|
A Look at Recycling Steel Facts and Carbon Footprint.One of the confusing things about recycling steel facts is knowing what type of units are being discussed, and being able to convert to a standard unit. In looking at steel recycling, as with all recycling, one of the common factors that crops up is the carbon footprint. The US EPA has a report called SolidWaste Management and Greenhouse Gases. In Chapter 2, they talk about the Greenhouse Gas (GHG) emissions in terms of Metric Tons Carbon Equivalent per ton of product.(MTCE) Say what? Care to explain? Since EPA works with metric tons and kg and I think in pounds and ounces, I needed to do some conversions. One of the best converters I've found is onlineconversions.com, which allows you to convert almost anything into anything. For starters, few people express their carbon footprint in carbon rather than carbon dioxide(CO2). You can always convert CO2 to carbon by multiplying with a factor 0.27 (1000 CO2 equals 270 carbon). Or you can convert carbon to CO2 by multiplying by a factor of 3.703 (1000 carbon equals 3703 of CO2) Now lets start looking at recycling some steel. One recycling fact that I didn't know is that making a new steel can from recycled cans saves 75% of the energy used in making the same can from virgin ore. Another recycling fact is that each steel can is made from at least 25% recycled steel. With those thoughts in mind, let's look at what happens with a can of soup, which weighs 2 ounces when it's empty. There are three areas that can be looked at for carbon release in the manufacturing of aluminum: the carbon released from the inputs; both virgin and recycled, the carbon released from the non-energy processing and the combination of the two. We will start with a look at the carbon released from the combination,(which includes transportaion). The MTCE per ton of Virgin Input and transportation energy emissions for steel is 1.01. Since I want to be working in pounds and ounces, I convert by multiplying the MTCE by the short ton conversion factor of 1.1023113109 and get 1.113 Short Tons of Carbon Equivalents per ton of input. Since a short ton weights 2000 pounds, there are 2,226.67 Pounds of Carbon equivalents per short ton. (1.113 times 2,000). That works out to 1.11 pounds Carbon Equvalents per pound of virgin input. The Carbon Equivalents convert to Carbon Dioxide by multiplying by a factor of 3.703, which results in 4.12 pounds of CO2 per pound of input. Since my can only weighs 2 ounces, that means that it is 0.125 parts of a pound (2 ounces divided by 16), we can multiply both the Carbon Equivalents per pound of input (1.11) and the CO2 per pound (4.12) by that factor and arrive at 0.139 pounds of Carbon Equivalent and 0.515 pounds of Carbon Dioxide that are saved for every 2 ounce steel can that is recycled. Now let's look at the same soup can made with 100% recycled steel. If that can was made from 1 metric ton of recycled material, it would produce 0.51 metric tons carbon equivilent (MTCE) per ton of steel. Let's see, that's 1,124.36 pounds of carbon equvalents per short ton, which converts to 0.56 pounds of carbon equvalents and 2.08 pounds of CO2 per pound of input. Since recycled steel only creates 0.56 pounds of carbon equvalents and 2.08 pounds of CO2 per pound of input, our 2 ounce can would only emit 0.26 pounds of CO2. With a 28% mix of recycled steel and virgin inputs per ton, we end up with 1,918.02 pounds of carbon per short ton and our can will create 0.12 pounds of carbon equivalents. This works out to 0.444 pounds (7.1 ounces) of CO2 per jar. In summary, the amount of carbon dioxide (CO2) released from making a 2 ounce steel soup can will be 8.25 ounces with virgin inputs, 4.16 ounces with all recycled material and 7.1 ounces with a 28% recycled mix. Obviously, if we could create all the new cans from nothing but recycled steel, we would have a much larger savings in co2 emmissions, but that isn't realistic. We do get an 13.86% reduction in emmissions from the current mix of 28% recycled steel, though. If the amount of steel recycled increases, then the amount available to be used in new manufacturing might increase, so always recycle your steel. Or, you could just reuse the cans and make storage containers, pen holders, lanterns, candle holders, flower pots and much more. You can also make music with empty cans! If you would like to know when I update this site or add some more content, email me and I'll add you to my notification list. One of my recommendations for maintaining a frugal household is that yousubscribeto my free, weekly newsletter, which always contains a dozen or so of my various tips. (I do put in one ad at the bottom for you to ignore.) There are several volumes of Non-Consumer tips and how to articles available here. Some recommended reading is available here. Return from recycling steel facts to The Frugal Non-Consumer
|
