302results about How to "Less by-products" patented technology

The present invention relates to a catalyst composition for ethylene oligomerization and the use thereof. Such catalyst composition includes chromium compound, ligand containing P and N, activator and accelerator; wherein the chromium compound is selected from the group consisting of acetyl acetone chromium, THF-chromium chloride and Cr(2-ethylhecanoate)3; general formula of the ligand containing P and N is shown as:in which R1, R2, R3 and R4 are phenyl, benzyl, or naphthyl. R5 is isopropyl, butyl, cyclopropyl, cyclopentyl, cyclohexyl or fluorenyl; the activatior is methyl aluminoxane, ethyl aluminoxane, propyl aluminoxane and / or butyl aluminoxane; the accelerator is selected from the group consisting of 1,1,2,2,-tetrachloroethane, 1,1,2,2-tetrabromoethane, 1,1,2,2-tetrafluoroethane, and compounds having a formula of X1R6X2, in which X1 and X2 are F, Cl, Br, I or alkoxyl, R6 is alkylene or arylene group; the molar ratio of chromium compound, ligand containing P and N, activator and accelerator is 1:0.5˜10:50˜3000:0.5˜10. After mixing the four components mentioned previously under nitrogen atmosphere for 10 minutes, they are incorporated to the reactor, or these four components are incorporated directly into the reactor. Then ethylene is introduced for oligomerization. Such catalyst can be used in producing 1-octene through ethylene oligomerization. It is advantageous in high catalysing activity, high 1-octene selectivity, etc. The catalytic activity is more than 1.0×106 g product·ma−1 Cr·h−1, the fraction of C8 linear α-olefin is more than 70% by mass.

The invention relates to a 1-aminopolypropylether-3-methylimidazolium chloride ion liquid catalyst and a preparation method thereof. The prepared catalyst makes an ion liquid structure contain an active amino-terminated functional group and a polyether large-molecular chain at the same time in a chemical bonding mode, the coordinative catalysis effect, base position isolation effect and infinite dilution effect of the catalyst are well achieved, the generation of byproducts is effectively reduced, and the catalyst has the excellent advantages of being high in activity and selectivity, stable in active component, small in consumption, easy to separate and recover, recyclable, long in service life, friendly to the environment and the like; no side effects happen in the catalysis process, and a new propylene carbonate product high in purity, yield, selectivity and transformation frequency can be obtained at low temperature and pressure.

The present invention belongs to the technical field of catalysts, and relates to a silicon-supported ionic liquid catalyst. First methylimidazole or alkyl imidazole is reacted with a halogen-substituted alkyl alcohol / acid to prepare an imidazole ionic liquid with reactive groups for standby use; then tetraethylorthosilicate and ethanol are added into a fixed volume container for mixing and heating, then stirred, and then added dropwise into a mixed ionic liquid solution, hydrochloric acid is added dropwise while stirring into a suspension system, and the suspension system is gradually solidified into a gel; and finally at 60 DEG C the gel is aged for 2-6h, the gel-like system is dried to give a solid product, and the solid product is ground into pale yellow powder, namely the silicon-supported ionic liquid catalyst Advantages of the silicon-supported ionic liquid catalyst are as follows: the silicon-supported ionic liquid catalyst has good catalytic synergy effect and base position isolation effect, high activity and selectivity, and can be recycled. Auxiliary catalysts or solvents are not used in catalytic processes, and high yield and high purity ethylene carbonate new products can be obtained under relatively mild conditions.

The invention discloses a synthesis method of a key intermediate of tebuthiuron, namely 2-methylamino-5-tert-butyl-1, 3, 4-thiadiazole. Derivatives of 4-methyl-3-thiosemicarbazide and trimethylacetic acid are taken as raw materials, and condensation and dehydration cyclization reactions are performed under acid conditions in the presence of an organic solvent medium and a hydration agent to obtain the 2-methylamino-5-tert-butyl-1, 3, 4-thiadiazole. According to the synthesis method disclosed by the invention, environmental pollution caused by a large amount of wastewater containing phosphorus, which is produced by taking phosphoric acid, polyphosphoric acid and the like as dehydration reagents, can be effectively avoided; simultaneously, the reaction yield is high, byproducts are few, and the solvent can be recovered and applied mechanically; and the synthesis method further has the advantage of very high atom economy and is in line with the direction of green chemical development.

The invention relates to a carboxyl-terminated polyether ionic liquid catalyst and a preparation method thereof. According to the prepared catalyst, an ionic liquid structure simultaneously contains active carboxyl-terminated functional groups and macromolecular polyether chains in a chemical bonding manner, so that the synergetic catalytic effects, site isolation effects and infinite dilution effects of the catalyst are well achieved, the generation of byproducts is effectively reduced, and the catalyst has excellent characteristics of high activity, high selectivity, stable active ingredients, small using amount, easiness in separation and recovery, reusability, long service life, environment friendliness and the like; the catalyst is used for a process of adding carbon dioxide and propylene oxide to prepare propylene carbonate, and a novel propylene carbonate product with high yield and high purity can be obtained under lower temperature and pressure.

The invention discloses a synthesis method of N-(Phosphonomethyl) iminodiacetic acid (PMIDA) using iminodiacetonitrile as the raw material. The method comprises the following steps: using mixed acid as a hydrolytic reagent, hydrolyzing the iminodiacetonitrile in the mixed acid water solution to obtain acid salt of the iminodiacetic acid, and then performing the condensation reaction of the hydrolyzation solution with phosphorous acid and formaldehyde at the presence of hydrochloric acid to obtain the N-(Phosphonomethyl) iminodiacetic acid, wherein the mixed acid is hydrochloric acid and sulfuric acid, or hydrochloric acid and orthophosphorous acid. According to the invention, the mixed acid is used as a hydrolytic reagent; meanwhile, high temperature and high pressure are adopted to enable the hydrolyzation to be more thorough; at the same time, no waste gas is emitted; and the periodic time of the whole synthesis process is short, the operation is simple, the utilization ratio of the raw materials is high, the side product is few, energy consumption is low and the three wastes are less.

The invention relates to a method of producing ethylene carbonate by catalytic addition from ethylene oxide and CO2. In the method, under the effect of an environment-friendly ionic liquid catalyst, the CO2 and the ethylene oxide are added to prepare the ethylene carbonate. When the reaction temperature is 90-130 DEG C, the reaction pressure is 1-3 MPa, the stirring speed is 200-300 r / min and the reaction time is 1-2 h, the conversion rate of the ethylene oxide reaches more than 98% and the yield of the ethylene carbonate reaches more than 94%. Conversion rate and yield are both higher than 90% even the catalyst is repeatedly used for seven times.