Does waste acid emit smoke and gas during nitration production?

This indicates that the nitrogen content in the waste acid is high; nitration occurred during extraction. Reduce the amount of nitric acid fed in, and reset the amount of nitric acid based on the analyzed dehydration value.

The above reasons have been ruled out. But the phenomenon still exists

1. Excess *ao acid is present in the waste acid, which continues to undergo nitration reactions with benzene; this leads to an increase in temperature as well as an increased amount of yellow smoke； 2. The presence of water in benzene may also require a high temperature during the extraction process ；

The reasons mentioned on the 4th floor are also ruled out. The phenomenon still exists

The increase in temperature is due to the heat of reaction resulting from the reaction between nitric acid and benzene； The yellow smoke is caused by dissolved nitrogen oxides in the waste acid (resulting from the decomposition of nitric acid); when the acid concentration is low, these nitrogen oxides escape as smoke! Extraction is a necessary step in the nitration of benzene; since an excess of nitric acid is required to ensure that the product meets the desired standards, extraction is essential! As for the nitrous fumes in spent acid, keeping the reaction temperature low reduces the amount of nitric acid that decomposes, and thus less nitrous fumes are produced; however, it is not possible to eliminate them completely. Also, your nitration setup is very important – is it a kettle-type nitration? Tubular nitration? Pump-type nitrification? Or adiabatic nitration? Different conditions lead to different results. We have experience with industrial nitration plants using these various processes, and we would be happy to exchange ideas if the opportunity arises.