Life Cycle Analysis of the Plastic bottle-PET PDF

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Life Cycle Analysis of the Plastic bottle-PET Submitted by Ali Moro-PG1539717 Making a plastic bottle is not the problem, making a plastic bottle with no or minimal damage to the environment is-(Moro, 2017) ABSTRACT Plastic is a substance of infinite shapes, of infinite uses, of infinite possibiliti...

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Life Cycle Analysis of the Plastic bottle-PET Moro Ali

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Life Cycle Analysis of the Plastic bottle-PET

Submitted by Ali Moro-PG1539717

Making a plastic bottle is not the problem, making a plastic bottle with no or minimal damage to the environment is-(Moro, 2017)

ABSTRACT Plastic is a substance of infinite shapes, of infinite uses, of infinite possibilities, but also of infinite time. There are 5 major stages involved in the life-cycle of the plastic bottler; raw material extraction, manufacturing, transportation and distribution, product use and disposal and recycling. The raw materials after when they are extracted go to a manufacturer which then takes everything and makes them into plastic pellets. These pellets are shrunk using heat and pressure and they reshape those pieces of plastics to a stable structured container. The sheer magnitude of plastic bottle production and its growth rate, contrasted by a worrying inability to dispose of it efficiently, has experts raising the alarm. Despite the growing span of knowledge regarding this biohazard, the world can’t seem to stop demanding it. Growing dependency on the product by populations is raising concern about the future of the world’s ecosystems and the health of emerging economies. There is no other material that has transcends all nations, all modern economies, and all social classes notwithstanding their wealth or way of life in the same manner as plastic has done is continuing to do.

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Table of Contents ABSTRACT ................................................................................................................................................. 1 INTRODUCTION....................................................................................................................................... 3 Brief history about plastic bottles .......................................................................................................... 4 DELIMITATIONS OF THIS PAPER ...................................................................................................... 5 LIFE CYCLE ANALYSIS ......................................................................................................................... 6 Raw Material Extraction ........................................................................................................................ 8 Manufacturing....................................................................................................................................... 10 Transportation and distribution .......................................................................................................... 11 Product use ............................................................................................................................................ 12 Dumping and Recycling ....................................................................................................................... 13 Other important things to note in the life cycle process .................................................................... 15 THE GHANA STORY ............................................................................................................................. 17 The way forward ................................................................................................................................... 22 EXTENSIONS TO THE LCA ................................................................................................................. 24 Plastic eating bacteria ........................................................................................................................... 25 Biodegradable bottles ........................................................................................................................... 25 Alternative use....................................................................................................................................... 27 CONCLUSION ......................................................................................................................................... 27 REFERENCES .......................................................................................................................................... 27

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INTRODUCTION The third Chapter of the World Summit on Sustainable Development (WSSD) Johannesburg Plan of Implementation (United Nations, 2002) included a call for, “…the development of a 10 year framework of programmes in support of regional and national initiatives to accelerate the shift towards sustainable consumption and production patterns that will promote social and economic development within the carrying capacity of ecosystems…” Globally, the use of plastic bottles has become a common commodity used by man. The plastic bottle is usually used to hold liquids with the holding and storage of drinking water being the most dominant. Other uses of the plastic bottle includes: storage of beverages (alcoholic and non-alcoholic), for holding medicines, motor oil, shampoos, cooking oil etc. it is estimated that the average American uses 167 plastic bottles annually. Africa and Ghana have also had its share of the increase in the demand and usage of the plastic bottle. In Ghana the use of plastic bottle was not common until the early 2000’s and the use of plastic bottle is always associated with affluence by the general public. For the purpose of this paper, plastic bottles made from polyethylene terephthalate (PET) will be considered. PET’s are blended with thermoplastic polymer which can be either opaque or transparent, conditional on the raw material composition. Most PET used in the production of plastic bottles are produced from petroleum hydrocarbons, which is as a result of a reaction between ethylene glycol and terephthalic acid (https://www.thomasnet.com).

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Brief history about plastic bottles Simplistically, a plastic bottle can be defined as a bottle constructed or made from plastic. The first for of natural plastic was in invented during the renaissance period by Leonardo Da Vinci. The plastic which was created by Da Vinci was made from both animal and vegetable glues combined with organic fibers materials. This mixture was then used to coat the leaves of cabbage and papers. When this combination dried Da Vinci was left with a product that would be described today as a plastic like substance. (Rossella, 2004). In 1862, Alexander Parkes was responsible for introducing the first man made plastic at the Great International Exhibition in London. This man made plastic was nicknamed Parkesine. Parkesine was an organic cellulose material that once heated, could be strategically molded into certain shapes and would keep shape when it was cooled. Unfortunately, Parkesine's life span lasted only a short period of time due to an extremely expensive production cost of raw materials. (Rossella, 2004). Next was the development of the celluloid which was produced from a mixture of shredded tissue paper, sulfuric acid and nitric acid to develop the first thermoplastic and this was developed by John Wasley Hyatt. Celluloid is still used in modern day to make photographic films. Leo Baekland may possibly be responsible for what is to be considered one of the greatest inventions of the 20th century. In 1907 Leo Baekland was trying to find a more efficient insulator for electrical energy, which was at that time becoming more expensive as the demand grew and the supply shrunk. After years of hard work Leo Baekland invented "Balelite". Baekland then combined one of his earlier inventions, the "bakelizer" (a heavy iron vessel that was part pressure cooker and part basement boiler) with the "Balelite" which allowed him to

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precisely control heat and pressure, therefore allowing him to also control the reactions of chemicals. With the help of this new invention Baekland was able to form a resin which when hardened, would keep the shape of the mold, wouldn't burn, boil, melt, or dissolve when touched with any common acid or solvent (American Plastics Council, 2005). All of these inventions led to the discovery of different type/categories of plastic such as polyvinyl chloride, polyvinylidence chloride, Teflon, low-density polyethylene, etc. Polyvinyl Chloride is the type of plastic that is mostly found in vegetable oil bottles as well as food wraps; PET is primarily used in water containers, beverage (soft drinks) and food containers but the most extensively used in Ghana are polyethylene, polypropylene, polystyrene, nylon, and polyesters Plastic bottles for the holding of drinking water and soft drinks were first seen in America in 1970, though the first bottled soda water in America was created in 1835, and the first PET bottle was made three years later after the water and soft drink bottle in 1977. Plastic bottles were first used commercially in 1947 but remained relatively expensive until the early 1960s when high-density polyethylene was introduced. They quickly became popular with both manufacturers and customers due to their lightweight nature and relatively low production and transportation costs compared with glass bottles. However, the biggest advantage plastic bottles have over glass is their superior resistance to breakage, in both production and transportation. Except for wine and beer, the food industry has almost completely replaced glass bottles with plastic bottles. DELIMITATIONS OF THIS PAPER There are several broad areas that can be considered when the life cycle of the plastic container is being assessed but this paper will focus on the following areas. This paper will only focus on plastic bottles made from extracted crude oil and natural gas. Due to environmental concerns,

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some manufacturing companies use bio-plastics. These plastic are made from plant materials processed from polymers, and they are thought to be environmentally friendly since they do not require extraction. Additionally they are biodegradable and have a short life expectancy making them unfit for long-term storage. Despite these various sources, most artificial polymers today are made from petroleum. Secondly, the paper will only consider the PET plastic bottles. These bottle are the bottles that are used for either water or soft minerals. The study will not consider plastic made from other resins. This paper will not also consider capping and branding of the bottle. LIFE CYCLE ANALYSIS Life Cycle Assessment (LCA) could also be defined as a systematic set of procedures for compiling and examining the inputs and outputs of materials and energy and the associated environmental impacts directly attributable to the functioning of a product or service system throughout its life cycle (ISO, 2014). The plastic bottle evolves through several stages of its life starting from raw material extraction and ending at either Disposal or recycling. LCA has its roots in the 1960s, when scientists concerned about the rapid depletion of fossil fuels. A few years later, global-modeling studies predicted the effects of the world’s changing population on the demand for finite raw materials and energy resource supplies (Franklin Associates, 1991). The predictions of rapid depletion of fossil fuels and resulting climatological changes sparked interest in performing more detailed energy calculations on industrial processes. In 1969, the Midwest Research Institute (and later, Franklin Associates) initiated a study of the Coca-Cola Company to determine which type of beverage container had the lowest releases to

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the environment and made the fewest demands for raw materials and energy (Franklin Associates, 1991). This was the first ever lifecycle analysis that was made on a plastic bottle. For this academic paper, the LCA of the plastic container will undergo five (5) phases: Phase 1: Extraction of raw materials- this phase includes all processes involved in the extraction of the resources from the earth. This will included drilling, refining, cracking, Polymerization etc. Phase 2: Manufacturing- this involves in all the processes that the extracted raw materials go through to the point that it has been fabricated to the bottle as we see such as Polymerization and molding. Phase 3: Transportation and distribution- This phase involves the transportation and distribution of the finished or manufactured bottle to the industry that will make use of it. Phase 4 Product use- this is the phase where the product (plastic bottle) is purchased and used buy the final consumer. Phase 5: end of life- this is the stage where the container is either disposed or recycled. Note: There is a special interaction which links one phase to the other and in-between these spaces, a lot of things take place involving the utilization of energy and movement. This interaction mostly have CO2 as a by-product

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(Source: http://www.environment.gov.au). Raw Material Extraction Oil is drilled worldwide due to its multiple purposes needed. In order to make plastic, oil is drilled to mold the plastic container. Majority of the oil is made from PET. The birth of a plastic bottle begins when crude oil and natural gas are extracted from the environment. There are two steps in the drilling of oil. Because the drilling operations are the only ones capable of certifying that oil is present in the target location, teams of scientists are first sent to perform lengthy analysis of the geological structures surrounding the location. The extraction process can start once the scientists have given their assent. Next, several wells are drilled, creating optimal networking for the reservoir. The crude oil is then extracted using water or gas pressure systems. At the well’s surface, specialized machinery separates liquids and gases. 8

Petroleum has been classified into two groups: ‘conventional’ oil that is liquid and easy to pump; ‘unconventional’ oil, such as shale oil or extra heavy oil, which are extracted using more sophisticated methods. Once the oil has been prospected, targeted, and extracted from the newlydug well by huge pumping stations, the crude oil is transported via a pipeline to an oil refinery. It is then heated up to hundreds of degrees, sent up a fractional distillation column, a tower that separates the oil’s thousands of components using condensation or boiling-point techniques (the higher the boiling point, the lower up the column the component stays). Several distinct oils are thus obtained at the end of distillation process, such as fuel (for heating), diesel fuel, kerosene, and naphtha, the primary component for plastic making which condenses between 180°C and 40°C. It is also used to make colorants, fertilizers, cosmetics, perfume, pharmaceuticals, and various household products. Next is the cracking stage. The collected naphtha needs to undergo an important transformation step before being used by the plastics engineers. Cracking is the fragmentation of naphtha’s big hydrocarbon molecules into smaller, and thus more easily processed, sections. First, the crude oil is mixed with water vapour. The mélange is then heated to 800°C, then very quickly cooled down to 400°C. The tiny molecules obtained (molecules with 2 to 7 carbon atoms called monomers) will be used to make chains called polymers, plastic’s basic building blocks. Natural gas can also be transformed to ethylene which is used to create polymer solids. Natural gas is obtained by roughly the same methods of extraction and cracking as crude oil (sometimes on the same site), but the plastic industry uses it for its potentially high ethane content, a gas that, once it has been condensed at below 100°C, is another raw material for plastic making. When heated to 850°C, ethane molecules separate and create a hydrogen and ethylene mix. Only the purified ethylene is then used to create the future polymer solids, also called polyethylene. It can

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be noted that, to create 1 ton of plastic material, 1.25 tons of ethane are needed, and the chemical industry annually produces a little over 130 000 tons of ethylene. Manufacturing The first stage in bottle manufacturing is polymerization. In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks (Young 1987, IUPAC 2000, Clayden et al 2000). As already stated above, PET is made from petroleum hydrocarbon which is the main ingredient used in the manufacture of most plastic bottles. PET is made by mixing hydrocarbons with chemical catalysts, triggering polymerization. Tests are then carried out to confirm whether PET is glossy, thick, or is permeable to carbon dioxide. The PET mixture is heated and placed in molds via a process called molding. Usually, the type of the mixture is dependent on the kind of the plastic to be made. Some plastic are harder while others are softer. This usually take place in a manufacturing company. The next stage of the manufacturing process is molding. There are several common molding methods for plastic containers (Extrusion Blow Molding (EBM), Injection Blow Molding (IBM), Stretch Blow Molding (SBM)) however the method mostly used in the manufacturing of PET plastic bottles in the injection blow molding.

At this stage of the manufacturing process, the PET which has been refined is heated (seen in the figure above) and placed in a mold, the tube of PET is then transferred into a second, bottleshaped mold. A thin mandrel steel rod is slid inside the prison where it fills the parison with 10

highly pressurized air.it is important to note that the parison is air tight; Once the rod is inside the parison then stretch blow molding begins and because of the pressurized air, heat and pressure, the parison is blown and stretched into the mold therefore making it to assuming a bottle shape. To ensure that the bottom of the bottle retains a steadily flat shape as it is always seen, an unconnected component of plastic is simultaneously joined to the bottle during blow molding to prevent the bottom of the bottle from deforming to an unwanted shape. This process is illustrated in the diagram above. The mold must be cooled very quickly, this is to enable the newly formed component to be set properly. There are several cooling methods, which can be both direct and indirect but can effectively cool the mold and the plastic. Water can be streamed through pipes surrounding the mold and this will lead to the indirect cooling of the mold and plastic. Direct methods include using pressurized air or carbon dioxide directly on the mold and plastic. Once the bottle has been cooled and set, it is ready to be removed from the mold. If a continuous molding process has been used, the bottles will need to be separated by trimming the plastic in between them. If a non-continuous process has been used, sometimes excess plastic can seep through the mold during manufacturing and will require trimming. After removing the bottle from the mold and removing excess plastic, the bottles are ready for transportation. Transportation and distribution After manufacturing the bottles are disinfected and packed, ready for transportation. It is important to note that transportation exist throughout the lifecycle of the plastic bottle such as transportation from the wells to the refineries through pipe as well as conveyor belt movement at the manufacturing stage. The plastic bottle literally moves from birth to its disposal and recycling. At this stage the interest is the movement of the formed bottles from the

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manufacturing house to where they will be used to hold or store what they were made for. Mostly this usually involves packaging them either boxes o...