A process for recovering organic gases in chemical production

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It’s been almost 2 years since my last post; at that time I had just started working there and didn’t yet fully understand our own manufacturing processes and products. Two years later, I’d like to talk briefly with you about how organic waste gases generated during chemical production can be recovered and treated. Many people are likely familiar with Nanjing Jiusi. Many years ago, we started working with pharmaceutical companies on the extraction of cephalosporin C; later on, we began working on the reuse of treated water. After that, we focused on the dehydration of organic solvents. Now, we have developed all three of these technologies, and we have established Jiangsu Jiuwu High-Tech (a company listed on the A-share market) as well as Jiangsu Jiutian High-Tech (which specializes in organic solvent dehydration and is listed on the Science and Technology Innovation Board). Currently, we are working on the recovery of VOCs and ensuring their discharge meets regulatory standards. Of course, our core principle remains unchanged: we always strive to transfer the technologies that exist \"on the shelf\" of research into practical industrial application. Over the years, as **emission standards have become increasingly strict, exhaust gases that could previously be easily made to meet these standards have become a major concern for various manufacturing companies. Halogenated hydrocarbons are particularly problematic: they are inexpensive, have low recycling value, and cannot be burned due to the risk of dioxin formation. Additionally, they freeze easily at low temperatures. Over the past few years, I have visited many chemical companies, and they said, \"Professor Yang, if you can solve the problem related to dichlorine, then there won’t be any major issues with the exhaust gases generated in our chemical production processes, as there are many other organic compounds for which more cost-effective treatment methods exist.\" There are many companies in the market that deal with VOC treatment; when faced with substances such as dichlorine, they tend to dilute them first and then use adsorption to reduce their concentration. I have a question for everyone: the best way to treat gases is through condensation, so why can’t we simply cool them down? It turns out that when the gas concentration drops to a certain level, it’s no longer possible to cool it further. So today I’d like to recommend a new method to achieve this: our approach of using condensation, membranes, and adsorption. For substances that can still be cooled, we first cool them; once further cooling isn’t possible, we use membranes to concentrate the substance before attempting to cool it again. In this way, the organic compounds can be almost completely recovered, right? Note that in this case, there is no need to use fans to dilute it; the amount of gas discharged by the vacuum pump, centrifuge, or three-in-one unit is exactly as it should be. This allows us to effectively avoid the burden on subsequent environmental protection equipment such as RTOs, since the volume of gas in question is very small. Next, by continuously evacuating and creating a circulation, we send the non-condensable gases back to the inlet for further concentration and condensation; as a result, the concentration of organic compounds in the incoming gas becomes very low. At this point, the gas enters our adsorption unit (currently, we use activated carbon as the adsorbent), and a very small amount of it is sufficient to achieve compliant emissions.