HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia; Algal Bio Co. Ltd, Todai-Kashiwa Venture Plaza, 5-4-19 Kashiwanoha, Kashiwa, Chiba, 277-0082, Japan.
HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia; Department of Biotechnology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, 602105, India.
Chemosphere. 2023 Nov;341:139953. doi: 10.1016/j.chemosphere.2023.139953. Epub 2023 Aug 25.
Life cycle assessments of microalgal cultivation systems are often conducted to evaluate the sustainability and feasibility factors of the entire production chain. Unlike widely reported conventional microalgal cultivation systems, the present work adopted a microalgal-bacterial cultivation approach which was upscaled into a pilot-scale continuous photobioreactor for microalgal biomass production into biodiesel from wastewater resources. A multiple cradle-to-cradle system ranging from microalgal biomass-to-lipid-to-biodiesel was evaluated to provide insights into the energy demand of each processes making up the microalgae-to-biodiesel value chain system. Energy feasibility studies revealed positive NER values (4.95-8.38) for producing microalgal biomass but deficit values for microalgal-to-biodiesel (0.14-0.23), stemming from the high energy input requirements in the downstream processes for converting biomass into lipid and biodiesel accounting to 88-90% of the cumulative energy demand. Although the energy balance for microalgae-to-biodiesel is in the deficits, it is comparable with other reported biodiesel production case studies (0.12-0.40). Nevertheless, the approach to using microalgal-bacterial cultivation system has improved the overall energy efficiency especially in the upstream processes compared to conventional microalgal cultivation systems. Energy life cycle assessments with other microalgal based biofuel systems also proposed effective measures in increasing the energy feasibility either by utilizing the residual biomass and less energy demanding downstream extraction processes from microalgal biomass. The microalgal-bacterial cultivation system is anticipated to offer both environmental and economic prospects for upscaling by effectively exploiting the low-cost nutrients from wastewaters via bioconversion into valuable microalgal biomass and biodiesel.
生命周期评估的微藻培养系统通常进行评估的可持续性和可行性因素的整个生产链。与广泛报道的传统微藻培养系统不同，目前的工作采用了微藻-细菌培养方法，该方法被放大到一个中试规模的连续光生物反应器，用于从废水资源生产微藻生物量用于生产生物柴油。从微藻生物量到脂质到生物柴油的多摇篮到摇篮系统进行了评估，以深入了解构成微藻到生物柴油价值链系统的各个过程的能量需求。能源可行性研究表明，生产微藻生物量的 NER 值为正（4.95-8.38），但微藻到生物柴油的 NER 值为负（0.14-0.23），这是由于将生物量转化为脂质和生物柴油的下游过程需要高能量投入，占累计能源需求的 88-90%。尽管微藻到生物柴油的能量平衡为负值，但与其他报道的生物柴油生产案例研究（0.12-0.40）相当。然而，与传统的微藻培养系统相比，使用微藻-细菌培养系统的方法提高了整体能源效率，特别是在上游过程中。与其他基于微藻的生物燃料系统的能源生命周期评估也提出了通过利用剩余生物质和减少从微藻生物质中提取下游提取过程的能量需求来提高能源可行性的有效措施。微藻-细菌培养系统有望通过有效利用废水中的低成本营养物质进行生物转化，生产有价值的微藻生物量和生物柴油，为扩大规模提供环境和经济前景。
