METHOD FOR PRODUCTION AND AUTOMATION OF CONTROL SYSTEM FOR N,N-DIMETHYLACETAMIDE PRODUCTION PROCESSES

摘要

FIELD: chemistry.;SUBSTANCE: method includes feeding gaseous dimethylamine and acetic acid into a tubular catalytic reactor, in the inter-tubular space of which a high-temperature heat carrier is fed in at least two points at different heights; reaction products are fed into a first fractionation column for distillation of unreacted dimethylamine, the vapour of which is returned into the reactor from the top of the column. The distillate from the first column is fed into the bottom of a second fractionation column for separating the aqueous-amine fraction, and the still residue is fed into a third fractionation column. The second fractionation column operates in periodic mode and its operating cycle consists of a dimethylamine distillation step, a technical acetone distillation step, a water-acetone fraction distillation step and a bottom residue discharge step. Technical dimethylacetamide in distillate form is fed from the third fractionation column into a fourth fractionation column where low-boiling fractions are distilled from dimethylacetamide. The bottom residue from the fourth fractionation column is fed into a fifth fractionation column where commercial-grade N,N-dimethylacetamide is distilled in distillate form, and the bottom residue is returned to the third fractionation column. An automated control system for the process of producing N,N-dimethylacetamide comprises three subsystems: a subsystem for automated adjustment of the ratio of the flow rates of acetic acid and dimethylamine fed into the reactor, a subsystem for automated control of the reactor and a subsystem for automated control of second fractionation column.;EFFECT: method enables to obtain N,N-dimethylacetamide with high output and a reduced amount of wastes.;2 cl, 1 dwg, 1 ex