Plastic Pollution

Currently, the average American throws away
approximately 185 pounds
of plastic every year…that is enough to circle the earth four times. Keep in mind that the circumference of the earth is 24,901 miles- yikes! Plastic constitutes approximately 90% off all the trash floating on the ocean’s surface, which can kill marine mammals. Frequently found on the ocean are plastic water bottles, possibly because Americans dispose of
35 billion plastic water bottles
yearly. Half of the plastic used, only gets used once, and only 5% of the plastic that gets thrown away is recovered. The main way of recovering plastic is recycling.

So why recycle?

Recycling reduces the amount of waste sent to landfills and incinerators. It also prevents pollution by reducing the need to collect new raw materials and conserves natural resources such as timber, water, and minerals. Recycling reduces greenhouse gas emissions that contribute to global climate change and helps sustain the environment for future generations, all while saving energy.

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Photo Credit: iStock Photo

In 2014,
California became the first state to ban the sale of plastic single-use bags
. San Francisco became the first jurisdiction in California to ban single-use plastic bags, in 2007. Last year, Los Angeles, the largest city in California and second largest in the United States, banned single-use plastic bags and placed a 10-cent charge on paper bags. When it comes to shopping bags and water bottles, it is advised to reuse. Although it may be easier to recycle and reuse plastic shopping bags and water bottles, it is harder to reuse and recycle food packaging. The plastic used for food packaging has several purposes. Most importantly, it protects food products from distribution damage, contains the food, and provides consumers with ingredient and nutrition information.

Really, the overall
goal of food packaging
is to contain food in a cost-effective way that satisfies industry requirements and consumer desires, maintains food safety, and minimizes environmental impact. So what are some innovative ways to do all of the above? Renewable plastic!

So what is renewable plastic?!

A novel way to make plastic from carbon dioxide and inedible plant material, such as agricultural waste and grasses has been discovered. Researchers say the new technology could provide a low-carbon alternative to plastic bottles and other items currently made from petroleum. The current goal is to replace petroleum-derived products with plastic made from CO
2
.
Scientists from Stanford
believe that by changing the formula for plastic by using Earth-friendly materials to create plastic, the goal will be feasible. Many plastic products today are made from a polymer called polyethylene terephthalate (PET), also known as polyester. PET is made from two components, terephthalic acid and ethylene glycol, which are derived from refined petroleum and natural gas. Manufacturing PET produces significant amounts of CO
2
, a greenhouse gas that contributes to global warming. A promising alternative to PET called polyethylene furandicarboxylate (PEF).
PEF is made from
ethylene glycol and a compound called 2-5-Furandicarboxylic acid (FDCA). PEF is an attractive replacement for PET because FDCA can be sourced from biomass instead of petroleum. Despite the many desirable attributes of PEF, the plastics industry has yet to find a low-cost way to manufacture it at scale. One approach is to convert fructose into FDCA from corn syrup. A better alternative is to make FDCA from inedible biomass, like grasses or waste material left over after harvest, such as furfural, a compound made from agricultural waste. However, making FDCA from furfural and CO
2
typically requires hazardous chemicals (carbonate) that are expensive and energy-intensive to make. By combining carbonate with CO
2
and furoic acid, a molten salt is formed which becomes the starting material for FDCA. The next step, transforming FDCA into PEF plastic, is a straightforward process that has been worked out by other researchers.

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Photo Credit: Cliparts

Chemistry can unlock the promise of PEF that has yet to be realized. This is just the first step. Some work still needs to be done to see if it is viable at scale and to quantify the carbon footprint. But as of now PEF has the potential to significantly reduce greenhouse emissions as it is made entirely from
vegetable raw materials and CO2
. Not only is PEF considered to be the packaging material of the future, particularly for food and beverages, but PEF can also be recycled or converted back to atmospheric CO
2
by incineration. Eventually, that CO
2
will be taken up by grass, weeds and other renewable plants, which can then be used to make more PEF. Lastly, PEF promises a greater level of impermeability to carbon dioxide and oxygen, thus ensuring a longer shelf life of packaged products. Overall, by providing a low-carbon and petroleum alternative to plastic packaging, PEF is looking like a promising replacement for polyethylene terephthalate due to the potential of reducing greenhouse emissions by a drastic measure. PEF will proved package modernization for consumer convenience, along with a makeover healthy to the environment- a double win!

This article is part of our on-going series “The Science of Food” which is comprised of essays from students in the M.S. in Food Science program at Chapman University. The essay was originally published on the Food Science Student Association’s blog, which you can read here: http://chapmanfsnsa.blogspot.com/. 

 

References:

Dianne Depra. Researchers Develop Renewable Plastic From Carbon Dioxide And Plants. 2016. Available from:
http://www.techtimes.com/articles/140066/20160312/researchers-develop-renewable-plastic-from-carbon-dioxide-and-plants.htm

Clare Goldsberry. 2015. Innovations and Trends in Plastic Food Packaging. Available from:
http://www.areadevelopment.com/FoodProcessing/Q4-2015-food-processing-guide/Innovations-Trends-in-Plastic-Food-Packaging-782311.shtml

Stanford University. Science Daily. Renewable plastic made from carbon dioxide and plants. 2016. Available from:
www.sciencedaily.com/releases/2016/03/160309135712.htm