FEED FORWARD PROCESS CONTROLS FOR NYLON SALT SOLUTION PREPARATION PROCESSES

摘要

Disclosed are process controls for controlling the continuous preparation of nylon salt solution. The process controls include feed forward controls. A model is generated to achieve a target pH and/or salt concentration. Feed rates are set for each of a dicarboxylic acid monomer, a diamine monomer, and/or water to a single continuous stirred tank reactor. The dicarboxylic acid is metered, based on weight, from a loss-in-weight feeder to the reactor. The nylon salt solution is formed continuously and has low variability from a target pH and/or a target salt solution concentration. The nylon salt solution is transferred directly to a storage tank, without further monomer addition, pH adjustment, or salt solution adjustment after exiting the continuous stirred tank reactor.

主权项

1. A process for controlling the continuous preparation of a nylon salt solution comprising:
a) generating a model for setting a target feed rate of dicarboxylic acid powder to produce the nylon salt solution having a target pH; b) controlling feed rate variability of the dicarboxylic acid powder by metering the dicarboxylic acid powder, based on weight, from a loss-in-weight feeder to a feeding conduit that transfers the dicarboxylic acid powder at the target feed rate into a single continuous stirred tank reactor; c) separately introducing diamine at a first feed rate and water at a second feed rate to the single continuous stirred tank reactor, wherein the first and/or the second feed rates are based on the model; and d) continuously withdrawing the nylon salt solution from the single continuous stirred tank reactor directly into a storage tank, wherein the withdrawn nylon salt solution has a pH less than ±0.04 from the target pH.