Sugar beet ethanol
Sugar beet ethanol is a type of bioethanol produced from sugar beets, a crop cultivated in various soil and climate conditions. As a renewable energy source, this ethanol is primarily utilized in the transportation sector in Europe, where it contributes to meeting energy demands and reducing greenhouse gas emissions. The production process involves several steps, including harvesting the beets, extracting juice, and converting that juice into ethanol, with by-products like dried beet pulp and vinasse also generated during processing.
Historically, ethanol has been used as a motor fuel for over a century, gaining widespread adoption during periods of oil shortages, such as in the 1970s. The cultivation and processing of sugar beets for ethanol play a significant role in European biofuel markets, although recent years have seen fluctuations in production levels. In the UK, for instance, the area dedicated to sugar beet cultivation for biofuel has decreased significantly, indicating market challenges.
Environmental considerations, such as climate change and greenhouse gas emission reductions, drive the promotion of sugar beet ethanol. However, the competition for agricultural land between fuel and food production remains a critical issue. There is ongoing interest in second-generation ethanol technologies, which leverage non-food biomass as feedstock, potentially addressing some of these land-use concerns.
Sugar beet ethanol
Summary: Ethanol fuel from sugar beets is used in the transportation sector in Europe.
Ethanol (ethyl alcohol) is a volatile, flammable, and colorless liquid. It is increasingly used not only as an energy carrier in the transportation sector but also in a wide variety of other applications: in beverages, industrial feedstocks, and solvents. Also called bioethanol, it can be produced from a variety of renewable feedstocks, including sugar beets (and molasses, a by-product of sugar production). Sugar beets can be grown in a wide range of soil and climate conditions. In 2022, Russia produced nearly half the world's supply of sugar beets, followed by France and the United States.
History of Bioethanol
Bioethanol has been known as a motor fuel for more than a century. Its use for transport started when Henry Ford designed the Model T in the expectation that bioethanol produced by American farmers would be used as its main fuel. The car was produced from 1903 to 1926 and was able to run on bioethanol starting with the 1908 model year. At the same time, several farmers also used self-produced bioethanol to fuel their own agricultural machinery.
By the mid-1930s, every European country was using gasoline blended with ethanol, and some countries even mandated its use. In France, a compulsory incorporation rate of 10 percent alcohol in all gasoline was imposed, whereas in Germany a blend of gasoline with potato-derived ethanol was sold under the name Reichskraftsprit. In Britain, gasoline was blended with 25 percent grain alcohol under the Discol brand. Discol was seen as a high-performance fuel and was often used in motor racing, aviation, and power-boat racing. During World War II, the use of bioethanol continued, helping to overcome oil shortages.
Nevertheless, oil became the major transportation fuel because of its better compatibility with the materials used to construct engines as well as the growing supply of cheaper fuel oil. The use of ethanol as a transportation fuel was mostly abandoned after World War II and was not resumed until the early 1970s, with the first world oil crisis. In 1975, Brazil started the Pró-Álcool (National Alcohol) program, a government-supported plan aimed at promoting the production and use of ethanol fuel from sugarcane. In 1978, large-scale production of corn-based bioethanol started in the United States. The United States and Brazil represent approximately 80 percent of the total worldwide production of bioethanol fuel: The United States produced more than 15.6 billion gallons in 2023, followed by Brazil, with more than 7.4 billion gallons. In Europe, ethanol fuel production started in 1992, but the sector soared after 2004, and it nearly septupled between then and 2009, reaching 1.18 billion gallons by 2010. By 2022, this number had fallen to roughly 1.4 billion gallons per year.
Production of Bioethanol From Sugar Beet
Sugar beet cultivation includes several steps: soil preparation (plowing), fertilizer application, sowing, weed control, and harvesting. After transportation to a processing plant, the beets are washed and sliced into chips. Slicing maximizes the efficiency of the next step, diffusion, in which the chips are passed into a hot-water solution to extract the sweet raw juice. Beet pulp is the most important product of beet processing and, after pressing and drying, can be sold as animal-feed concentrate or burned for process heat. Approximately 75 kilograms of dried beet pulp are produced per ton of sugar beet processed.
The raw juice exiting the diffuser can be used for bioethanol or sugar production. Market conditions drive the determination of sugar and bioethanol production shares. Each ton of sugar beets processed, at 16 percent sugar content, yields about 100 liters of ethanol. Vinasses (stillage) is a by-product from ethanol distillation and, after concentration, can be sold as an additive for animal feed or fertilizer. Per liter of bioethanol produced, nearly 0.6 kilogram of concentrated vinasse is obtained.
Biofuel derived from sugar beets plays a significant role in meeting the energy demands of the United Kingdom. In 2023, the country dedicated roughly 2.6 thousand hectares to growing sugar beets for biofuel generation. This marked a 71 percent decrease from 2022, showing a significant decline in the market. That same year, the country utilized more than 19 million liters of sugar beet biofuels.
Energy and Environmental Issues
In addition to security of energy supply and rural development support, climate change is another rationale driving the promotion of bioethanol as a transport fuel. According to the EU renewable energy directive, 2009/28/EC, typical savings in greenhouse gas (GHG) emissions attributable to sugar beet ethanol amount to 61 percent.
However, this figure does not take into account soil carbon emissions from (direct and indirect) land-use change (LUC). LUC is an emergent topic in the literature, as it may have a significant impact on the GHG balance of biofuels. Bioethanol fuel production from sugar beets is constrained by the agricultural land available, which may trigger competition with the food sector. Even though the technology is not yet mature at a commercial scale, production of ethanol from cellulosic biomass (so-called second-generation ethanol)—namely straw, grass, and wood—seems very attractive for ensuring a plentiful and low-cost supply of such feedstock.
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