4results about How to "Reduce waste acid" patented technology

The application discloses a preparation method of 1,2,3-trichloro-4,6-dinitrobenzene, which comprises the following steps: (1) sulfuric acid and 1,2,3-trichlorobenzene are sequentially added into a batching kettle, mixed uniformly and heated to 60-75 DEG C to obtain a mixture A; (2) nitric acid and sulfuric acid are sequentially added into another batching kettle and mixed uniformly to obtain a nitrosulfur mixed acid; (3) two feed modes are adopted, the mixture A obtained in the step (1) and the nitrosulfur mixed acid obtained in the step (2) are pumped into a two-stage tubular reactor with a diameter of 10 mm respectively to carry out nitration reaction; (4) after the nitration reaction is completed, the reaction liquid obtained in the two-stage tubular reactor is transported into a receiving tank, waste acid and an organic phase are separated, the residual waste acid in the organic phase is neutralized and washed to neutral to obtain 1,2,3-trichloro-4,6-dinitrobenzene. According to the application, the conversion rate of the 1,2,3-trichlorobenzene is greater than 99%, the yield of the obtained product 1,2,3-trichloro-4,6-dinitrobenzene is greater than 98%, and the purity is greater than 99.5%.

The invention discloses a method for continuously preparing mononitro-aromatic hydrocarbon, which comprises the following steps: respectively pumping an aromatic hydrocarbon compound and a polyfluoro-substituted alcohol solution of nitric acid from two inlets of a microreactor, mixing, reacting, quenching with ice water, extracting with an organic solvent, washing with water, and drying to obtain mononitro-aromatic hydrocarbon, the aromatic hydrocarbon compound is selected from at least one of benzene, monosubstituted aromatic hydrocarbon toluene, tert-butylbenzene, fluorobenzene, chlorobenzene, and disubstituted aromatic hydrocarbon o-xylene, m-xylene and p-xylene; the polyfluoro substituted alcohol is selected from at least one of trifluoroethanol, hexafluoroisopropanol and nonafluoro tert-butyl alcohol. The polyfluoro-substituted alcohol which is easy to recover is used as the cosolvent, so that the aromatic hydrocarbon raw material and the nitration reagent in the microreactor form a homogeneous nitration system, the mononitro aromatic hydrocarbon selectivity is controllable, and the problem of excessive nitration of the heterogeneous nitration system of nitric acid and sulfuric acid is effectively avoided. The method is safer, more efficient and easy to amplify, and a new way is provided for large-scale preparation of mononitro-aromatic hydrocarbon by a micro-reaction technology.

The application discloses a kind of purification processes of ultra-pure electronic grade nitric acid, it is related to electronic chemical purification technical field, comprising the following steps: S1: unloading filtration: industrial grade nitric acid raw material is pumped into raw material tank by unloading pump, normal temperature and pressure, then is transported to raw material filter by raw material delivery pump and is filtered, after removing large particles, it enters raw material buffer tank, and is stored at normal temperature and pressure;S2: waste heat preheating: the nitric acid raw material with the concentration of 70-71% is pumped into preheater by feed pump, and is preheated by waste acid as heat medium from the bottom of reboiler, after preheating, it enters rectifying column, and waste acid is cooled and enters waste acid tank.The application is coupled by "waste heat recovery preheating+reboiling rectification+staged condensation", the raw material is preheated by waste acid waste heat from the bottom of reboiler, which significantly reduces steam consumption, while staged condensation improves the separation efficiency and product purity of nitric acid, reduces NO compound emission, and overall energy consumption is reduced by 5%-10% compared with traditional process.

The invention discloses a preparation method of 1, 2, 3-trichloro-4, 6-dinitrobenzene, which comprises the following steps: (1) sequentially adding sulfuric acid and 1, 2, 3-trichlorobenzene into a batching kettle, uniformly mixing, and heating to 60-75 DEG C to obtain a mixture A; (2) sequentially adding nitric acid and sulfuric acid into another batching kettle, and uniformly mixing to obtain nitric acid and sulfuric acid mixed acid; (3) respectively feeding the mixture A obtained in the step (1) and the mixed nitric acid and sulfuric acid obtained in the step (2) into a secondary tubular reactor with the diameter of 10mm through a pump by adopting a two-stream feeding mode, and carrying out nitration reaction; and (4) after the nitration reaction is completed, conveying a reaction solution obtained in the secondary tubular reactor into a receiving tank, separating out waste acid and an organic phase, neutralizing the residual waste acid in the organic phase, and washing to be neutral to obtain the 1, 2, 3-trichloro-4, 6-dinitrobenzene. The conversion rate of the 1, 2, 3-trichlorobenzene is greater than 99%, the yield of the obtained product 1, 2, 3-trichloro-4, 6-dinitrobenzene is greater than 98%, and the purity is gt; the content is 99.5%.