Alcohol fermentation off-gas
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What are the components of alcohol fermentation off-gases? I searched online, but couldn’t find it anywhere. The main components, in addition to CO2, include H2S and hydrocarbons as well, right? So where do H2S and hydrocarbons come from in the fermentation feedstock? What are the respective contents? The composition of the fermentation off-gases may vary from one household to another, but the approximate amounts of the main components should be similar, right? Additionally, I’m looking for: the \"International Beverage Technology Association Quality Standards for Liquid Carbon Dioxide\" – I’ve tried many places to find it; let’s see if I can locate it here.
The exhaust gas from alcohol fermentation mainly consists of carbon dioxide; hydrogen sulfide may be present due to sulfur elements in the culture medium, while light hydrocarbons might include methane and similar compounds!
I have an indicator here; I’m not sure if it’s the one from the International Beverage Association that you’re looking for. The details are as follows: Serial Number, Item, Parameter: 1. Volume fraction of carbon dioxide, 10-2 – ≤99.9; 2. Volume fraction of moisture, 10-5 – ≤20; 3. Acidity – must meet the requirements specified in 5.4; 4. Volume fraction of nitric oxide, 10-6 – ≤2.5; 5. Volume fraction of nitrogen dioxide, 10-6 – ≤2.5; 6. Volume fraction of sulfur dioxide, 10-6 – ≤1.0; 7. Total sulfur volume fraction (excluding sulfur dioxide, expressed as sulfur), 10-5 – ≤0.1; 8. Total volume fraction of hydrocarbons (expressed as methane), 10-6 – ≤50 (with non-methane hydrocarbons not exceeding 20); 9. Volume fraction of benzene, 10-6 – ≤0.02; 10. Volume fraction of methanol, 10-6 – ≤10; 11. Volume fraction of ethanol, 10-6 – ≤10; 12. Volume fraction of acetaldehyde, 10-6 – ≤0.2; 13. Volume fraction of other oxygen-containing organic substances, 10-6 – ≤1.0; 14. Volume fraction of vinyl chloride, 10-6 – ≤0.3; 15. Mass fraction of oils and fats, 10-6 – ≤5; 16. Odor, taste, and appearance of the aqueous solution – must meet the requirements specified in 5.10; 17. Mass fraction of evaporation residue – ≤10; 18. Volume fraction of oxygen, 10-6 – ≤30; 19. Volume fraction of carbon monoxide, 10-6 – ≤10; 20. Volume fraction of ammonia, 10-6 – ≤2.5; 21. Volume fraction of phosphine, 10-6 – ≤0.3; 22. Volume fraction of hydrogen cyanide, 10-6 – ≤0.5. Note: Other oxygen-containing organic substances include dimethyl ether, ethylene oxide, propylene, n-propanol, isopropanol, n-butanol, isobutanol, ethyl acetate, and isopentyl acetate
The exhaust gases from alcohol fermentation depend on the raw materials used; in the case of production using grains as raw materials…
Due to an operational error, the reply was not complete! The fermentation off-gases from alcohol production, which uses grains as raw material, consist mainly of carbon dioxide, as alcohol fermentation is simply a yeast-based process that utilizes glucose; according to the principles of fermentation, only carbon dioxide is produced. If contamination occurs, other gases may be generated! Additionally, proteins present in the raw materials will also produce other gases during the fermentation process! However, these gases are released in the fermentation stage, and some more gases are released in the alcohol distillation stage.1
This post was last edited by Ahooloo on 2009-5-13 20:17. The main component of alcohol fermentation off-gases is carbon dioxide, along with some water, alcohol, acetaldehyde, and volatile organic acids; when contamination is severe, the levels of organic acids and aldehydes increase. The H2S content should be relatively low, and its source is likely the decomposition of proteins, amylases, glycosidases, etc., in the raw materials. As for hydrocarbons, there shouldn’t be any.
There is not much H2S; the sulfur content also depends on the raw materials used