Publications

Abstract not provided.

Abstract not provided.

Microsystem technologies have the potential to significantly improve the performance, reduce the cost, and extend the capabilities of solar power systems. These benefits are possible due to a number of significant beneficial scaling effects within solar cells, modules, and systems that are manifested as the size of solar cells decrease to the sub-millimeter range. To exploit these benefits, we are using advanced fabrication techniques to create solar cells from a variety of compound semiconductors and silicon that have lateral dimensions of 250 - 1000 μm and are 1 - 20 μm thick. These fabrication techniques come out of relatively mature microsystem technologies such as integrated circuits (IC) and microelectromechanical systems (MEMS) which provide added supply chain and scale-up benefits compared to even incumbent PV technologies. © The Electrochemical Society.

Abstract not provided.

In the current study, processes to produce either ethanol or a representative fatty acid ethyl ester (FAEE) via the fermentation of sugars liberated from lignocellulosic materials pretreated in acid or alkaline environments are analyzed in terms of economic and environmental metrics. Simplified process models are introduced and employed to estimate process performance, and Monte Carlo analyses were carried out to identify key sources of uncertainty and variability. We find that the near-term performance of processes to produce FAEE is significantly worse than that of ethanol production processes for all metrics considered, primarily due to poor fermentation yields and higher electricity demands for aerobic fermentation. In the longer term, the reduced cost and energy requirements of FAEE separation processes will be at least partially offset by inherent limitations in the relevant metabolic pathways that constrain the maximum yield potential of FAEE from biomass-derived sugars.

Abstract not provided.

Two separate processes to produce either ethanol or a fatty acid ethyl ester (FAEE) - identical to oil-derived biodiesel - via the fermentation of sugars obtained from lignocellulosic materials were analyzed in terms of economic and environmental metrics. Simplified process models were introduced and employed to estimate fuel production, net energy consumption, minimum fuel selling price, and water consumption for both processes. Monte Carlo analyses were carried out to identify the parameters governing process performance, and an analysis of the impact of potential improvements to the FAEE process was performed. The results of the analyses, capturing both the current state of technology development as well as paths to improve the performance of the FAEE process relative to that for producing ethanol, are presented. This is an abstract of a paper presented at the 2012 AIChE Spring National Meeting and 8th Global Congress on Process Safety (Houston, TX 4/1-5/2012).