Thursday, March 4, 2010

Digging Deeper


The ongoing low hanging fruit discussion here was the preamble to the last posting about scratching the surface (or, as one of my grinding expert friends says ... when it comes to abrasive process research we've only just scratched the surface! Sorry... engineering humor).

It is necessary to understand the magnitude of the challenge and where to best concentrate our efforts. And, sometimes the easiest stuff doesn't do much to advance the cause, specially with respect to greening manufacturing.

Last time I presented some perspectives on what it really means to be sustainable and this referred back to the earlier discussions about "technology wedges." An analysis of some of the potential wedges was presented from the Vattenfall report. Many of those technology wedges were related to manufacturing as noted.

One can find similar data on what kinds of reductions in CO2 emissions (in terms of parts per million in the atmosphere) are needed to get the atmospheric concentration of CO2 at a "sustainable" level. Again, I point out that not everyone agrees with the data and I am not promoting any specific interpretation. But (and a significant but) agencies, states, countries and regions are making regulations based on these discussions, consumers are making choices based on products and companies that respond to this data and companies are changing business plans and strategies based on this. So, in keeping with the "Everett and Jones" philosophy... we'd better be at least watching this carefully (and if you don't recall what this is - search Everett and Jones on this blog page!)  If you check the pages of Environmental Leader (link at bottom) on any day you see a growing list of reports of companies responding.

Ok...we've got the motivation. Now, what will really work.

Last July in this blog referred to a presentation in 2005 by Professor Julian Allwood of Cambridge University on "What is Sustainable Manufacturing" as a good place to start this discussion (see http://green-manufacturing.blogspot.com/2009/08/dimensions-and-metrics-of-green.html for the blog and http://www.ifm.eng.cam.ac.uk/sustainability/seminar/documents/050216lo.pdf for a download of Allwood's slides).

Allwood discusses in detail strategies for reducing the carbon footprint and other impacts of manufacturing. He specially discusses these with reference to targets for reduction set by governmental agencies in the UK and elsewhere. For example, the figure below shows the reduction targets set by the UK and EU to allow surface temperature stabilization. The target is a 60% absolute cut in yearly carbon emissions by 2050 compared to 1990 levels. What is seen is the slope of reductions (in CO2 equivalent)


needed to meet this ambitious goal (in blue), the actual reductions observed over the first few years (and reference to the Kyoto target, in red) and, gulp, these actual reductions adjusted to "off shore" effects. That is, moving the production and associated CO2 generation out of the region of calculation (i.e. out of the UK and EU) in orange. That curve is moving in the wrong direction.

This is not a pretty picture and emphasizes the complexity and difficulty of the task. Smoke and mirrors are not going to get this done.

Since consumption increases annually with additional production of products to meet growing demand fueled by, at least, growing populations (and compounded by increasing expectations of quality of life - recall the "impact equation" we discussed some postings ago on the drivers of impact including impact/GDP) we need to accommodate both reduction in per unit impact (CO2 here) as well as the increased production with demand. A double whammy.

Allwood puts some numbers on this. He summarizes data from an EU project on reducing CO2 in steel production. If demand for steel doubles then stablizes, and every efficiency known is perfectly implemented, the carbon target requires that two thirds of all steel is re-used without re-smelting, and the energy of all forming processes is halved.

Think about this (and keep in mind the Ricoh comet cycle; see http://green-manufacturing.blogspot.com/2009/09/sustainability-angst.html). Two-thirds of all steel re-used without re-smelting! That cuts out a major part of the present strategy for recovery and recycling steel (and many other materials as well.) That means, effectively, if we are to meet this aggressive target (but the type of target many feel is absolutely needed and being discussed by other countries and regions in the world) we'll be taking the steel hood off of our Chevy and re-assembling it onto another with little additional processing! That is, we have to be able to facilitate the loops closest to the consumer to make this work.

Hopefully, this will spur research on and development of a whole host of imaginative re-processing technologies that can cut out the "dirty" part of recycling.

We'll look at some ideas about this next time.

Finally, Professor Allwood has just written a paper to be published in  Environmental Science and Technology Journal (ES&T) detailing some potential next steps. The article, titled "Options for Achieving a 50% cut in Industrial Carbon Emissions by 2050" introduces the idea of material efficiency with reduced primary production. We will delve into this more in the future.

No comments:

Post a Comment