Is the hydrogenation of dichloroacetic acid feasible?
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During the batch production of chloroacetic acid, a large amount of mother liquor is generated. How can chloroacetic acid and dichloroacetic acid be recovered from it? Is the hydrogenation approach feasible? I appreciate your guidance
It is feasible; the mother liquor hydrogenation process is a development direction for the chloroacetic acid process.
The process in Aksu already includes a hydrogenation step designed to reduce dichloroacetic acid to chloroacetic acid.
It’s a confidential manufacturing process, but it is said to be a design created by Tianchen Institute.
This problem existed over 10 years ago, with palladium being used as a catalyst
The drawback of the chloroacetic acid industry is technical blockade
The process in Aksu includes a hydrogenation step, which can increase the yield.
Comparison of technical upgrades for chloroacetic acid: Chloroacetic acid is a major chlorine-consuming product with mature technology, but it requires high amounts of raw materials and generates significant energy consumption. Under the current production conditions, energy conservation and reduction of consumption are undoubtedly key aspects for this industry; therefore, we carried out revolutionary technical upgrades to the chloroacetic acid production facility. Before modification: chlorination, first cooling (circulating water), second cooling (brine at -15 to -20°C), third cooling (brine at -35°C; at this temperature the saturated vapor pressure of acetic acid is approximately 0.15 mmHg, while that of acetyl chloride is 15 mmHg). The organic substances present at this stage are mainly acetyl chloride and thionyl chloride, which have catalytic properties. There was significant loss of raw materials, high energy consumption, and the by-product hydrochloric acid had poor quality and contained free chlorine. After the modification: chlorination and special solvent recovery units, primary cooling (circulating water) and secondary cooling (-10°C saline; at this temperature the total saturated vapor pressure of organic compounds in the exhaust gas is approximately 1.55 mmHg). The raw material consumption is reduced, energy usage is significantly lowered, and the reaction rate increases markedly. The process operates in a continuous, fully automatic manner, with virtually no free chlorine in the exhaust gas; the by-product hydrochloric acid has good quality and contains no free chlorine. Suitable for technical upgrading and renovation of old devices. For inquiries, please contact: 13861289383 QQ: 349921807 ff6605js94@163.com
The idea of hydrogenating the mother liquor is good, but due to the high impurity content in it, fully hydrogenating it would result in catalyst costs that are several times higher than the revenue generated from the product. The process is feasible, but it results in losses; several companies in China have conducted tests on it, with no viable solution emerging.