History of Sugar and Ethanol Production in Brazil
Sugarcane is cultivated in two main regions of Brazil: the Southeast and Midwest regions, including the South, Southeast and Midwest regions, encompassing the states of Paraná, São Paulo, Minas Gerais, Rio de Janeiro, Espírito Santo, Mato Grosso do Sul and Goiás; and the North and Northeast regions, encompassing the states of Alagoas, Pernambuco, Paraíba, Sergipe, Rio Grande do Norte and Bahia.
There are two harvesting periods in Brazil, one in each region, and the land on which sugarcane is cultivated accounts for circa of 1% of Brazil’s total fertile land, or approximately 9.5 million hectares, according to CONAB. In the Southeast and Midwest and North regions, the harvesting period runs from April to December, whereas in the Northeast region, it runs from August to March. The Southeast and Midwest regions accounted for approximately 90% of the total sugar and ethanol production in Brazil.
Historically, due to soil, climate and economic conditions, production of sugar and ethanol has been concentrated in the Southeast and Midwest regions of Brazil. Brazil’s vast territory and favorable climate provides a large supply of available land for sugarcane production. Brazil’s favorable conditions permit sugarcane to be harvested five to six times before requiring re-planting. Brazil is the world’s largest producer of sugarcane.
Brazilian sugarcane mills are also powered by bagasse and leaves, sugarcane’s by-products, which when burned in boilers generates steam and electric energy. A large portion of Brazilian mills are energy self-sufficient. As a result, Brazilian sugar and ethanol has some of the lowest production costs in the world.
Brazilian Sugar Production
Brazil is one of the lowest-cost producers of sugar in the world due to its favorable climate and its development of agricultural and industrial technology related to the production of sugarcane, sugar and ethanol over the last 30 years.
Brazil’s technological developments have resulted in longer harvesting cycles, higher sugarcane production per hectare, higher sucrose contents from the crushed sugarcane and lower losses during production of sugar and ethanol, which has yielded larger sugar outputs.
Production costs for raw sugar in the Southeast and Midwest regions of Brazil are lower than those in the North-Northeast region due to a more favorable topography and climate, a more developed transportation infrastructure and the close proximity of the sugarcane mills in the Southeast and Midwest regions to ports and the major consumption centers in Brazil. Privatization of various highways, port facilities and railroads have improved Brazil’s transportation and export infrastructure, resulted in reduced sugar costs and shorter delivery times of sugar to world markets.
Sugarcane to ethanol
The process of industrializing sugarcane to produce ethanol basically consists of receiving and processing the raw material, extracting the sugarcane juice, which is rich in sucrose, treating it to remove impurities and using it for the production of ethanol.
The raw material arrives at the plant by truck and then the sugarcane is weighed and an analysis is carried out on its sugar content. After the cleaning process, the shredded sugarcane passes through several mills, which allow the juice, which is rich in sugar, to be separated from the fibrous part, known as bagasse.
The sugarcane juice that flows from the mills is treated through processes of heating, clarification and filtration, and, after it has been mixed with the residual honey from the sugar factory, the mash is obtained. Subsequently, this sugar-rich mixture is fermented and then distilled to obtain ethanol. The fermentation process is essentially carried out in three stages. First, there is the separation and recovery of the yeast cream from the fermented mash (crude wine) by centrifuge. Next, the cream is prepared and treated with water and sulfuric acid. Finally, the mash is mixed with yeast cream and fermentation begins. After approximately eight hours, almost all of the sugar contained in the mash is transformed into ethanol. As this transformation occurs, carbon dioxide is released along with energy in the form of heat.
In the separation phase of the yeast cream, centrifuged wine is also obtained, which contains 7%-12% ethanol. This product is sent to the distillation and dehydration columns to obtain hydrous or anhydrous ethanol.
Sugarcane to sugar
Sugar production follows the same initial steps as ethanol production. The process of industrializing sugarcane to produce sugar basically consists of receiving and processing the raw material, extracting the sugarcane juice, which is rich in sucrose, treating it and using it for the production of sugar.
The treatment of sugarcane juice for the production of sugar essentially consists of six stages pre-heating, sulphitation, setting, heating, clarification and evaporation. The evaporation phase basically consists of removing the water present in the juice until obtaining a sucrose-concentrated product called syrup. The next step involves producing sucrose crystals through a process of evaporation-crystallization (with the syrup as the raw material), separating the crystals with the centrifuge and subsequently drying them. After these processes, the sugar is packaged and stored before being sent to the consumer. The residue from the sugar manufacturing process, known as residual honey, is used in the manufacture of ethanol.
Sugarcane to energy
Within the sugarcane processing plants of the Tonon Bioenergia Units, there are Thermal Power Plants (TPPs) that basically consist of boilers, turbo-generators and water treatment systems. A TPP is a facility used to convert the energy generated for burning fuel into electricity. The TPP’s basic objective within a mill is to meet the electricity needs of the plant producing sugar and ethanol, however there is the possibility of maximizing the generating capacity and the available fuel to generate surplus electricity that will be made available to distributors of electricity.
At the Tonon Bioenergia Units, the cellulosic fibrous reside (bagasse) obtained after the extraction of the sugarcane juice (milling) is sent to the boilers on conveyor belts and used as fuel for the production of thermal energy in the form of high-pressure steam, which is used to power the turbo-generators that transform the thermal energy into mechanical energy and, subsequently, electricity. Part of the energy is then used within the plant and the excess is marketed and made available through the National Interconnected System (SIN).
The steam used in the Mill and the TPP is classified as direct steam, extraction steam and exhaust steam. The direct steam, which is high-temperature and high-pressure, is used to power the turbo-generators. The extraction steam, which has intermediate temperature and pressure, is removed from the turbine housing. When the direct steam is sent to a back pressure turbine, it generates exhaust steam, which has low pressure and temperature. Both extraction steam and exhaust steam are used in the sugar and ethanol manufacturing process. The direct steam can also be sent to a condensation turbine and, in this case, it is cooled and exits the machine as condensed water, which will be reused to generate steam.