Microalgae fractionation using steam explosion, dynamic and tangential cross-flow membrane filtration

Bioenergy from Microalgae – Vision or Reality?

“…In order to improve extractability of the algal ingredients, various cell disruption methods have been tested that aim at breaking down the often multi‐layered and highly stable cell wall, even though this goal is at least in part already achieved by applying the above‐mentioned drying methods. Often, mechanical processes such as high‐pressure homogenization, sonication, or bead milling are used, however, also osmotic shock, enzymatic and thermic disruption methods, or steam explosion have been shown to be suitable methods , . Since they have often only been tested in the laboratory, optimization and application of these technologies on an industrial scale is one key objective of current research in the field.…”

Steam Explosion and Vibrating Membrane Filtration to Improve the Processing Cost of Microalgae Cell Disruption and Fractionation

“…The process unit operations needed in order to proceed to microalgae biorefining depend very much on the strain and products to be sought (i.e., commodity or high-added value products), but a typical sequence is: Culture in open ponds or photobioreactors [14,15], dewatering [16][17][18][19][20][21], cell disruption [22][23][24][25][26][27], and fractionation [13,20,28].…”

“…Depending on the strain cell wall characteristics, cell disruption can be a cost-intensive operation and several procedures have been reported at the laboratory level, including the use of ultrasounds, microwave, or high pressure [25,30]. Steam explosion is proposed in this work as an innovative technique for this application and is easy to scale-up with pilot plant results because of the nature of the equipment and because it is widely used industrially [22,24]. Steam explosion has given the best results when compared with other methods for cell disruption such as ultrasonication, microwave, and autoclave [29].…”

“…Membrane filtration and solvent extraction are methods to be used for fractionation [24,28]. In a first unit operation, membrane filtration can be used to obtain two streams: a retentate containing lipids and proteins and a permeate containing water with the hydrolyzed monosaccharides [24]. As in microalgae dewatering, fouling is a main drawback.…”

“…To recover non-polar lipids from the retentate stream of the first operation, a hexane extraction is used. In our previous work [24], the microalga Nannochloropsis gaditana was selected to investigate the fractionation strategy for lipids and carbohydrates recovery. In this study, we intend to validate the selected fractionation path when different common microalgae species were used: Chlorella sorokiniana [34], Nannochloropsis gaditana [35], and Dunaliella tertiolecta [36].…”