Low-freezing-point nitric oxide reducing agent and preparation method thereof

Abstract

The invention provides a low-freezing-point nitric oxide reducing agent and a preparation method thereof. The low-freezing-point nitric oxide reducing agent consists of, by mass, 20%-32.5% of urea, 5%-10% of dimethyl sulfoxide, 40%-55% of pure water and one or more of 10%-20% of acid amide, amides and low molecular alcohols. The preparation method comprises the following steps of preparing raw materials, performing full mixing at the temperature ranging from 10 DEG C to 30 DEG C till all raw materials are completely dissolved into a water solution and mixed evenly, using a filter element with the filter accuracy ranging from 0.5 mum to 5 mum and filtering the raw material water solution under the pressure of 0.2-1 MPa to obtain a finished product. The anti-freezing agent raw materials have the advantages of being safe and easy to obtain, good in anti-freezing effect, non-toxic, harmless and the like. The freezing point of the reducing agent is greatly reduced, the problems of low-temperature crystallization and icing are solved, the anti-freezing performance of the nitric oxide reducing agent can be remarkably improved, and the freezing point can be lower than subzero 25 DEG C. A test shows that after engine exhaust gas is filled into an SCR aftertreatment system of the low-freezing-point nitric oxide reducing agent to be treated, the exhaust gas emission can be up to the national IV standard.

Description

Technical field [0001] The present invention involves the field of dairy engine at the post -processing of diesel engines. It is specifically a low -free nitrogen oxide reducing agent and its preparation method. Background technique [0002] In recent years, with the frequent emergence of haze weather across my country, the environmental pressure of my country's government has increased.The control of motor vehicle emissions, which has contributed to the haze weather pollution sources, is also accelerating. Following Beijing in March 2008, Beijing, Shenzhen, Guangzhou, Xi'an and other cities have successively implemented motor vehicle countries IV IV.standard.In the past two years, cities that have been implemented in the country's fourth emission standards have increased. It is expected that the state will comprehensively implement the IV emissions standards of motor vehicle countries in 2015. [0003] According to the current production technology of diesel engines, if diesel v...

AI Technical Summary

Problems solved by technology

Compared with this patent, the composition of this patent is more complex, which increases the difficulty of production

In addition, most of the alcohol reagents are volatile, and the product is not tightly sealed or placed in the open for a long time, which will not only affect the product quality, but also cause certain pollution to the ambient air