12-04-2018 4:00 pm
Wherever the eye can see, you will find plastic. Plastic can be found in the clothes we wear, vehicles we drive, in building materials, household products, as well as electronic devices. Plastic is literally everywhere and used in almost everything. Over the past 60 years plastic consumption has exploded at a tremendous rate worldwide as plastics play an important role in all aspects of a modern lifestyle. (Thompson, 2009) From what was once considered to be an inferior material, today outpaces any other manufactured material on the planet. (Geyer, 2017) Plastics are incredibly versatile materials; they are inexpensive, lightweight, strong, durable, and corrosion-resistant. (Thompson, 2009) Few human made inventions have been as revolutionary as plastic, making the plastics industry one of the most successful industries in modern times. (Joyce, 2017) Is plastic too good to be true? In this essay, I will attempt to explain the global impact plastic has on the environment and the implications of plastic consumption.
Globlisation - The problem and solution:
The problem is, plastic is simply too good. Today, an average person living in Western Europe or North America consumes 100 kilograms of plastic each year, mostly in the form of packaging. Every year approximately 300 million tons of plastics are produced around the world, and only a fraction is recycled. Where does the plastic end up? Theoretically, every little bit of plastic ever produced since its conception is still here in some form. According to the United Nations Environmental Program between 22 % and 43 % of the plastic used worldwide is disposed of in landfills while the rest end up in the world's oceans. (Gourmelon, 2015) It is estimated that about 8 million tons of plastic debris such as plastic packaging and plastic bottles are being washed into the oceans worldwide each year breaking down into smaller micro-plastics releasing chemical toxins that eventually are digested by marine life. As revolutionary as plastic has become globally, it is described as the worst "environmental plague of our time". (Bondareff, 2017)
How then do we solve the increasing problem of global plastic waste? Environmental issues such as plastic pollution are never as simple as we think. Solutions that seem to help the environment in obvious ways often have major drawbacks, doing more damage in other ways. Because of plastics unique property profiles, plastics are often made in combination with other materials which they are not all easily separated. The challenge for the global community is developing scientific solutions where non-degradable plastics can be chemically modified for reuse. (Woodford, 2017) Studies have shown that mechanical and chemical technologies today are able to recover the energy contained in some plastics. Plastics have a high energy content that can be converted to electricity, synthetic gas, fuels and recycled feedstocks for new plastics and other products. While conventional recycling is still the most sustainable method of reducing landfill deposits and ocean pollution, the development of chemical recycling is an alternative approach to processing plastic solid waste. State of the art techniques to chemically degrade plastic waste to its original form or other chemicals will allow for manufacturing of plastics into new products or as an alternative fuel, minimising the negative impact plastic has on the local and global environment. (Scheirs, 1998)
Age of Plastic:
Celluloid is the first known compound to demonstrate the ability to mould when heated and maintain its shape when cooled, which was pioneered by metallurgist Alexander Parkes in 1856 when he patented and trademarked "Parkesine", the first man-made "thermoplastic". Plastics are primarily derived from oil and natural gas, while a small portion of plastics is also made from plants like corn and sugarcane. (Gourmelon, 2015) Plastics are manufactured from polymers or long chains of repeating molecules. An example of a "polymer" is polyethylene (PE) which is primarily used in packaging (eg. plastic bags, containers and bottles). Ethylene (ethane) is the monomer, and when many monomers are connected in a chain by a chemical reaction, it breaks the double bond, forming a polymer. Monomers are obtained by refining petroleum which are usually found naturally in crude oil or can be easily manufactured through chemical processes. (Petroleum UK, 2015)
Today there are many different types of plastic and each one has its own properties and uses, from commercial to residential, and can be grouped into two basic categories: thermoset plastics and thermoplastics. Thermoset plastics are plastics that after being heated and shaped become hard and durable when cooled, and are difficult to recycle. This type of plastic cannot return to its original form and are resistant to degradation. Thermoplastics soften on heating and remain soft when cooled, allowing them to be remoulded and re-used into a product of almost any shape. Thermoplastics can be re-melted and essentially returned to their original state. The four main ways of recycling plastics are: primary recycling refers to the process of recycling clean uncontaminated single-type waste material which is the most conventional method of recycling used today. Mechanical recycling or secondary recycling refers to separating polymers from the additives. The disadvantage of mechanical recycling is the deterioration of the product properties in every cycle. Chemical or feedstock recycling is the process of partial or total depolymerisation to the monomers to regenerate the original polymer. Energy recovery refers to the recovery of plastics energy content. (Scheirs, 1998)
Implications of plastics on the environment:
Plastic was first developed for industry use in the 1920s evolving from the use of natural plastic materials, to the use of chemically modified materials by the 1940s. From 1950 to 2012, the production of plastics averaged 8.7 % per year booming from 1.7 million tons to the nearly 300 million tons that are produced, generating revenue of about $600 billion each year. General purpose plastics such as packaging used in our daily lives are mostly thermoplastics and account for 96 % of waste plastics. Plastic packaging represents 40 % of demand in Europe and 42 % in the United States replacing materials such as glass, metal and paper. (Plastics Europe, 2014) However only 15-20 % of all waste plastics can be effectively recycled by conventional recycling methods. Beyond this, plastics become contaminated with foreign materials such as soil, dirt, aluminium foil, paper labels and food remnants.
In a groundbreaking study that quantifies how much plastic waste flows into the ocean each year, a group of engineers and environmental scientists have analysed population and economic data from 192 coastal countries bordering the Atlantic, Pacific and Indian Oceans in addition to the Black and Mediterranean Seas. The study shows that, "eight million tons of plastic trash ended up in the ocean", identifying countries like China, USA, and Brazil as the major sources of the ocean's plastic waste. 8 million tons of plastic trash is likened to lining up 5 grocery bags on every foot of coastline around the globe. Scientists estimate that 5 grocery bags will increase to 10 by 2020 equivalent to 155 million tons of plastic waste if waste management practices stay the same. (Jambeck, 2015) Equally devastating to the environment is the overwhelming amounts of plastic waste that ends up in landfills. An American study from 2011 found that only 6 % of plastic waste in the US are recycled, 7.7 % are combusted for energy recovery while a staggering 85.8 % of plastics are landfilled. (Themelis, 2011) According to Plastics Europe, "The most effective measure to promote recycling and energy recovery of plastic waste would be the elimination of landfilling". (Plastics Europe, 2014) Plastics that are landfilled are estimated to take up to 500 years to decompose because they rarely see sunlight, and disposed of in the ocean, plastic is bathed in as much light as water breaking down into small bite sized pieces that is ingested with dire consequences for some 700 species of marine wildlife. (Parker, 2015)
Over the past decade, scientists have developed various chemically altering techniques capable of converting plastic waste into fuels, monomers, or other valuable materials by thermal and catalytic cracking processes. One such technique is a thermal depolymerisation technique called "pyrolysis" which is likened to the natural geological process thought to be involved in the production of fossil fuels. In its simplest definition pyrolysis is the degradation of polymers at high temperatures. Pyrolysis is also referred to as polymer cracking and its main advantages are that it can deal with plastic waste which is otherwise difficult to recycle creating reusable products. This process can be applied to transform both thermoplastics and thermosets into high quality fuels and chemicals allowing for the treatment of mixed, unwashed plastic wastes. This means that heavily contaminated plastic wastes can be processed without difficulty drastically reducing landfill and ocean pollution. (Scheirs, 2015)
In summary, the global production of plastic and development of new synthetic plastic materials will increase to meet the growing demands of our modern lifestyles, undoubtedly at the same rate as landfills and oceans will continue to be littered with millions of tons of plastic waste that are presently devastating global environments. While some plastics have the potential to be recycled many times retaining their value and functional properties with minimal impact on the environment, the waste of non-recyclable plastic being discarded globally is as much the solution as the problem that needs to be addressed before there is more plastic in our oceans than fish. Plastics as a synthetic material or it's natural substance is a resource that can be utilized globally, either recycled back into their original forms or into a new product, and where it is not possible or sustainable, can be used for energy recovery as a substitute for virgin fossil fuels to meet the global needs of energy resources.
This is my science essay I wrote in 2018. The criteria was to write about a "man-made problem" affecting the environment - I chose plastics. If you are interested in the sources I have used in researching my essay, drop me a line.