Are eucalyptus harvest residues a truly burden-free biomass source for bioenergy? A deeper look into biorefinery process design and Life Cycle Assessment
Are eucalyptus harvest residues a truly burden-free biomass source for bioenergy? A deeper look into biorefinery process design and Life Cycle Assessment
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DOI：
10.1016/j.jclepro.2021.126956
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发表时间：
2021-04-08
影响因子：
11.1
通讯作者：
Cavaliero, Carla Kazue Nakao
中科院分区：
文献类型：
--
作者：
Nogueira, Guilherme Pessoa;McManus, Marcelle C.;Cavaliero, Carla Kazue Nakao
随着RenovaBio的到来，巴西为纤维素乙醇的生命周期带来了新的曙光。第二代方法曾被认为是实现相同生物燃料的资源密集型替代途径，但由于其潜在的较低碳足迹，现在可以提供经济优势。为此目的开发木质纤维素收获残留物可能是有益的，因为在不扩大种植面积的情况下可以提高生产率。桉树森林残留物是一个例子，是伐木和收获程序的结果，是一种低成本和容易获得的生物质。通过乙醇和电力联产的综合生物精炼过程模拟和生命周期评估，分析了在探索这种材料时林业负担是否真的相关，确定了技术和环境瓶颈。生物炼油厂的设计实施了厌氧消化和能源整合，使乙醇的生产率提高了20%，电力的生产率提高了115%。以80公里的收集半径，坎皮纳斯地区的年产能可达到30.3毫升。酶被确定为主要的环境热点，但公布的数据集不一致和缺乏透明度导致关于这一输入的结果不确定。虽然与木质纤维原料有关的负担在大多数影响类别中都是相关的，但主要瓶颈存在于生物精炼厂本身，投入与预处理和水解、锅炉排放和水消耗有关。然而，桉树收获残留物不能被认为是一种无负担的资源，因为其他作业，如回收和运输，不能被忽视，而且经常超过上述林业活动的影响潜力。
With the advent of RenovaBio, Brazil has cast a new light towards the life cycle of cellulosic ethanol. Once considered a resource intensive alternative pathway to achieve the same biofuel, second-generation approaches can now provide an economic advantage due to their potentially lower carbon footprint. The exploration of lignocellulosic harvest residues to this end can be beneficial, since productivity can be increased while not expanding cultivated areas. Eucalyptus forest residues are an example, result of logging and harvest procedures, being a low-cost and readily available biomass. Through an integrated biorefinery process simulation and a Life Cycle Assessment of the coproduction of ethanol and electricity, it was analyzed whether forestry burden is truly relevant when exploring this material, identifying technical and environmental bottlenecks. The biorefinery design implementation of anaerobic digestion and energy integration allowed a productivity boost of 20% for ethanol and 115% for electricity. With a 80 km collection radius, an annual production capacity of 30.3 ML could be achieved in the Campinas region. Enzymes were identified as the main environmental hotspot, but inconsistent published datasets and lack of transparency lead to inconclusive results regarding this input. While the burden associated with the lignocellulosic feedstock is relevant in most impact categories, the main bottleneck resides within the biorefinery itself, with inputs related to pretreatment and hydrolysis, boiler emissions and water consumption. Nevertheless, eucalyptus harvest residues cannot be considered a burden-free resource, since additional operations such as retrieval and transportation cannot be dismissed and often surpasses the impact potential of the aforementioned forestry activities.& nbsp; (c) 2021 Elsevier Ltd. All rights reserved.