Pharmaceutical fine chemical closed feeding process waste gas membrane separation and recovery equipment, customized equipment manufacturing enterprise Luoyang Wo Hong Petrochemical.

The closed feeding process of pharmaceutical fine chemical industry relies on the closed feeding station and vacuum feeding system to complete the feeding operation of solid powder and liquid solvent. VOCs waste gas will be continuously generated during the stages of material feeding, nitrogen replacement in the kettle, pressure breaking exhaust, batch feeding and equipment flushing. The waste gas components include ethyl acetate, acetone, dichloromethane, tetrahydrofuran and various alcohol medicine common solvents. Closed feeding belongs to intermittent operation conditions, feeding replacement exhaust instantaneous organic steam concentration instantaneous high, equipment closed feeding stage exhaust gas concentration fell back, multiple reactor staggered peak feeding operation, exhaust gas air volume and organic concentration showed random fluctuation characteristics. Exhaust gas flow is easy to entrain material powder, solvent droplets and saturated water vapor, and some halogenated solvents are hydrolysed with water vapor to generate corrosive medium, which is easy to cause corrosion damage to collection pipelines and internal components of equipment. The pharmaceutical feeding area belongs to Class A explosion-proof control place, with high toxicity of materials and flammable and explosive organic solvents. Therefore, very strict comprehensive requirements are put forward for the pretreatment capacity of powder droplets, resistance to instantaneous concentration impact, explosion-proof safety design, adaptive operation capacity under wide working conditions and solvent resource recovery effect of membrane separation and recovery equipment.

The traditional exhaust gas treatment process faces the exhaust gas condition of the pulse fluctuation of the closed feeding process, and there are many practical application short boards. The incineration process can oxidize and decompose organic pollutants, but the organic solvent with recovery value in the waste gas is directly incinerated, and the material loss remains high. When the exhaust gas contains halogenated hydrocarbon components, high-temperature combustion will produce corrosive and toxic by-products, the flue gas post-treatment supporting system is complex, and the equipment investment, fuel consumption and daily operation and maintenance costs are high for a long time.activated charcoalAdsorption is a pollutant transfer treatment method, and solvent recovery and utilization cannot be realized. In the face of waste gas with random high and low concentration switching in the feeding process, powder and solvent droplet impurities entrained in the intake air are superimposed, the adsorption filler is easily gummed and blocked, and adsorption saturation is quickly reached. Frequent shutdown is required to replace adsorption consumables. The output of hazardous waste is large, and the later operation and maintenance burden of the enterprise is heavy. The simple condensation process relies on low temperature to realize solvent liquefaction, and the recovery effect is better only under the condition of high concentration of feed replacement exhaust gas. The partial pressure of organic vapor in the low concentration stage of sealed loading of equipment is insufficient, the recovery efficiency of solvent liquefaction is greatly attenuated, and a large number of organic components are emptied with the exhaust gas, which cannot realize stable resource treatment in the whole cycle. A large number of project practice shows that a single process mode is difficult to adapt to the real operating conditions of intermittent fluctuations in the closed feeding process, the equipment load is insufficient at the time of feeding exhaust impact, the emission index is easy to exceed the standard under low concentration conditions, and can not meet the multiple demands of workshop safety production, environmental protection compliance and solvent recovery income at the same time.

The compression condensing film is coupled with a complete set of all-physical treatment processes, and there is no combustion or chemical reaction in the operation process, which is highly suitable for the waste gas membrane separation and recovery equipment in the closed feeding process of pharmaceutical fine chemical industry. The exhaust gas generated by the exhaust port replaced by each closed feeding station and reactor is collected and transported through the negative pressure closed gas collecting pipeline network. The exhaust gas first enters the equipment pretreatment unit, and relies on the multi-stage filtration defoaming and dust removal structure to remove solid powder, solvent mist droplets and free moisture carried by the airflow, so as to avoid impurities from entering the back-end compressor, heat exchanger and membrane module, causing blockage, glue formation and irreversible pollution of membrane components. In view of the working conditions that the exhaust gas of the closed feeding process is easy to entrain solid powder, the pretreatment unit adopts a hierarchical interception structure, and the filtration and purification are completed step by step according to the particle size of impurities, which effectively protects the precision core components at the back end and prolongs the service life of the whole set of equipment. After undergoing preliminary purification, the waste gas enters the compression unit, where the partial pressure of organic vapors is increased to create favorable conditions for solvent liquefaction. The gas is then fed into a multi-stage gradient condensation module, which utilizes the boiling point differences among the components of the mixed solvent to achieve staged cooling. As a result, the majority of the organic solvents are condensed and separated, completing the initial solvent recovery process.

After condensation, the tail gas still contains some unliquefied organic components, which then enter the organic membrane separation unit. There, the difference in permeation rates between organic solvent molecules and air molecules through the polymeric membrane material is utilized to enrich and concentrate the organic components. The treated exhaust gas is discharged to the atmosphere, while the high-concentration organic gas stream enriched on the membrane side is recirculated back to the compressor inlet, forming a closed-loop system that further enhances the overall recovery rate of the multi-component solvent. The recovered liquid mixed organic solvent can be returned to the production process for reuse after the quality meets the requirements of the pharmaceutical production process through precipitation filtration and index detection, so as to recover the solvent resources originally lost by volatilization of tail gas with feeding replacement, reduce the amount of hazardous waste generated from the source, and reduce the enterprise's solvent procurement cost and hazardous waste disposal expenses. The whole set of equipment can adopt the skid-mounted integration mode, the factory prefabrication is completed, the on-site installation work quantity is small, and the original negative pressure gas collecting pipe network of the closed feeding station can be directly connected to the closed feeding station, so as to minimize the shutdown and transformation cycle and reduce the interference to the feeding and synthesis operation of the workshop.

The entire system is designed in strict compliance with pharmaceutical and chemical explosion-proof standards. All pipelines, valves, and heat-exchange components that come into contact with the exhaust gas are fabricated from corrosion-resistant materials to withstand the acidic corrosion caused by hydrolysis of halogenated media, thereby ensuring long-term, continuous operation of the equipment. The equipment is equipped with comprehensive overpressure, overtemperature, and combustible gas detection systems, as well as automatic interlock protection mechanisms, to handle the instantaneous concentration spikes caused by feed charging and purging, thereby mitigating various safety risks associated with flammable and explosive media. The intelligent variable-frequency control system dynamically adjusts the equipment’s operating load in real time based on the incoming air volume and concentration, accommodating the intermittent exhaust gas emissions resulting from staggered material feeding across multiple workstations. This prevents equipment overload and unnecessary no-load operation, thereby optimizing overall energy consumption. Based on field-measured flue gas flow rates, component compositions, concentration fluctuation ranges, dust impurity levels, ductwork layouts, and on-site space constraints at the feeding stations, we deliver customized designs that do not rely on standardized, off-the-shelf models. We provide end-to-end services covering process design, equipment manufacturing, on-site installation and commissioning, operator training, and post‑commissioning operations and maintenance.Standardized manufacturing, standardized on-site construction, and routine inspection and maintenance ensure the long-term reliable operation of the entire membrane separation recovery system, achieving the dual objectives of compliant treatment of exhaust gases from closed-feed processes in the pharmaceutical and fine chemical industries and cost reduction through the resource recovery of organic solvents.