This article aims to apply the Energy Sustainability Analysis (ESA) to the process of Anaerobic Digestion (AD), considering five different feedstocks: the organic fraction of municipal solid waste (OFMSW), agro-industrial products (energy crops) such as maize and sorghum silages, and agro-zootechnical wastes (slurry and manure) from cattle and pig livestock. The case study focuses on an AD bioreactor which is fed with a constant flow (50 ton/d) at a fixed total solids (TS) concentration (15% TS w/w). The processing chain is divided into three phases: pre-digestion operations, AD and the cogeneration of biogas, and post-digestion operations. The ESA methodology uses dedicated metrics and considers the entire technology chain from the energy resources up to useful energy. Energy crops present important energy footprints that must be spent for their production, while in the AD process, the pre-digestion and post-digestion phases present different energy costs for each analyzed feedstock. The results indicate that although the produced energy depends on the energy potential of the biomasses, the pre-digestion and post-digestion phase have an important weight in the overall energy sustainability of the system. In addition, in the case of the use of agro-zootechnical wastes and energy crops as feed, the availability of sufficient land to spread digestate on the field is essential to ensure the sustainability of AD technology, in its absence the energy sustainability can be critical as shown for the case of maize silage.

本文旨在将能源可持续性分析（ESA）应用于厌氧消化（AD）的过程，同时考虑五种不同的原料：城市固体废物（OFMSW）的有机成分，诸如玉米和玉米等农产品的工业产品（能源作物）高粱青贮饲料，以及牛和猪牲畜的农业动物技术废物（浆液和肥料）。案例研究集中于以固定总固体（TS）浓度（15％TS w / w）恒定流量（50吨/天）进料的AD生物反应器）。处理链分为三个阶段：消化前操作，AD和沼气热电联产以及消化后操作。ESA方法论采用专用指标，并考虑了从能源到有用能源的整个技术链。能源作物呈现出必须用于生产的重要能源足迹，而在AD过程中，消化前和消化后各阶段所消耗的每种原料的能源成本却不同。结果表明，尽管产生的能量取决于生物质的能量潜能，但是消化前和消化后阶段在系统的整体能量可持续性中具有重要的分量。此外，在使用农业技术废物和能源作物作为饲料的情况下，