Lignocellulosic biomass holds a crucial position in the prospective bio-based economy, serving as a sustainable and renewable source for a variety of bio-based products. These products play a vital role in displacing fossil fuels and contributing to environmental well-being. However, the inherent recalcitrance of biomass poses a significant obstacle to the efficient access of sugar polymers. Consequently, the bioconversion of lignocellulosic biomass into fermentable sugars remains a prominent challenge in biorefinery processes to produce biofuels and biochemicals. In addressing these challenges, extensive efforts have been dedicated to mitigating biomass recalcitrance through diverse pretreatment methods. One noteworthy process is Ammonia Fiber Expansion (AFEX) pretreatment, characterized by its dry-to-dry nature and minimal water usage. The volatile ammonia, acting as a catalyst in the process, is recyclable. AFEX contributes to cleaning biomass ester linkages and facilitating the opening of cell wall structures, enhancing enzyme accessibility and leading to a fivefold increase in sugar conversion compared to untreated biomass. Over the last decade, AFEX has demonstrated substantial success in augmenting the efficiency of biomass conversion processes. This success has unlocked the potential for sustainable and economically viable biorefineries. This paper offers a comprehensive review of studies focusing on the utilization of AFEX-pretreated biomass in the production of second-generation biofuels, ruminant feed, and additional value-added bioproducts like enzymes, lipids, proteins, and mushrooms. It delves into the details of the AFEX pretreatment process at both laboratory and pilot scales, elucidates the mechanism of action, and underscores the role of AFEX in the biorefinery for developing biofuels and bioproducts, and nutritious ruminant animal feed production. While highlighting the strides made, the paper also addresses current challenges in the commercialization of AFEX pretreatment within biorefineries. Furthermore, it outlines critical considerations that must be addressed to overcome these challenges, ensuring the continued progress and widespread adoption of AFEX in advancing sustainable and economically viable bio-based industries.

中文翻译：

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AFEX预处理生物质在生产第二代生物燃料、反刍动物饲料和增值生物产品中的多方面应用


木质纤维素生物质在未来的生物基经济中占有重要地位，是各种生物基产品的可持续和可再生来源。这些产品在取代化石燃料和促进环境福祉方面发挥着至关重要的作用。然而，生物质固有的顽抗性对糖聚合物的有效获取造成了重大障碍。因此，木质纤维素生物质生物转化为可发酵糖仍然是生产生物燃料和生物化学品的生物精炼过程中的一个突出挑战。为了应对这些挑战，人们做出了大量努力，通过各种预处理方法来减轻生物质的顽抗性。一个值得注意的过程是氨纤维膨胀 (AFEX) 预处理，其特点是干对干性质和最少的用水量。在此过程中充当催化剂的挥发性氨是可回收的。 AFEX 有助于清洁生物质酯键并促进细胞壁结构的打开，增强酶的可及性，并使糖转化率与未经处理的生物质相比增加五倍。在过去的十年中，AFEX 在提高生物质转化过程的效率方面取得了巨大的成功。这一成功释放了可持续且经济可行的生物精炼厂的潜力。本文对经 AFEX 预处理的生物质在第二代生物燃料、反刍动物饲料以及酶、脂质、蛋白质和蘑菇等附加值生物产品生产中的利用的研究进行了全面综述。 它深入研究了实验室和中试规模的 AFEX 预处理工艺的细节，阐明了作用机制，并强调了 AFEX 在开发生物燃料和生物产品以及营养反刍动物饲料生产的生物精炼厂中的作用。在强调所取得的进步的同时，本文还解决了生物精炼厂中 AFEX 预处理商业化面临的当前挑战。此外，它还概述了克服这些挑战必须解决的关键考虑因素，确保 AFEX 在推进可持续和经济上可行的生物基工业方面不断取得进展和广泛采用。