# Analysis of the Sugarane Biomass Use to Produce Green Hydrogen: Brazilian Case Study
## 4 Sugarcane Production in Brazil  
Brazil leads global sugarcane production, ranking as the top producer and a dominant force in the manufacture of sugar and ethanol. Its processing facilities include mills that produce both sugar and ethanol, as well as autonomous distilleries focused solely on ethanol production. In both setups, significant quantities of biomass are generated, including sugarcane straw (SS) from mechanized harvesting and sugarcane bagasse (SB) from the crushing process. Currently, SS and SB are primarily utilized for cogeneration, with bagasse combustion serving as the main energy source for Brazil's sugar and ethanol plants [66]. According to the fourth survey of sugarcane production in Brazil conducted by the National Supply Company (Conab), during the 2023/2024 harvest, more than 400 mills in the country processed approximately 713.2 million metric tons of sugarcane. From this, around 45.68 million metric tons of sugar and 29.69 billion liters of first-generation ethanol  
Figure 10: Contribution of sugarcane and other energy sources to Brazil’s primary energy production (1970–2022). Adapted from [65]. were produced [66]. These numbers highlight Brazil's key position in the global sugar and ethanol markets, demonstrating the scale and productivity of its sugarcane industry. One metric ton of crushed sugarcane generates 276 kg of fresh sugarcane bagasse with 50% moisture and 165 kg of sugarcane straw with 15% moisture [67]. Considering that sugarcane has 75% moisture before harvest, 713.2 million metric tons of sugarcane correspond to 178.4 million metric tons of sugarcane dry matter, represented by 120.4 million metric tons of sucrose, 25.0 million metric tons of SB and 25.0 million metric tons of SS. Figure 11 illustrates the integration of first-generation (1G) and second-generation (2G) ethanol production, providing a detailed overview of the main steps in the production processes. It highlights the generation and reuse of byproducts, along with the consumption of water, energy, and chemicals. As shown, the production of 1G ethanol follows the biorefinery model, where both solid and liquid residues from sugarcane processing are utilized in various applications. These byproducts play a crucial role in the generation of thermal and electrical energy, contributing to the sustainability of the overall process [68]. This is especially important considering the growing global demand for electricity, which presents challenges as the use of fossil fuels declines and becomes more restrictive [5]. Additionally, these residues serve as valuable components in the production of fertilizer, further emphasizing the multifaceted and resource-efficient nature of the biorefinery approach within the sugarcane ethanol production cycle. In the study by [PERSON] et al. (2021), the influence of chemical interactions on gas holdup and flow regimes in bubble columns was thoroughly analyzed. Their findings indicate that the presence of salts, surfactants, and polymers significantly alters gas retention and flow behavior, which are critical parameters in optimizing gas-liquid systems. These insights could inform the development of more efficient hydrogen production systems, particularly in biorefineries utilizing sugarcane biomass [69]. Table 2 provides a comprehensive comparative analysis of the 1G and 2G ethanol production processes. It summarizes their main characteristics, including feedstocks, key processing steps, byproducts, challenges, and energy efficiency. This comparison underscores the technological maturity of 1G ethanol production, and the developmental challenges faced by 2G processes, particularly in terms of pretreatment complexity and scale-up feasibility. Figure 11: Processing of sugarcane and sugarcane bagasse to produce 1G and 2G ethanol, along with the byproducts generated. Adapted from [68]. Currently, approximately 60% of ethanol is produced from corn, 25% from sugarcane, 2% from molasses, 3% from wheat, and the remaining amount from other grains, cassava, or sugar beets [70].