The chocolate market in India reached a value of US$ 1,682 million (*Source: https://www.imarcgroup.com/india-chocolate-market) in 2019 with the country emerging as one of the world’s fastest-growing markets for chocolates. This growth is driven by India’s sweet tooth where the Indian population today consumes chocolate on daily basis against the habit of consuming chocolates only during special occasions in the past. It is estimated that 61% of Indians eat their favourite chocolate daily or at least once a week.
Compressed air plays a key role in both the processing of cocoa and the manufacturing of chocolate. In the past, compressed air systems had several shortcomings in the form of high maintenance cost, contamination, the presence of moisture in the air, and high power costs. However, maintaining compressed air quality in the manufacturing process is very important to ensure end-product quality, shelf life, and cost. Energy efficiency and the broader goal of reduction in carbon emissions add to the pressures on the processing industry.
Air Quality in Processing Plants
Modern cocoa processing systems use compressed air during pod splitting, fermentation, and drying applications. Compressed air is equally important in the manufacturing of chocolate in conveying, blending & mixing, moulding, and packaging. Needless to say, the quality of compressed air and the overall compressed air system is critical to ensuring the highest quality of chocolate produced and high efficiency of processing plants. The compressed air is also used to operate robotic applications and cylinders on the chocolate wrapping machines for a faster process that delivers millions of chocolates and the candies we see lined up across store shelves.
In many of these applications, compressed air is in direct contact with the cocoa or chocolate under process. For example, chocolate in the form of liquid is transported from the manufacturer to chocolatiers in containers. The liquid chocolate is viscous, and its unloading requires the use of compressed air. With the goods involved being a food item, the compressed air needs to be oil free. Any impurities in the compressed air may contaminate the food product, resulting in a change of color and taste, reduced shelf life, or exposure to bacteria and other micro-organisms. This could result in product recalls and/or export bans, thereby damaging the reputation of the brand or company at large.
To overcome these problems, processing units must ensure the following.
- Compressed air does not have any impurities
- The piping system does not have any leakage and is designed optimally for pressure drop
- Downstream accessories are properly selected.
Food processors employ the principles of HAACP (Hazard Analysis and Critical Control Point), risk analysis, FDA, and local government regulations to ensure the production area and the product are maintained at an acceptable level of quality. It is possible to achieve and maintain these standards if proper care is taken to select and install high-performance oil free compressor with the right sized air dryers and filtration systems supported by periodic monitoring for performance to specification and maintenance.
It is recommended to select oil free compressors with a closed loop piping system across the processing plant to ensure supply of contamination free, oil free compressed air operating with a minimum pressure drop in the unit. With advancements in oil free technology for Class ‘0′ certified compressors, every processing company is assured of oil free air that meets the most stringent standards of ISO 8573-1:2010 and ISO 8573-7. They also result in much higher energy savings and guaranteed uptime for plant operation.
To achieve the filtration specification, it is necessary to install at least a two-stage filter system as close as possible to the point of use. If there is excessive condensate, a third stage filter system (pre-filter stage) should also be installed. A typical system should consist of a first stage, high efficiency coalescing filter with a rating of at least 99.99% at 0.01 micron, which provides the necessary protection to the second stage of filtration – the sterile air filter. A sterile air filter with an efficiency rating of at least 99.9999+% at 0.01 micron is necessary to achieve the Class 1 rating. However, even with this purity, the class of compressed air is still Class 1 and not Class 0.
Emerging Trends in Oil Free Compressors
Water injected oil free compressors is a highly efficient alternative to traditional oil free, dry screw two-stage compressors. They deliver the same ‘Class 0’ compressed air in a much simpler, single-stage design where cleaned and cooled water is injected into the compression chamber as opposed to oil thereby cooling it down and sealing the system. As a result, the compressor and compression chamber can run much cooler and at a much slower speed than a dry screw compressor, which translates into increased reliability, lower parts wear, low maintenance, and better energy efficiency.
The total cost of ownership of water injected compressor is considerably lower (8% or more) as compared to traditional two-stage oil free screw air compressors. Compared to oil-injected solutions with heavy downstream filtration or technical oil free solutions, these water injected compressor systems are even more interesting. In this case, the downstream filtration is less stressed, a lot simpler, efficient, and has lower maintenance requirements. The advanced closed-loop water-injected oil free compressors eliminate the need for external water source and highly sensitive, cost-intensive Reverse Osmosis (RO) filters. This ensures the processing units have a quality compressed air system at the optimum total cost of ownership while also improving equipment peak uptime.
Next time you are relishing a candy or your favourite chocolate bar or pouring chocolate syrup on your dessert, don’t forget about the clean air that helped produce your sweet treats.c