Is a multi-stage process more efficient than a single-stage process? !
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I often hear terms like multi-stage spraying and multi-stage adsorption. Is multi-stage more efficient than single-stage? But from a balance perspective, that doesn’t make sense either; if the corresponding masses are the same, where does higher efficiency come from?
Personally, I believe that with multi-stage adsorption, the concentration of the substances being adsorbed decreases after each adsorption stage; the adsorption capacity for these substances remains the same. However, the concentration gradient between them increases, which helps to effectively reduce the concentration of the adsorbed substances in the material being treated. Whether that is more cost-effective depends on specific circumstances; ultimately, it comes down to your process requirements.
I used to discuss secondary adsorption with people at HaiChuan; it’s not very meaningful. There is no increase in the concentration gradient.
From a process perspective, they are actually the same; the reason for using a multi-stage process might be due to factors other than process considerations.
I see. But in the bizarre field of environmental protection projects, various \"experts\" run amok, with secondary and multiple levels becoming the norm!
In engineering terms, that’s indeed the case – after all, there is a difference between theory and practice, not to mention cost considerations
If the theories don’t hold up, how can engineering work? The residence time is different, that’s all.
Whether it is spraying or adsorption, calculations show that an effective packing height is required, and the packing must be manufactured to meet this height. It’s fine to do just level one. Spray towers are built to 20-30 meters in height, which increases the requirements for the equipment, leading to higher costs for investment and maintenance. Divide it into several towers 4 to 5 meters tall; using PP for construction is sufficient, as it is cost-effective and easy to maintain. After grading, different chemicals can be used at various stages according to the process requirements
Environmental protection is an industry that has seen a resurgence. In previous years, those involved in this field switched to other occupations; but in the past two years, due to **policy incentives**, many people have flocked to this area. It no longer seems important whether one has prior experience in environmental protection or not. Companies from various backgrounds are trying to get involved in this field, and those who want to take advantage of this trend have started to get involved as well. People from all walks of life are now involved, which has also given rise to a large number of so-called experts in environmental protection; some of them don’t even understand the relevant techniques, yet they still start making grand claims. What I said might be too one-sided, but such situations do exist; I welcome any criticism and suggestions from everyone.
It’s not one-sided at all. Once, at an environmental impact assessment meeting, an expert in that field said that adsorption occurs through the surface of activated carbon. I told him that adsorption actually takes place thanks to the pores inside the activated carbon, and he got very angry, thinking that I had embarrassed him.
Mm-hmm, yes, that’s the professional term. However, in this important field of environmental protection, experts don’t hold such views; for example, they believe that stacking activated carbon at a height of 0.6m is completely different from stacking it in two layers, each 0.3m high!