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ABSTRACT The objective of this research was to develop a multiobjective optimization model to deploy emissions reduction technologies for nonroad construction equipment to reduce emissions in a cost-effective and optimal [...]

The purpose of this paper is to develop a methodology to evaluate the feasibility of using landfill gas (LFG) as a liquefied natural gas (LNG) fuel source for heavy-duty refuse trucks operating on landfills. Using LFG as a vehicle fuel can make the landfills more self-sustaining, reduce their dependence on fossil fuels, and reduce emissions and greenhouse gases. Acrion Technologies Inc. in association with Mack Trucks Inc. developed a technology to generate LNG from LFG using the C[O.sub.2] WASH process. A successful application of this process was performed at the Eco Complex in Burlington County, PA. During this application two LNG refuse trucks were operated for 600 hr each using LNG produced from gases from the landfill. The methodology developed in this paper can evaluate the feasibility of three LFG options: doing nothing, electricity generation, and producing LNG to fuel refuse trucks. The methodology involved the modeling of several components: LFG generation, energy recovery processes, fleet operations, economic feasibility, and decision-making. The economic feasibility considers factors such as capital, maintenance, operational, and fuel costs, emissions and tax benefits, and the sale of products such as surplus LNG and food-grade carbon dioxide (C[O.sub.2]). Texas was used as a case study. The 96 landfills in Texas were prioritized and 17 landfills were identified that showed potential for converting LFG to LNG for use as a refuse truck fuel. The methodology was applied to a pilot landfill in El Paso, TX. The analysis showed that converting LFG to LNG to fuel refuse trucks proved to be the most feasible option and that the methodology can be applied for any landfill that considers this option., INTRODUCTION Energy consumption throughout the world has increased substantially over the past few years and the trend is projected to continue well into the future. The primary sources of energy [...]

Byline: Josias Zietsman, Laurence R. Rilett, Seung-Jun Kim This paper provides a description of how decisions concerning transportation programmes and projects can be made in the context of sustainable transportation. It provides information on identifying appropriate performance measures for sustainable transportation and then quantifying these measures with a traffic simulation model (CORSIM) as well as transportation environmental models. The quantified performance measures were then used with three decision making methodologies. The test bed used for this study comprised a transportation corridor in Tshwane, South Africa and one in Houston, Texas. A method based on the multi-attribute utility theory (MAUT) techniques was found to be the best because a broad range of quantitative and qualitative sustainability issues can be included in the decision-making process. In addition, the disaggregate approach proposed in this paper made it possible for decisions to be made at the individual link level.