Question Description: Discuss the microbiological, economic, and chemical engineering implications of foam generation in industrial fermentations.
Course Hero Answer & Explanation:
Microbiologically, foam generation has an impact on industrial fermentation.
The presence of foam-active substances in the fermentation broth, escaping gas/air, and turbulences within the fermenter all contribute to the formation of foam during the fermentation processes. The substrates used in most cases are high in carbohydrates, which are partially converted into sugar substrates by enzymes. Sugars, starches, and proteins act as foam-promoting substances on their own, and they may be aided by other substances or ingredients that contain trace elements for the microorganisms. Furthermore, amino acids and proteins produced by microorganisms during fermentation can cause significant foam activity.
The nature of the gases released is determined by the fermentation method. Essentially, we must differentiate between anaerobic and aerobic fermentation processes. Alcohol production is a common example of anaerobic fermentation. Substrates containing various sugars and starches are converted into alcohol and carbon dioxide using yeast during this process. Depending on the substrates used, the escaping carbon dioxide creates more or less foam. Aerobic fermentation processes, on the other hand, are far more important for the use of antifoam agents. In this case, we must distinguish between processes for microorganism propagation (such as the production of baker’s yeast) and the production of various “biotechnology products” (such as antibiotics and enzymes) using special microbes. During aerobic processes, air is blown into the fermentation vessel to provide oxygen to the microorganisms. Excess air is released, resulting in foam. Aerobic processes are typically much more foam intensive than anaerobic processes because the amount of air released is significantly greater than the amount of carbon dioxide released.
Foam generation also posed impact in industrial fermentation economically.
Foaming reduces productive volume, increasing process costs, and can cause outlet blockage, threatening the sterility of a fermenter. Antifoam action can take the form of antifoam agent addition, mechanical agitation, or ultrasound.
Excessive foaming can cause the fermentation broth to be displaced and leak from the vessel. Foam’s effects can reduce productivity in either case. To effectively destroy foam, it is critical to detect foam formation as soon as possible. For continuous fermentation processes, antifoam level probes are used.
Increasing costs usually have a negative impact on a business, making it more difficult to operate economically. They are likely to raise the BEP or decrease the company’s profit. With rising costs, a company would have to sell more products to break even or make a profit. As a result, the company is more likely to lose money.
Chemical engineering impact the fermentation industries greatly during foam generation.
Silicone foam control agents are an important segment of the foam control process aids category, which is the largest single category of process aids used in the chemical industry. The use of silicone fluids in combination with hydrophobic particulates to control aqueous foams has been extensively discussed, and it is beyond the scope of this article. Silicone polyethers are used as foam control agents in diesel fuel defoaming, the production of plastics such as polyvinyl chloride, polymer dispersions, inks, paints and coatings, and some household products.
Diesel fuel typically contains moisture, which has a strong influence on the action of foam control additives, which must be chosen to function over the expected range of moisture contents. Although the cause of the foaminess is unknown, silicone polyethers are effective defoamers as long as they are not completely soluble in the fuel and are not absorbed and deactivated by water.
Copolymers containing polyoxypropylene appear to be the most effective. Silicone polyethers become less soluble in water as temperature rises, and copolymers with certain polyoxyalkylene content ranges have a cloud point. These copolymers are effective defoamers in the vicinity of the cloud point, though few applications specifically mention this as the controlling mechanism.