Ethanol has fueled Brazil for decades. At the gas pump, it seems like a single, homogeneous product with no history. In the fields and in industry, however, the fuel carries distinct stories, linked to the land, the climate, the logistics, and the raw materials that give rise to each liter. Sugarcane, corn, agricultural waste. Each source shapes a type of ethanol, with its own costs, environmental impacts, and production chains.
The country has built a unique relationship with biofuels. No other large economy has integrated ethanol so deeply into its energy matrix. This trajectory necessarily involves agriculture and the choices made over time regarding which raw materials to plant, process, and transform into energy.
What is ethanol and what is it used for?
Ethanol, also called ethyl alcohol, is an organic compound from the alcohol family, represented by the chemical formula C₂H₆O. Produced from the fermentation of sugars or starch present in plants, it has become one of the world's main biofuels.
In Brazil, ethanol has gone beyond being an alternative energy source and has taken on a central role in the transportation system. It is used directly as automotive fuel, in the case of hydrated ethanol, or mixed with gasoline, as anhydrous ethanol. The Brazilian blend reaches 27%, a percentage higher than that adopted by most countries that use biofuels on a large scale.
The function of ethanol goes beyond powering vehicles. The product improves the quality of gasoline combustion by increasing the oxygenation of the mixture, reducing local pollutant emissions. Technical studies indicate that sugarcane ethanol can reduce greenhouse gas emissions by up to 90% when compared to fossil-based gasoline, considering the entire fuel lifecycle.
Performance is also a factor. Ethanol has a high octane rating, a characteristic that allows for a higher compression ratio in engines. This translates into better thermal efficiency and greater power. Flex-fuel technology, developed and disseminated in Brazil from the 2000s onwards, exploits this advantage by allowing the use of ethanol, gasoline, or any proportion between the two.
Outside of gas stations, ethanol is present in alcoholic beverages, medicines, cosmetics, cleaning products, and various industrial processes. The versatility of the compound explains its presence in production chains ranging from the pharmaceutical industry to heavy chemicals.
What are the raw materials for ethanol?
Ethanol production relies on renewable sources of plant origin. These sources are classified into three main groups, according to the predominant type of carbohydrate: sugar, starch, or cellulose. This division defines the technological route adopted by the plants, the cost of the process, and the byproducts generated.
The sector typically works with two main categories. First-generation ethanol is obtained from simple sugars or starch. Second-generation ethanol, known as cellulosic ethanol, uses cellulose present in plant waste. The difference between these routes helps to understand the technological stage of each country and the prospects for expansion of the biofuel.
Sugar cane
Sugary raw materials offer operational advantages. The sugars are already ready for fermentation, which reduces industrial steps, energy consumption, and process complexity.
Sugarcane is the basis of Brazilian ethanol. The tropical climate, high agricultural productivity, and decades of technological improvement have transformed the country into the world's largest producer of sugarcane ethanol. The key difference lies in the almost complete utilization of the plant.
First-generation ethanol is produced from the extracted juice. The remaining product yields significant industrial byproducts:
- Bagasse, used to generate electricity and steam in the plants themselves, as well as serving as an input for second-generation ethanol.
- Straw, used for bioenergy or retained in the soil, contributing to agricultural conservation.
- Vinasse, applied in fertigation of sugarcane fields
- Filter cake, used as an organic fertilizer
- Molasses, aimed at the additional production of ethanol or other industrial uses.
This integrated model allowed Brazilian sugar mills to evolve into biorefineries, capable of producing fuel, sugar, and electricity in a single industrial complex.
Other sugar crops appear in specific contexts. Sugar beet dominates ethanol production in several European countries. Sweet sorghum emerges as an alternative in regions with water restrictions, although it still has a limited market share.
Corn
Starchy raw materials also give rise to first-generation ethanol, but require an additional step. The starch needs to be converted into simple sugars before fermentation.
Corn is the prime example. In the United States, it accounts for the largest share of ethanol production. In Brazil, corn ethanol has gained ground in recent years, especially in the Midwest, a region with a large supply of the grain and logistics integrated with animal protein production.
The process generates byproducts with commercial value:
- DDG and DDGS, used in animal feed
- Corn oil, applied in the food, chemical and biodiesel industries
Wheat, barley, and cassava can also be used in ethanol production, although on a smaller scale. Cassava, for example, appears as an alternative in tropical regions, where cultivation is traditional and logistics favor local processing.
Cellulose
Cellulosic raw materials form the basis of second-generation ethanol. This group includes sugarcane bagasse and straw, agricultural residues, wood chips, and energy crops developed for this purpose.
The technological route is more complex. Cellulose has a resistant structure that requires physical, chemical, and enzymatic pretreatments to release fermentable sugars. The technical challenge is offset by environmental and productive gains.
Using waste products increases ethanol production without needing to expand agricultural land. It also reduces competition with food production. Among the byproducts of this process is lignin, used in energy generation and the development of industrial materials.
In Brazil, second-generation ethanol still occupies a limited space, but it is seen as a strategic tool to increase national production with less environmental impact.
Check out the comparison table of the main raw materials.
| Feedstock | Type | Ease of processing | Ethanol productivity per hectare | Example of use |
|---|---|---|---|---|
| Sugar cane | Sugar | High | Very tall | Brazil, Hydrated Ethanol |
| Sugar beet | Sugar | High | Moderate | Europe |
| Sweet sorghum | Sugar | Moderate | Moderate | Localized production |
| Corn | Starch | Media | High | EUA |
| Wheat | Starch | Media | Media | Secondary production |
| Barley | Starch | Media | Media | Secondary production |
| Manioc | Starch | Media | Media | Tropical regions |
| Agricultural waste | Cellulose | Low | Variable | Cellulosic ethanol |
| Wood chips | Cellulose | Low | Variable | Advanced ethanol |
| Energy crops | Cellulose | Low | High (potential) | Future production |
How ethanol is produced
The industrial logic of ethanol production follows well-defined steps, with variations depending on the raw material used.
Pre-treatment opens the process. In the case of starch, enzymes break down the long chains into simple sugars. Cellulosic materials undergo more intensive processes, which combine grinding, heat, chemical reagents, and enzymatic action.
Fermentation transforms sugar into alcohol. Yeasts such as Saccharomyces cerevisiae Specific bacteria convert the sugars into ethanol and carbon dioxide. The process takes place in tanks with strict temperature and pH control. The resulting liquid is called "beer" in industry jargon.
Distillation separates ethanol from water. Heating the mixture causes the alcohol to evaporate first, as it has a lower boiling point. The vapor is condensed and collected. Further steps refine the product.
Purification and dehydration remove residual water. Techniques such as molecular sieves and selective membranes allow the required degree of purity for use as fuel to be achieved.
Denaturation differentiates fuel ethanol from alcohol intended for human consumption. Small amounts of gasoline or other substances render the product unfit for ingestion, as required by law.
Ethanol in Brazil
Brazil leads the world in sugarcane ethanol production and holds the second position globally, behind only the United States. In the 2023-2024 harvest, national production reached approximately 35,9 billion liters. Most of this volume remains in the domestic market, fueling flex-fuel vehicles or being used in gasoline blends.
The efficiency of the Brazilian model is linked to sugarcane productivity, favorable climate, and the integration between different production chains. Sugarcane bagasse generates electricity. Vinasse returns to the field as fertilizer. The industry closes cycles and reduces waste.
The history of ethanol in the country gained momentum in the 1970s. The 1973 oil shock exposed external dependence and led the federal government to launch the National Alcohol Program, ProÁlcool. This public policy encouraged planting, the construction of plants, and the development of alcohol-powered engines.
To give you an idea of Brazil's relationship with ethanol, in 1979 the Fiat 147 made history as the world's first mass-produced car designed to run exclusively on alcohol. The model faced poor roads, extreme weather variations, and helped solidify the technology. Then-President João Figueiredo participated in a symbolic test drive, which became a period image.
Alutal and national technology at the service of the ethanol industry.
Brazil's leading role in ethanol production isn't limited to farming or volume. The industry has developed its own solutions for process control, automation, and operational efficiency. Alutal operates in this segment with instruments and systems applied to the different stages of production.
The company offers a portfolio of equipment and instruments used in different stages of the production process, such as level, flow, pressure and temperature control, as well as specific applications in fermentation, distillation and energy generation from sugarcane bagasse.
These solutions directly contribute to the operational stability of plants, reducing losses and increasing the reliability of industrial processes. In a sector that deals with large volumes, load variations, and stringent environmental requirements, precise measurements and robust equipment make all the difference in the final result.
With a consolidated presence in the renewable energy sector, Alutal keeps pace with the technological evolution of ethanol in Brazil, offering solutions aligned with the routines of sugar mills and the current demands of the market.
Learn more about Alutal's solutions for biofuels.
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