How to treat the solvent exhaust gas from the production of edible spices? Collection and recycling of reaction purification and filling processes

How to treat the solvent exhaust gas from the production of edible spices? The idea is threefold: first, classify the emission sources according to the stages - respiratory emissions from synthesis reaction vessels, non condensable gases from distillation and purification, open volatilization from blending and filling, and intermittent emissions from equipment and container cleaning; Collect according to the characteristics of each point, and enclose the reaction and purification points with closed conduits and open operation points locally; Finally, the main treatment route for condensation recovery is selected based on the composition and concentration. The production of spices can be batched and centralized, and the management and recycling can be solved together. The recovered solvents can be reused as ingredients after passing the laboratory test, and both the material and environmental accounts are good.

Where does the solvent exhaust gas from the spice workshop come from

The synthesis of spices requires the use of organic solvents as reaction media and carriers, and the breathing emissions during the heating and stirring stages of the reaction kettle are a continuous source; The concentration of non condensable gas during the purification stage is high but the gas volume is small; The open operation in the mixing and filling process results in fluctuations in volatile content with the batch; Cleaning kettles and tanks with solvents, high concentration for short periods of time; The breathing emissions from the solvent storage and intermediate tanks are concentrated in the storage area. There is a significant difference in air volume and concentration among the four types of points, so they should be accounted for separately when configuring.

How to collect the reaction and purification steps

The breathing port of the reaction kettle and the vacuum pump discharge are separately led into branch pipes, which are first stabilized by a buffer tank before flowing into the main pipe. The high-temperature section of the pipeline is insulated to prevent premature condensation of steam; After passing through the condenser, the uncondensed gas at the top of the distillation tower is connected to the collection manifold. Use sealed conveyors or enclosed feeding ports for reaction feeding to reduce opening time; The residual gas in the batch gap kettle is discharged after replacement, and the replacement gas is also connected to the collection pipeline.

How to collect the filling and cleaning links

The mixing tank and filling port are semi enclosed with directional ventilation, and the escape between the filling nozzle and the barrel mouth is controlled by the wind speed on the cover surface; The washing area is enclosed as a whole, and cleaning operations are concentrated at fixed workstations. Ventilation and cleaning are interlocked for start and stop. After the low concentration branch flows into the main pipe, it is merged into the condensation section or equipped with adsorption units according to the concentration. The ventilation rate is determined based on the space and solvent turnover, without excessive dilution of the entire room with high air volume. The emission characteristics and configuration methods of each link are shown in the following table:

How should condensation recovery be configured?

The solvent components used in spice production are relatively clear, and the condensate recovered from condensation has high value for reuse: the pre cooling stage cools and dehumidifies the exhaust gas, and the post cooling stage condenses most of the solvent vapor, with cold recovery between the two stages; After verifying the components and moisture content of the condensate, it is reused for ingredients. The batches mixed with impurities are sent to the refining unit or entrusted for disposal. The ledger records the recovery amount and destination according to the batch. In the case of batch production, the processing equipment is configured according to the peak value of each batch, and buffering is used to maintain the working conditions between batches. Food grade applications require high quality for recycled solvents, and the scope of reuse is determined according to the enterprise's quality management system. Batches that do not meet quality requirements are converted to low use or entrusted for disposal, and are not forcibly reused.

How to promote the implementation of technological transformation

1. On site investigation, confirm the emission source, concentration, and air volume point by point, with a focus on verifying the working conditions of the reaction kettle and filling station;
2. Develop a collection plan by location: implement equipment breathing ducts, enclosure ventilation, and kettle washing area collection one by one;
3. Approve the concentration monitoring and interlocking scheme, and confirm the safety entry before the recovery entry;
4. After construction and installation, adjust the balance of air volume and verify the collection effect point by point;
5. After putting into operation, the discharge port shall be inspected periodically, and the condensate shall be tested in batches and checked for reuse.

Frequently Asked Questions

Will the breathing tube of the reactor affect the reaction conditions?

The diameter and resistance of the inlet pipe are determined according to the breathing volume inside the kettle, and when configured reasonably, it does not affect stirring and reaction; During the debugging phase, observe the pressure inside the kettle and the smoothness of feeding. If negative pressure suction or pressure build-up occurs, adjust the pipe diameter.

Can recycled solvents still be used for food grade ingredients?

The scope of reuse shall be determined according to the enterprise quality management system: if the condensate meets the quality requirements for the corresponding use after inspection, it shall be reused within the approved scope; Directly convert unsatisfactory items to low use or entrust them for disposal, without resorting to hard funding.

Does the workshop batch gap exhaust still need to be opened?

The collection branch and equipment operation interlock start and stop, and the processing device and the main pipe can be kept in operation; The ventilation of the whole room shall be approved according to the solvent retention, and no invalid long-open large air volume shall be made, taking into account the energy consumption and stable working conditions.

What supporting services does WoHong offer?

Luoyang Wohong Petrochemical Equipment Co., Ltd. provides design, manufacturing, installation, and commissioning services for waste gas treatment and solvent recovery devices in edible spice production workshops. Welcome to contact and exchange ideas.

This article is organized by Luoyang Wohong Petrochemical Equipment Co., Ltd. If you need an assessment of exhaust gas treatment in the spice workshop or on-site investigation, please feel free to contact and exchange ideas.