“The sugar industry today is not only about sugar but also about the various by-products obtained during the processing of sugarcane. A typical mill gets about 10 tonnes of sugar from every 100 tonnes of sugarcane crushed. In addition, about 30 tonnes of bagasse and 4.5 tonnes of molasses are generated as by-products.”
An Agricultural Product- Sugarcane is the main raw material for manufacturing of sugar as it is the sugarcane juice which is ultimately converted into crystals and becomes a marketable commodity.
Stalk is known as “millable cane”. It develops from the bud of another stem piece planted for vegetative propagation. The stem pieces used for planting are known as “setts” which contains one or several buds. The bud sprouts under favourable conditions gives rise to a primary stalk from which secondary stalk, thus inducing tillering process.
Sugarcane Trash is a much neglected high calorific value biomass which is available in proximity of every sugar mill and is also a residue of the sugarcane crop itself, which could enable the cogeneration units to achieve their maximum output potential. This wonder waste is sugarcane trash – the dry leaves of sugarcane crop – which is left in the farms itself after sugarcane harvesting.
Sugarcane tops are one of the main by-products of sugarcane milling. At harvest time, the sugarcane biomass includes stalks which can be milled, tops, dead and dying leaves, stubble and roots. Sugarcane tops represent 15 to 25% of the aerial part of the plant. They generally consist of green leaves, bundle sheath and variable amounts of immature cane.
Sugar is a crystalline food substance. Mainly sucrose, lactose and fructose are present in it. Sugar is mainly prepared from sugarcane. Brazil has the highest per capita sugar consumption in the world. India consumes the most sugar as a country. Sugar categories are based on the crystal size ranging from small, medium and large. Uttar Pradesh Produced 101.98 lakh tonne sugar in season 2021-2022.
Regular sugar
White sugar, also called table sugar, or regular sugar, is a commonly used type of sugar, made either of beet sugar or cane sugar, which has undergone a refining process. White sugar produced from sugar cane may be refined using various methods. For this reason white sugar from sugar cane may not be vegan.
Refined Sugar
After undergoing the process of refinement, sugar loses its nutrients. It also becomes more concentrated. The result is a seriously sweet substance which is super energy-dense, giving it a high calorie count.
Refined sugar is metabolised rapidly, which causes a sudden raise (or ‘spike’) of glucose and insulin levels within the bloodstream.
Bagasse refers to the dry residue left after the juice is extracted from the Sugarcane. It is a great renewable source of energy. One of the key uses of bagasse is to produce electricity. It has been used in several countries in the sugar mill itself and is seen as a viable option. It is even stored and used to generate electricity throughout the year. However, storage poses a challenge. Different methods of storage are being tried and tested. Bagasse also serves as a good raw material for producing paper. It serves as an alternative to wood pulp. Bagasse is also used to produce particle board which is also known as chipboard. Furfural is also produced, which is a flammable chemical substance. It can also produce methane gas. In addition to all this, it is also used as cattle feed. In places, efforts are being made to make packaging material out of bagasse.
Sugarcane tops from sugar production are harvested at maturity, which coincides with the dry season, but tops from sugarcane grown for animal feeding can be harvested at an immature stage. Sugarcane tops are used fresh, dried or ensiled for feeding livestock.
During the process of making sugar, juice extracted from sugarcane is boiled until the sugar crystals crystallize and precipitate out. The syrup that is left after this crystallization is molasses. The juice undergoes three cycles of boiling and crystallization to extract the maximum amount of molasses. The more the number of cycles, the molasses contains less sugar. Variation in the color, sweetness and nutritional content can vary in molasses depending on how much sugar has been extracted.
Molasses is one of the most important by-products of sugar production from Sugarcane. In fact, the importance of the production of ethanol has taken the centre stage and there are discussions to divert the entire production of Sugarcane to produce Molasses so that it can be processed to produce ethanol. Ethanol is seen as a fuel and is blended with petroleum. Molasses refers to the effluent produced after the continuous crystallization process. It is the last syrup left after all the sucrose has been obtained. Molasses can also be used to produce acetic acid, yeast, ethanol and Rum.
Sugarcane press mud is the residue of the filtration of sugarcane juice. The clarification process separates the juice into a clear juice that rises to the top and goes for manufacture, and a mud that collects at the bottom. The mud is then filtered to separate the suspended matter, which includes insoluble salts and fine bagasse. Sugar cane press mud has been used as carrier material for biofertilizer production.
ENA is a raw material to Country Liquor and IMFL wherein additives (dilution, distillation and essence) are added to it, to make it fit for human consumption, reduction of strength of Alcohol (like 42.8% v/v of Alcohol Strength in IMFL) is also necessary.
There are two type of ENA, one is Molasses based which is used for CL manufacturing and to produce Ethanol. The other one is Grain based, used for IMFL manufacturing and to produce Ethanol as well. ENA when mixed with Denaturant is entered into industrial Alcohol and thereafter converted to Ethanol.
Ethanol means Anhydrous Alcohol of minimum 99% strength.
Ethanol can be produced naturally from the fermentation of grains (i.e. “grain ethanol”) or synthetically via petrochemical processes. Ethanol in India is produced from sugar cane, wheat, corn, beetroot etc.
The different types of ethanol are as below:
Uses- With every ton of molasses, 220 liters of ethanol can be produced. To reduce vehicle emissions and promote environment friendly fuels, Government established the Ethanol Blending Petrol (EBP) programme. The mixing of ethanol (upto 10%) with petrol is mandatory in India but now Government is ready to meet the target of 20% ethanol blending by 2025. Today Uttar Pradesh has become the second largest ethanol supplier state in India. The ethanol demand which was 370 crore liters in 2017-2021 is estimated to be1350 crore liters in 2022-2025, in which sugar industry will contribute more than half. In the current season 2022-23 (Dec- 22 to Oct 23), OMC offered for supply of 952850 kilo litres ethanol from UP. The sugar mills are capable for the production of over 200 Crore litres of ethanol.
Ethanol, also known as ethyl alcohol or sometimes grain alcohol, is commonly use for a variety of industrial and manufacturing operations. It can be used as a chemical solvent, a fuel, a cleaner or antiseptic, and a chemical intermediate. It is also commonly known by the general public as the psychoactive substance in alcoholic drinks.
Spent wash is the residual liquid waste generated during alcohol production and can be classified as a dilute organic liquid fertilizer with high potassium content. Despite standards imposed on effluent quality, untreated or partially treated effluent very often finds access to water courses. The distillery wastewater with its characteristic unpleasant odor poses a serious threat to the water quality in several regions around the globe.
The bagasse available after crushing of sugarcane is fired in boilers. This steam is fed to the turbine for generation of power and the extractions taken from the turbine are used in various processes of sugar manufacturing.
Dry ice is the solid form of carbon dioxide. It is commonly used for temporary refrigeration as CO2 does not have a liquid state at normal atmospheric pressure and sublimates directly from the solid state to the gas state.
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work.
Indian sugar mills are generating biomass-based ‘green’ energy from bagasse, a waste product that comes from sugarcane cultivation. The process by which sugar mills are generating the power is called cogeneration – it essentially implies the production of two forms of energy, electricity and heat.
Cogeneration of bagasse is one of the most attractive and successful energy projects that have already been demonstrated in many sugarcane producing countries such as Mauritius, Reunion Island, India and Brazil. Combined heat and power from sugarcane in the form of power generation offers renewable energy options that promote sustainable development, take advantage of domestic resources, increase profitability and competitiveness in the industry, and cost-effectively address climate mitigation and other environmental goals.
According to World Alliance for Decentralized Energy (WADE) report on Bagasse Cogeneration, bagasse-based cogeneration could deliver up to 25% of current power demand requirements in the world’s main cane producing countries. The overall potential share in the world’s major developing country producers exceeds 7%. There is abundant opportunity for the wider use of bagasse-based cogeneration in sugarcane-producing countries.
Using bagasse to generate power represents an opportunity to generate significant revenue through the sale of electricity and carbon credits. Additionally, cogeneration of heat and power allows sugar producers to meet their internal energy requirements and drastically reduce their operational costs, in many cases by as much as 25%. Burning bagasse also removes a waste product through its use as a feedstock for the electrical generators and steam turbines.
Bio fertilisers are products containing carrier based (solid or liquid) living microorganisms which are agriculturally useful in terms of nitrogen fixation, phosphorous solubilisation or nutrient mobilisation to increase the productivity of the soil. The present market for biofertilizers is Rs.1200 crores which is likely to rise to Rs. 2000 crores in the coming years. (Niti Aayog 2023). During 2019-20 India produced 79,446 metric million tonnes of solid carrier based and 30,106 KL of Liquid biofertilizers from 537 bio fertiliser producing units. Bio compost is an important bio fertiliser form the Sugar industry made by composting press mud with spent wash. It is rich in nitrogen, phosphate solubilising bacteria and useful fungi which increase soil fertility and produce quality. Farmers including the sugarcane industry are using bio fertilisers, vermicompost and poultry manure as a source of organic enrichment. Distillery spent wash can also serve as a Bio-stimulant and/ or Bio-nutrient supplement.
Well known as the only sulphurless sugar available, Pharma grade sugar or Sucrose I.P. does not use sulphur dioxide for bleaching but is produced through the “Phospho-flotation” process in conjunction with a double stage ion exchange purification system while adhering to the strictest national and international quality standards. Pharma grade sugar producing units need to be certified for FSSAI, Drug Licence,IP and BP Food safety management systems. With most pharmaceutical companies now turning to pharma grade sugar instead of commercial sugar the market is expanding widely. Pharma grade sugar is generally used in the manufactures of tablets, syrups and capsules etc., where it imparts taste and texture and also assists in transport and storge. Sugar coating helps in prevention of damage against air and moisture. Pharma grade invert sugar syrup apart from tastes also imparts viscosity to a product and add to the bulk. India plays an important role in the growth of the pharma grade invert sugar syrup industry.
Industrial alcohol is the form of alcohol that is used in industrial needs. The most common type of industrial alcohol is methanol. Typically, about 12 million tons of methanol is produced per year for industrial needs. The other most common industrial alcohol is ethanol, which was one of the earliest alcohols that were produced as industrial alcohols.
Industrial alcohols can come in two types: pure form or denatured form. Pure form does not contain a considerable amount of impurities, and it is useful in some industrial applications where we need a pure form without contaminants. Denatured alcohol is the form of alcohol with additives.
Industrial alcohol is mainly used as a solvent for industries. Moreover, this chemical substance is important as a raw material for the production of chemical compounds such as acetaldehyde, ethyl acetate, acetic acid, ethylene dibromide, glycols, and ethyl chloride.
A potable alcohol (drinkable) liquid containing ethyl alcohol or ethanol of 0.5 percent or more by volume is termed as ‘alcoholic beverage’. Alcohol is mobile, volatile fluid obtained by fermenting a liquid containing sugar.
All alcohol or alcoholic beverages are obtained by a process called fermentation. It is concentrated or increased in strength by distillation. The percentage of alcohol in a drink varies from 0.5-9.5%, depending on the method by which the alcohol is obtained.
Fermentation is the process in which the yeast acts on sugar and converts it to ethanol and gives off carbon dioxide. The fermented liquid has 3-14% alcohol and it can be concentrated up to 95% by a series of distillations.
Distillation is the process of separating elements in a liquid by vaporization and condensation. In the distillation process, the alcohol which is present in the fermented liquid (alcoholic wash) is separated from water.
Alcohol based sanitisers were of great help during the recent COVID pandemic and the critical demand for sanitisers was met through the efforts of the sugar units in the state. The National Sugar Institute has developed a sanitiser containing 80% ethyl alcohol, Hydrogen peroxide and glycerol enriched with Aloe Vera extract. The ethyl alcohol was manufactured from molasses, a byproduct of the sugar Industry.
Sanitisers are generally manufactured with Isopropyl alcohol (IPA), n-propanol, water, excipients and humectants, buthave also been found to be effective when made from Sugar by-products ethanol/ethyl alcohol/ENA. As of July 2021, India’s Hand sanitiser production capacity went up by almost 1000 times to 30 lakh litres per day to meet the challenges of the COVID-19 pandemic.Surplus has been exported bringing in a lot of goodwill to the country.
Biorefineries sustainably process biomass into a range of food and feed material, chemical products and energy. The sugar industry is a good source of sugar and chemicals and currently the largest platform for the production of chemicals from biomass. Sugars generally serve as the primary substrate for many biological fermentation processes and provide access to not only a number of important chemicals like alcohols, organic acids, lipids and hydrocarbons but also to high value fine chemicals and products like amino-acids, vitamins, antibiotics and enzymes. Some innovative fermentation products are Itaconic acid, Adipic Acid, 3-Hydroxy propionic acid/aldehyde, Isoprene/Farnesene, Glutamic Acid, Aspartic acid and 1, 4 butanediol.
Sugars can also be a key intermediate in chemically catalysed processes to give useful products such as sorbitol, furfural, glucaric acid, hydroxy methyl furfural and levulinicacid and xylitol.
Waste /Bio- mass sources like agricultural residue, cattle dung, sugarcane press mud, municipal solid waste and sewage treatment plant waste , etc produce bio-gas through the process of anaerobic decomposition. The bio-gas is purified to remove hydrogen sulfide (H₂S), carbon dioxide (CO2 ), water vapor and compressed as Compressed Bio Gas (CBG), which has methane (CH₄) content of more than 90%.
CBG has calorific value and other properties similar to CNG and hence can be utilized as green renewable automotive fuel. Thus it can replace CNG in automotive, industrial and commercial areas, given the abundant biomass availability within the country.
Invert sugar is a liquid sweetener made from table sugar (Sucrose) and water. It’s formed when the bonds between the sugars in sucrose are broken, resulting in a thick, sweet syrup comprised of 50% Fructose and 50% Glucose. It is 1.3x sweeter than table sugar and foods that contain invert sugar retain moisture better and crystallize less easily than those that use table sugar instead.
This mixture is an optical rotation opposite to that of the original sugar, and therefore called Invert Sugar.
EBP: Ethanol Blended Petrol (EBP) Programme
The “Roadmap for Ethanol Blending in India 2020-25” lays out an annual plan to increase domestic ethanol production in line with target of the amended National Policy on Biofuels (2018) as well as with its Ethanol Blended Petrol (EBP) Programme to reach a blending of 20% of ethanol in petrol (E20) by 2025/26.
Ethanol is one of the principal biofuels, which is naturally produced by the fermentation of sugars by yeasts or via petrochemical processes such as ethylene hydration. It has medical applications as an antiseptic and disinfectant. It is used as a chemical solvent and in the synthesis of organic compounds, apart from being an alternative fuel source.
