348results about How to "Increased space-time yield" patented technology

In a process for preparing amines, in which at least one compound containing at least one nitro group is reacted with hydrogen in the presence of a supported catalyst comprising, as catalytically active metal, nickel, if desired together with at least one metal of transition group I, V, VI and/or VIII, the reduced and stabilized supported catalyst comprises nickel crystallites having a bimodal nickel crystallite size distribution having maxima at 30-80 Angstr+E,uml o+EE m and 81-150 Angstr+E,uml o+EE m on a support comprising ZrO2, ZrO2-HfO2 and/or SiO2-ZrO2 and/or SiO2-ZrO2-HfO2 and in the reduced and passivated state has a nickel content of 60-80 percent by mass, an SiO2 content of 0-20 percent by mass, a ZrO2 content of 0-40 percent by mass, an HfO2 content of 0-4 percent by mass and after further reduction for one hour at 100 DEG C. has a degree of reduction of at least 70%.

A process for regenerating a catalyst used in the preparation of acrolein from glycerol, which comprises tungsten compounds and has acidic properties and at least one promoter.

The invention describes a process for preparing acetone starting from acetyl-coenzyme A comprising process steps A. enzymatic conversion of acetyl-CoA into acetoacetyl-CoA B. enzymatic conversion of acetoacetyl-CoA into acetoacetate and CoA and C. decarboxylation of acetoacetate to acetone and CO₂, which is characterized in that the coenzyme A is not transferred in process step B to an acceptor molecule. In addition, process step B is surprisingly catalysed by enzymes of the classes of acyl-CoA thioesterase, acyl-CoA synthetase or acyl-CoA thiokinase.

A completely novel metabolic pathway is concerned, because the enzymatic hydrolysis of acetoacetyl-CoA without simultaneous transfer of CoA to a receptor molecule has never previously been described for any microbial enzyme.

The invention relates to a technology and a device system for producing dimethyl oxalate by high-pressure carbonylation of industrial synthesis gases and producing ethylene glycol through dimethyl oxalate hydrogenation. The technology comprises the following steps: adopting industrial NO, O2 and methanol as raw materials for an esterification reaction to produce methyl nitrite; adopting industrial CO and methyl nitrite for a carbonylation reaction in a plate reactor to produce carbonylation products, which mainly include dimethyl oxalate and dimethyl carbonate; separating the carbonylation products to obtain dimethyl carbonate products; subsequently adding hydrogen into dimethyl oxalate in the plate reactor to produce ethylene glycol products; conducting the coupling recovery treatment on waste acids in the esterification reaction and purge gases in the carbonylation reaction for recycling. The device system comprises an esterification reaction system, a carbonylation reaction system, a coupling recovery system for purge gases and waste acids and a hydrogenation reaction system. The technology has the characteristic that device consumption is remarkably reduced, and particularly the nitric acid waste liquid recycling and purge gas recycling technologies as well as the separation technologies thereof are highly coupled; recycling of the raw materials in reaction waste gases is realized, and the effect is remarkable.

A process/apparatus is disclosed for continuously separating a liquid medium comprising diluent and unreacted monomers from a polymerization effluent comprising diluent, unreacted monomers and polymer solids, comprising a continuous discharge of the polymerization effluent from a slurry reactor through a discharge valve and transfer conduit into a first intermediate pressure flash tank with a conical bottom defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the slurry/polymer solids and an exit seal chamber of such diameter (d) and length (l) as to maintain a desired volume of concentrated polymer solids/slurry in the exit seal chamber such as to form a pressure seal while continuously discharging a plug flow of concentrated polymer solids/slurry bottom product of said first flash tank from the exit seal chamber through a seal chamber exit reducer with inclined sides defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the polymer solids which remain after removal of about 50 to 100% of the inert diluent therefrom to a second flash tank at a lower pressure.

An isocyanate is produced by reacting a primary amine with phosgene in the gas phase above the boiling point of the amine over an average contact time of 0.05 to 15 seconds under adiabatic conditions.

The invention relates to a process for producing dimethyl carbonate from industrial synthetic gas. According to the invention, O2, CO, N2, NO, and methanol are delivered into an esterification system for esterification; heavy component drawn from the esterification system is subjected to recovery treatment in a wastewater tower; light component drawn from the esterification system passes a compressor II and is subjected to a carbonylation reaction in a carbonylation reactor; the carbonylation reaction product is delivered into a second condensation separation tower, and is subjected to gas-liquid separation; separated liquid phase is refined in a pressurized rectification tower; part of non condensable gas is discharged from the separated gas phase, and the gas phase is continued to be subjected to a reaction in the esterification system; the discharged non-condensable gas is delivered into a denitration reactor; light component at a top of the pressurized rectification tower is subjected to further recovery treatment in a methanol recovery tower; heavy component from the pressurized rectification tower is delivered into a product tower; dimethyl carbonate is drawn from the top of the product tower, and dimethyl oxalate is drawn from the bottom of the product tower. The process has the economical and practical characteristics of low equipment investment, environment friendliness, energy saving, high catalyst efficiency, high raw material utilization rate, and the like.

The invention relates to a carbon monoxide gas phase coupling oxalate synthesis catalyst and a preparation method and application thereof. The problem that the oxalate synthesis caviation yield is low due to the fact that an existing catalyst is low in active component Pd dispersity and microcrystal content is mainly solved. The catalyst prepared from, by weight, 0.02-3 parts of an active component Pd and 97-100 parts of at least one carrier of alpha-aluminum oxide or a molecular sieve or silicon oxide is prepared through the method comprising the steps of impregnation, vacuum freeze drying and calcination, wherein the dispersity of the active component Pd is larger than 26%. The problems are well solved, and the carbon monoxide gas phase coupling oxalate synthesis catalyst can be used for industrial production of carbon monoxide gas phase coupling oxalate synthesis.

A process for milling amorphous solids using a milling apparatus can result in particles having a median particle diameter d₅₀ of <1.5 μm. The process includes: operating a mill in a milling phase with an operating medium selected from the group consisting of gas, vapor, steam, a gas containing steam and mixtures thereof, and heating a milling chamber in a heat-up phase before the actual operation with the operating medium in such a way that a temperature in the milling chamber, the mill exit or both, is higher than a dew point of the operating medium.

The invention discloses a 7beta-hydroxysterol dehydrogenase mutant with increased activity and stability which is obtained through molecular evolution, recombinant expression plasmid containing the 7beta-hydroxysterol dehydrogenase mutant gene and a recombinant expression transformant and a preparation method of a recombinant mutant enzyme preparation, and the invention also provides an application of the recombinant mutant enzyme preparation in ursodeoxycholic acid synthesis. The 7beta-hydroxysterol dehydrogenase has excellent activity and heat stability, can efficiently catalyze asymmetric reduction of 7-carbonyl lithocholic acid to prepare the ursodeoxycholic acid; the 7beta-hydroxysterol dehydrogenase is subjected to immobilization and then is subjected to couple by an enzyme method with the immobilized 7beta-hydroxysterol dehydrogenase, epimerization of a substrate chenodeoxycholic acid with low cost can be directly catalyzed, ursodeoxycholic acid can be prepared through continuous conversion, and the operation is simple. Compared with the prior art reported currently, ursodeoxycholic acid prepared by hydroxysterol dehydrogenase through catalysis has the advantages of high substrate concentration, short reaction time, complete reaction, and high product purity, and has strong industrial application prospect.

A process for modifying the TiSi zeolite used as catalyst features that the said TiSi zeolite is modified by making the ammonia contained aqueous solution in liquid or gas phase contact with it or the oxide copmosition containing TiSi zeolite at 80-600 deg.C for 0.5-1200 hr. When the modified catalyst is used to prepare epoxy propane by epoxidizing propene, the output rate can be greatly increased.

A process of converting a loop reactor into multiple loop reactors comprising starting with a loop reactor comprising at least 8 vertical legs, at least two non-vertical conversion runs, each non-vertical run connected in fluid flow communication with two vertical legs; at least two feed inlets; and at least two continuous discharge conduits; disconnecting at least one connection of each conversion run; and reconnecting each conversion run in fluid flow communication with a different vertical leg in such a manner to form multiple loop reactors each having at least one feed inlet and at least one continuous discharge conduit.

The present invention relates to a process for the production of carboxylic esters by reaction of carboxylic acids and/or carboxylic anhydrides with at least one alcohol selected from alkanols having at least 5 carbon atoms, cycloalkanols, and alkoxy-alkanols, in the presence of an acidic esterification catalyst. The invention further relates to the use of the resultant carboxylic esters as plasticizers or in a plasticizer composition for thermoplastic polymers and elastomers.

The invention provides a preparation process of a composite copper powder catalyst, comprising the steps of cutting an electroplating copper plate into a copper block and machining into copper scales; grinding the copper scales into sheet-shaped copper powder; obtaining sheet pure copper powder through a magnetic selection and air flow grading technology; smelting and atomizing a copper-tin-zinc alloy to prepare needed copper-tin-zinc alloy powder; drying and screening, and grinding to obtain scale-shaped copper-tin-zinc alloy powder; magnetically selecting and screening to obtain the needed copper-tin-zinc alloy powder; and mixing the sheet pure copper powder with the copper-tin-zinc alloy powder according to a ratio to obtain the needed composite copper powder catalyst. According to the preparation process of the composite copper powder catalyst, elements which are harmful to an environment are not introduced in a whole process, the quality stability of a product is good, concave-convex defects of the surface of powder grains are more and the specific surface is large; the catalysis property of the composite copper powder catalyst is obviously better than that of common composite copper powder so that the effect of an organic silicon monomer synthesized metal catalyzing system is improved, the time-space yield of an organic silicon monomer synthesized fluidized bed is increased, a synthesis reaction period is prolonged, the selectivity is improved, the cost is reduced and good economic benefits are created.

The invention relates to a method for preparing a catalyst, which is used in making low-carbon mixed alcohol carbon nanometer tube promoting Co-Cu group. The catalyst comprises Co, Cu and carbon nanometer tube, wherein the mass percent is: Co:40-75wt%,Cu:15-50wt%,CNTs:5-25wt%, the CNTs is a multi-wall carbon nanometer tube. The catalyst is prepared through coprecipitation, which has high activity and stability, and the C2+ alcohol has high selective, besides, both the conversion rate of CO and space time productivity of the low-carbon mixed alcohol are higher than the present catalyst.

The invention discloses a copper-iron based catalyst in the technical field of catalyst preparation and application thereof in preparing low mixed alcohols by catalyzing synthesis gas. According to the invention, a copper-magnesium-iron hydrotalcite precursor is prepared by a nucleation-crystallization isolating method, and then the copper-magnesium-iron hydrotalcite precursor is roasted and then subjected to reduction treatment to obtain the copper-iron based catalyst of highly dispersed nanoparticles. The catalyst has the characteristics that the catalytic active ingredients are highly dispersed, the catalytic active ingredients have strong interaction with one another, and are high in stability, and as a result, the activity and selectivity of the catalyst are improved. After the copper-iron based catalyst is applied to preparing low mixed alcohols from the synthesis gas, the CO conversion rate is high, and the selectivity and space time yield of the low mixed alcohols are also improved; besides, the conversion rate of CO for synthesizing low mixed alcohols through CO hydrogenation is 56.89% and the selectivity of alcohols is 49.07%.

A process for preparing 4-substituted 2,2,6,6-tetramethylpiperidin-N-oxy compounds (II) or mixtures of (II) and 4-substituted 2,2,6,6-tetramethylpiperidin-N-hydroxy compounds (III)

where X+Y can be O or can represent a cyclic ketal with the radicals

or can represent an open-chain ketal in which X═O—R and Y═O—R′, where R and R′ can be identical or different and can each be CH₃, CH₂—CH₃, CH₂—CH₂—CH₃, CH(CH₃)—CH₃, CH₂—CH₂—CH₂—CH₃ and CH₂—CH(CH₃)—CH₃,

by oxidizing corresponding 4-substituted 2,2,6,6-tetramethylpiperidines (I)

with hydrogen peroxide in the presence of alkali metal hydrogencarbonate and/or ammonium hydrogencarbonate and in the presence or absence of a solvent, in which the reaction is carried out with the addition of Brönsted acids which have an acid strength greater than that of the hydrogencarbonate.