Ethylene, H2 C = CH2, the lightest olefin. It is a colorless, flammable gas, produced mainly by thermal decomposition in the presence of steam (steam cracking) from petroleum-based raw materials. Ethylene has virtually no direct inhalation, but almost exclusively acts as an intermediate in the production of other chemicals, especially plastics. Polyethylene, which is the most commonly used plastic, is directly produced from ethylene by its polymerization. Ethylene can also be chlorinated or combined with benzene to produce 1,2-dichloroethane, a precursor of plastic polyvinyl chloride to produce ethylbenzene, which is another important plastic used in the manufacture of polystyrene. Lesser amounts of ethylene are oxidized to produce chemicals containing ethylene oxide, …show more content…
The plastic obtained from polyethylene can be pressed into varying shapes, ranging from the simplest to the most complicated. The ethylene market is indirectly driven by the increased polyethylene consumption for the production of several plastic components. In 2011, the global propylene market is valued at more than $ 90 billion and significant growth is anticipated in the coming years. Acrylic fibers and coatings, PVC plasticizers and coatings, polyurethane resins, epoxy resins and propylene polymers are applied on polycarbonates and solvents, that are used in the production of propylene. The automotive industry is the biggest end-user of polypropylene. The enormous expansion of ethylene and propylene production will contribute to the growth of the ethylene and propylene market, along with the rising demand for downstream products from India, China, and the Middle East. Tight environmental regulations, fluctuations in raw material prices and political uncertainties in crude oil producing regions are the main factors limiting the ethylene and propylene market [9].
hydrocarbons that forms during the extraction of natural gas and is used as a thinning
PVC or Polyvinyl Chloride (Poly (chloroethene)) is a type of plastic used all over the world for a range of things such as pipes, clothing and electrical cables. PVC is considered a thermoplastic resin meaning it resoftens when heated. It’s molecular formula is (C2H3CL)n and is a white powder that’s resistant to oxidation and degradation. However, it can be harmful to the environment but since it’s economically beneficial to many countries this is often overlooked.
The most common form of polyethylene is petroleum based or olefins based; as before mentioned polyethylene compounds have a wide commercial applicability and are made from non-renewable resources (Harding, Dennis, von Blottnitz, Harrison, & S.T.L., 2007). Its manufacturing processes are regarded as energy intensive and release significant amount of CO2 and heat into the atmosphere (Broderick, 2008). Next a little more detailed description of polyethylene’s production processes will be presented, with a focus on the way the material inputs are extracted and synthesized.
Describe in detail the production of a typical plastic like High density Polythene or PVC. from cracking to monomer and polymer.
Clive Maier, Theresa Calafut. 1998. ‘Polypropylene: The Definitive User's Guide and Databook’. USA: William Andrew Inc.
According to the American Council of Chemistry, plastics, which are otherwise known as polymers, are comprised of carbon, hydrogen, chlorine, nitrogen, sulfur, oxygen, and other elements that are combined through the conversion of natural products like oil, natural gas, or coal (ACA, n.d.). Between 7 and 8 % of the oil and natural gasses produced annually are used either directly in the conversion of such fossil fuels to plastics, or in powering the processes to produce plastics (Hopewell, Dvorak & Kosior, 2009). Plastic combinations can either form as thermoplastics, which are plastics whose atoms are connected in long chains that can be melted and reused, or thermosets, which are plastics whose atoms are arranged in three dimensional patterns that cannot be melted or reused (ACC, n.d.). Plastics are used in a wide range of products. For example, polyesters are used in textiles and fabrics, polyvinylidene chlorides are used for food packaging, polycarbonates are used for glasses and disks, and more. By the United States energy averages of 2015, each kg of plastic produced requires 62-108 mega joules of energy. The plastic requiring the largest amount of energy per kg is silicon which required about 235 mega joules of energy per kg. Three hundred and twenty two million metric tons of plastic produced in 2015 alone, and that value continues to raise, (Global plastic production,
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
These synthetic polymers can be produced in a wide variety, such as common plastics, nylons, or the surface of a non-stick frying pan. These man made polymers have a disadvantageous impact on the ecosystems. Polymers are often used in almost everything because of their physical properties like strong, resistant to corrosion, easy to shape, colour, and inexpensive. It is inexpensive for the users but leaves a huge scar to the environment that is very expensive to cover up. Petroleum is the main raw source of these polymers.
Polymers and plastics, particularly polyethylene, polypropylene, polyvinyl chloride, polyethylene, terephthalate, polystyrene & polycarbonate involve about 80% of the business' yield around the world. Chemicals are utilized to make a wide mixture of buyer products, and additionally a huge number of inputs to agribusiness, assembling, development, and administration commercial ventures. The substance business itself devours 26 percent of its own yield. Chemicals are almost a $3 trillion worldwide endeavor, and the EU and U.S. substance organizations are the world's biggest makers.
The non-biodegradability of petroleum-based plastics make a substantial challenge for the environmental ability to remove and recycling of them that offer drawback to health and environmental systems including soil infertility, the greenhouse gas and carcinogenic agents release under disposing process, landfill and incineration (approximately 60% of total products) (1-3).
Polystyrene is a very common polymer, making up such everyday items as Styrofoam cups, plastic cutlery, packing “peanuts”, CD jewel cases, and insulation. German apothecary Eduard Simon originally distilled the monomer, Styrene, from the resin of the Sweetgum tree. It was later found that when these monomers formed chains, they shared several properties of rubber, and was thus proved to be a versatile polymer. Although it only makes up about one percent of solid waste produced in the United States, th...
The world has become very dependent upon plastic products. From household items to industry and aerospace, plastic in its many formulations has transformed modern manufacturing and created conveniences and economies unimagined in the early decades of the 20th century.
"polyethylene (PE)." Encyclopaedia Britannica. Encyclopaedia Britannica Online Academic Edition. Encyclopædia Britannica Inc., 2014. Web. 10 Apr. 2014. .
Jessica Knoblauch, an author for the Environmental Health News, writes about the toll plastic has on the environment, "the process of creating plastic can produce biological effects in a range of wildlife species, crippling the local ecosystem." All forms of plastic are created using oil. Oils are refined, mixed with poisonous chemicals, and cooked at high temperatures in order to produce items. This process produces toxic byproducts and greenhouse gases, reducing our air quality and can disrupt the
made from oil and natural gas. Using plastics to replace packaging materials such as metal