Industries across the world are making a transition from fossil resources to renewable biological feedstock for the production of chemicals, fuels, and materials, as a strategy to promote sustainable development and economic growth. However, limited biomass availability can halt the expansion of bio-based sectors, unless alternative raw materials are employed and cascading uses are implemented on a large scale. Key Enabling Technologies (KETs) can contribute to feedstock diversification and improved biomass conversion efficiencies along supply chains, although concerns arise about their actual viability and competitiveness. A systematic review of Life Cycle Assessments (LCAs) and related process-based approaches is carried out to evaluate the sustainability of advanced bio-based technologies, defined as those that use either non-food feedstock or circularity principles –or both– for delivering diverse products. A classification scheme is proposed to categorise KETs based on the feedstock employed (plant residues and perennials, designer crops, algae, or biological waste) or the underlying technological configuration (enzyme/microbial assisted processing or biorefineries). Results show that producing biofuels and biochemicals from perennial plants, lignocellulosic residues and algae has advantages in terms of greenhouse gas emissions relative to their fossil counterparts, while trade-offs occur with other environmental impacts and sustainability dimensions. Cradle-to-cradle systems can deliver additional sustainability gains, but their implementation poses technical and socio-political challenges. Further harmonisation of LCA methodologies is desirable to compare KETs in different sectoral, geographical and policy contexts. In spite of the diversity of outcomes and approaches, this review provides an overview of advanced bio-based technologies, while shedding light on the often overestimated sustainability benefits of the bioeconomy.

作为促进可持续发展和经济增长的战略，世界各地的工业正在从化石资源向可再生生物原料过渡，以生产化学药品，燃料和材料。但是，除非采用替代性原材料并大规模实施级联用途，否则有限的生物质可利用性将阻止生物基产业的发展。关键使能技术（KET）可以促进原料的多样化和改善整个供应链中的生物质转化效率，尽管人们对其实际生存能力和竞争力产生了担忧。对生命周期评估（LCA）和相关的基于过程的方法进行了系统的评估，以评估先进的基于生物技术的可持续性，定义为使用非食品原料或圆形原则（或两者同时使用）来交付各种产品的公司。提出了一种分类方案，根据所用原料（植物残渣和多年生植物，名优作物，藻类或生物废物）或基础技术配置（酶/微生物辅助加工或生物精炼厂）对KET进行分类。结果表明，从多年生植物，木质纤维素残留物和藻类生产生物燃料和生物化学物质，在温室气体排放方面相对于其化石同类物具有优势，而在其他环境影响和可持续性方面则需要权衡取舍。摇篮到摇篮系统可以带来更多的可持续发展收益，但是其实施带来了技术和社会政治挑战。为了比较不同部门，地理和政策环境下的关键绩效指标，需要进一步统一LCA方法。尽管成果和方法各不相同，但本综述还是对先进的基于生物的技术进行了概述，同时阐明了通常被高估的生物经济的可持续性收益。