How to handle the gases after combustion
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I used to work in chemical engineering processes, so I’m not very familiar with environmental protection issues. The main component in the exhaust gas is carbon monoxide, with about 0.5% hydrogen sulfide and phosphine present. One approach being considered is to burn this gas directly; this would result in the formation of sulfur dioxide and phosphorus oxides. I’d like to treat this exhaust gas after it has been burned. Are there any devices or methods for collecting such exhaust gas after combustion? Please give me some guidance. Thank you!
Middle school textbooks say that lime water should be used for absorption.
These waste gases of yours are acidic; they can be absorbed and removed using alkaline substances. Lime is the commonly used one
Reply to 3# Kind Cat: I know that alkaline substances can be used as well, but what equipment is available for that? It’s not possible to just pour them onto the flame directly. Is there any method that allows for the collection of this gas after it has been burned, so that it can be reused later? Thank you
The gas can first be washed with water to remove hydrogen sulfide and phosphine, after which the flue gas is burned to check the carbon monoxide level; if this level is high, recycling it is more advantageous than releasing it
If the main component of the gas is carbon monoxide and its concentration is high, recovering carbon monoxide as an energy source should be considered first. Dilute ammonia water can be used to wash the gas, removing trace impurity gases such as hydrogen sulfide and phosphine, after which the recovered carbon monoxide can be used as a fuel gas for processes that require heating. :P
They say that lime water absorption is harmful; theoretically it does absorb things, but can anyone show me this in practice? Any equipment would have already become clogged with scale, so one must consider things comprehensively! If combustion followed by absorption is indeed required, specialized absorption tower equipment should be used to carry out the absorption with liquid alkali.
For small-scale projects, alkalis can be used for absorption; smoke needs to be guided out and passed through specialized absorption towers. Actually, large-scale waste gas treatment facilities all use lime! Using alkali is not cost-effective at all, unless the factory has some leftover alkaline solution