41 results about "Gaseous formaldehyde" patented technology

The invention discloses an M-MnOx-CeO2 catalyst. The catalyst is prepared by adopting citric acid complexometry through the steps of taking MnOX and CeO2 as active ingredients and taking M as an adulterant; M is FeOx, CuO, CoOx or K2O; the molar ratio of Mn to Ce in the catalyst is (6 to 1) to (1 to 1); when M is FeOx, CuO or CoOx, the molar ratio of metal ions to Ce in M is (1 to 4) to (1 to 1),and when M is K2O, the doping content of K2O is 1wt%. The catalyst can be used for catalytic oxidation of gaseous formaldehyde in a normal temperature condition or used for thermal catalytic oxidationof CVOCs.

The invention relates to a preparation method of a quartz crystal microbalance (QCM) formaldehyde sensor based on amino-functionalized SBA-15, belonging to the technical fields of sensitive materials and gas sensors. By first using functionalized SBA-15 as the sensitive material of the QCM mass type sensor to construct the formaldehyde sensor having favorable performance, the preparation method comprises the following steps: carrying out ultrasonic dispersion on self-prepared beta-carboxyl ethyl trimethoxysilane functionalized SBA-15 of which the pore diameter is 2-50 nm in a certain medium for 20-50 minutes to obtain a coating liquid, wherein the used medium is any one of water, acetone or ethanol; and uniformly spreading the coating liquid on the electrode surface of a cleaned quartz crystal microbalance, and drying at 80-120 DEG C for 3-8 hours to obtain the formaldehyde sensor. The mass type sensor has sensitive response to indoor air pollutant gaseous formaldehyde (the lower detection limit can reach the ppm level), and has the advantages of good selectivity, high stability, economy and environmental friendliness. Thus, the invention provides a favorable formaldehyde sensitive material for QCM and opens up a new application area for functionalized SBA-15.

A method for reducing formaldehyde emission from a fibrous product prepared using a binder based on a formaldehyde-containing resin, the method comprising isolating the fibrous product in an enclosed space, introducing a gaseous formaldehyde scavenger into the space and maintaining the gaseous scavenger in the space for a time sufficient to reduce the level of formaldehyde emission, with the result that the fibrous product exhibits a reduced level of formaldehyde emissions.

The present invention relates to a device and method of visible light photocatalytic degradation of gaseous formaldehyde with dye-sensitized TiO<2>, and belongs to the field of photocatalysis. The device is mainly composed of a stainless steel cubic reaction vessel, a constant temperature water bath tank, a gas sampler, a diaphragm vacuum pump and a gas absorption bottle. The method using the reaction device comprises the following steps: a dye-sensitized TiO<2> thin film is used as a base material, then a formaldehyde standard liquid and the dye-sensitized TiO<2> thin film are put into the reaction device, the initial formaldehyde gas concentration after a vaporization balance is detected, then light source is turned on to conduct the photocatalytic degradation experiment of the gaseous formaldehyde, after 3 h of the lighting, a sampling inspection of the degraded formaldehyde concentration is conducted, the degradation rate of the formaldehyde is calculated to obtain the degradation rate of the gaseous formaldehyde after the photocatalytic degradation with the dye-sensitized TiO<2>. The device has many advantages of being circular and high in efficiency, green and healthy, simple in operation, low in costs, etc., and has important values and research significances for solving environmental pollution, indoor air purification, etc.

For solving the problem that an existing technology for removing formaldehyde in air is not ideal in formaldehyde removing effect or is not suitable for industrial production, the invention provides a normal-temperature formaldehyde-removing modified activated carbon and a preparation method thereof. The modified activated carbon is prepared by using a granular, cylindrical, spherical or honeycomb coconut shell activated carbon with large specific surface area as a carrier, using CuCl2 and FeCl3 mixed metal salt as a modified component and adopting dipping, drying and calcination processes. The modified activated carbon has the advantages of rapid capture, efficient adsorption, long working cycle and the like to gaseous formaldehyde and can meet the requirement for long-time effective formaldehyde removal in an indoor environment.

The invention belongs to the technical field of energy and chemical industry, and provides a preparation method of a fuel additive and an environment-friendly solvent polyoxymethylene dimethyl ether (DMMNn, generally n=3-8), which comprises the following steps: mixing a formaldehyde water solution and polyol according to a certain proportion, and conducting heating and dehydrating under vacuum conditions to obtain flowing polyoxymethylene with lower moisture content in one step; heating and gasifying flowing polyformaldehyde with the lower moisture content to obtain purer gaseous formaldehyde,mixing the obtained gaseous formaldehyde with methylal, mechanically used last-batch low-boiling-point substances, macromolecules and the like in the presence of a catalyst, carrying out catalytic reaction at a certain temperature, filtering out the catalyst after the reaction is balanced, purifying the synthetic liquid, respectively carrying out atmospheric pressure and reduced pressure distillation, conducting separating to obtain a low-boiling-point substance, macromolecules and a DMMn finished product, and carrying out reduced pressure distillation on the DMMn finished product to obtain each single component; and after the formaldehyde is gasified, returning the residual polyhydric alcohol for application of next-batch concentrating of formaldehyde to prepare the flowing polyformaldehyde with lower moisture content.

The invention relates to a standard gas state formaldehyde dynamic toxin coating device that is made up of environment climate compartment (I), formaldehyde analyzer (II), and 8.4L aeration glass toxin coating jar. The main feather is that it uses environment climate compartment as source generator, using standard formaldehyde solution produced by Sigma Corp., standard gas state formaldehyde of the needed thickness would be generated by environment climate compartment humidity controlling system to take standard gas state formaldehyde toxin coating to biology sample and take real time dynamic accuracy testing to ensure the stability of the formaldehyde state and thickness. It is a reliable gas state formaldehyde toxin coating device.

The invention discloses a method for degrading gaseous formaldehyde by using a methylotrophic bacterium. The methylotrophic bacterium used is Methylobacterium sp.XJLW. A mesh bracket is arranged abovea formaldehyde gas source to be treated, and a polymer water absorbent resin SAP is placed on the mesh bracket as a bacterium carrier, and the methylotrophic bacterium is placed in the bacterium carrier to degrade the gaseous formaldehyde. XJLW has the significant capability to reduce the formaldehyde in the air in a closed environment that continuously releases the high-concentration gaseous formaldehyde.

The invention relates to a nanoscale Co3O4 (at) Pt oxidation-reduction preparation method, which comprises the following steps: adding a solution containing non-zero oxidation state Pt into nanoscale Co3O4, carrying out oxidation-reduction reaction between Co (II) and high oxidation state Pt, and loading reduction product Pt nanoparticles on the surface of the nanoscale Co3O4. Pt particles in the prepared catalyst have excellent dispersity on a Co3O4 carrier with a large surface area, adsorption of gaseous formaldehyde molecules is enhanced through interaction between the carrier and metal, and the HCHO catalyst formed by loading the Pt nanoparticles with nanoscale Co3O4 as the carrier can be subjected to catalytic oxidation at room temperature under air conditions, so that the catalyst can be applied to the field of catalytic oxidation of formaldehyde. The HCHO catalytic efficiency of the rod-like Co3O4 (at) Pt catalyst can reach 100%.

The invention provides an adhesive-free non-photocatalytic diatom ooze material for removing gaseous formaldehyde in air and relates to a diatomite wall material capable of purifying air. The existing problems that a diatomite coating added with a chemical adhesive is hardened and solidified and loses original filtration and absorption functions and that chemical adhesive-free diatomite is poor in adhesiveness and has such serious problems as dusting and peeling off after moisturizing are solved. The diatomite wall material is mainly prepared from diatomite, starch, lanthanide oxide and opal in parts by weight. The adhesive-free non-photocatalytic diatom ooze material for removing gaseous formaldehyde in air in the invention is chemical adhesive-free and thus harmless to human body, and achieves true green and environmental protection.

The invention relates to the technical field of carbon and nitrogen containing compound production, in particular to circulating fluidized bed pyridine base preparing reaction equipment. The equipmentcomprises a regenerator, a reactor assembly, a regenerated catalyst circulation line and a spent catalyst circulation line I; the mode of connecting a first reactor, a second reactor and a third reactor in series is adopted for making gaseous formaldehyde, acetaldehyde and ammonia gas make sufficient contact with and react with a catalyst, and meanwhile the third reactor makes the reaction conducted more thoroughly; the contact efficiency of reactant is greatly improved, and the yield of products is increased; feeding adopts spray nozzle spraying, and compared with an original distribution loop distributor, a spray nozzle is not subjected to coking; the regenerated catalyst circulation line and the spent catalyst circulation line are adopted, the activity of the catalyst and the catalyst-oil ratio can be flexibly adjusted, and the tube catalyst concentration can be improved. The whole device is simple in structure, capable of saving materials, low in manufacturing cost, easy to make and beneficial to continuous and automatic production and environmental protection processing of the production process.

The invention relates to a reactive distillation-vapor permeation coupling process for the polyoxymethylene dimethyl ether synthesis. According to the coupling process, a methylal and a formaldehyde solution, a hydrous trioxymethylene, a hydrous paraformaldehyde, a hydrous gaseous formaldehyde or a mixture of substances are used as raw materials, a polyoxymethylene dimethyl ether mixed product with multiple polymerization degrees is obtained by carrying out a reaction under the action of an acidic catalyst, by the separation action of a polyoxymethylene dimethyl ether reactive distillation tower, reaction products with polymerization degrees of more than 2 are extracted out from the tower kettle, DMM2 with low polymerization degrees, unreacted methylal, reaction by-product methanol, and water in the reaction system are extracted out from the tower top, the extracted products from the tower kettle is subjected to product refining tower separation, and the target product DMM3-5 is obtained. According to the process, defects in the existing process that the target product DMM3-5 has low yield, the circulation amount in the process is large, the energy consumption is high, and the likeare solved, the reaction balance limit can be broken, the conversion rate of the raw material and the selectivity and yield of DMM3-5 are greatly improved.

Various embodiments disclosed related to flexible fibrous surface-treating articles with low formaldehyde off-gassing. In various embodiments, the present invention provides a flexible fibrous surface-treating article including an open, lofty, nonwoven web including fibers. The flexible fibrous surface-treating article also includes a binder that coats the fibers of the nonwoven web. The binder includes a cured product of a curable composition including a latex and a crosslinker. The flexible fibrous surface-treating article heated to 65° C. in a closed space for 30 minutes emits less than about 6 micrograms of gaseous formaldehyde total per gram of the flexible fibrous surface-treating article.

The invention discloses a cold volatilization type formaldehyde removal device and a working principle thereof. The device comprises a main shell, wherein a front air outlet module is arranged on thefront face of the main shell; a rear air inlet module is arranged on the back face of the main shell; a moisture absorption and formaldehyde removal module, an electric control module and a fan are arranged in the main shell; and the fan is located on the back of the front air outlet module. According to the working principle, the self-absorption siphon effect of a wet curtain is utilized, a formaldehyde removal active liquid forms a molecular-level dispersion liquid film on the surface of the wet curtain, formaldehyde in air blown through the wet curtain can be rapidly captured and removed, and moisture is volatilized in a cold mode and enters the air for humidification. The device is easy and convenient to assemble, adjustable in air speed, free of consumable consumption and capable of efficiently removing indoor polluting formaldehyde and adjusting space humidity, and a formaldehyde bonded product does not enter air and is safe and reliable; 2400 mg or more of gaseous formaldehyde in the air can be effectively removed by filling a water tank with 100 mL of the active liquid at a time, and the amount is far higher than the accumulated purification amount of 1500 mg prescribed inthe national standard F4 for a household air purifier; and a formaldehyde content can be reduced to 0.02 mg/m<3> or below from 1-1.2 mg/m<3> after the device is tested in an environment cabin with a volume of 3 m<3> for 20 min, and the removal efficiency is higher than 98%.

The invention provides an environment-friendly water-based paint capable of quickly decomposing formaldehyde. The environment-friendly water-based paint comprises the following components in parts by mass: 45-55 parts of alkyd resin; 25-35 parts of a solvent; 15-25 parts of color paste; 0.5 to 0.8 part of a defoaming agent; 1.0 to 1.5 parts of a dispersant; 5-15 parts of a curing agent; 5 to 15 parts of Pt/Bi2O3 powder; the Pt/Bi2O3 powder is added into the environment-friendly water-based paint capable of quickly decomposing formaldehyde, the Pt/Bi2O3 powder can degrade gaseous formaldehyde on the outer side of a paint surface and reduce the concentration of the formaldehyde on the outer side of the paint surface under the same action of room temperature and indoor illumination, so that outward volatilization of the formaldehyde on the paint surface is accelerated, the volatilized formaldehyde can be continuously decomposed by the Pt/Bi2O3 powder, and the formaldehyde can be quickly decomposed by the Pt/Bi2O3 powder. The virtuous cycle is achieved, and formaldehyde volatilization of the paint surface is accelerated; formaldehyde volatilized after the paint surface is arranged can be decomposed in time, so that the damage to the health of people is avoided.

The invention discloses a device and a method for producing high-concentration formaldehyde by using methanol. The device comprises a fan, a heat exchanger, a fixed bed reactor, an absorption tower, arefining tower and a pyrolysis tower which are connected in sequence. According to the method, air is pressurized by a fan, mixed with a methanol raw material, flows through a heat exchanger and thenenters a fixed bed reactor for an oxidation reaction, a primary product flows through the heat exchanger and then enters an absorption tower for a hemiacetal reaction, a secondary reaction product sequentially flows through a refining tower and a pyrolysis tower for separation and pyrolysis, an absorbent is discharged from the bottom of the tower for cyclic utilization after pyrolysis, and a gaseous formaldehyde product is collected at the tower top. The product disclosed by the invention is dry gas formaldehyde and is quite stable, so that the method has obvious economic benefits and environmental protection advantages; and the product provided by the invention has excellent quality: the concentration of formaldehyde is greater than or equal to 99.9%, and water is less than or equal to 0.05%.