Compressed air applications in industrial yeast production: the vital role of reliable and energy-efficient blowers and air compressor solutions
There are many processes in industrial yeast production which require low-pressure air or compressed air. Large-scale fermentation (the cultivation process) is one of the most critical. Here, blowers must reliably aerate and agitate the yeast mixture to achieve optimal yields. Aeration can account for up to 50% of a yeast plant’s total energy consumption. This makes the reliability and energy efficiency of the blowers even more important in order to minimise the impact on the production costs per ton of yeast. In this blog post, we explore the typical applications of low-pressure air and compressed air in industrial yeast production, and highlight how KAESER’s advanced compressed air and blower solutions can reliably and energy-efficiently meet these requirements.
Typical compressed air applications in industrial yeast production
Intelligent KAESER compressed air solutions in use in industrial yeast production
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Process diagram in detail
Compressed air in industrial yeast production
Large-scale fermentation
Large-scale fermentation (aerobic cultivation) is a vital process for the creation of yeast required in the food industry for example, to produce bread. From the mother fermentation stage to the commercial fermentation stage, low-pressure air is essential during the entire growth process of yeast cells in large-scale fermentation tanks.
Blowers are used to aerate and agitate the yeast mixture within the fermentation tanks. Aerating the mixture directly influences the growth of yeast cells by providing the yeast with oxygen. Agitating the mixture ensures homogenous conditions and enhances the mass transfer of nutrients and oxygen. Yeast is usually produced in a fed-batch process.
This means that after an initial starting phase, substrate is continuously fed into the bioreactor, to prevent a very high sugar concentration in the beginning.
Too high sugar concentrations would inhibit the growth of the yeast cells. Due to the feeding of substrate, the volume of the bioreactor contents continuously increases. For consistent oxygenation, the blower system must therefore adapt to the continuously changing situation - raising the pressure to compensate for the higher volume and increasing the flow rate to provide a sufficient amount of oxygen to supply the increasing amount of yeast cells. The aim of the fermentation is to keep the yeast cells in the exponential growth phase. The control of the fermentation, with an optimal substrate supply and the associated aeration, is essential to achieve an optimal result of the yeast production.
Especially the blower needs to adapt instantly to the continuously changing process parameters. Aerating too little or too much can spoil the product, and it can be costly in time, resources, and energy, to dispose of the spoilt batch, clean the fermentation tanks, and restart the production process.
The aeration requirements of large-scale fermentation is typically one of the largest energy consumers in a biotechnical production plant, accounting for up to 50% of a plant’s total energy consumption. A reliable and efficient supply of low-pressure air is therefore not only critical to the success of the aerobic process, but also to the overall energy consumption of the aeration blowers.
KAESER works closely with its customers to deliver high-performance blower systems for optimum aerobic fermentation results, maximum efficiency, and low energy consumption. To achieve peak performance with a multiple blower station, the SIGMA AIR MANAGER 4.0can be integrated, dynamically adjusting blower operations based on real-time flow and pressure demands, for optimal low-pressure air production at all times.
Learn more about KAESER solutions for large-scale fermentation
Yeast finishing
High-purity instrument air, requiring a typical pressure of 6-7 bar(g), is essential for controlling valves and actuating pneumatic devices throughout an industrial yeast production facility. In particular it is required for a number of finishing processes:
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Drying plant operations
Thanks to their simplicity and effectiveness in removing moisture, fans are commonly used in the drying process required to produce dry yeast. There are however alternative drying methods that utilise compressed air, which may offer improved drying efficiency and product quality, such as:
Fluidised bed drying: this method uses compressed air to fluidise yeast particles ensuring even drying. Consistent airflow is crucial in maintaining uniform drying conditions and optimal drying temperatures, enhancing the overall efficiency of the drying process.
Spray drying: compressed air is required in this method to atomise yeast cream into fine droplets. Clean and dry compressed air is critical for efficient drying and consistent droplet sizes, contributing to the quality of the final product.
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Yeast conveying systems
Vacuum conveying is employed once the yeast is dried, to gently and efficiently transport the dry yeast from the drying equipment to packaging without compromising its integrity. This type of dilute-phase pneumatic conveying requires high-velocity, low-pressure compressed air to effectively transport the yeast. For optimal performance, the air must be free from moisture and oil to prevent disruptions in material flow and system efficiency as well as to prevent contamination.
As with all air compressor and blower applications in industrial yeast production, clean and dry compressed air is essential to meet the high air purity standards typically required for food production. Through close consultation with process equipment OEMs, and the application of relevant standards like ISO 8573-1, KAESER offers tailored blower and compressed air system solutions that reliably and efficiently meet the stringent air quality standards required for industrial yeast finishing.
Learn more about KAESER solutions for yeast finishing:
Yeast packaging
Instrument air is required during the final packaging stages of yeast, from powering the pneumatic actuators that drive the mechanical movements of packaging machines, to preventing contamination in filling and sealing mechanisms.
This may include powering air knives or blow-off systems used to blow off excess yeast particles and maintain cleanliness on for example, packaging materials or machinery surfaces. Such applications depend on a reliable supply of clean and dry compressed air to ensure cleanliness and to prevent contamination.
KAESER works with packaging machinery OEMs and customers to identify and deliver the optimal compressor or blower solution, tailored to meet specific packaging set-up requirements, while ensuring the required purity classes as specified by ISO 8573-1 are met.
Learn more about KAESER solutions for yeast packaging
On-site water treatment
Low-pressure air - and, in some cases, compressed air - is crucial for on-site water treatment. In the biological treatment stage for example, low-pressure air is required to aerate the wastewater . Blowers generate air flows to aeration systems that deliver fine air bubbles which are injected into the wastewater. This aeration, provides bacteria with the oxygen required to break down organic matter.
This aeration, provides bacteria with the oxygen required to break down organic matter.
Yeast influent typically has a high biological oxygen demand (BOD) due to elevated levels of sugars, proteins, and yeast residues. The means that a significant amount of oxygen is required to support the microbial activity for the biological treatment process.
Adequate oxygen delivery is therefore critical in maintaining effective microbial activity, which means the performance of the blowers directly influences treatment success.
Industrial yeast production uses large volumes of water, with plants consuming thousands of litres daily. In addition, aeration is a major energy consumer in wastewater treatment. Effective and energy-efficient on-site water treatment of yeast influent is therefore essential, not only for sustainable water management, but for optimised energy usage. This makes the selection of reliable and energy-efficient aeration blowers ever more important.
KAESER offers tailored blower system solutions that reliably and energy-efficiently meet the aeration requirements of on-site water treatment.
Learn more about KAESER solutions for on-site water treatment:
Compressed air for the workshop
A reliable supply of compressed is typically required in a yeast production plant’s workshop for miscellaneous tasks, such as operating air tools and cleaning workshopped components or parts. KAESER’s reciprocating compressors present an ideal solution for workshops with intermittent compressed air requirements.
Available in both portable models (the CLASSIC and PREMIUM series), and stationary models (the KCT and AIRBOX series), these compressors offer flexibility and reliability. Rotary screw compressors offer a highly efficient solution for larger workshops with a continuous compressed air demand . KAESER’s AIRCENTER series integrates a high-efficiency rotary screw compressor, a refrigeration dryer, and an air receiver in one compact, all-in-one system.
The AIRCENTER is ideal at point of use thanks to its quiet operation. Alternatively, the SXC series provides a robust compressor package, featuring a refrigeration dryer and air receiver, all housed in a durable polyethylene enclosure.
Learn more about KAESER solutions for workshop air: