Low temperature-resistant tail gas catalytic reduction agent and preparation method thereof

Abstract

The invention relates to a tail gas catalytic reduction agent and a preparation method thereof, and belongs to the technical field of chemical industry. Aiming at the characteristic that due to low-temperature performance, the conventional vehicular tail gas catalytic reduction agent only can be used at the temperature of -11 DEG C, a vehicular low temperature-resistant tail gas catalytic reduction agent which can be used at the low temperature of between -25 and -40 DEG C normally and accords with a selective catalytic reduction (SCR) system is compounded on the basis of the fundamental mechanism of a reduction agent. The tail gas catalytic reduction agent comprises the following components in percentage by weight: 30 to 60 percent of Adblue, 10 to 40 percent of ammonium carbonate, 10 to 40 percent of methanol, 0.02 to 0.2 percent of low-molecular weight polyether amine and 10 to 35 percent of ultrapure water. A blending process comprises the following steps of: dissolving, purifying and filling. The tail gas catalytic reduction agent is suitable to be used at the temperature of -11 DEG C and meets the requirement of the normal operation of the SCR system completely.

Description

technical field [0001] The invention relates to a tail gas catalytic reducing agent and a preparation method thereof, belonging to the technical field of chemical industry. Background technique [0002] At present, the freezing point of the exhaust catalytic reduction agent for SCR technology—vehicle exhaust catalytic reduction agent (AUS32) is -11°C, so the winter temperature in northern China is generally lower than -11°C. The exhaust gas catalytic reductant used in vehicles causes adverse effects of freezing. The vehicle must first be heated through the heating system, which not only increases the cost of the SCR system, but also uses the heating system to start using the SCR system, which has a certain adverse effect on the OBD of the SCR system. This has led to violations of the National IV emission regulations during the implementation process. Foreign countries have also studied the low temperature resistance of exhaust gas catalytic reduction agents for a long time....

AI Technical Summary

Problems solved by technology

[0002] At present, the freezing point of the exhaust catalytic reduction agent for SCR technology—vehicle exhaust catalytic reduction agent (AUS32) is -11°C, so the winter temperature in northern China is generally lower than -11°C. The exhaust gas catalytic reductant used in vehicles causes adverse effects of freezing. The vehicle must first be heated through the heating system, which not only increases the cost of the SCR system, but also uses the heating system to start using the SCR system, which has a certain adverse effect on the OBD of the SCR system. Leading to violations of the National IV emission regulations during the implementation process

Foreign countries have also studied the low temperature resistance of exhaust gas catalytic reduction agents for a long time. The applicant learned that the formulation of low temperature resistant exhaust gas catalytic reduction agents is mainly through the compounding of some ammonium substances, and a qualified low temperature resistant exhaust gas catalytic reduction agent is prepared through a certain blending process. , but due to the strong corrosiveness of ammonium substances, the corrosion of metals in the exhaust system has always been concerned, and it has not been widely used

The addition of low-carbon alcohols to qualified Adblue is also the focus of research. Since low-carbon alcohols have the ability to lower the freezing point, adding an appropriate amount of low-carbon alcohols can reduce the freezing point of the tail gas catalytic reducer. characteristics, the conversion efficiency of NOx will be reduced, so it has not been widely promoted

In China, because the SCR system has only been paid attention to in recent years, the market for exhaust catalytic reductants used in SCR systems is small, and there is no research on low-temperature exhaust catalytic reductants. However, in the low temperature of winter in northern China, vehicles are in urgent need of Low temperature resistant exhaust gas catalytic reducer reduces adverse effects of freezing