干旱区生态环境知识资源中心(Arid): First-principles flocculation as the key to low energy algal biofuels processing.

Arid

DOI	10.2172/1090222
报告编号	SAND2012-8099
来源ID	OSTI_ID: 1090222
	First-principles flocculation as the key to low energy algal biofuels processing.
	Hewson, John C.; Wyatt, Nicholas B.; Pierce, Flint; Brady, Patrick Vane; Dwyer, Brian P.; Grillet, Anne; Hankins, Matthew G; Hughes, Lindsey Gloe; Lechman, Jeremy B.; Mondy, Lisa Ann; Murton, Jaclyn K.; O'Hern, Timothy J; Parchert, Kylea Joy; Pohl, Phillip Isabio; Williams, Cecelia Victoria; Zhang, Xuezhi; Hu, Qiang; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton
英文摘要	This document summarizes a three year Laboratory Directed Research and Development (LDRD) program effort to improve our understanding of algal flocculation with a key to overcoming harvesting as a techno-economic barrier to algal biofuels. Flocculation is limited by the concentrations of deprotonated functional groups on the algal cell surface. Favorable charged groups on the surfaces of precipitates that form in solution and the interaction of both with ions in the water can favor flocculation. Measurements of algae cell-surface functional groups are reported and related to the quantity of flocculant required. Deprotonation of surface groups and complexation of surface groups with ions from the growth media are predicted in the context of PHREEQC. The understanding of surface chemistry is linked to boundaries of effective flocculation. We show that the phase-space of effective flocculation can be expanded by more frequent alga-alga or floc-floc collisions. The collision frequency is dependent on the floc structure, described in the fractal sense. The fractal floc structure is shown to depend on the rate of shear mixing. We present both experimental measurements of the floc structure variation and simulations using LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). Both show a densification of the flocs with increasing shear. The LAMMPS results show a combined change in the fractal dimension and a change in the coordination number leading to stronger flocs.
出版年	2012
报告类型	Technical Report
语种	英语
国家	美国
URL	http://www.osti.gov/scitech/servlets/purl/1090222
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/270558
推荐引用方式 GB/T 7714	Hewson, John C.,Wyatt, Nicholas B.,Pierce, Flint,et al. First-principles flocculation as the key to low energy algal biofuels processing.,2012.