structure for a vinyl acetate synthesis reactor. An upper ring-shaped distributor and a lower ring-shaped distributor are uniformly disposed at upper and lower ends of the shell side structure along peripheral directions respectively, the upper ring-shaped distributor is provided with at least two discharge ports, the lower ring-shaped distributor is provided with at least two inlet ports, at least two discharge ports among the at least two discharge ports are in a flow communicatio with each other through an annular channel arranged in the upper ring-shaped distributor, and at least two inlet ports among the at least two inlet ports are in the flow communication with each other through an annular channel arranged in the lower ring-shaped distributor. A shell and tube vinyl acetate synthesis reactor comprising the novel shell side structure is further related. By means of the shell side structure and the shell and tube vinyl acetate synthesis reactor with the same, uniform flow and uniform heat removing of water and steam which serve as heat removing mediums can be achieved in a shell side, the radial temperature difference of the reactor can be reduced, so that the overall performance of the shell and tube vinyl acetate synthesis reactor can be improved, the synthesis reaction heat can be reasonably utilized, the operation cost is lowered, and the investment and operation costs of devices of a heat-conducting medium circulating pump and the like can be reduced.

Recovery of acid, and in particular acetic acid, in a vinyl acetate production process. Vinyl acetate production produces heavy ends that comprise acetate containing compounds, such as monomers and polymers. Acid preferably is recovered by hydrolyzing the heavy ends and separating the resulting hydrolyzed stream to recover acid formed from the from acetate containing compounds.

The invention relates to a production method of vinyl acetate, which comprises a vinyl acetate synthesis process, a vinyl acetate refining process and a vinyl acetate and ethyl acetate separation process. The device comprises an acetic acid evaporator, an oxygen mixer, a vinyl acetate synthesis reactor, a first gas separation tower, a second gas separation tower, a degassing tank, a water washingtower, an absorption tower, a desorption tower, an ethylene recovery tower, a recycle gas compressor and a recovery gas compressor, and the vinyl acetate refining process comprises an acetic acid tower, a crude VAC tower, a refined VAC tower, an aldehyde ester concentration tower, an acetaldehyde tower, a dehydration tower, a water phase receiving tank, an extractive distillation tower and an acetic ether tower. In the separation process of vinyl acetate and ethyl acetate, an extractive distillation process taking acetic acid as an extracting agent is adopted. According to the method, acetic acid is adopted as an extracting agent, the content of vinyl acetate in the stream without the ethyl acetate impurities is reduced from 90% or above to 5% or below, the adopted extracting agent is acetic acid carried in the feeding stream, and the process greatly reduces the operation cost of the device.

The invention relates to a catalyst for acetylene-method vinyl acetate synthesis and a preparation method thereof. The catalyst is mainly used for solving the problem in the prior art that the content of a byproduct benzene in the vinyl acetate product is high. According to the catalyst for acetylene-method vinyl acetate synthesis, through the catalyst comprising a carrier which is activated carbon, an active ingredient which is zinc acetate and a cocatalyst which is a Cr(III) salt, the problem is better solved; and the catalyst can be applied to the industrial production of synthesizing acetylene-method vinyl acetate.

The invention discloses a vinyl acetate production device and method in cooperation with a heat accumulating type calcium carbide production process. The device comprises a heat accumulating type calcium carbide production unit, wherein a calcium carbide outlet of the heat accumulating type calcium carbide production unit is connected with a calcium carbide acetylene drying unit, the calcium carbide acetylene drying unit is provided with a process water inlet, an acetylene outlet of the calcium carbide acetylene drying unit is connected with a fixed-bed vinyl acetate synthesis unit, and the fixed-bed vinyl acetate synthesis unit is provided with a vinyl acetate outlet. The heat accumulating type calcium carbide production unit is provided with a raw coal inlet and a calcined lime inlet, a calcium carbide furnace tail gas outlet of the heat accumulating type calcium carbide production unit is connected with a pressure swing adsorption carbon monoxide extracting unit, a CO outlet of the pressure swing adsorption carbon monoxide extracting unit is connected with a carbonylating acetic acid synthesis unit, and an acetic acid outlet of the carbonylating acetic acid synthesis unit is connected with the fixed-bed vinyl acetate synthesis unit. The vinyl acetate production device has the advantages of being good in raw material adaptability, low in calcium carbide production power consumption, low in pollution, high in energy conversion efficiency, high in economical efficiency and the like.

Processes for forming an ethanol mixture by hydrogenating an acetaldehyde feed stream in the presence of a catalyst. The acetaldehyde feed stream comprises acetaldehyde and at least one of acetic acid and ethanol. Preferably the acetaldehyde feed stream is a by-product stream from a vinyl acetate synthesis process.

The present invention relates to a catalyst for acetylene method vinyl acetate synthesis, and a preparation method thereof. A purpose of the present invention is mainly to solve the problems of low catalyst activity and low acetylene single-process conversion rate in the prior art. The technical scheme of the present invention comprises that the catalyst comprises an active component and a carrier, the active component is zinc acetate, the carrier is modified active carbon modified by a modifier, and the modifier is at least one selected from ZnCl2, KOH, NaOH, and H3PO4. With the technical scheme, the problems in the prior art are well solved. The catalyst of the present invention can be used in the industrial production of acetylene method vinyl acetate.

The invention relates to a catalyst for acetylene method vinyl acetate synthesis and a preparation method thereof, and mainly aims to solve the problem of high benzene content in a vinyl acetate product in the prior art. According to the technical schemes of the invention, the catalyst for acetylene method vinyl acetate synthesis comprises an active component and a carrier; the active component iszinc acetate; the carrier is nitrogen-doped activated carbon; the content of the N element in the carrier is 2.8-10wt%; and therefore, the problem is better solved, and the method can be used for industrial production of acetylene-method vinyl acetate.

The invention discloses a method and device for recycling acetylene during the production process of vinyl acetate. The method is characterized in that an absorbing tower, a degassing tower, and a water washing tower are arranged, the reaction gas discharged from the top of a gas separation tower in the vinyl acetate synthesis step is subjected to an acetylene absorbing treatment, an acetylene releasing treatment, and an acetylene water washing treatment in sequence so as to remove the inert gas and acetaldehyde in the reaction gas, and acetylene with a concentration of 98% or more is obtained. The acetylene in the production process of vinyl acetate is comprehensively recycled and utilized, the utilization rate of raw material is improved, the consumption of raw materials and energy is reduced, and the cost is greatly reduced.

The invention relates to a vinyl acetate synthesis method. When vinyl acetate is prepared from methyl acetate through the route of carbonylation and cracking, vinyl acetate yield and selectivity are low. The invention mainly aims at solving the problems. The vinyl acetate synthesis method comprises the following steps: methyl acetate carbonylation is carried out, such that ethylene diacetate is obtained; and ethylene diacetate is cracked, such that vinyl acetate is obtained. A carbonylation catalyst adopts SiO2, Al2O3 or a mixture thereof as a carrier, and has active components comprising rhodium, alkali metal and at least one metal element selected from IVA and VA. With the technical scheme, the technical problem is well solved. The method can be used in industrial production of vinyl acetate.

The present invention relates to a catalyst for production of acetylene method vinyl acetate. A purpose of the present invention is to mainly solve the problem of not high activity of the acetylene gas phase catalyst in the prior art. The technical scheme of the present invention is that the catalyst uses active carbon as the carrier, and the active components comprise zinc acetate, potassium acetate, and a compound of at least an element selected from metalloid or group VIIB metal. With the technical scheme of the present invention, the problem in the prior art is solved. The catalyst of the present invention can be used for the vinyl acetate synthesis through the acetylene gas phase method in the industrial production.

The invention relates to a catalyst used for acetylene method vinyl acetate synthesis, and mainly solves a problem of low catalyst activity existing in the prior art. The catalyst used for acetylene method vinyl acetate synthesis comprises an active carbon carrier, zinc acetate, diether and aromatic acid ester, and the content of zinc acetate in the catalyst is 60-180g/L. The catalyst can well solve the problem, and can be used in the industrial production of the acetylene method vinyl acetate synthesis.

The present invention provides a technique capable of adjusting the loading positions of gold and palladium in a VAM catalyst by a method of producing a palladium-gold loaded catalyst for vinyl acetate synthesis. The method includes a step of impregnating a spherical porous molded carrier of an inorganic oxide with a mixed aqueous solution containing a palladium precursor as a catalytically active species and a gold precursor as a co-catalyst component, and subsequently impregnating the resultant spherical porous molded carrier with an aqueous alkaline solution to water-insolubilize the palladium precursor and the gold precursor in the spherical porous molded carrier to obtain a palladium-gold immobilized spherical porous molded carrier; and a subsequent step of adjusting the moisture content of the palladium-gold immobilized spherical porous molded carrier.

The invention discloses a device and method for decreasing moisture in vinyl acetate synthesis raw material acetylene gas. The device is characterized by being provided with a water scrubbing tower, an adsorption tank and a gas separating tower, the moisture contained in acetylene gas after alkali washing and impurity removal is further removed through the three unit processes of low-temperature water washing, adsorption drying and reaction liquid washing, and the moisture content in the acetylene gas is reduced to 0.01% or below. By effectively removing the moisture in the vinyl acetate production process, side reactions are decreased, the utilization rate of raw materials is improved, the production cost is reduced, and product quality is improved.