Methods and Applications of Life Cycle Material and Energy Flow Analysis in Product/Process Comparisons and Design


Friday, February 11, 2005, 3:30 PM

Room 825 SWM Building

Dr. Nikhil Krishnan

Earth Engineering Center, Department of Earth & Environmental l Engineering Columbia University , New York


Increasingly, product and process decisions are influenced not only by performance and economic issues, but also by overall environmental implications. The appreciation that industrial decision making drives economy-wide environmental impacts has led to the development of various methodologies for Life Cycle Assessment (LCA) within the context of the overall field of industrial ecology.

In this talk, I first review alternative methods to track material and energy flows associated with engineered products or processes. Specifically I will examine detailed process-model based SETAC LCA methodologies, input-output techniques and emerging hybrid approaches.

I then describe applications of these techniques to environmental decision making in semiconductor manufacturing. Design for Environment (DFE) is especially challenging in semiconductor manufacturing, owing to short product and manufacturing process lifetimes, the multiple chemicals used, the complexity of the manufacturing process, and stringent quality requirements. With rapid growth in this sector over the past few decades, environmental impacts are increasingly a cause for concern. I examine two specific case studies in this area:

  • the application of a hybrid approach to track life cycle environmental implications of semiconductor process modules and
  • the development of an effective methodology and a tool with a narrower scope to support DFE and cost analysis in semiconductor manufacturing, called the Environmental Value Systems (EnV-S) Analysis.

Different types of analyses can be performed, including uncertainty analysis based on model parameters and the ability to support DFE by evaluating a large number of design options. Enough detail is available to directly inform the design of semiconductor equipment and make equipment selection and process decisions.

Over the last few years, the EnV-S tool has been gaining wider acceptance within the semiconductor industry. It is currently being used as a part of environmental services offered by Applied Materials Inc., and also to determine market requirements for innovative environmental products.

Finally, I conclude this talk with a discussion of current and future research directions in the area of material flow assessment and LCA associated with industrial products and processes.


Dr, Nikhil Krishnan has a B.S. in Mechanical Engineering from the Indian Institute of Technology, Madras , India , and a M.S. and Ph.D. in Mechanical Engineering from the University of California at Berkeley . He is an expert in assessing the environmental impacts of manufacturing processes and materials, and in industrial ecology. Dr. Krishnan is a 2004 Earth Institute Fellow at Columbia University .