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ABSTRACT Emissions of fine particulate matter, P[M.sub.2.5], in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or water-based) ESPs are well suited [...]

Abstract On February 15, 2008, the National Academy of Engineering unveiled their list of 14 Grand Challenges for Engineering. Building off of tremendous advancements in the past century, these challenges were selected for their role in assuring a sustainable existence for the rapidly increasing global community. It is no accident that the first five Challenges on the list involve the development of sustainable energy sources and management of environmental resources. While the focus of this review is to address the single Grand Challenge of "develop carbon sequestration methods", is will soon be clear that several other Challenges are intrinsically tied to it through the principles of sustainability. How does the realm of biological engineering play a role in addressing these Grand Challenges?

Microalgae are one of the most promising feedstocks for biodiesel production due to their high lipid content and easy farming. However, the extraction of lipids from microalgae is energy intensive and costly and involves the use of toxic organic solvents. Compared with organic solvent extraction, supercritical CO2 (SCCO2) has demonstrated advantages through lower toxicity and no solvent-liquid separation. Due to the nonpolar nature of SCCO2, polar organic solvents such as methanol may need to be added as a modifier in order to increase the extraction ability of SCCO2. In this paper, pilot scale lipid extraction using SCCO2 was studied on two microalgae species: Spirulina sp. and Schizochytrium sp. For each species, SCCO2 extraction was conducted on 200 g of biomass for 6 h. Methanol was added as a cosolvent in the extraction process based on a volume ratio of 4%. The results showed that adding methanol in SCCO2 increased the lipid extraction yield significantly for both species. Under an operating pressure of 4000 psi, the lipid extraction yields for Spirulina sp. and Schizochytrium sp. were increased by 80% and 72%, respectively. It was also found that a stepwise addition of methanol was more effective than a one-time addition. In comparison with Soxhlet extraction using methylene chloride/methanol (2:1, v/v), the methanol-SCCO2 extraction demonstrated its high effectiveness for lipid extraction. In addition, the methanol-SCCO2 system showed a high lipid extraction yield after increasing biomass loading fivefold, indicating good potential for scaling up this method. Finally, a kinetic study of the SCCO2 extraction process was conducted, and the results showed that methanol concentration in SCCO2 has the strongest influence on the lipid extraction yield. [ABSTRACT FROM AUTHOR]

Liquid Transportation Fuels from Coal and Biomass: Technological Status, Costs, and Environmental Impacts. National Academy of Sciences, National Academy of Engineering, and The National Research Council. The National Academies Press, [...]

This paper aims to propose a modeling method for algae powered neighborhoods through GIS-BIM integration. In the first part of the paper, the applicability of different types of algae systems in an urban neighborhood are studied. The various systems of algae provide different strengths and weakness that affect their performance and suitability for given urban scenarios. Through extensive literature review, the variables that affect the performance of the micro-algae in the built environment are identified, with a focus on flat-panel photo bio-reactors and tubular photobioreactors. A previous GIS model for data management, performance analysis and design of the algae systems is reviewed [1] , which shows its limitations in managing fine-grained structures and functions of algae systems. A bottom-up BIM approach to deal with these limitations is further explored. The algae-embedded built environment can be modeled in the parametric 3D BIM and Rhinoceros with a set of building parameters for the roof, façade, window to wall ratio, etc. Subsequently, solar exposure on building surfaces, the use of the buildings and their respective façade types would be studied. Parametric 3D models of the buildings allows for faster design modification and the creation of multiple design options. These models can be used to perform energy analysis using the parametric energy analysis tool to check for building energy use intensity (EUI). The bottom-up approach explored in this research design aims to facilitate visualization and analysis of the built environment and gauge the productivity of microalgae. Finally, a platform for BIM –GIS integration and its possibility is explored in this paper. [ABSTRACT FROM AUTHOR]

10:45 Acid mine drainage (AMD) impacts numerous streams worldwide. During June of 2000, 18 stream segments located within the Black Fork subwatershed in southeastern Ohio, USA were sampled for diatom [...]