bagasse is an agricultural residue that has the potential to be used as feedstock biorefineries. However, its complex structure requires a pretreatment step to facilitate the accessibility to carbohydrates for its subsequent conversion. In this study, the capital and operative expenses (CAPEX and OPEX) were simulated for industrial plants processing 500 ton/d of bagasse using different pretreatment platforms for methane production and power generation on experimental data. The scenarios consisted of i) biological, ii) enzymatic, iii) dilute acid, and iv) steam explosion pretreatments and a case-based scenario without pretreatment. All these scenarios included milling, pretreatment, anaerobic digestion, and cogeneration stages. The results showed that those pretreatments carried out under soft conditions (biological and enzymatic) decreased between 2.1 and 2.8 times CAPEX compared to the highest value obtained in the diluted acid and case-based scenarios. The steam explosion, a pretreatment carried out under severe conditions, was less effective reducing CAPEX by only 1.2 times compared to the highest value. Furthermore, compared to the case-base scenario, only the biological pretreatment reduced the OPEX by a factor of 2, whereas the other pretreatments resulted in OPEX that were 2.0 to 3.5 times higher. Among the utilities (cooling water, steam generation, and energy) the steam generation contributed 47% to 76% of the total OPEX. The energy produced (kW⋅h/yr) was approximately twice the energy consumed for all scenarios. A sensitivity analysis demonstrated the robustness of the platforms since fluctuations in the prices of feedstock and raw materials did not impact the total production cost of methane, except for biological and enzymatic pretreatments. For all platforms, the solid loading was the process parameter with the highest impact on the production cost of methane. Overall, the study showed that biological and enzymatic pretreatments had the best economic performance. However, low substrate conversion and the high cost of enzymes and equipment, respectively, remained the main challenges to address in future research.

中文翻译：

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不同预处理龙舌兰甘蔗渣生产甲烷和电力的工艺设计和经济评价

甘蔗渣是一种农业残留物，有潜力用作生物精炼厂的原料。然而，其复杂的结构需要预处理步骤，以促进碳水化合物的可及性并进行后续转化。在本研究中，根据实验数据，模拟了使用不同预处理平台进行甲烷生产和发电的日处理 500 吨甘蔗渣的工厂的资本和运营费用（CAPEX 和 OPEX）。这些场景包括 i) 生物预处理、ii) 酶预处理、iii) 稀酸预处理和 iv) 蒸汽爆炸预处理以及未经预处理的基于案例的场景。所有这些场景包括研磨、预处理、厌氧消化和热电联产阶段。结果表明，与稀酸和基于案例的方案中获得的最高值相比，在软条件（生物和酶）下进行的预处理将资本支出减少了 2.1 至 2.8 倍。蒸汽爆破是一种在恶劣条件下进行的预处理，其效果较差，与最高值相比，仅降低 CAPEX 1.2 倍。此外，与基于案例的场景相比，只有生物预处理将 OPEX 降低了 2 倍，而其他预处理的 OPEX 高出 2.0 至 3.5 倍。在公用事业（冷却水、蒸汽发电和能源）中，蒸汽发电占总运营支出的 47% 至 76%。在所有情况下，产生的能量（千瓦·小时/年）大约是消耗能量的两倍。敏感性分析证明了该平台的稳健性，因为除生物和酶预处理外，原料和原材料价格的波动不会影响甲烷的总生产成本。对于所有平台，固体负载是对甲烷生产成本影响最大的工艺参数。总体而言，研究表明生物和酶预处理具有最佳的经济性能。然而，底物转化率低以及酶和设备的高成本仍然是未来研究需要解决的主要挑战。