Quality issues associated with the electrodialysis drainage from the processing of high-acid crude oil
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Our plant’s 12-million-ton facility processes high-acid crude oil, and the quality of the water produced by electrodesalination is poor, with a COD level of around 3,000–5,000; sometimes this water turns black. I wonder what the quality of the water generated by electrodesalination is like in other refineries that process high-acid crude oil
I； From what I understand, in units that process highly acidic crude oil, the COD level of the electrodialysis drainage is generally high, ranging from 2000 to 3000; there are also cases similar to those in your unit. It is difficult to solve due to the properties of crude oil. It’s Hui Lian’s device, I guess. With oil in the flow, electrodialysis becomes difficult to use; mixing is the only option. For other aspects, you can contact colleagues from Liaohe Petrochemical to find out more; they handle high-acid crude oil, and their electrodialysis processes are operating normally.
Didn’t Hui Lian also conduct an appraisal? The metrics are great. It’s an advanced technology that’s unique in the whole world – absolutely terrifying.
The sulfur content of the raw materials we process is 3.3%, the ammonia nitrogen level in the electrodialyzed water is 60–100 mg/l, and the COD level is 2400–3000 mg/l
Everyone should push this post up. I’d like to ask everyone: what happens to the water that is of poor quality, and what are the methods for dealing with it?
It mainly involves the selection of demulsifiers; another aspect is the installation of specialized pipelines leading to the sewage tank for sedimentation
High-acid crude oil-containing saline wastewater has a high content of organic matter, with a significant amount of organic acids; this is the fundamental reason why such wastewater is difficult to treat. These organic acids are hard to be degraded by organic substances, and even after hydrolytic acidification, the biodegradability improves only slightly. In addition, the gums and asphaltenes present in the wastewater are also factors that contribute to their difficulty in being degraded. Most of this type of wastewater comes from electrodialysis, with a smaller portion coming from crude oil dehydration; of course, there is also some other saline wastewater from various units, but it is the first two sources that primarily cause difficulties in degradation.