445results about "Carbonic/haloformic acid esters preparation" patented technology

The invention discloses a process for synthesizing methyl carbonate from alcoholysis of methanol and urea in a high pressure reactor, wherein the catalyst is a amine salt type ionic liquid having a molecular formula of R1R2R3NHX-MaXb, the raw material methanol and urea are subject to alcoholysis reaction and methyl carbonate is synthesized in one step.

The urea alcoholizing process for synthesizing dimethyl carbonate includes adding solid alkali into reactor, adding urea solution comprising urea and methanol in the molar ratio of 0.01-100 and the material feeding rate radio of 0.01-100 into the reactor, and reaction at 150-250 deg.c and 0.1-10 MPa in the conditions of reactor bottom temperature 70-200 deg.c, stripping section temperature 70-200deg.c, rectifying section temperature 70-200 deg.c and reflux ratio of 1-20. The present invention has the advantages of continuous process, mild reaction condition, etc.

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 belongs to the synthesis of organic carbonates and relates to a technology of synthesizing diethyl carbonate by a urea alcoholysis method. The technology comprises the steps of: adding anhydrous ethyl alcohol, ethyl carbamate and a catalyst into a high pressure reaction kettle, wherein the mole ratio of the anhydrous ethyl alcohol to the ethyl carbamate is 2 to 25, and the catalyst is combined metal oxide, and accounts for 0.5 to 10 percent of the whole system by mass percent; raising the temperature to 150 to 200 DEG C by stirring so as to carry out reaction for 1 to 15 hours; and taking out the reaction liquid after the reaction, and realizing the separation of the catalyst and the reaction liquid by simple filtration. The combined metal oxide is prepared by 2 to 3 metal oxide precursors among Li, Na, K, Ca, Mg, Ba, Sr, Al, Sn, Pb, La, Ti, W, Zr, Fe, Co, Ni, Cu and Zn through thermal decomposition method or coprecipitation method. The preparation method of the technology is simple, the catalyst activity is high, the stability is good, and the separation and recycling are easy.

A catalyst for synthesizing the propylene carbonate is composed of potassium salt (10-20 wt%), and activated carbon, metal oxide, or molecular sieve (80-90 wt%). The propylene carbonate is prepared through reaction between potassium salt, epoxy propane and iodomethane at 120-180 deg.C and 2-6 MPa for 0.5-2 hr. Its advantages are high catalytic activity, low cost and cyclic use.

A process for producing an aromatic polycarbonate through an ester interchange reaction between an aromatic carbonic acid diester and an aromatic dihydroxy compound, wherein the aromatic carbonic acid diester is obtained through the decarbonylation reaction of an aromatic oxalic acid diester represented by the following general formula (1):wherein two Ar's are the same or different aromatic hydrocarbon groups having 6 to 14 carbon atoms, and has a hydrolyzable halogen content of 5 ppm or less.According to the present invention, an aromatic polycarbonate having a high molecular weight and excellent color can be easily produced without impairing ester interchange reactivity for the production of the aromatic polycarbonate by using an aromatic carbonic acid diester obtained through the decarbonylation of an aromatic oxalic acid diester and controlling the amount of hydrolyzable halogen contained in the aromatic carbonic acid diester to a value smaller than a predetermined value.

The invention discloses a copper-based catalyst prepared by an ammonia distillation method and an application of the copper-based catalyst in a reaction system for oxidation carbonylation synthesis of alkyl carbonate. The use of a chlorine-containing compound is completely avoided in the preparation process of the catalyst, so that the problems of equipment corrosion and deactivation caused by chlorine loss are completely solved; and the catalyst prepared by the ammonia distillation method is high in selectivity, long in service life, low in preparation cost and relatively simple in process.

The invention provides a catalyst for preparing dimethyl carbonate by using urea alcoholysis and a preparation method thereof. The catalyst has a specific surface area of 150-350 m / g, a specific pore volume of 0.5-2.0 cm / L and the pore-size distribution of 50-150, gamma-Al2O3 as a carrier accounts for 50-80 percentage of the catalyst by weight, and the balance comprises active constituents. The main active constituent comprises at least one of ZnO, CaO and PbO, and an active constituent oxide and an alumina carrier can form a stable spinelle structure. The catalyst has good stability, can achieve the stable operation service life longer than 500 hours, reacts with a urea methanol solution to synthesize the dimethyl carbonate with higher catalytic activity, has the simple preparation method, can finish load without special equipment, is beneficial to industrialized amplification, is a fixedly-carrier catalyst and solves the problem that the prior homogeneous catalyst is difficult to recycle.