VOCs organic solvent recovery system in synthetic pharmaceutical workshop, Luoyang Wo Hong Petrochemical, the industry's preferred supplier.

Synthetic pharmaceutical workshop in the synthesis reaction, extraction, crystallization, distillation, vacuum devolatilization and material transfer process, will continue to release a large number of VOCs organic solvent waste gas, waste gas composition is complex, containing acetone, ethyl acetate, dichloromethane, tetrahydrofuran, alcohols and other solvent media. Pharmaceutical production to batch intermittent operation, exhaust emissions show obvious intermittent, air volume and concentration fluctuations are large, the reactor pressure relief stage exhaust gas concentration suddenly increased, equipment standby stage exhaust gas concentration quickly fell back. The exhaust gas flow often carries material droplets, suspended impurities and saturated water vapor. Some halogenated solvents will hydrolyze when they meet water to generate acidic substances, which will cause corrosion to pipelines and equipment. Most organic components are flammable and explosive media. The workshop production environment has strict standards for the safety performance, material corrosion resistance and working condition adaptability of the whole recovery system. Traditionalwaste gas treatmentIt is difficult to balance emission standards, solvent recovery and production safety, and it is difficult to adapt to the actual production needs of synthetic pharmaceutical workshops.

The incineration process can realize the purification treatment of tail gas, but it will directly destroy the organic solvent with high economic value, resulting in a large loss of raw material resources. After the waste gas containing halogenated components is incinerated at high temperature, corrosive flue gas will be generated, which will cause erosion to the subsequent pipeline equipment. A complex tail gas post-treatment system is required, and the equipment investment and daily operation and maintenance costs remain high.activated charcoalAdsorption is only to complete the transfer of organic pollutants, and solvent recovery cannot be achieved. Under the conditions of multi-component, high humidity and frequent fluctuation of concentration, the adsorption material is easily saturated in advance, resulting in adsorption penetration. Frequent downtime is required to replace adsorption consumables, and hazardous waste is continuously produced. Long-term operation will bring heavy cost pressure to enterprises. The simple condensation process relies on low temperature to realize solvent liquefaction, which is obviously restricted by the partial pressure conditions of organic steam, and has a better recovery effect only under the condition of high concentration exhaust gas.

The compression condensation film coupling process belongs to the pure physical treatment route, the whole process does not occur combustion and chemical reaction, very suitable for the complex exhaust gas conditions of the synthetic pharmaceutical workshop. The waste gas first enters the pretreatment unit, and relies on the multi-stage filtration and defoaming structure to remove liquid droplets, solid impurities and free moisture in the airflow, so as to avoid blockage damage caused by impurities entering the back-end core unit. The exhaust gas after pretreatment and purification is sent to the compression unit to increase the partial pressure of organic steam and create more favorable liquefaction conditions, and then enter the multi-stage gradient condensation module to complete layered cooling according to the different boiling points of various solvents, and most organic solvents are directly liquefied and precipitated to realize preliminary recovery.

The residual tail gas after condensation treatment still retains part of the organic solvent and will be sent to the organic membrane separation unit to complete the enrichment and separation of solvent components by relying on the selective permeation difference between the organic solvent and air by the membrane material. The clean tail gas is discharged outward, and the enriched high-concentration organic gas stream flows back to the front end of the compressor and re-enters the whole system for recycling treatment. The closed-loop operation mode fully exploits the solvent recovery potential. After precipitation, filtration and testing, the recovered organic solvent can be reused in the pharmaceutical production process to reuse the solvent resources in the waste gas, reduce the output of hazardous waste from the source, and reduce the double overhead of raw material procurement and hazardous waste disposal.

Combined with the working conditions of the synthetic pharmaceutical workshop, the system configuration design needs to fit the actual conditions of the site. The pipeline, valve body and heat exchange components in contact with the exhaust gas are made of corrosion-resistant materials to resist the corrosion caused by the hydrolysis of halogenated media and ensure the stable operation of the equipment for a long time. The whole system is equipped with complete overpressure, overtemperature, medium leakage monitoring and automatic interlocking protection mechanism to avoid safety risks under flammable and explosive conditions. The automatic control system adopts a frequency conversion control mode, which can follow the real-time changes of exhaust gas air volume and concentration, automatically adjust the operating load of the equipment, adapt to the fluctuation of working conditions brought about by batch production, and avoid equipment overload or idling energy consumption. The pre-pretreatment unit intercepts droplets and impurities in stages, effectively protects precision core components such as heat exchangers and membrane modules, and prolongs the service life of the equipment. The process design needs to collect the real measured data of exhaust gas air volume, component proportion, concentration interval, water content and impurity on site to carry out customized accounting, and cannot directly apply the general model, so as to ensure the stable compliance of VOCs treatment and truly give full play to the actual value of solvent resource recovery and cost reduction.