Sunday, March 8, 2009

Recycling: It's Importance To Energy Efficiency

I have always been interested in the pros and cons of recycling. Over the years, I have heard mixed opinions on the benefits of recycling paper and the recycling aluminum is the most effective and important material to recycle. I decided to use this blog as an opportunity to investigate these various materials with more detail, which also stems from our recent life cycle analysis class.

The major benefits of recycling include:
1) Conservation of natural resources
2) Reduction of carbon emissions
3) Reduction in the amount of waste buried & burned
4) Energy Savings

The conservation of natural resources applies mostly to recycling paper, which lowers the amount of trees cut down to produce paper. By recycling paper we are able to decrease the need to cuty down our forests, a precious and valuable natural resource. Reduction in carbon emissions is becoming more critical as we become more concern with the potential consequences of global warming. The EPA estimated that the United States reduced its carbon emission by 49 million tonnes in 2005 by recycling, this decrease in carbon emissions is dir As our recycling efforts become more efficient this reduction in carbon emissions should continue to increase. The reduction in the amount of waste buried and burned creates other subordinate benefits of recycling. These additional benefits include increasing the capacity life of landfills and lowering the pollution emitted from waste incineration. Most importantly may be the energy saved from recycling, this applies mostly to recyclinig metals where it requires less energy to re-smelt than to process natural ore.

The negative aspects of recycling revolve around economies of scale where recycling is not a profitable venture in low populated counties that do not have a sufficient volume of recyclable materials. The solution to this problem is likely to develop one centralized, large scale operation that covers many smaller operations. This is currently being implemented in Wisconsin, where three counties formed a tri-county co-op to reduce recycling and landfill costs. Another negative part of recycling may stem directly from paper recycling. The EPA examined both virgin paper processing and recycled paper processing for toxic substances. Five toxic substances were found only in vergin processes, eight only in recycling processes, and twelve in both processes, where amoung these twelve toxic substances all but one had higher concentrations in the recycling processes (Office of Technology Assessment, 1989). Initially curbside recycling was thought by many to increase fuel consumption as more trucks were needed to collect the same amount of trash. But as single stream recycling becomes more effective and recycling process more efficient, the amount of fuel consumption saved from material processing outweighs the fuel consumption of collecting curbside recycling.

The best example of downstream energy savings outweighing the upstream collection of recyclable materials is in recycling metals, aluminium in particular. The following is a list from the Economist (The Truth About Recycling, 2007) of materials and the percentage of energy saved by recycling them.
1) Aluminum - 95%
2) Plastics - 70%
3) Steel - 60%
4) Paper - 40%
5) Glass - 30%

It is hard to argue that recycling aluminum is not the most effective material to recycle. Aluminum is a sustainable metal that can be recycled over and over again without losing its material characteristics. In 2007, 54 billion cans were recycled, saving the energy equivalent of 15 million barrels of crude oil. This amount of oil savings is equivalent to America's entire gas consumption for one day. The problem with aluminum is that it does not occur naturally in our Earth. Therefore, it is an energy intensive process to extract aluminum from its natural ore, bauxite. The fact that aluminum can be melted and recycled in a relatively easy process, significantly lowers the need to process the natural ore. Aluminum has a high market value and continues to provide an economic incentive to recycle.

The final conclusion from my brief research of recycling is that if you are going to recycle one thing from your trash, it should be aluminum.

For more insight into the aspects of recycling I encourage you to read an article from The Economists, called "The Truth About Recycling".

3 comments:

Nate said...

Stuart, last weeks (feb 28th-mar. 6th) Economist edition has a special report on trash and recycling.
http://www.economist.com/specialreports/displaystory.cfm?story_id=13135337

One of the more interesting articles compares two recycling operations, one in San Fran. and the other in Mumbai, India. The U.S. recycling facility is state of the art with a complex system of conveyor belts, shoots and tubes. The Mumbai opertion is all people power, separating recyclables by hand and collection being done by residents and the many people who sift through trash at the "landfills".
The conclusion was that the Mumbai operation is more effective as it sorts to a higher degree of categories, makes less mistakes, is very low cost and is able to sort a large volume quickly. In Mumbai it is relatively profitable to recycle and much of the collection and sorting is done by the consumer in an effort to save money.
I've heard about some recycling programs in the U.S. that have a microchip in your recycling can and when the collection trucks pick up the can and empty it, it is weighed and scanned. The result is that each household gets sent a monthly check for their recycling efforts. This has encouraged better sorting at home and more diligent recycling. For the cities/towns who have this type of program they benefit from a steady recycling stream that allows them to plan and invest more confidently. I would like to see this "incentivized" recycling program all over. We need a system that directly rewards people for recycling.

Zoe said...

I've read a number of interesting articles on how the recycling industry is suffering due to the worldwide recession. Recyclers are having trouble finding buyers for their recycled goods and when they do find buyers, the prices are often too low to produce a profit. For instance, in August of 2008, mixed paper was selling for $120 to $135 a ton but it's now selling for a fraction of that, at $10 to $25 a ton. Much of our recycled materials are sold to Asian countries to be used to make other products, but manufacturing is slowing and recycled materials aren't in high demand.

Recycling Industry Not Recession-Proof

David Wogan said...

Great point, Zoe. I remember reading how the recession was affecting recycling operations, particularly Ecology Action here in town.

Speaking of recycling in Austin, what about our Single Stream Service?