49results about How to "Reduce aldehyde content" patented technology

The invention discloses an interval or continuous catalytic hydrogenating for ethandiol (weight density at 10-100%), which is characterized by the following: adopting aggregate nickel or palladium carbon as catalyst; transmitting C=C and C-O into saturated material not to adsorbed by ultraviolet in the ethandiol; reducing the content of aldehyde; improving ultraviolet transmission rate; controlling the reacting temperature between 45 deg. c and 95 deg. c; setting the reacting pressure between 0. 05 and 0. 5Mpa and air speed not less than 60h-1; obtaining the product with ultraviolet transmitting rate more than 90% at 220nm, more than 95% at 275nm, more than 99% at 350nm.

The invention relates to a preparation method of an automobile urea solution. The method comprises the following steps: (1) selecting agricultural grade urea and pure water serving as raw materials, and preparing the raw materials into a urea solution; (2) purifying the urea solution prepared in the step (1) through a filter; (3) adding an aldehyde treatment agent into the urea solution obtained in the step (2) to lower the aldehyde content of the urea solution; and (4) loading the urea solution obtained in the step (3) through an ion exchange resin column, and removing metal ions and other impurities from the urea solution to obtain the urea solution which meets automobile use requirements. The preparation method disclosed by the invention is simple and easy to implement, and has high technical adaptability and high raw material yield. The obtained urea solution has low impurity content and good development and application values.

The invention relates to an automobile roof polyurethane composition which mainly solves the problems existing in the prior art such as high VOC value and great odor due to relatively high aldehyde content. With the adoption of the technical scheme of the invention, the low-VOC low-odor automobile roof composition is composed of a component A and a component B, wherein a ratio of the weight percentage of the component A to the component B is 1:(1.1-2.0); the component A comprises polyether polyol, polyester polyol, polypolyols, a chain extender, a foam stabilizer, a catalyst, water and at least one aid of colorants, antioxidants and dispersing agents; and the component B refers to polymethylene polyphenyl isocyanate or modified polymethylene polyphenyl isocyanate. The problems are well solved, and the composition can be used in industrialized production of the low-VOC low-odor automobile roof composition.

This invention provides an ecological tanning method. The method comprises: pre-tanning with aldehyde tanning agent, tanning with tetrahydroxymethyl phosphonium salt, and then adding collagen to enhance the bonding of the tanning agents. The method utilizes the reaction among aldehyde tanning agent, tetrahydroxymethyl phosphonium salt and collagen to enhance the bonding of the tanning agents as well as increase the shinkage temperature. Besides, the addition of collagen can improve the comprehensive properties of leather and reduce the aldehyde content in leather. The method can be used to replace chrome tannage, thus can avoid the harm of chrome salt to human body and environment.

The invention discloses a stabilizing treatment method for polyformaldehyde. The method comprises the following steps: (1) uniformly mixing polyformaldehyde having a stable end group with a composite auxiliary agent to form a premix; and (2) uniformly mixing the premix with polyformaldehyde having an instable end group in a screw extruder and converting polyformaldehyde having the instable end group into polyformaldehyde having the stable end group through fused termination in the screw extruder; wherein the composite auxiliary agent comprises an aldehyde absorbing agent, an anti-oxidant and a lubricant. With the method provided by the invention, uniformity of dispersion of the auxiliary agent in polyformaldehyde can be improved; furthermore, appearance performance, heat resistance and environmental protection performance (e.g., aldehyde content on the surface of polyformaldehyde is reduced) of a product can be improved.

The invention relates to a refining method for reducing aldehyde content and odor of polyether polyol. The refining method comprises the following steps: 1) adding water accounting for 0.1-10.0% of the total mass of crude polyether polyol into the crude polyether polyol at 25-100 DEG C, and carrying out uniform mixing; 2) adding an adsorbent accounting for 0.1-3% of the total mass of the crude polyether polyol into the polyether polyol obtained in the step 1), controlling an adsorption temperature to be 80-130 DEG C, carrying out filter pressing circulation after adsorption equilibrium, and testing the contents of potassium and sodium ions in the polyether polyol having undergone filter pressing; 3) repeating the step 2 until the contents of potassium and sodium ions in the polyether polyol are less than required contents; 4) adding a desired amount of an antioxidant into the polyether polyol obtained in the step 3); and 5), carrying out heating and vacuum dehydration to obtain refinedpolyether polyol. The method can reduce both aldehyde content and odor.

The invention provides a method for treating acetaldehyde wastewater through cooperation of microorganisms and enzymes. The method specifically comprises the following steps: (1) proportionally mixingmicroorganisms and enzymes to obtain a composite biological preparation; (2) adding a certain amount of a nutrition regulator and sodium hydroxide into industrial acetaldehyde wastewater, and regulating carbon, nitrogen and phosphorus in and the pH value of the wastewater; and (3) adding the composite biological agent into the adjusted acetaldehyde wastewater, carrying out stirring and mixing, maintaining a temperature at 30 DEG C, carrying out treating for 48 hours to remove aldehyde organic matters in the wastewater, and introducing the wastewater into a biochemical pool for subsequent treatment. According to the method, organic matters such as acetaldehyde in the wastewater are degraded by utilizing the synergistic effect of the microorganisms and the enzymes, so the biotoxicity of theacetaldehyde wastewater is reduced, and subsequent biochemical treatment efficiency is improved.

Stable dispersions of phenolic resins, particularly bisphenol-A/formaldehyde resins, for use in e.g., baking enamels, coatings, adhesives, binders, etc., are disclosed. The dispersions have low levels (e.g., <0.1% by weight) of free aldehyde, thereby reducing environmental harms associated with aldehyde emissions. Low free aldehyde levels are achieved using melamine as an aldehyde scavenger during preparation. It has now been discovered that melamine, in contrast to other scavengers of aldehydes, does not adversely affect dispersion stability, interfere with later processing operations, or negatively impact the final resin product quality (e.g., after curing).

The invention discloses a brewing technology of healthy selenium-enriched Baijiu, and relates to the technical field of selenium-enriched liquor. The technology comprises the following steps of (1) preparation of selenium-enriched brewed liquor, (2) preparation of distilled Baijiu and (3) preparation of the selenium-enriched Baijiu. The brewed liquor has low ester and aldehyde contents and higheralcohol and lactic acid contents; the ester and aldehyde contents of the first-cut distilled liquor are high, and the higher alcohol and lactic acid contents are lower; by combining the brewed liquorand the first-cut distilled liquor, component complementing and quantity relative ratio coordination are achieved, and not only can the traditional flavor of a liquor body be guaranteed, but also whenthe combined Baijiu is drunk, balance of human body vasoconstriction and angiectasis can be achieved to make blood circulation of the human body always in the normal state; the healthy selenium-enriched Baijiu is tasty and delicious, and a person feels comfortable after drinking and is not prone to be drunk.

The invention provides a preparation method of acetyl-terminated allyl alcohol polyether, which comprises the following steps: (1) adding reactants allyl alcohol polyether and acetic anhydride into a reaction kettle at room temperature, conducting replacing with inert gas, conducting heating to 125-135 DEG C, and conducting reacting for 3-5 hours; (2) heating the mixture in the reaction kettle to 135-145 DEG C, and then carrying out vacuum nitrogen charging and degassing for 3-5 hours; (3) stopping nitrogen charging and degassing, cooling the mixture in the reaction kettle to 70-80 DEG C, adding an aldehyde adsorbent, and conducting stirring; (4) vacuumizing the reaction kettle for one hour, and cooling the mixture to 40-50 DEG C; and (5) discharging the mixture in the reaction kettle, and conducting packaging and bagging under the protection of inert gas. The method has the beneficial effects that the peroxide value of acetyl-terminated allyl alcohol polyether can be effectively reduced, and meanwhile, the taste and the aldehyde content of polyether polyol can be remarkably reduced.

Methods to minimize aldehyde content of a polymer are provided. An effective amount of an additive that contains a P-H functionality is incorporated into the polymer in the presence of an acidic of basic catalyst compositions are also provided.

The present invention relates to process and apparatus for removing aldehydes from acetone. More specifically, the present invention relates to a process and apparatus for removing aldehydes from acetone by reacting the aldehydes with caustic in an acetone column and washing the organic phase with a plurality of water streams.

The invention discloses a negative pressure mash tower degassing, aldehyde-discharging and acid-discharging device for fuel ethanol and edible alcohol. The device comprises a negative pressure mash tower. A first tower plate is arranged in the negative pressure mash tower; a degassing section is arranged above the negative pressure mash tower, a second tower plate is arranged in the degassing section, an aldehyde discharging section is arranged above the degassing section, and fillers are arranged in the aldehyde discharging section. The invention also discloses a production method for improving the alcohol quality by using the device. Compared with the traditional mash tower, the relatively pure crude wine steam rising from the negative pressure mash tower is used for degassing fermentedmash and discharging aldehyde from crude alcohol without increasing steam consumption, pre-impurity removal of the fermented mash and the crude alcohol is achieved, carbon dioxide in the fermented mash and most low-boiling-point aldehydes and volatile acids in the crude alcohol are removed in the degassing section and the aldehyde discharging section, the aldehyde content and the acidity of the crude alcohol are reduced, the subsequent tower impurity discharging load is effectively reduced and the comprehensive quality of the alcohol is improved.

The invention relates to the technical field of ethylene glycol production, and provides a purification method for preparing ethylene glycol from coal-based synthesis gas. According to the present invention, ethylene glycol is purified by using a 1# resin tower and a 2# resin tower, the resin filled in the 1# resin tower is SQYJ-2 enhanced ultraviolet resin, and the resin filled in the 2# resin tower is SQYJ-1 dealdehyding catalyst resin; and the SQYJ-2 resin can improve the ultraviolet light transmittance of ethylene glycol and has a slight dealdehyding effect, and the SQYJ-1 resin can reduce the aldehyde content of ethylene glycol. According to the specific condition of the ethylene glycol extracted from the side line of the product tower, the ethylene glycol is selectively introduced into the 1# resin tower or the 2# resin tower, or the ethylene glycol is introduced into the 1# resin tower and then into the 2# resin tower, so that the purification of the ethylene glycol is realized. The ethylene glycol purified by the method disclosed by the invention is high in ultraviolet light transmittance and low in aldehyde content, and can reach the standard of superior products in GB/T4649-2008.