Dimethyl formylamine solution three-effect rectification recovery method for wet synthesis of leather

Abstract

A triple-effect distillation and recovery method for wet synthetic leather dimethylformamide(DMF) solution includes: feeding, preheating, condensing and separating it by a concentration tower and a distillation tower to output it to complete the recovery process, in which, low-pressured steam is the heating media, using decompressed concentration for step I, atmospheric concentration for level II and vacuum distillation, the decompressed concentration processes in the packing tower, atmospheric concentration processes in the plate column, decompressed concentration processes in the combined packing and plate column. In the described cycle process, energy can be recycled between the steam in the top, heating at the bottom, feed preheating, preheating of finished condensation, distillation, reboilling processes.

Description

technical field [0001] The invention relates to a three-effect rectification recovery method of wet-process synthetic leather dimethylformamide solution. Background technique [0002] In the past ten years, the domestic synthetic leather industry has developed rapidly and the competition is fierce, resulting in a sharp drop in product unit profits. In the past two years, the energy shortage has caused the price to rise in a straight line. Energy consumption has become the main factor in the production cost of PU leather products. All manufacturers are trying to tap the potential to reduce consumption and improve market competitiveness. DMF (Dimethylformamide) is a solvent widely used in PU leather production plants. It is mainly used for batching dilution. After the coagulation process is completed and dissolved in water, DMF is recovered and recycled by the supporting recovery device or sold as a by-product. , About 80% of the cost of DMF recovery is used for heat energy c...

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Problems solved by technology

[0004] The traditional three-effect DMF recovery process at home and abroad uses heat transfer oil or medium-pressure steam as the heat medium, and adopts atmospheric distillation and decompression concentration technology, while the double-effect DMF recovery process commonly used in China uses low-pressure steam as the heat It is very difficult to transform the distillation and atmospheric pressure concentration technology into a traditional three-effect recovery process

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