Biodiversity Improves Life Cycle Sustainability Metrics in Algal Biofuel Production
Biodiversity Improves Life Cycle Sustainability Metrics in Algal Biofuel Production
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DOI：
10.1021/acs.est.9b00909
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发表时间：
2019-08-06
影响因子：
11.4
通讯作者：
Savage, Phillip E.
中科院分区：
文献类型：
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作者：
Carruthers, David N.;Godwin, Casey M.;Savage, Phillip E.
藻类生物燃料尚未实现其作为商业和可持续生物能源的潜力，这主要是由于在大规模种植的能量和材料输入方面最大化和维持生物质生产的挑战。实验研究表明，与单一培养相比，多物种藻类混养可以提高生物量产量、稳定性和养分循环利用。然而，目前尚不清楚生物多样性的这些影响是否使混养比单一种植更具可持续性。在这里，我们展示了藻类生物精炼厂的比较生命周期评估（LCA）结果，以比较六种淡水藻类的单一栽培和混养的可持续性指标。我们的结果表明，当在室外实验池塘中种植藻类时，与最佳单一栽培相比，某些双养的能源投资回报 (EROI) 和温室气体排放 (GHG) 分别提高了 20% 和 16%。混合栽培通过同时执行多种功能（例如，提高稳定性、营养效率、生物原油特性）而优于单一栽培，这超过了单一栽培可实现的更高生产力。我们的结果表明，具有优化多功能性的藻类混养可以增强生命周期指标，突显生态工程在实现未来环境可持续的藻类生物精炼方面的巨大潜力。
Algal biofuel has yet to realize its potential as a commercial and sustainable bioenergy source, largely due to the challenge of maximizing and sustaining biomass production with respect to energetic and material inputs in large-scale cultivation. Experimental studies have shown that multispecies algal polycultures can be designed to enhance biomass production, stability, and nutrient recycling compared to monocultures. Yet, it remains unclear whether these impacts of biodiversity make polycultures more sustainable than monocultures. Here, we present results of a comparative life cycle assessment (LCA) for algal biorefineries to compare the sustainability metrics of monocultures and polycultures of six fresh-water algal species. Our results showed that when algae were grown in outdoor experimental ponds, certain bicultures improved the energy return on investment (EROI) and greenhouse gas emissions (GHGs) by 20% and 16%, respectively, compared to the best monoculture. Bicultures outperformed monocultures by performing multiple functions simultaneously (e.g., improved stability, nutrient efficiency, biocrude characteristics), which outweighed the higher productivity attainable by a monoculture. Our results demonstrate that algal polycultures with optimized multifunctionality lead to enhanced life cycle metrics, highlighting the significant potential of ecological engineering for enabling future environmentally sustainable algal biorefineries.