摘要:
The invention relates to a method for the selective catalytic reduction of nitrogen oxides using ammonia in exhaust gases of vehicles, whereby solutions of guanidine salts with an ammonia forming potental of between 40 and 850 g/kg, optionally in combination with urea and/or ammonia and/or ammonium salts, are catalytically decomposed in the presence of catalytically active, non-oxidation-active coatings of oxides selected from the group containing titanium dioxide, aluminium oxide, silicon dioxide or the mixtures thereof, and hydrothermally stable zeolites which are fully or partially metal-exchanged. The guanidine salts according to the invention enable a reduction of the nitrogen oxides by approximately 90 %. Furthermore, said guanidine salts can enable an increase in the ammonia forming potential from 0.2 kg, corresponding to prior art, up to 0.4 kg ammonia per litre of guanidine salt, along with freezing resistance (freezing point below -25°C). The risk of corrosion of the guanidine salt solutions used according to the invention is also significantly reduced compared to that of solutions containing ammonium formiate.
摘要:
The invention relates to the use of aqueous guanidinium formiate solutions, optionally combined with urea and/or ammonia and/or ammonium salts, for the selective catalytic reduction of nitrogen oxides using ammonia in exhaust gases of vehicles. The inventive guanidinium formiate solutions enable a reduction of the nitrogen oxides by appoximately 90 %. Furthermore, said guanidinium formiate solutions can enable an increase in the ammonia forming potential from 0.2 kg, corresponding to prior art, up to 0.4 kg ammonia per litre of guanidinium formiate, along with freezing resistance (freezing point below -25°C). The risk of corrosion of the inventive guanidinium formiate solutions is also significantly reduced compared to that of solutions containing ammonium formiate.
摘要:
A method of treating wooden parts is described in which a) the wooden parts are impregnated with an aqueous cyanamide solution and subsequently b) the impregnated wooden parts, where appropriate after drying, are subjected to a heat treatment of 130 to 250°C. Here it has surprisingly emerged that impregnation with cyanamide even in small amounts has a significantly positive influence on the performance properties of the treated wooden parts, such as high hardness, low water absorption and very good weathering stability, for example. Moreover, only small amounts of a toxicologically and environmentally unobjectionable impregnating agent are needed in order to obtain these advantageous properties.
摘要:
A process is proposed for preparing creatine, creatine monohydrate or guanidinoacetic acid, wherein N-methylethanolamine or ethanolamine is first catalytically dehydrogenated, in each case in alkaline solution, and the sarcosinate or glycinate solutions thus obtained are finally reacted under acidic conditions with a guanylating agent, for example O-alkylisourea or cyanamide. In this way, products are obtained in high yields and very good purity, but, in contrast to the prior art, no traces whatsoever of hydrocyanic acid, formaldehyde, chloroacetic acid or ammonia are present. The formation of the toxicologically unsafe dihydrotriazine is also avoided.
摘要:
The invention relates to novel salts and/or addition compounds and/or complex compounds of guanidinoacetic acid and malic acid, aspartic acid, ascorbic acid, succinic acid, pyruvic acid, fumaric acid, gluconic acid, a-oxoglutaric acid, oxalic acid, pyroglutamic acid, 3-nicotinic acid, lactic acid, citric acid, maleic acid, sulphuric acid, acetic acid, formic acid, 2-hydroxybenzoic acid, L-carnitine, acetyl-L-carnitine, taurine, betaine, choline, methionine and lipoic acid, also in the form of potassium-, calcium- or sodium guanidinoacetate. Said salts have improved physiological and therapeutic characteristics and are particularly suitable for use as nutritional supplements, feed and in cosmetic or dermatological preparations, in which their marked stability and excellent bioavailability come to the fore.
摘要:
The invention relates to novel salts and/or addition compounds and/or complex compounds of guanidinoacetic acid and malic acid, aspartic acid, ascorbic acid, succinic acid, pyruvic acid, fumaric acid, gluconic acid, α-oxoglutaric acid, oxalic acid, pyroglutamic acid, 3-nicotinic acid, lactic acid, citric acid, maleic acid, sulphuric acid, acetic acid, formic acid, 2-hydroxybenzoic acid, L-carnitine, acetyl-L-carnitine, taurine, betaine, choline, methionine and lipoic acid, also in the form of potassium-, calcium- or sodium guanidinoacetate. Said salts have improved physiological and therapeutic characteristics and are particularly suitable for use as nutritional supplements, feed and in cosmetic or dermatological preparations, in which their marked stability and excellent bioavailability come to the fore.