Evaluating microalgae‐to‐energy ‐systems: different approaches to life cycle assessment (LCA) studies

Abstract

Life cycle assessment (LCA) is a valuable tool for determining the environmental impacts associated with different products and has been widely used to assess biofuel production. As a scientific methodology rather than a standardized test, every LCA may be thought of as unique in terms of the selection of functional units or determination of system boundaries. Researchers generally tailor the method to meet the specific goals of their own investigations. This review examines a number of LCAs used to evaluate microalgae-to-energy systems, and evaluates their contributions in terms of their ability to support commercialization efforts in this sector. To this end, a new scoring system for LCAs is proposed based on input/output flows, data origin, production technologies and system boundaries, selection of assumptions and variables, as well as the ability to track environmental, economic, and social impacts. The review suggests that, while a wide variety of new technological pathways for microalgae-to-energy systems are being assessed, the majority of studies reported employ relatively limited system boundaries that may not capture the full impacts of the processes. The number of environmental impact factors being tracked is limited, and many studies do not consider important impacts such as water or land use. Most studies do not incorporate critical information about economics related to new process configurations, which will be essential to support commercialization efforts in this area. © 2016 Society of Chemical Industry and John Wiley & Sons, Lt

Life cycle assessment of algae‐to‐biodiesel shallow pond production systems in the Mediterranean: influence of species, pond type, by(co)‐product valorisation and electricity mix

“…After the cultivation stage the microalgae produced need to be recovered and dried. This is an energy‐intensive procedure and therefore it could affect the overall environmental sustainability of the microalgae‐to‐biodiesel systems. Initial biomass separation can be achieved by physical, chemical and/or biological methods, such as centrifugation, flocculation, sedimentation, flotation and filtration .…”

“…Nonetheless, with current technology, algae‐to‐biodiesel systems are energy intensive, which potentially affects their overall cost and environmental sustainability. Several studies dealing with the environmental performance of algae‐to‐biodiesel systems exist, e.g . but to the best of our knowledge, none deals with southern Greece's promising climatic conditions .…”

An Assessment Of Microalgal Biodiesel With Acetone, Butanol and Ethanol Using LIfe Cycle Assessment (LCA) Methodology

“…Thus, the impact category for this study is climate change only (see Table 2.12 in section 2.5). This limited impact category selection is unfortunate yet typical of most studies using LCA methods (Collotta et al, 2016). However, even though this study does not include other impact categories, such as eutrophication or ozone depletion, for assessment, this study has taken into account the recommendations of other microalgal-energy system LCAs concerning environmental improvements and created a microalgal BD and ABE production model accordingly.…”

“…However, even though this study does not include other impact categories, such as eutrophication or ozone depletion, for assessment, this study has taken into account the recommendations of other microalgal-energy system LCAs concerning environmental improvements and created a microalgal BD and ABE production model accordingly. For example, high energy and environmental impact of microalgal biomass growth associated with nutrient requirements and land area requirements respectively has been accounted for by wastewater use and PBR use (Collotta et al, 2016). Little waste is generated in this process and the use of chemicals is minimalized (e.g., use of energy instead of large volumes of non-recyclable chemicals).…”

Life Cycle Assessment of Exopolysaccharides and Phycocyanin Production with Arthrospira platensis

“…Based on prevailing literature, a predominant focus has been observed in LCA studies, with the majority concentrating solely on reporting global warming potential as part of the climate change impact category [23,24]. In contrast, our present study takes a different approach by selecting indicators relevant to the specific system under analysis.…”