Lignocellulosic biomass has been regarded as an important future energy source due to its excessive availability; however, the wide application of this material for many applications is restricted by the high costs associated with densification, transportation, thermo-chemical pretreatment and conversion. In order to increase the density of lignocellulosic biomass, it is typically compressed into pellets or briquettes. This frequently requires the addition of additives, which may negatively impact the economics of the process. Environmentally-friendly binding agents that can be obtained inexpensively are therefore desirable. This study examines the change in physicochemical properties of densified Miscanthus straw where algae were used as a binding agent.
The algae (Rhizoclonium spp.) was obtained as a waste product from a local algal-based wastewater treatment system, dried and then added as a fine powder to milled Miscanthus. The material was then compressed into discs using a mounting press, which were then assessed for calorific value, compressive strength and sugar content.
We found that the algae-Miscanthus discs with blends of up to 30 % algae had similar calorific values compared to Miscanthus alone (17.4 MJ kg−1), with significantly reduced calorific values at higher blends. Furthermore, Miscanthus discs mixed with algae had significantly greater compressive strength at blends at or above 20 % algae content compared to pellets made from 100 % Miscanthus (39 N). The strength of the discs was directly proportional to the percentage of algae in the mixture, with a maximum strength of 189 N for blends with 90 % algae. The glucose content of blends below 30 % was not statistically different than 100 % Miscanthus.
These data provide support for the use of algae as a binding agent for biomass destined for bioenergy and bioproduct processes, and highlight an additional end use for algal biomass.
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Somerville, C., Youngs, H., Taylor, C., Davis, S.C., Long, S.P.: Feedstocks for lignocellulosic biofuels. Science 329(5993), 790–792 (2010)
Li, Y., Li, X., Shen, F., Wang, Z., Yang, G., Lin, L., Zhang, Y., Zeng, Y., Deng, S.: Response of biomass briquetting and pelleting to water-involved pretreatments and subsequent enzymatic hydrolysis. Bioresour. Technol. 151, 54–62 (2014)
Stelte, W., Clemons, C., Holm, J.K., Sanadi, A.R., Ahrenfeldt, J., Shang, L., Henriksen, U.B.: Pelletizing properties of torrefied spruce. Biomass Bioenergy. 35, 4690–4698 (2011)
Lehmann, B., Schroder, H.-W., Wollenberg, R., Repke, J.-U.: Effect of Miscanthus addition and different grinding processes on the quality of wood pellets. Biomass Bioenergy. 44, 150–159 (2012)
Kaliyan, N., Morey, R.V.: Factors affecting strength and durability of densified biomass products. Biomass Bioenergy. 33(3), 337–359 (2009)
Kuokkanen, M., Vilppo, T., Kuokkanen, T., Stoor, T., Niinimaki, J.: Additives in wood pellet production—a pilot-scale study of binding agent usage. Bioresources 6(4), 4331–4355 (2011)
Finney, K.N., Sharifi, V.N., Swithenbank, J.: Fuel pelletization with a binder: part I–identification of a suitable binder for spent mushroom compost-coal tailing pellets. Energ. Fuels 23(6), 3195–3202 (2009)
Pittman, J.K., Dean, A.P., Oundeko, O.: The potential of sustainable algal biofuel production using wastewater resources. Bioresour. Technol. 102(1), 17–25 (2011)
Park, J.B.K., Craggs, R.J., Shilton, A.N.: Wastewater treatment high rate algal ponds for biofuel production. Bioresour. Technol. 102(1), 35–42 (2011)
Ometto, F., Whitton, R., Coulon, F., Jefferson, B., Villa, R.: Improving the energy balance of an integrated microalgal wastewater treatment process. Waste Biomass Valor. 5(2), 245–253 (2014)
Craggs, R.J., Heubeck, S., Lundquist, T.J., Benemann, J.R.: Algal biofuels from wastewater treatment high rate algal ponds. Water Sci. Technol. 63(4), 660–665 (2011)
Singh, A., Nigam, P.S., Murphy, J.D.: Mechanism and challenges in commercialization of algal biofuels. Bioresour. Technol. 102(1), 26–34 (2011)
BS EN 14918:2009. Solid biofuels. Determination of calorific value
Sluiter, A., Hames, B., Ruiz, R., Scarlata, C., Sluiter, J., Templeton, D., Crocker, D.: Determination of structural carbohydrates and lignin in biomass. NREL/TP-510-42618 (2008)
Sluiter, A., Hames, B., Ruiz, R., Scarlata, C., Sluiter, J., Templeton, D.: Determination of ash in biomass. NREL/TP-510-42622 (2008)
Carroll, J.P., Finnan, J.: Physical and chemical properties of pellets from energy crops and cereal straw. Biosyst. Eng. 112(2), 151–159 (2012)
Wang, X., Jin, M., Balan, V., Jones, A.D., Li, X., Li, B.Z., Dale, B.E., Yuan, Y.J.: Comparative metabolic profiling revealed limitations in xylose-fermenting yeast during co-fermentation of glucose and xylose in the presence of inhibitors. Biotechnol. Bioeng. 111(1), 152–164 (2014)
Chen, R., Thomas, B.D., Liu, Y., Mulbry, W., Liao, W.: Effects of algal hydrolyzate as reaction medium on enzymatic hydrolysis of lignocelluloses. Biomass Bioenergy. 67, 72–78 (2014)
http://pelletheat.org/wp-content/uploads/2011/11/standards-table.jpg (May 22, 2014)
This research was funded by an award to Canam and Johnson from the Council on Faculty Research (Eastern Illinois University), and an award to Canam and Liu from the President’s Research Fund (Eastern Illinois University). Additional funding was provided by The Graduate School at Eastern Illinois University as a Research/Creativity Activity award to Thapa. The algal biomass used in this study was provided by OneWater, Inc.
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Thapa, S., Johnson, D.B., Liu, P.P. et al. Algal Biomass as a Binding Agent for the Densification of Miscanthus. Waste Biomass Valor 6, 91–95 (2015). https://doi.org/10.1007/s12649-014-9326-3