الوصف

Jiangsu Hengmao is leading the design and construction of methylal plant in China, Mthylal production technology is our another core competitive product besides formaldehyde plant.

Features of our methylal equipment

1) Diversified Processes: One-tower Process, Two-tower Process, External Hanging Process, Pressure Distillation Process

2) The methylal machine have a small land coverage

3) Methylal concentration from *4.4% to *9.9%

4) Environment friendly with zero wastewater discharge

5) Catalyst durable and easy to change for External Hanging Process

Summary

Due to methylal production line's low boiling point and excellent dissolving power, methylal  is widely used in cosmetics, medicines, household products, automobile products, pesticides, leather polishing agent, detergent, rubber products, paint, ink and so on. For example, it can be used as an alternative for F*1, F**3 and chlorine contained detergents, for Freon to reduce volatile organic（VOCs） emission and air pollution; it is an excellent gasoline additive to increase combustion efficiency and reduce waste emission; especially, high concentrated methylal is mainly applied as molecular weight adjuster for polyformaldehyde, plasticizer, hypnotic agent, analgesic, spice, high grade cosmetics and solvents for Grignard & Reppe reactions.

Advantage

After several years' engineering practice by our methylal production line, Hengmao's engineering staff have developed a new proprietary technology of methylal production, wherein pressure swing distillation is employed; solid acid catalyst is easy to regenerate and replace; conversion rate and output is increased; COD content in waste water is reduced to less than **0ppm.

Process Description

1) Common Concentration Methylal

Methanol and formaldehyde are pumped into the fixed bed catalysis reactor in proportion. The reaction temperature is controlled at *0℃～*5℃. The obtained mixing solution of methylal, methanol and water is heated for evaporation by the re-boiler steam at the bottom of distillation column. The compositions with low volatility are collected at the top through screen packing, while the heavy fraction remains at the column bottom. The azeotropic fraction of methylal and methanol from the column top is condensed and sent to the reflux tank. Part of it returns to the top of the tower for circulation, and part of it is collected as final product. The COD load in waste water at the tower bottom can be controlled below **0ppm.

2) High Concentration Methylal whith our methylal machine

First, common concentration methylal process is used to obtain *2% methylal solution, which is pumped to multi-pressure distillation column with a pressure range of 1.2 Mpa to 1.5Mpa. The temperature at the top of the distillation coloumn is controlled at **0℃, while temperature at the bottom is controlled at **5℃. High concentration methylal can be withdrawn from the column bottom, and fractions from the top are refluxed to reactor and pressure distillation column.