DMAC Recovery Plant

说明 Brief Introduction

本套DMAC回收系统采用负压MVR浓缩+二效真空精馏工艺将DMAC与水分离，结合真空脱酸塔（精制塔）可得到指标优异DMAC产品。结合蒸发过滤、残液蒸干系统，可使废液中的PVP形成固体残渣排出系统，提高回收率的同时减少污染。

This DMAC recovery plant uses negative pressure MVR concentration + two-effect vacuum distillation process to separate DMAC from water, and combines with vacuum deacidification tower (refining tower) to obtain DMAC products with excellent index. Combined with evaporation filtration and evaporation of residual liquid, PVP in the waste liquid can be discharged from the system as form of solid residue, which improves the recovery rate and reduces pollution.

本次设计在工艺流程设计、设备选型、安装施工等方面有针对性的进行了优化改进，以求实现使装置运行更稳定、成品品质更优良、运行成本更低、生产环境更环保的目标。

In this DMAC recovery plant design, the process design, equipment selection, installation and construction are targeted to optimize and improve, in order to achieve the goal of making the device run more stable, the finished product quality is better, the operating cost is lower, the production environment is more environmentally friendly.

工艺技术指标 Technical Index

1、DMAC废水处理量 Treatment capacity ≥10t/h

DMAC含量 Content : 3~5% 、FA≤100 ppm 、PVP(K85)<0.1％

2、DMAC成品品质 Quality of final DMAC product

3、塔顶水的品质：Quality of tower top water

4、 DMAC回收率 DMAC Recovery rate : ≥99 %

5、装置区所需的公用工程条件 Utilities required

蒸汽：1.3t/h  压力5bar 饱和蒸汽 Steam : 1.3t/h 5 bar Saturated steam

循环水Circulation water：压力 Pressure: ≥0.4 Mpa

（中温Medium temp.）100t/h

压缩空气 Compressed air：0.5m³/min, 压力≥0.25MPa Pressure（无油、无尘、露点-30, oil free, dust free, dew point-30）

一次水补充 Water supplement ： ~5t/h

装置运行容量 Total running power：520 kwh (400V).

工艺流程简述：Introduction of flowchart

本装置采用MVR+二效真空精馏工艺的主体流程，大体分为浓缩、蒸发、除渣、精馏、脱酸、尾气吸收等六部分。

This DMAC recovery plant adopts the main process of MVR+ two-effect vacuum distillation process, which is roughly divided into six parts, such as concentration, evaporation, residual removal, rectification, deacidification and waste gas absorption

1、浓缩：Concentration

由罐区废液泵输送来的DMAC废液进入回收装置区，经过预热后，进入一级浓缩塔浓缩,进料流量由变频器进行调节。

The DMAC waste liquid transported by waste solvent pump in tank area enters the recovery unit area, and then after preheating, it enters the primary concentration tower for concentration, the feed flow is regulated by the inverter.

一级浓缩塔（MVR浓缩塔）为微负压操作。塔釜再沸器热源其一来自MVR压缩机出口蒸汽，不足部分用蒸汽补充。一级浓缩塔顶蒸汽经压缩机压缩后在塔釜再沸器中冷凝。

The primary concentration tower (MVR concentration tower) is operated with a slight negative pressure. The heat source of the tower kettle reboiler comes from the outlet steam of the MVR compressor, and the insufficient part is supplemented with steam. The steam at the top of the tower is compressed by the compressor and condensed in the tower kettle reboiler.

经过一级浓缩后的DMAC废液送入二级浓缩塔，由调节阀对流量进行调节。

二级浓缩塔为高负压操作。塔釜再沸器热源来自精馏塔的塔顶蒸汽。二级浓缩塔顶蒸汽在塔顶冷凝器中冷凝，冷凝水进入T102塔顶液罐，由T102回流泵提供二级浓缩塔的回流，多余部分由T102出水泵送至污水处理系统 。

经过二级浓缩后的DMAC废液送入一级蒸发器，由调节阀对流量进行调节。

The DMAC waste liquid after the primary concentration is sent to the secondary concentration tower, and the flow rate is adjusted by the regulating valve.

The secondary enrichment tower is operated with high negative pressure. The heat source of the tower reboiler comes from the top steam of the rectification tower. The steam at the top of the secondary enrichment tower condenses in the top condenser, and the condensed water enters the liquid tank at the top of the T102 tower. The reflux pump provides the reflux of the secondary enrichment tower, and the excess part is sent to the sewage treatment system by the T102 outlet pump.

The DMAC waste liquid after secondary concentration is sent to the primary evaporator, and the flow rate is adjusted by the regulating valve.

2、蒸发：Evaporation

二级浓缩塔塔釜DMAC废液浓度提高后送入一级蒸发器，一级蒸发器为高效降膜蒸发器，热源来自脱酸塔的DMAC蒸汽，蒸发出的蒸汽进入到蒸发罐内，进行一级蒸发后的物料进入到蒸发罐内，由调节阀控制流量。

进入到蒸发罐的物料通过进料循环泵使DMAC废液在蒸发罐和进料加热器之间不断循环，强化加热效果；进料加热器利用来自锅炉的蒸汽来对DMAC废液进行加热。蒸发罐中汽化的含DMAC蒸汽经过汽液分离后进入提馏塔进行分离，同时部分浓缩后的废液进入回收锅去除其中的PVP，防止堵塞设备。

The primary evaporator is an efficient falling film evaporator. The heat source comes from the DMAC steam of the deacidification tower. The steam evaporates into the evaporation tank.

The material entering the evaporation tank is continuously circulated between the evaporation tank and the feed heater through the feed circulation pump to strengthen the heating effect; The feed heater uses steam from the boiler to heat the DMAC waste. The vaporized DMAC steam in the evaporation tank is separated by vapor and liquid and then enters the distillation tower for separation, while the partially concentrated waste liquid enters the recovery pot to remove PVP in order to prevent clogging of the equipment.

3、除渣：Residual removal

配备回收锅可将系统所排放釜残液（俗称残渣）直接送入回收锅中，在负压状态下将残渣蒸干，残渣中的水、DMAC气化后重新返回系统精制, PVP残渣由回收锅排渣口排出。

Equipped with a recovery pot, the residual liquid (commonly known as residue) discharged by the system can be directly sent into the recovery pot, and the residue is dried under negative pressure. The water and DMAC in the residue are vaporized and returned to the system for refining. The PVP residue is discharged from the slag outlet of the recovery pot.

4、精馏：Distillation

DMAC与水在精馏塔中分离，水由塔顶蒸出，在塔釜得到高纯度的DMAC。精馏塔为负压操作，塔釜再沸器利用来自外管的蒸汽为精馏塔提供热能，水蒸汽在塔顶冷凝器中冷凝，冷凝水提供精馏塔的回流，多余部分送至塔顶水罐。

经过精馏后的DMAC汽体送入脱酸塔，进一步精制。

DMAC and water are separated in the rectification tower, and the water is steamed out from the top of the tower, and high purity DMAC is obtained in the tower kettle. The distillation tower is operated under negative pressure, and the tower kettle reboiler uses the heat steam from the outer pipe to provide heat energy for the distillation tower. The water steam condenses in the top condenser, and the condensed water provides reflux for the distillation tower, and the excess part is sent to the top water tank.

After distillation, the DMAC vapor is sent to the deacidification tower for further refining.

5、脱酸：Deacidification

进入脱酸塔的DMAC会含有少量的乙酸，利用脱酸塔得到品质好的DMAC成品，脱酸塔为减压操作，利用真空泵维持其真空。侧线采出的DMAC经过冷却后进入到DMAC出料罐，一部分由下回流泵提供脱酸塔的侧线回流，一部分由DMAC出料泵输送到罐区，在DMAC成品罐中储存。

The DMAC entering the deacidification tower will contain a small amount of acetic acid, and the deacidification tower will be used to obtain high-quality DMAC products. The deacidification tower is operated as a decompression operation, and the vacuum pump is used to maintain its vacuum. After cooling, the DMAC extracted from the side line enters the DMAC discharge tank. Part of it is provided by the lower return pump for the side return of the deacidification tower, and part of it is transported by the DMAC discharge pump to the tank farm for storage in the DMAC finished tank.

6、尾气吸收（业主可选配）：Waste gas absorption (Optional)

来自真空泵出口的尾气和水进入到汽水分离罐后，水被分离收集后重复供给真空泵使用，带有二甲胺的尾气从汽水分离罐顶通过管道输送到尾气冷凝器进行冷凝，冷凝后的尾气通过管道输送到吸收塔a与来自塔顶喷淋下来的硫酸进行初步的中和吸收，后进入到吸收塔b进行进一步的中和吸收，从吸收塔b出来的尾气输送到吸收塔c进行最后的处理。三个吸收塔中的硫酸来自储酸罐，利用硫酸上料泵进行输送。

中和后的尾气在排入大气前设置了碱中和系统进一步去除尾气逸出的酸味后高空排放。

After the exhaust gas and water from the outlet of the vacuum pump enter the soda water separation tank, the water is separated and collected, and then supplied to the vacuum pump again. The exhaust gas with dimethylamine is transported from the top of the soda water separation tank to the exhaust gas condenser for condensation, and the condensed exhaust gas is transported to the absorption tower a through the pipeline for preliminary neutralization and absorption with sulfuric acid sprayed down from the top of the tower. After entering the absorption tower b for further neutralization and absorption, the tail gas from the absorption tower b is transported to the absorption tower c for final treatment. Three absorption towers of sulfuric acid to self-storage acid tank, using sulfuric acid feeding pump for delivery.

Before the neutralized exhaust gas is discharged into the atmosphere, an alkali neutralization system is set up to further remove the acid smell from the exhaust gas and then discharge it at high altitude.