Cyclic fractionation process for Saccharina latissima using aqueous chelator and ion exchange resin

Abstract

A new approach to process Saccharina latissima algal biomass was developed using sodium citrate and a polyvalent cation-specific resin to sequentially extract the alginate into several usable fractions. The fractionation was performed in a cyclic manner, utilizing a stepwise removal of the native polyvalent ions present in the algae to isolate fractions of alginate with different solubility in the presence of these ions. Sodium citrate was used in different concentrations in the extraction solution to remove polyvalent cations to adjust the alginate liberation while AMBERLITE IRC718 resin was added to further remove these ions and regenerate the extraction solution. Alginate was recovered by acid precipitation and analyzed for its uronic acid composition and molecular weight, and the carbohydrate compositions of the insoluble and soluble parts of the algal biomass residue were determined. Finally, the fractionation method was assessed with a life cycle analysis to determine the energy and water efficiency as well as the greenhouse gas emissions and the results were compared to conventional alkaline extraction. The results indicate that the energy and water use as well as the emissions are considerably lower for the cyclic extraction in comparison with the conventional methods.Electronic supplementary materialThe online version of this article (doi:10.1007/s10811-017-1176-5) contains supplementary material, which is available to authorized users.

A Strategy for the Sequential Recovery of Biomacromolecules from Red Macroalgae Porphyra umbilicalis Kützing

“…The additional value and yield from the algal biomass of course require additional processing and energy consumption. Therefore, it is important not only to use green raw materials but also to develop as green and efficient processes as possible and to benchmark new processes from a lifecycle analysis perspective against conventional processes . Still, a process that may not be cost-effective based on one component only can be enabled if other components are also utilized and sold as valuable new materials.…”

Hybrid Filaments from Saccaharina lattisima Biomass: Engineering of Alginate Properties with Maleic Anhydride Grafted Linseed Oil

“…Sodium alginate was extracted from the brown algae Saccharina latissima using a cyclic fractionation process in which diluted sodium citrate was used in 18 sequential extractions from the same biomass [ 4 ]. The alginate fraction used in this work was recovered, by acid precipitation followed by centrifugation, from the 16th extraction cycle.…”

“…Filaments were prepared from two grades of alginate in parallel: Commercial alginate from Sigma-Aldrich (Sweden) and alginate extracted in an in-house developed cyclic biorefinery fractionation process [ 4 ] (herein denoted as extracted alginate). Alginate solutions, 2% or 4% ( w / w ), were mixed with grafted linseed oil (prepared as described in Section 2.2 ) in a 2:1 ratio with respect to the weight of alginate and the weight of oil.…”

“…Alginate normally constitutes 20−40% of the brown algal dry weight. Brown macroalgae ( Saccharina latissima ) grow naturally and are also cultivated at high yield along the Swedish west coast [ 1 , 2 , 3 ] and hence present a promising biomass for alginate recovery via biorefining [ 4 ]. Alginate is composed of two uronic acid structural units: mannuronic (M) and guluronic (G) acid.…”

Removal of methylene blue from wastewater using hydrogel nanocomposites: A review

“…113 Alginate can be extracted from its salt forms by ion-exchange methods. 114 Because of the 62 presence of divalent ions, monovalent, water-soluble salts of alginates can transform into water-insoluble salts. The COO À and -OH functional groups on the alginate backbone will allow adsorption of cationic dye pollutants.…”