@GeorgeG: I don't think I agree with your statement that "in the long view, the more frequently a material is recycled, the more energy it uses." Obviously, recycling takes energy -- but the recycled product is presumably taking the place of a new (virgin) product, so the net energy usage is less than making two parts out of virgin material.
It sounds like you are saying that throwing things away is less wasteful than recycling them. That just doesn't compute.
That being said, the steel industry's lifecycle assessments may be significantly overstating actual recovery rates for recycling. A recent study published in Science magazine shows that, even though metals are infinitely recyclable in principle, the reality falls far short of that. Recovery rates, even for commonly-used metals such as steel, are not much above 50%. A typical piece of steel might be recycled 2 or 3 times in its lifetime before it becomes unrecoverable, certainly not hundreds or thousands of times.
I'm hoping to interview the author of this study for Design News later this month, so stay tuned.
Thanks for that detail, George. In the study on steel I read, it wasn't specific about what was meant by "processing." I would guess that is pretty much everything that happens from raw materials to vehicle manufacturing.
I think GeorgeG's points are very well-taken. Although my article discusses European issues, the biofuel-and-food-crops situation is a global one, and anything that far-reaching is complex, with multiple parameters and multiple variables. Plus, as Greg mentions, our tools have become more fine-tuned. Although we might prefer it otherwise, alternative solutions have had to be tested in the field, so to speak, before we could get to this point in our understanding.
It's too bad that it's taken six years since the global food crisis began for the role of biofuels to be publically recognized by policymakers. That's six years too late for millions of people in the developing world. But at least this problem is finally being taken seriously.
It is always interesting to see what happens when the unanticipated results of decisions made based on emotion instead of logic become a bit more obvious. The short term problem of bidding up food prices is only one aspect that should have been expected. It will be very educational to see where the EU winds up after the full reality of their choices becomes clearer.
It may be a bit like the consequences of that ROHS set of rules, which have caused quite a few unintended results. Once again, acting on emotions instead of facts does cause problems.
" the steel industry's claim that composites eat more energy than steel during processing, and that steel costs less to recycle." -- ah, the complexities of the problem. This argument shows that if you choose to optimize on specific components you can come up with huge fails. The first rule of optimizing a system is to avoid local optimization. When it comes to minimizing total energy use, composites win by a large margin. Aluminum is awful but gets quite a bit better because of low energy intensity and environmental impact when recycled: ~5% energy recycled to raw. Steel is never a challenger for anything as it is less malleable and less stable - particularly it's environmental impact because of chemical processes needed to make a finished product. Recycled steel uses ~26% of the energy for raw steel. Having worked with composites, steel and aluminum for automotive and aircraft construction, I'm not sure what 'processing' they're even talking about - the heat load required to form and shape composites is much smaller than for the other two. Of course, if you were to consider the lifetime energy consumption of transportation products, composites and aluminum have a substantial energy use advantage over steel. One should also consider material turns i.e. what is the lifetime of the material in use, because, in the long view, the more frequently a material is recycled, the more energy it uses. One of the technical problems with sourcing aluminum, especially extruded or cast components, is that the majority of the price is energy content. Of course, the contribution of steel to acid rain is well known.
Is it possible that the Europeans have seen the light? While they may make the public pronouncement why they are considering alternatives to "food" sources for fuel, could it be that this is just a mask to restrict outrage from the far left that has been at the forefront in demanding the use of these raw materials into fuel supplies? Maybe they've seen the astronomical rise in the price of a bushel of corn in the U.S., since we've gone to ethanol supplements, AND maybe they're beginning to reel seriously from their recent catastrophic directives of ROHS, etc.
As more conservative leaders in Europe emerge, they may be attempting to shift the thinking to an incremental approach to change, instead of a revolutionary approach to change. Just as you cannot stop a rolling steam engine on a dime, so too you cannot stop an entire economy or process on that same dime! It just may be that someone has calculated the tillable land available in the greater European Continent, and decided that it would be too extreme to commit more of this arable soil to production of biofuel sources than human food production.
Like anything with broad ranging economic as well as ecological impacts, it quickly becomes very complicated. Also, how you tune multi-parameter systems depends on what you wish to optimize. From an economic point of view, biofuels have an attraction to net importers - every time a country imports oil it exports cash which drags down its currency making all imports more expensive and this is a persistant economic impact since a one time purchase exerts this pressure until the cash is repatriated. On the other hand, biofuel from foodstocks seems a crazy idea given the context of declining oil, increased demand for fuels and increasing demand for food based on population growth - when you do a little of this, it's not a problem but when you project forwards, it could be a form of population control. One ecological effect is that biofuels are naturally cleaner than the stuff that comes out of the ground, especially as extraction shifts towards unconventional sources. The US started into corn ethanol partly as a step towards security and to plump US agriculture. Overall, its not a really smart approach as the total energy input required to produce it is nearly 6 times the net energy produced. By comparison, European production of ethanol from root crops is significantly more energy efficient while Central and South American production from sugar cane is very much more energy efficient and produces a cheaper product. The US plan was obviously mainly directed at assisting domestic production given the major efforts to restrict imports of inexpensive ethanol from countires like Brazil which already have a well developed biofuel economy. From a carbon budget perspective, fossil fuels take carbon that was more or less permanently sequestered and releases it into the environment while biofuels recycle the carbon that is already in the atmosphere and oceans and the biosphere slightly distorting the balance between them but not adding to the total.
Great article which takes a deeper dive into biofuel reality. As we gain more experience with biofuels, some of the intial economic perceptions that we had will continue to need adjustment. As we use entire life-cycle carbon and cost calculations, surprising numbers will continue to be found.
Good point on taking in consideration the whole cycle of production on the biofuels, Naperlou. That's the only want to get a good comparison. Another example is the steel industry's claim that composites eat more energy than steel during processing, and that steel costs less to recycle.
Siemens and Georgia Institute of Technology are partnering to address limitations in the current additive manufacturing design-to-production chain in an applied research project as part of the federally backed America Makes program.
Most of the new 3D printers and 3D printing technologies in this crop are breaking some boundaries, whether it's build volume-per-dollar ratios, multimaterials printing techniques, or new materials types.
Independent science safety company Underwriters Laboratories is providing new guidance for manufacturers about how to follow the latest IEC standards for implementing safety features in programmable logic controllers.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.