47results about How to "Reduce waste acid" patented technology

The invention relates to a mercury-free catalyst used for acetylene hydrochlorination for synthesizing vinyl chloride, and a preparation method and an application thereof. The preparation method comprises the following steps: 1, dissolving alkali metal salt and an amide solvent in water to prepare a mixed solution; 2, adding active carbon into the mixed solution obtained in step 1, and dipping the active carbon; and 3, filtering the active carbon obtained in step 2, draining the filtered active carbon, and heating and drying the drained active carbon to obtain the catalyst. The concentration of raw gas on the surface of the catalyst is increased through using the synergism of the alkali metal salt and the amide solvent and the adsorbing and dissolving ability of the amide solvent to raw materials comprising acetylene and hydrogen chloride, and the amide solvent is a high-polarity aprotic polar solvent, and has a polarization effect on reactants, so the reaction efficiency is further improved, the low temperature activity of the catalyst is high, and the selectivity and the stability are good.

The invention relates to a non-noble metal mercury-free catalyst for acetylene hydrochlorination reaction, a preparation method and application thereof. The preparation method comprises the steps of: 1) preparing a mixed solution of a copper salt, an ammonium salt and phosphoric acid, or a mixed solution of a copper salt, an ammonium salt and phosphate; 2) adding activated carbon into the mixed solution obtained in step 1 for soaking; 3) spin-drying the soaked activated carbon, and conducting heating and drying to obtain the catalyst. Through the synergistic effect of multiple components, the catalyst prepared by the method provided by the invention acquires good catalytic stability and high low-temperature activity, and under a reaction temperature of 130DEG C and the existing mercury catalyst running pressure condition and feeding intensity, more than 96% of conversion per pass and more than 99% of vinyl chloride selectivity can be obtained. As the technical conditions of the catalyst for acetylene hydrochlorination reaction are similar to those of the existing mercury catalyst, renovation of existing equipment is unnecessary, and the mercury catalyst can be replaced easily on the existing equipment.

The invention provides an oxidizer used in the di-chlorine quinoline acid synthesis technology, which can effectively improve the problems that the time of the oxidation operation is long, the production capacity is limited, and the generated waste acid is not easy to be processed in the prior art. The oxidizer is oxyacid of chlorine, bromine and iodine and salts thereof, and peroxide. The invention further provides a novel method for synthesizing di-chlorine quinoline acid oxo by utilizing the novel oxidizer.

The invention belongs to a process for preparing white carbon black and in particular relates to a process for producing precipitated white carbon black by silicon tetrachloride. The process comprises the following steps: adding the silicon tetrachloride into 29 to 33 mass percent hydrochloric acid aqueous solution which contains a dispersant, controlling the temperature to between 28 and 45 DEG C for reaction to generate silica sol and chlorine hydride gas, standing and ageing the silica sol to form colloidal white flocculent sediment, filtering, separating and washing the sediment, and pelletizing and drying the sediment to obtain the precipitated white carbon black. The process has short flow, relatively simple production equipment and process control, and available raw materials, effectively utilizes the silicon tetrachloride, totally reclaims the product chlorine hydride, reduces the processing expense, the amount of waste acid and the environmental pollution, and has low production cost, wide application and large market capacity.

The invention pertains to a preparation method of 5-n-butyl-2-benzimidazole methyl formate, that is, parbendazole, and includes five reaction steps of acetylation, nitrification, hydrolysis, reduction and ring formation; n-butyl aniline is taken as the raw material, acetic anhydride is firstly used for acetylation, nitric acid is then used for nitrification, potassium hydroxide solution is used for hydrolysis, after that, Pd/C is used for the reduction to form 4-n-butyl-o-phenylenediamine, finally a ring closing agent of methyl formate cyanamide is used for ring closing, thus preparing the 5-n-butyl-2-benzimidazole methyl formate. The technique adopts p-n-butyl aniline which is cheap and easy to obtain as the raw material, the acetylation and the nitrification are completed in a same reactor, thus simplifying operation procedure and reducing production cost. The acetic anhydride is adopted as an acetylation reagent for protecting amino group, the reaction conditions are mild, and the acetic acid and the excessive acetic anhydride which are generated by the reaction can be used as a solvent and a dehydrating agent, thus reducing the amount of the waste acid. Palladium carbon is adopted as a catalyst for the reduction of the amino group, and the catalyst can be recycled and is characterized by high conversion rate, green and clean properties.

The first problem to be improved in the invention is to provide a method for preparing methyl R-(+)-2-(4-hydroxyphenoxy)propionate. Dimethyl sulfate and water, methanol and sulfuric acid generated during an esterification reaction continuously catalyze the reaction, so the esterification conversion rate is improved to above 99.5%, and the average esterification yield of the whole process is about99%; and no catalyst is excessively added in the reaction process, and a reaction system is sealed, so the environment is protected. The reaction rate of methanol in the system is high, and the methanol can be repeatedly used, so the problem of low conversion rate of pure methanol when reacted under the action of the catalyst is improved, the yield is increased, and the cost is reduced. An alkali-washed mother liquor can be recycled to solve the problem of high COD of alkali washing wastewater during dehydration, so the wastewater treatment cost is reduced. Experiments in the invention show that the average yield of the method is 99%, and the purity of the product is 99% or more.

The invention provides a novel method for post-processing vat yellow GCN to greatly reduce the amount of waste acid. A crude product of vat yellow GCN is added into a solvent tetrachloroethylene, stirred, heated to 120 DEG C, subjected to a backflow reaction for 6 hours, cooled to the room temperature and then filtered, and the residue naphthaline in a filter cake is cleaned in multiple times by using rationed tetrachloroethylene; the filter cake in which the naphthaline is removed is added into a hydrochloric acid solution to remove copper, stirred, added with sodium chlorate, heated to 70-90 DEG C, thermally insulated for 2 hours, filtered while being hot, washed to neutral state and dried, the pre-processed vat yellow GCN dry product is added into a sulfuric acid concentrated solution, stirred, heated to 130-150 DEG C and reacted for 2-4 hours, a sample is taken and observed by using a microscope, if a crystal becomes transparent, then the crystal transformation is completed, the mixture is cooled to the room temperature, added with water to separate the material and filtered in a suction manner, the filter cake is washed with water to the neutral state, reacts in a sodium hypochlorite solution again at 70-80 DEG C for 2 hours and filtered, and the filter cake is washed to the neutral state and dried to obtain the vat yellow GCN dry product.

The invention discloses a continuous synthesis method of m-acetamido phenol. The method comprises the following steps: respectively preparing two solutions from m-aminoacetanilide, sulfuric acid, sodium nitrite and the like, respectively continuously pumping the solutions into a tubular reactor by a metering pump at a preset flow velocity, performing diazotization and hydrolysis reactions, and cooling, extracting, drying and desolventizing the obtained reaction product to obtain the product, wherein the diazotization reaction and the hydrolysis reaction are completed in the same tubular reactor. The method has the characteristics of sufficient sources and low price of raw materials, high safety in the synthesis process, high product yield, less pollution of three wastes, and high industrialization values.

The invention relates to preparing methods of p-aminophenyl-beta-hydroxyethylsulfonyl and p-minophenyl-beta-hydroxyethylsulfonyl sulphonate. The preparing methods both comprise the steps that p-aminophenyl-beta-hydroxyethylsulfonyl and hydrogen are used as raw materials, modified framework nickel is used as a hydrogen-adding catalyst, a catalytic hydrogenation reaction is conducted in a solvent toobtain reduction liquid, and modified framework nickel and the solvent in the reduction liquid are separated and removed to obtain p-minophenyl-beta-hydroxyethylsulfonyl sulphonate; according to modified framework nickel, nickel is used as a framework, and modified framework nickel is prepared from, by mass, 75-95 parts of Ni, 3-15 parts of Al and 2-10 parts of metal adjuvant; the metal adjuvantcomprises the combination of any one or at least two of Mo, Cu and Cr. The yield can reach 94% or above; preparation of p-minophenyl-beta-hydroxyethylsulfonyl sulphonate is a continuous production technology, the technology is simplified, the production efficiency is high, the quality is stable, the production cost is low, and the economic benefit and social benefit are obvious.

The present invention belongs to the field of fined chemical intermediate synthesizing technology, and is process of preparing 4-amino-3-nitro phenol. The process of preparing 4-amino-3-nitro phenol includes the following three steps: acetylation of p-aminophenol as material with acetic anhydride, the subsequent nitration with nitric acid, and final hydrolysis of 4-acetoxy-2-acetamino nitrobenzene with sodium hydroxide. The present invention has simple operation and low cost.

The invention discloses a method for decreasing the waste acid content in titanium dioxide production. Sulfur trioxide and 55% sulfuric acid are adopted to be premixed with titanium concentrate for an acidolysis reaction in the rutile-type titanium dioxide production process through a sulfuric acid method, and then the method for decreasing the waste acid content in titanium dioxide production is achieved.

The invention relates to a preparation method of piperonal. The specific steps are: mix water, glyoxylic acid and sulfuric acid in proportion, add piperonyl cyclocyclone dropwise at a temperature of 0-5°C, stir at a high speed for 5-8 hours, add After diluting with 80-100ml of water, filter with suction to obtain solid 3,4-dimethoxymandelic acid, and the filtrate is the mother liquor containing dilute sulfuric acid; the mass ratio of water, glyoxylic acid, and sulfuric acid is 1.5-1.7:10- 11:10‑11; take 30%‑70% dilute sulfuric acid mother liquor, add solid 3,4‑dimethoxymandelic acid to it, then add 80 mL of dichloromethane, add 3% dilute nitric acid 18‑1 dropwise at 20°C 20mL, heated, and reacted for 1-3 hours until the reaction was complete; layers were separated, washed, concentrated and distilled under reduced pressure to obtain the product piperonal.

The invention discloses a method for preparing zirconium oxychloride by a hydrogen chloride gas method. The process steps of the method are: S1, taking zirconium oxychloride leaching solution and putting it into a reaction kettle; When the acidity of the zirconia leaching solution increases to a set value, stop feeding the hydrogen chloride gas; S3, heat to dissolve the crystallization material completely, and when the temperature drops to the set temperature, suction filter; S4, rinse with dilute hydrochloric acid to obtain zirconium oxychloride crystals. The beneficial effects of the present invention are: 1) The hydrogen chloride gas is passed into the zirconium oxychloride solution to increase the acidity of the solution to achieve the purpose of crystallization, and at the same time reduce the increase in the amount of liquid in the system and reduce the amount of waste acid; at the same time, it improves the utilization of equipment 2) The concentration process, an important part of the current zirconium oxychloride production process, is omitted, and a large amount of steam is no longer consumed. A single ton of zirconium oxychloride crystals saves about 6 tons of steam, effectively reducing production costs.

The invention relates to a preparation method of 2-nitro-4-methylsulfonylbenzoic acid. Based on a nitric acid oxidation scheme, p-methylsulfonyltoluene is dissolved into a chloroalkane solvent, nitricacid is dropwise added into sulfuric acid with the mass fraction of 80-90wt%, a chloroalkane solution of p-methylsulfonyltoluene and a mixed acid solution are simultaneously and continuously added into a reaction system for a nitration reaction, the sulfuric acid is repeatedly used after the nitration reaction material liquid is treated, the sulfuric acid can be used both in the nitration reaction and the oxidation reaction, the sulfuric acid in the oxidation reaction can be repeatedly used, the total molar yield of the 2-nitro-4-methylsulfonylbenzoic acid can achieve more than 90%, and the content is more than 99%. By means of the method, the amount of waste acid in production of 2-nitro-4-methylsulfonylbenzoic acid can be reduced by 90% or above, the use amount of vanadium pentoxide isreduced by 90% or above, three wastes are greatly reduced, the process is safe and environmentally friendly, the amount of the three wastes is small, and the method is suitable for industrial large-scale production.