Processed seaweed and winemaking waste co-fermentation for biogas extraction: pilot study

Abstract

Abstract. Marine macroalgae (seaweed) conventionally has been used for environmental and commercial purposes; recently a growing interest has been focused also on seaweed detritus as a sustainable/cost-efficient feedstock for biogas (biomethane) anaerobic production. A wide set of factors influence the yield of biogasnevertheless, the recent paper emphasizes pretreatment of processed algal material (substrate) with winemaking waste (inoculum) as a particularly promising project for biogas production. Relevant pilot study carried out at the Liepaja University clearly demonstrates advantages of such a combination (i.e. co-fermentation of mixed substances) for biofuel feedstock design: winemaking waste considerably increases biogas (biomethane) output from seaweed substrate. Still, the results of these preliminary experiments have to be supported by further research.Keywords: processed seaweeds, winemaking waste, anaerobic digestion, biogas, substrate-inoculum. IntroductionRapid growth of energy consumption escalates global community's dependence on nonrenewable fossil fuel (which supplies about 80 % of the world's energy needs [1]) making it more and more urgent to search for alternative, more secure energy sources.Recently different energy types have been appraised and are already in use to replace fossil fuels -e.g. wind, solar, geothermal, tidal, nuclear, hydroelectric, biofuel, etc. energy. However, these alternative energy resources often possess specific disadvantages, like costliness, dependence on environmental conditions, damage to ecosystems, a lot of space needed (for discussion see, e.g. [2]) -consequently, viability considerations are of particular importance, when deciding about alternative energy projects.Bearing in mind this viability/sustainability approach the authors of the present paper are focusing on easy-to-access organic waste materials (namely, macroalgae detritus enhanced by winemaking waste inoculum) derived biogas as a particularly promising option within the spectrum of fossil fuel substitutions. Liepaja District (Baltic Sea coastal area in Western Latvia) has been used as a research site, where algae raw biomaterial has been collected and seaweed biofuels related experiments carried out.

Production of seaweed derived bioplastics

“…Further research is needed to make the final material suitable for practical use. 5. Besides economic gains, Furcellaria lumbricalis bioplastic projects would facilitate the Baltic Sea coastal environment quality improvement through beach cleaning from seaweed waste.…”

“…Seaweed communities on Western Latvia coast (the site of the current research) are represented predominantly by black carrageen Furcellaria lumbricalis populations. Dead carrageen is washed ashore by waves and frequently piles up on a seashore and, accordingly, has been perceived as an annoying garbage by local community (according to rough calculations, about 300-400 tons of seaweed detritus have been removed from Liepaja beach annually [5]). Nevertheless, dead seaweed biomass could be recognized not as a waste but, on the contrary, as an underestimated valuable multipurpose feedstock for biogas, ethanol, agar, cosmetic products, bioplastics, etc.…”

Valorisation of Seaweed Waste from Agar Processing Industry

“…So more attention should be given towards the extraction of nutraceuticals and bioactive compounds from agar processing industrial waste. Such ingredients having health beneficial value can be introduced in the formulation of novel food products with specified health beneficial effects and pharmaceutical value [55][56][57][58][59][60].…”

Anaerobic fermented algae furcellaria lumbricalis tablets as a dual-purpose fertilizer and substrate for sustainable seedling growth

“…A gas storage tank, connected to the gas outlet pipe and featuring a valve for closure. Setup installation included a pressure relief valve/siphon [6]. On February 20, 2022, a biomass collecting, and drainage procedure was carried out, extracting biomass from the anaerobic fermentation equipment.…”