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Environment, Health, Safety & Security

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Tackling environmental challenges

| By Chemical Engineering

Last month marked the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change (COP21). World leaders gathered in Paris, France with the goal of working out an international agreement aimed at minimizing global warming and thereby avoiding potentially catastrophic climate-related events. The negotiations resulted in a landmark agreement, with 195 countries committing to lower greenhouse gas (GHG) emissions in order to limit the rise in global temperatures to less than 2C above pre-industrial temperatures.

The historic global accord reached in Paris has wide-reaching implications for economics, government policies and the scientific community. The ongoing efforts by scientists and engineers to reduce GHG emissions will undoubtedly get a boost. Our Newsfront in this issue, Progress to Limit Climate Change (pp. 16–19), highlights some of the technological advances that have been made in this area to date.

 

Recycling gains momentum

In addition to reducing GHG emissions, much more is needed for environmental sustainability. Another area that has been gaining momentum is recycling. A recent report*, released jointly by the Association of Plastic Recyclers (APR) and the American Chemistry Council (ACC) states that for the twenty-fifth year in a row since surveying began in 1990, the number of pounds of plastic bottles collected for recycling in the U.S. has increased. In 2014, the increase was 97 million pounds over 2013, for a total surpassing 3 billion pounds of plastic bottles collected.

Plastic bottle resins are identified by their corresponding numbers: 1) polyethylene terephthalate (PET); 2) high-density polyethylene (HDPE); 3) polyvinyl chloride (PVC); 4) low-density polyethylene (LDPE); 5) polypropylene (PP); and 6) polystyrene (PS). According to the report, the bulk of the U.S. plastic bottle market is made up of PET and HDPE, which together comprise around 97% of that market. Recycled HDPE resin is used primarily in non-food-application bottles as well as pipe and lawn products. Recycled PET resin is used mainly for fiber and food bottles. More information about recycling can be found in the report for interested parties. Also, see PET Recycling on p. 7 of this issue. Recycling of much more than plastic is, of course, also needed. See, for example, our report on New Frontiers in Metals Recycling in the April 2015 issue.

 

In this issue

Our Cover Story on distillation takes an in-depth look at flooded condenser control (pp. 37–49). The Feature Report on pressure-swing adsorption shows that this versatile technology can be used for more than just hydrogen purification (pp. 50–53). Our Newsfront on modular construction points out the pros and cons to this widely growing trend (pp. 20–24). Important information about bulk solids handling is in this month’s Solids Processing article (pp. 58–63), and there is much more in this issue. We hope you enjoy it. ■

1Dorothy Lozowski, Editor in Chief

 

 

 

* 25th Annual National Post-Consumer Plastics Bottle Recycling Report, available on http://plastics.americanchemistry.com/Education-Resources/Publications/2014-National-Post-Consumer-Plastics-Bottle-Recycling-Report.pdf