Liquid urea for vehicles and preparation method thereof

Abstract

The invention discloses a liquid urea for vehicles and a preparation method thereof. The liquid urea comprises following components in percentage by weight: 32.5% of urea solution, 5 to 7% of methanol, 4 to 6% of ammonium formate, 5 to 8% of ammonium sulfate, 2 to 4% of alkyl phenol polyoxyethylene, 5 to 8% of propylene glycol, 2 to 5% of polyoxyethylene stearate, 5.5 to 8% of chelating agent, and21.5 to 39% of deionized water. The formula of provided liquid urea is reasonable, ammonium formate and ammonium sulfate will promote the degradation of urea to generate ammonia gas, moreover, ammonium formate, ammonium sulfate, and ammonia gas can generate a synergistic effect to greatly improve the conversion rate of catalytic reduction of NOx; methanol, propylene glycol, and polyoxyethylene stearate can improve the compatibility; the anti-freezing performance of the liquid urea is good, the stability is high, the application range is largely enlarged; the chelating agent has a strong chelating performance for all raw materials, NOx in tail gas can be radically processed, the processing effect is good, and the urea is environmentally friendly.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a urea solution for vehicles and a preparation method thereof. Background technique [0002] With the continuous increase of the number of automobiles in our country, the harm of nitrogen oxides and particulate matter emitted by automobiles to human health and the atmospheric environment has attracted great attention. According to reports, all countries in the world are committed to reducing these two emissions. As far as my country is concerned, the "National IV" emission standard that has been implemented means that more advanced technologies must be used for vehicle exhaust emissions. A large number of experimental studies have shown that selective catalytic reduction technology (SCR) is the most suitable "National IV" emission solution for diesel vehicles, and this technology must use urea solution to reduce NO in exhaust gas. X Therefore, the urea solu...

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Problems solved by technology

At the same time, low-quality diesel exhaust treatment fluid will pollute the catalyst in the SCR catalytic reaction tank, causing serious consequences

[0003] At present, the freezing point of traditional vehicle urea is around -11°C. In order to meet the needs of vehicles using SCR technology in low-temperature environments, traditional vehicle urea systems are generally equipped with antifreeze circulation heating or electric heating systems and insulation systems. , that is, the addition of additional parts such as heating pipe circuits, temperature sensors, and insulation layers will undoubtedly increase the complexity of the system and cause a high failure rate. , relying on circulating coolant to melt frozen urea and other disadvantages

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