Here’s How Sugar Is Manufactured In India

The Indian sugar industry is implementing sustainable ways to produce and supply natural sweeteners such as cane sugar, jaggery, unrefined raw/brown sugar, and syrups following a circular approach which spans the entire product life cycle.

Sugar is manufactured in India through a process of pressing sugarcane to extract the juice, boiling the juice until it begins to thicken, and sugar begins to crystallize, and spinning the crystals in a centrifuge to remove any remaining juice or syrup. This process is known as cane sugar processing and is used to produce raw sugar.

Broadly, there are three variants of sugarcane available in the market. the first type is early, the second type is unapproved, and the third type is general. The early sugarcane variety has higher sugar content as compared to the general sugarcane variety. Every year, sugarcane seeds are sown in February & October. When the seed grows, the first growth is called a plant. When the plant is harvested, the subsequent growth of the stem is called ratoon.

From Sugarcane To Sugar: Sugar Making Process In India

In India, plantation white sugar is produced for direct consumption. The sugar manufacturing process comprises four stages- sugar juice extraction, sugar juice clarification, sugar juice evaporation and sugar juice crystallization.

Sugar Juice Extraction–

The process of extracting sugar has three steps:

• Sugarcane Delivery- The farmers harvest the sugarcane and send it to the sugar mills by trucks, trailers, bullock carts and in railway wagons. There, the cane is weighed on an electric weight scale and unloaded into carriers through wagon truck tipplers or overhead traveling cranes on the cane carrier.
• Sugarcane Preparation- Before milling even starts, the sugarcane is prepared for making sugar by shredders and knives. The sugarcane is passed through a set of sugarcane cutters & shredder fibrizer. In India, since modern preparatory pieces of equipment are used for the facilitation of good cane preparation, approx 75% – 80% of tissue cells are opened without juice extraction.
• Sugarcane Milling- In this process, juice from sugarcane is extracted. The prepared cane is passed through a milling tandem (which generally has about four-six) roller mills. When juice is extracted, a residue- bagasse is left behind. Before the last mill, hot water is mixed with the bagasse mat & the juice extracted by the mill is recirculated into the bagasse to improve the extraction process.  

Sugar Juice Clarification

The extracted juice is weighed before the juice is heated up & clarified for removing non-sugars. In India, the most common process for juice clarification is the double sulphitation process. Having said that, double carbonation & double sulphitation process are also used by some sugar mills for the sugar juice purification process.

Double Sulphitation Process

In this process, the raw cane juice is heated in multi-circulation juice heaters at a temperature of 70 degree Celsius – 73 degrees Celsius. The heated cane juice is sulphited in a continuous sulphitor to a pH of 7.0-7.2. Then, the sulphited juice is heated at a temperature of 100 degrees Celsius to 103 degrees Celsius. For settling down, it is sent to the continuous clarifier. For evaporating, the clear juice from the clarifier is poured into evaporators to a brix of about 55 degrees Celsius – 60 degrees Celsius.

Challenges

In the world cane sugar industry, the process instrumentation and automation specifically in countries like Australia and South Africa is very extensive. When it comes to the Indian sugar industry, we are lagging in different domains of automation and process control in the sugar industry such as boiler operation control, mill operation control, evaporator control, clarification control, pan control, packing control, and sugar dying.

On the bright side, slowly, some Indian sugar mills have started adopting different process control systems. To a limited extent, automation has already unfurled its wings when it comes to cane feed control and pH control during juice clarification and boiler combustion control.

Insight

The Indian sugar industry has been making use of sustainable strategies both in the field and in the factory in an attempt to lower carbon footprints. Several incentives and directives are in place to facilitate such activities aimed at reducing the carbon footprint of the sugar industry.