144results about How to "Avoid Polymerization" patented technology

The invention relates to a method for preparing aromatic hydrocarbon and cyclopentenone from biomass derivative gamma-valerolactone by catalytic conversion, which comprises the following steps: (1) using biomass derivative gamma-valerolactone as a raw material, which is prepared by carrying out hydrogenation reaction on levulinic acid; (2) introducing one or more transition metals into a zeolite molecular sieve, and preparing a reaction catalyst at the reaction temperature of 350-550 DEG C by using a fixed bed or fluid bed as a reactor; (3) in an inert or reducing atmosphere, carrying out contact reaction on the raw material gamma-valerolactone and catalyst under the reaction pressure of 0-10 MPa; and (4) after the pyrolysis gas is condensed, collecting the liquid product in the condensation receiver, thereby obtaining the aromatic hydrocarbon product (of benzene, toluene and xylene) and the cyclopentenone product. By using the renewable biomass derivative gamma-valerolactone as the raw material, the method has the advantage of milder reaction conditions, and the catalyst is simple to prepare and easy to recover and reuse.

The invention relates to a work-starting method of FCC gasoline hydrodesulfurization to degrade the alkenes. According to the invention, on the basis of regular wet process thiolaction, it adopts reformed generating oil as the sulfurized oil so as to avoid the extra high temperature in the early starting time, decrease the carbon deposition of the catalyst and increase the stability and activity of the catalyst. The invention can be used in different kinds of gasoline that contains molecular sieve reforming catalyst thiolaction, especially the gasoline that contains high molecular sieve.

The invention discloses a method for modifying attapulgite clay. The method comprises the following steps: adding an organic water repellent compound in attapulgite clay powder with the fineness of 200 to 400 meshes; adding an organic solvent and stirring for 1-4 hours; then standing for 2-3 hours to obtain slurry; adding a nonionic surfactant in the slurry, heating at the temperature of 60-80 DEG C for 3-7 hours and filtering; and drying the filtered powder to obtain the modified attapulgite clay powder. The modified attapulgite obtained by the method disclosed by the invention is favorable in dispersity in water and is suitable for preparing water-based paint.

The invention discloses a method for modifying attapulgite clay. The method comprises the following steps: adding inorganic particles into attapulgite clay powder; adding mixer in water and stirring for 2-4 hours; then standing for 1-4 hours and drying; adding a compound activating agent of organic carboxylic acid and a nonionic surfactant; stirring for 3-7 hours, standing for 2-4 hours; and filtering and drying to obtain modified attapulgite clay powder. According to the method disclosed by the invention, the compatibility and the dispersity of attapulgite in an alcohol-based solution are improved.

The invention discloses an apparatus and method to produce isooctane by an indirect alkylation technique. The apparatus comprises fixed-bed reactor I, a catalytic distilling column, an extracting column and a recycling column which are connected in sequence. The method comprises: allowing mixed C4 and a polymerization inhibitor to react in reactor I, feeding part of the product into the catalyticdistilling column, and removing reaction heat from the other part by a heat exchanger before returning; after catalytic distillation, feeding the overhead product into fixed-bed reactor II, reflowingafter reacting, and feeding the bottom product into the extracting column; after extracting, feeding overhead biopolymer into a desulfurizing column, and feeding the bottom product into the recyclingcolumn; after recycling, returning an extracting agent into the extracting column and the polymerization inhibitor to the reactor I; subjecting the biopolymer and hydrogen to hydrodesulfurization in the desulfurizing column to obtain isooctane that may act as a gasoline blend component. Existing MTBE (methyl tert-butyl ether) production equipment is modified into isooctane production equipment; the produced isooctane may act as an ethanol-gasoline blend component; byproducts of the isooctane may also act as other materials for reuse.

The invention discloses a preparation method of a hydrogenation catalyst. The hydrogenation catalyst takes activated carbon as a carrier, and adopts palladium as an active metal component. The catalyst has a palladium content of 0.1wt%-0.7wt%. An impregnation method is employed to prepare the catalyst. Specifically, a palladium-containing impregnation solution is prepared by: dissolving palladium acetylacetonate in an organic solvent, and using a low carbon organic carboxylic acid to regulate the pH value of the impregnation solution. The method adopts a special process to prepare the palladium acetylacetonate impregnation solution, can make palladium crystal grains highly dispersed and loaded on the inner and outer surfaces of the activated carbon carrier, and at the same time, no inorganic ion is introduced, no high-temperature roasting is needed, and migration and grain growth of the palladium metal are effectively controlled, thus improving the activity and selectivity of the catalyst. Moreover, the utilization rate of noble metal palladium is enhanced, noble metal waste is avoided, and the cost is reduced. The hydrogenation catalyst is applicable to a selective hydrogenation process of unsaturated C4 hydrocarbon fraction. The polymerization reaction of unsaturated hydrocarbon on the catalyst surface can be effectively inhibited, and the service life of the catalyst is prolonged.

The invention discloses the preparing method of monodisperse micron-size polymer microballoon. The method comprises the following steps: adding organic solvent containing monomer, initiating agent and dispersing agent into inhibitor at 50-80Deg.C, carrying out reaction for 10-14 hours, getting the product. The invention obtains the monodisperse microballoon whose diameter is 1- 10 mum.

The invention discloses a synthetic method of N,N'-dibenzyl-1,2-ethanediamine. The synthetic method comprises the following components: in a reaction vessel, a liquid phase catalytic hydrogenation reaction is carried out for N,N'-dibenzylidene-1,2-ethanediamine in the effects of a nitrogen doped meso pore carbon loaded precious metal catalyst in order to prepare and obtain N,N'-dibenzyl-1,2-ethanediamine. In the nitrogen doped meso pore carbon loaded precious metal catalyst, the precious metal is Pd or Pt, and the load capacity of the precious metal is 1-10wt%. The synthetic method has the advantage of high selectivity of target products.

The invention discloses a synthesis of Li twice battery organic free radical polymer PTMA polar material and application, which comprises the following steps: choosing HTMP and MMA as forerunner; adopting optimum ester interchange synthesized method; preparing MTMP; choosing eldopaque or metal copper as inhibitor; choosing metallic sodium or magnesium methylate as accelerant; preparing MTMP; using MTMP as monomer; choosing AIBN trigger; polymerizing through free radical body in toluene solution; preparing polymer PMTMP; using Na2WO4-H2O2-EDTA as oxidant in the methanol solution; getting PTMA with side chain as nitrogen oxygen stabilizing free radical. This invention can eliminate safe hidden danger of temperature increment, which possesses good electrolytic solution mutual dissolving property.

The invention relates to an olefin isomerization catalyst passivation treatment method which is as follows: a passivation agent is led alone, or led simultaneously with an olefin isomerization reaction raw material, into a catalyst bed for contacting with a catalyst for 2-10 hours, the passivation agent is a by-product of an olefin isomerization process, and preferably is a heavy component in by-products. By means of the passivation treatment method, the problems that the initial-stage reaction activity of the catalyst in the olefin isomerization reaction is high, polymerization side reactions are serious, the catalyst bed temperature is risen, and the like can be solved, and the yield and selectivity of isomerization target products can be effectively improved. At the same time, because the passivation agent used is the by-product of the olefin isomerization process itself, the passivating agent after use can directly enter into follow-up processes together with the isomerization products, energy sources of a reaction system itself can be fully used, the postprocessing process is simplified, the pollution is reduced, and the cost is reduced. In addition, the method has the advantages of simple operation, easy control of the process and good passivation effect.

The invention discloses a method for preparing a composite nickel coating on the surface of a magnesium alloy micro-arc oxidation film, and belongs to the technical field of metal surface treatment. The method comprises the following steps: putting a magnesium alloy matrix in a silicate series electrolyte to prepare a micro-arc oxidation ceramic layer, carrying out surface hole sealing and pre-nickeling treatment of the matrix ceramic layer by adopting a nickel salt-containing self-assembled nano-penetrant and an alcoholic solution of sodium borohydride, and carrying out composite chemical nickeling treatment to form the composite nickel coating on the surface of the film. The method is an improvement on tradition chemical nickeling technologies, and adopts a palladium salt-free activation process at room temperature, so the composite chemical nickeling operation is simplified, and the pollution of the process to the environment is reduced. The prepared composite coating has the advantages of good protection thickness, good bonding force with the substrate, good corrosion resistance, high hardness, good surface brightness, shininess, effective solving of the protection requirements on the high wear resistance and the corrosion resistance of a magnesium alloy, and provision of a powerful guarantee for the further application of the magnesium alloy.

The invention discloses an attapulgite-clay-based electromagnetic wave absorber in a metal-surface-coated electromagnetic wave-absorbing coating. The electromagnetic wave absorber refers to the attapulgite-clay-based electromagnetic wave absorber which is prepared by combining carbon nano-tubes with high-temperature-resistant attapulgite clay powder. Particularly, a preparation method of the attapulgite-clay-based electromagnetic wave absorber includes the steps of activating and dispersing common attapulgite clay to obtain attapulgite clay suspension excellent in activation performance, adding a specific number of carbon nano-tubes, using activity of the surface of the attapulgite clay to absorb the carbon nano-tubes to obtain one-dimensional nano-tube/attapulgite clay compound powder, plating metal ions on the surface of the compound powder through chemical plating, centrifuging and drying so as to obtain the attapulgite-clay-based electromagnetic wave absorber. The attapulgite-clay-based electromagnetic wave absorber is excellent in electromagnetic wave absorption performance, high in absorption performance and wide in spectrum band and is capable of absorbing 90% of electromagnetic waves within a range of 5-18 GHz, and the maximum reflection loss can be up to -44 dB (5 GHz).

The invention provides a preparation technique of high-purity hydroxyethyl methacrylate. A rectification process is added in a purification process; a polymerization inhibitor is replenished through a spraying way in a phase transformation process of the rectification process; meanwhile, the vacuum degree and the working temperature of a tower top are controlled; the flash polymerization, in a rectifying tower, of the hydroxyethyl methacrylate is avoided, so as to achieve the purposes of being stable in operation, being capable of effectively preventing polymerization and improving product quality, thereby improving the purity of a hydroxyethyl methacrylate product.

The invention discloses a preparation method of a magnesium alloy surface micro-arc oxidized nano self-assembling composite protective coating, and belongs to the technical field of magnesium alloy surface treatment. The method comprises the following steps: firstly performing micro-arc oxidation on a magnesium alloy matrix surface to form a porous ceramic layer, spraying modified water-based paint on the porous ceramic layer surface to form a water-based coating so as to form a composite protective coating composed of the porous ceramic layer and the water-based coating on the magnesium alloy matrix surface. The multilayer composite protective coating formed on the magnesium alloy surface has the features of good binding force, good compactness, high hardness, high corrosion resistance, high wear resistance and the like; the preparation method is simple, convenient and environment-friendly; the composite protective coating is an expected composite protective coating of the magnesium alloy application, and the protective requirement on the magnesium alloy product in severe environment is satisfied.

The invention discloses a technology for preparing high-purity 2-hydroxyethyl acrylate and relates to the field of 2-hydroxyethyl acrylate preparation technologies. The technology has the advantages that a rectification process is added during purification, a polymerization inhibitor is supplemented through spraying during phase transformation in the rectification process, and the vacuum degree and the operating temperature of a tower top are controlled to eradicate flash polymerization of the 2-hydroxyethyl acrylate in a rectifying tower, so that operation stability is achieved, polymerization can be prevented effectively, the product quality is improved, and the purity of the 2-hydroxyethyl acrylate is enhanced.

This invention relates to a method for producing alkoxylated trimethylolpropane tris-acrylate. The method comprises: dissolving alkoxylated trimethylolpropane into part of water-carrying agent, adding catalyst, polymerization inhibitor and acrylic acid, introducing 0.5-1.5 L/min air or oxygen, adding the rest normal-temperature water-carrying agent into the reaction kettle, collecting the azeotrope of water-carrying agent and water into a metered glass container, demixing, refluxing for 3.5-4.5 h, pumping the reaction solution into a neutralization kettle, adding soda solution for neutralization, washing with water until the pH value is 6-8, standing for demixing, transferring the upper layer organic phase into a distillation kettle, adding polymerization inhibitor, distilling, purifying to obtain alkoxylated trimethylolpropane tris-acrylate, stopping distillation when the content of polymerization inhibitor is below 300 ppm, and vacuum-filtering to obtain the product. The method has a high yield, and the chroma of the product is lower than 50# of Pt-Co color mark.

The invention provides a polyurethane elastomer modified by using hydroxylation carbon nanotubes and a preparation method of the polyurethane elastomer. The polyurethane elastomer comprises the following components in parts by weight: component A including 50-80 parts of macromolecule polyhydric alcohols, 10-20 parts of polyisocyanates, 1.5-1.7 parts of an oxime sealing agent, 0.1-0.5 part of a catalyst, component B including 3-5 parts of hydroxylation carbon nanotubes, and 1-2 parts of a dispersing agent. The surfaces of the hydroxylation carbon nanotubes comprise hydroxyl groups which can react with isocyanic acid radicals, so that the problem that the carbon nanotubes are poor in compatibility with polyurethane can be solved, the carbon nanotubes can be used as a cross-linking agent, the mechanical property and the thermal stability of the polyurethane elastomer can be improved, and meanwhile the polyurethane elastomer has conductivity and heat conduction.

The invention discloses a preparation method of durable and flame retardant preparation for cotton fabric. The method is to put into a reaction kettle four hydroxymethyl phosphorus compound and high nitrogen content substance according to a ratio of 4:0.5-4:1, heating and stirring to dissolve; using the phosphoric acid solvent to adjust the pH value of the reaction mixture to 4.5-6, adding in catalyst; when the system temperature rises to 60-70 DEG, the heating is stopped and the reaction is continued for 1.5-2.0 hours; then adding in the terminator, stirring evenly, cooling and cycling to lower the temperature to the normal level, and obtaining the durable and flame retardant preparation for cotton fabric. The method is simple in preparation process, short in reaction time, low in cost, and good in flame retardant effect. The effect of the preparation is lasting and the wash durability lasts 200 times.