Tiba Abdulrazak

DES 040A - A03

Topic: Synthetic Rubber Eraser

Professor Cogdell (TA: Diana)

Dec. 10, 2014

Synthetic Rubber Erasers _ Raw Materials

            Raw materials are considered to be essential part of the synthetic rubber eraser's life cycle. Erasers can be either natural or synthetic. Over the years, it was proven that synthetic rubber erasers are more convenient  than natural erasers, "Several synthetic rubber compounds have been used to make erasers. These include ... styrene-butadiene ... Synthetic rubber began to replace natural rubber in erasers by the 1960s. Since the mid-1990s, erasers have been made nearly exclusively with synthetic rubber, primarily polyvinyl chloride. The driving force to complete the changeover was to help prevent allergic reactions to latex, mainly in schoolchildren." (PUBS). Synthetic erasers are more efficient than natural erasers for varieties of reasons such as it eliminates the need of using latex, which causes allergies and diseases for some people, and it is easier to produce. Also, the raw materials for synthetic erasers are more available, which could lead to more production of erasers.

            The raw materials for the synthetic rubber eraser come in the form of chemicals, secondary raw materials, which are almost always available. The most common synthetic rubber is made of chemicals such as styrene and butadiene. "Styrene is a liquid derived from ethylbenzene. Ethylbenzene is usually made from ethylene and benzene, both of which are derived from petroleum. Butadiene is a gas, derived either directly from petroleum or from substances known as butanes and butenes, which are derived from petroleum." (madehow). Additional to that, petroleum is derived from crude oil. Crude oil is considered the major component. (sciencedirect). Some other ingredients are usually added to the rubber to add pigments that change the color of the eraser. For example, the color white is achieved by adding zinc oxide and titanium oxide, also red erasers can be made by using iron oxide. Other colors can be produced by using different organic dyes. An important ingredient that is added to almost all rubber erasers is sulfur, which vulcanizes rubber. It is a process that was invented by Charles Goodyear in 1839, "It uses heat and sulfur to make rubber more durable and resistant to heat." (madehow). Some natural materials, such as vegetable oil, can be added to help make the rubber softer and easier to shape, and pumice which would make the eraser more abrasive. (madehow). Lastly, a very important raw material that has to be added in order to make erasers is water, H2O. Most of these components are considered secondary raw materials which are almost always available and if we ever run out of any of these materials, they might be made or extracted from different materials instead. The natural rubber eraser is made basically from latex, which is derived from a latex tree. Latex trees are limited and they take a long time to grow which caused a big shift during WWII to synthetic rubber due to the fact that they didn't have enough raw materials to produce natural rubber erasers, "About 35% of the rubber currently used is natural, obtained from trees ... The remaining 65% is man-made - synthesized from petroleum and other minerals in plants." (IISRP 8). Another side-effect of producing natural rubber erasers is that many people had allergies because of the latex that is used to produce the erasers. It also caused some diseases in the past. (notes from lecture). This is why the best solution was to shift to styrene-butadiene rubbers, "The wartime styrene-butadiene rubbers were essentially an emergency substitute for natural rubber." (IISRP 18). Lastly, the price of natural rubber erasers is higher than synthetic eraser which was less affordable for people to buy, "The high price of natural rubber was largely artificial and, consequently, short-lived." (IISRP 16). The side effects associated with natural rubber erasers cause the synthetic erasers to be considered more useful. Raw materials that goes into the synthetic erasers are as important as the raw materials needed to get the process of producing erasers going.

            The synthetic rubber is made in an emulsion process. First of all, fossil fuels, coal and petroleum or natural gas, are the most needed raw materials for this stage. Kinetic and thermal energies are also required. The process, fractional distillation, is used to obtain chemicals from petroleum. It involves heating petroleum to around 600-700° F (315-370° C). Then the vapor passes through a tall vertical tower which then cools as it rises. With various boiling points, chemicals change from gas to liquid which then gets collected. Some chemicals, with very high boiling points, remain in liquid, then it gets removed from the bottom of the tower.  Other chemicals remain in the form of gases, with very low boiling points, which gets removed from the top of the tower. Additional to that, other chemicals can be obtained by catalytic cracking, "This process involves heating petroleum to about 850-900° F (454-510° C) under pressure in the presence of a catalyst. The catalyst causes chemical reactions to take place. The new mixture of chemicals are then separated by fractional distillation." (madehow). The styrene is liquid; however, the butadiene is a gas and it has to be stored under pressure in order to keep it in a liquid form. Afterwards, the liquids get pumped into a container and get mixed with water, soap, and a catalyst, causes the styrene and butadiene to react and form particles of synthetic rubber. On the other hand, the soap causes these particles to disperse into water in a smooth emulsion. Lastly, constant agitation helps to keep the rubber particles from setting out. Other chemicals are added to the mixture which satisfy some of the needs to improve the structure of the synthetic eraser. Such chemicals are stabilizers, prevents rubber from breaking down and modifiers, changes the prosperities of rubber. Finally, unconverted styrene and butadiene get removed and reused. (madehow).

            Once the rubber arrives to the eraser factory, it gets mixed with pigments and other ingredients to modify the eraser's prosperities. In terms of mixing the ingredients and pigments, it is easier to do so with synthetic rubber than natural rubber because synthetic rubber arrives as powder or liquid while natural rubber arrives in bales and has to be pulverized into powder or it has to get dissolved in a solvent before it gets mixed. Afterwards, the mixture is heated which  causes the sulfur to vulcanize the rubber to make it more stable. In order to make flat erasers, an injection molding process is used most of the time. The mixture that is in a warm liquid form gets into molds which has to be cooled later on to turn into solid. Once they get into the form, they get removed from the molds. (madehow). Therefore, synthetic eraser is better than natural erasers in terms of mixing ingredients and pigments. Raw materials are also essential for packaging and needed for transportation. 

            There are some different ways to do the packaging of the eraser and transport it into stores. Erasers can be marked with the name of the brand/manufacturer which could be achieved in different forms. It could be done by stamping the eraser with pressing an inked stamp on it. Also, this could be achieved by moving an inked roller over a sheet of silk or any other material that covers the eraser, this procedure is called screen printing. Ink is usually made of pigment, resin, oil or carrier, and additives. (Chhetro, Arjun B. and Islam, M. Rafiqul). Embossing, three-dimensional markings, is the third way to label the erasers through "Cutting into the eraser with a sharp die." (madehow).  Erasers get transported through trucks that uses fossil fuels such as coal. In conclusion, the erasers are "packed into cardboard boxes and shipped to retailers." (madehow). The erasers get shipped from the country that produced the erasers to other countries which then can be found in retail stores, where consumers can buy them. (Erfurt, Chiara). This shows that raw materials are not only used in one stage of the eraser's life cycle, instead, raw materials are needed throughout the whole life-cycle.

            People use the synthetic erasers to remove unwanted marks, writings, etc. from paper. First of all, it is important to understand how an eraser works, "Pencils work because, when they are put to paper, their graphite mingles with the fiber particles that comprise the paper. And erasers work, in turn, because the polymers that make them up are stickier than the particles of paper -- so graphite particles end up getting stuck to the eraser instead. They're almost like sticky magnets." (Garber Megan). The particles of the eraser are designed to remove pencil marks. Erasers are considered so important that they are used in large amounts. I found this information from a book about synthetic rubber, "Rubber is one of a small group of industrial materials, including metals, fibers, concrete, wood, plastics and glass, on which modern technology depends. The western world alone used seven and a half million metric tons of it in 1972, and the amount is increasing at a rate of well over six percent annually." (IISRP 10). This shows that synthetic erasers are so useful to the point that they make them in huge amounts since the modern technology depends on them. On the other hand, natural rubber is not as useful since it can't be produced in such amounts because of the limits of its raw materials, such as the latex tree.

            In terms of recycling, erasers rarely get recycled. Erasers are mostly classified as non-recyclable mainly due to their small size which makes them difficult to collect in huge amounts. Therefore, there are few, if none, eraser recycle companies that exist. There is a useful way of taking advantage of erasers as much as possible though which is called the three Rs, that I found on a website, "We can begin by following the three Rs: reduce, reuse and recycle. It is as simple as reducing the number of erasers we purchase, reuse the ones we have and maybe recycle it if our collection will take it." (Wehri, Maggie). However, if the erasers are to be recycled, then it would be easier to recycle the synthetic erasers, "The advantage of synthetic erasers is that their 'shavings' or 'crumbs' can be rolled into a ball and removed easily. As opposed to natural erasers they don't spoil and don't stick to a working surface." (erasersworld). Not being able to recycle natural erasers is considered another side affect because this means that the raw materials will be wasted later on, this would be unhealthy for the environment that people live in. On the other hand, even if it would still be difficult to recycle synthetic erasers, at least they can easily shape into a ball that could be removed. In terms of recycling, synthetic erasers are more efficient than natural erasers.  

            Synthetic erasers don't  produce waste as much as natural erasers do. Natural rubber caused some issues which influenced the oxygen uptake, "COD versus time in the ozonation of rubber and tire waste water at different standard cubic feet per hour bubbling rates. It was demonstrated that ozone treated effluents exerted substantial influence on oxygen uptake, as compared to untreated effluent." (Bode, H. B., K. Kerkhoff, and D. Jendrossek).  This required to have a treatment in order to fix this issue of waste, "This suggests that ozonation of persistent organic compounds followed by conventional biological treatment may be a solution to the problem of treatment of many non-biodegradable organic compounds." (Bode, H. B., K. Kerkhoff, and D. Jendrossek).  This was the way to find a solution to this issue of waste; however, natural erasers also caused some waste issues in the form of bacterial strains which lead to the growth of synthetic rubber.  Such bacteria weren't able to grow on synthetic rubber, "We conclude that S. lividans 1326, S. exfoliatus K10, and the latex-mutants are unable to grow significantly on SR or on any soluble or volatile carbon source that might be present in the air of a lab."  (Bode, H. B., K. Kerkhoff, and D. Jendrossek). This proves the efficiency of synthetic rubber and the side affects associated with natural rubber erasers.

            In order for the synthetic rubber eraser to be produced, different raw materials have to be used throughout the eraser's life cycle. The raw materials used to produce synthetic rubber erasers are considered secondary raw materials and some of the major materials are rubber, fossil fuels such as crude oil, and sulfur. Synthetic rubber erasers are more efficient than natural rubber erasers.

Works Cited

Bisio, Attilio and IISRP. Synthetic Rubber: The story of an industry. IIORP (International Institute of Synthetic Rubber Producers, 1973. Print.

Bode, H. B., K. Kerkhoff, and D. Jendrossek. "Bacterial Degradation of Natural and Synthetic Rubber." Biomacromolecules 2.1 (2001): 295-303. ProQuest. Web. 22 Oct. 2014. <https://vpn.lib.ucdavis.edu:11005/docview/72374508?accountid=14505>.

Chhetro, Arjun B. and Islam, M. Rafiqul. Inherently-Sustainable Technology Developments. Nova Science, 2008. Print.

Connan and Cassou. "Properties of Gases and Petroleum Liquids Derived from Terrestrial Kerogen at Various Maturation Levels." Science Direct. Elsevier B.V., 2014. Web. 20 Nov. 2014.

“Eraser.” How Products Are Made, Volume 5. How Products Are Made., n.d. Web. 22 Oct. 2014. <http://www.madehow.com/Volume-5/Eraser.html>.

Erfurt, Chiara. “Life Cycle of an Eraser.” Prezi. Prezi., 03 May. 2013. Web. 22 Oct. 2014.  <http://prezi.com/u7dzicnlvvpl/life-cycle-of-an-eraser/>.

Garber, Megan. "10 Things You Probably Did Not Know About Eraser Technology." The Atlantic. The Atlantic Monthly Group, 2014. Web. 22 Oct. 2014. <http://www.theatlantic.com/technology/archive/2013/08/10-things-you-probably-did-not-know-about-eraser-technology/279028/>.

PUBS. "Erasers." PUBS. American Chemical Society, 2002. Web. 10 Dec. 2014. <http://pubs.acs.org/cen/whatstuff/stuff/8050erasers.html>

"Structure of Erasers." Erasers World. Ieo Eanoeeia, 2014. Web. 22 Oct. 2014. <http://www.erasersworld.com/eng/sostav.htm>.

Wehri, Maggie. "Practicing the Three Rs with Rubber Erasers." 1800recycling. Electronic Recyclers International, 2014. Web. 29 Oct. 2014.       <http://1800recycling.com/2014/05/practicing-three-rs-rubber-erasers>.

Lisa Gurlin

DES 40A

Christina Cogdell

TA Section A03

12/11/14

The Embodied Energy of the Synthetic Rubber Eraser

The synthetic rubber eraser is as widely used today as its history is rich.  When graphite was first used as a writing tool in the 1560s, moist bread was the first eraser, used to rub out the graphite marks (American Chemical Society). In the 1770s, Europeans first encountered natural rubber as a raw material in the Americas, where it was used by indigenous people for a variety of purposes (Synthetic Rubber: The Story of an Industry 10). One of these uses included using it to “rub” out graphite marks, a discovery attributed to Joseph Priestley (American Chemical Society). In 1839, Charles Goodyear invented the process of adding sulfur and using heat and pressure to cure rubber into a more durable material (American Chemical Society). With a growing demand for rubber in the late 19th and early 20th centuries, chemists around the world tried to devise a way to replicate the rubber molecule (a type of hydrocarbon) using synthetically derived materials (Synthetic Rubber: The Story of an Industry 14-16). By the mid-20th century, synthetic rubber began to replace natural rubber in erasers, and by 1990, most erasers have made use of the manufactured material. The most popular kind of synthetic rubber used in the manufacture of rubber erasers is styrene-butadiene rubber, also known as SBR (American Chemical Society). Very large quantities of chemical energy are used during every stage of the manufacturing process of SBR synthetic rubber erasers and their life cycle as a consumer product. This chemical energy is primarily produced through the use of fossil fuels, as fossil fuels are dense sources of high energy.

            The extraction of the most significant raw materials used to compose the synthetic rubber eraser requires the use of massive amounts of energy, primarily originating in the form of chemical energy through fossil fuels. The most prominent raw material used to create the SBR synthetic rubber[1] for erasers is crude oil (Siemens Industry 2). Crude oil is manually extracted in locations where it is found to be abundant by drilling a well into the earth (World Petroleum Council). The mechanism used to provide mechanical energy to the oil well has advanced over the late 19th and early 20th centuries, beginning with diesel-to-mechanical transfer of energy through the internal combustion engine. Mechanical energy was also derived from chemical energy in other ways, including steam power. During the advent of electrical energy conversion, rigs were developed which first converted the chemical energy of diesel fuel into electricity, and then used the electric energy to power a motor that would operate the well (Gow 161-166). Today, electric energy can be transported great distances through a comprehensive electricity infrastructure. According to the Carnegie Mellon University Green Design Institute, as much as 82% of the energy ultimately needed to extract crude oil in the 21st century is derived from burning natural gas. Sulfur, used in the curing process of both natural and synthetic rubber, can be extracted from the earth through mining, but is more easily extracted using the Frasch method (Chemistry Explained). In this method, both air and super-heated water are forced down concentric pipes into the ground where sulfur is present, causing the sulfur to become melted and forced up another pipe (Chemistry Explained). In this process, thermal and mechanical energy are necessary to prepare the water and air for this extraction process, in addition to the energy necessary to power the drilling of the well (Combs). Sulfur can also be derived as a byproduct in the manufacture of crude oil where sulfur is seen as a contaminant (Combs). The extraction of these primary raw materials relies heavily on the convenience, versatility, and prominence of chemical energy and its ability to be converted into many other forms of energy as needed.

            The eraser is largely composed of synthetic rubber, which must first be processed from its primary raw source of crude oil into a secondary raw material. The large amounts of kinetic and thermal energies needed during the conversion of crude oil to synthetic rubber, and then synthetic rubber into the eraser, requires the use of chemical energy. Many types of synthetic rubber can be produced from the hydrocarbon source of crude oil. Isoprene-isobutylene (butyl rubber) and styrene-butadiene are among the most popular choices for creating the eraser (American Chemical Society). In general terms, crude oil (or another hydrocarbon) first has to be refined in a process called fractional distillation. In this process, super-heated steam is needed to heat the boil the crude oil into a gas, where it distills in a chamber depending on the content of the oil  (Freudenrich). This process requires high thermal energy in order to heat the material. Later, the refined oil is combined with natural gas that contains the necessary chemical monomer (Siemens 2). This process also requires steam-heating. In both cases thermal energy is manually created by the conversion of chemical energy sources (such as fossil fuels) into thermal energy in a boiler. When the synthetic rubber is ready to become part of an eraser, it is mixed with sulfur in a physical process that incorporates it evenly. A process called vulcanization necessitates both thermal and kinetic energy as the refined oil is physically mixed with sulfur and treated with pressure and heat in order to form the rubber (Synthetic Rubber: The Story of an Industry 24). Once in the form of a large eraser “sheet,” the eraser slab must undergo cutting, drying, and tumbling (How It’s Made). The variety of physical and chemical processes involved in producing synthetic rubber and the rubber eraser is dependent on the use of thermal energy and electricity that can be converted from fossil fuels.

            Transportation is a vital concern for the life cycle of the synthetic rubber eraser. Not only do the raw materials and secondary raw materials have to be transported to highly specialized plants, but the distribution of the eraser as a consumer product is also a significant statistic, resulting in the heavy use of fossil fuels rich in chemical energy. According to the Carnegie Mellon University Green Design Institute, while an estimated 27,800 Ton-Kilometers are travelled for every one million dollars spent in petrochemical manufacturing, another 78,900 Ton-Kilometers are travelled in synthetic rubber manufacturing for non-tire, non-hose synthetic rubber products.[2] Rail, water, and truck were the most prevalent categories for transportation method in synthetic rubber product manufacture. According to the National Academy of Sciences, approximately 86% of the fuel used in transportation in the United States comes from petroleum-based fuels (Transportation”). The convenience of having energy-rich fossil fuel source means that most of the transportation involved in the production and distribute of the synthetic rubber eraser is powered by the chemical energy of fossil fuels.

            Once in the consumer’s hands, the synthetic rubber eraser does not require additional maintenance throughout its usefulness as a product, however energy is used in the removal of its waste. The tiny amount of kinetic energy used in rubbing the eraser on a pencil mark is enough to achieve the desired outcome of the product. Since the eraser becomes smaller with use, the practicality of collecting and recycling the synthetic rubber product is virtually non-existent. The energy needed to coordinate the collection and perform the devulcanization of the synthetic rubber into a downcycled product would outweigh the energy expended to simply toss it away.

            Waste is produced in the production of synthetic rubber products such as the eraser, along with their raw material extraction. The efforts to clean up and treat the waste products lead to the use of more energy consumption, primarily through fossil fuels. Crude oil, a large component of both the raw material and fuel source used in petrochemical manufacture and transportation, is not immune to oil spills both on land and water (Clark). Transportation of clean up crews and the resources needed to clean up dangerous oil slicks facilitates the use of more petroleum-based fuels. Some oil spills in water can be deemed as less dangerous and can be broken down by the sun’s nuclear energy (Clark). The treatment of wastewater produced by oil-extraction takes place in water treatment facilities. While the treatment method of different industrial wastewater treatment companies varies, it is generally both a physical and chemical process that requires the use of machinery in a plant run by electricity. In both of these examples, it is apparent that even the treatment and clean up of waste products in the synthetic rubber eraser life cycle involves the use of energy derived from fossil fuels.

            In conclusion, the life cycle of the synthetic rubber eraser involves the embodiment of energy in a variety of ways. In order to look into the embodied energy of the synthetic rubber eraser, all steps of the life cycle, from the extraction of raw material all the way to the wastes produced, must be considered. All of these processes require the use of thermal and kinetic energies that are largely converted from the heavy use of chemically energy-rich fossil fuels. The revelation that such high amounts of energy go into the life cycle of such a humble product demonstrates the disconnect between the simple concepts of everyday objects and lifestyle of high-energy consumption that consumers rely on today. It is impossible for us as a society to continue using these non-renewable fossil fuels that we depend on for so much of our energy. In order to prepare for a future of energy consciousness and responsibility, every aspect of the way we use energy—from transportation, electricity, and even the embodied energy of the simplest of products—must be considered.

Works Cited

American Chemical Society. "C&EN: WHAT'S THAT STUFF? - ERASERS." C&EN: WHAT'S THAT STUFF? - ERASERS. Chemical and Engineering News, 16 Dec. 2002. Web. 29 Nov. 2014. <http://pubs.acs.org/cen/whatstuff/stuff/8050erasers.html>.

Carnegie Mellon University Green Design Institute. "Results for Petrochemical Manufacturing." Economic Input-Output Life Cycle Assessment (EIO-LCA) US 2002 (428 Sectors) Producer Model. Carnegie Mellon University Green Design Institute., 2014. Web. 11 Dec. 2014. <http://www.eiolca.net/>

Chemistry Explained. "SULFUR." Sulfur, Chemical Element. Advameg, Inc., 2014. Web. 27 Nov. 2014. <http://www.chemistryexplained.com/elements/P-T/Sulfur.html>.

Clark, Josh. "How Do You Clean up an Oil Spill?" HowStuffWorks. HowStuffWorks.com, n.d. Web. 11 Dec. 2014. http://science.howstuffworks.com/environmental/green-science/cleaning-oil-spill.htm.

Combs, Susan. "Sulphur Production Manual." Sulphur Production Manual. Window on State Government, Oct. 2005. Web. 27 Nov. 2014. <http://www.window.state.tx.us/taxinfo/audit/sulphur/ch1.htm>.

Freudenrich, Craig. "Fractional Distillation - How Oil Refining Workds." HowStuffWorks. HowStuffWorks.com, n.d. Web. 09 Dec. 2014. <http://science.howstuffworks.com/environmental/energy/oil-refining4.htm>.

Gow, Sandy. Roughnecks, Rock Bits and Rigs: The Evolution of Oil Well Drilling Technology in Alberta, 1883-1970. Calgary: U of Calgary, 2005. Print.

How It’s Made. "How It’s Made - Erasers." Online video clip. YouTube. YouTube, 12 June 2013. Web. 11 Dec. 2014.

Siemens Industry. Synthetic Rubber Plants - Maxum Process Gas Chromatograph Measures and Optimizes (n.d.): n. pag. Siemens Industry, Inc., 2013. Web. 29 Nov. 2014. <http://www.industry.usa.siemens.com/automation/us/en/process-instrumentation-and-analytics/process-analytics/pa-case-studies/Documents/PIACS-00010-0813-Gas-chromatograph-rubber.pdf>.

Synthetic Rubber: The Story of an Industry. New York: International Institute of Synthetic Rubber Producers, 1973. Print.

"Transportation." How We Use Energy, Transportation. The National Academy of Sciences, n.d. Web. 08 Dec. 2014. <http://needtoknow.nas.edu/energy/energy-use/transportation/>.

World Petroleum Council. "How Do We Get Oil and Gas out of the Ground?" World Petroleum Council. World Petroleum Council, 2009. Web. 29 Nov. 2014. <http://www.world-petroleum.org/index.php?/Education/how-do-we-get-oil-and-gas-out-of-the-ground.html>.

[1] Several other chemicals are used in extremely minute amounts in order to derive the finished synthetic rubber product. [2] While this model category seems very broad and generally refers to automobile parts, it is cited here as a model upon which the unknown transportation model of the SBR rubber eraser product may be compared.

Kira Lai

DES 040A - A03

Professor Cogdell

December 11, 2014

Waste & Emission of Synthetic Rubber Eraser

There are two major types of eraser in the market, nature rubber eraser and synthetic rubber eraser. Main raw material for making nature rubber eraser is latex, a milky sap of rubber tree (Threapeuric Pillow Australia). Due to the demand and price hike of nature rubber, and the long plantation time of rubber trees, scientists started to find alternative material to produce rubber since early 1800s. The British introduced export restriction of nature rubber from British Malaya in 1922 (ACS Chemistry for Life). This foreshadowed the shortage of natural rubber during World War II, and stimulated the transition of natural rubber to synthetic rubber. Nowadays, most of the erasers are made from synthetic rubber. Although the eraser itself does not produce a lot of waste, the waste and emission produced before going to the hands of consumers is more than you can imagine.

The major materials for synthetic rubber erasers include styrene-butadiene rubber (styrene and butadiene), and sulfur. Other ingredients added to the production include color pigments, and vegetable oil (madehow). I will be focusing on the emission and waste produced from the major materials. Styrene, butadiene, and sulfur can all be derived from petroleum. Before sending the major materials for eraser production, oil extraction and refining process need to take place in order to get the materials ready.

Produced water is the largest waste produced during the oil drilling process. Produced water is mainly salty water trapped in the reservoir rock and brought up along with oil or gas during production (The Produced Water Society). This water is at least four times saltier than ocean water and often contains to ‘industrial strength’ quantities of toxins such as benzene and ethylbenzene, and heavy metals such as barium, and mercury (O’Rourke, Connolly). Therefore, produced water is being considered as hazardous and toxic effluent. The ratio of produced water to oil is approximately 10 barrels of produced water per barrel of oil (U.S. Environmental Protection Agency). Since the volume of produced water is so large, even though most of them were re-injected into the oil wells, the remaining waste is discharged into surface water (O’Rourke, Connolly), which poses threat to marine life and the environment.

Drilling wastes and associated wastes are the solid wastes produced during extraction.  Drilling wastes include drilling mud and cuttings that cannot be pumped (Scott Environmental Services). 58% of these solid wastes in the U.S. are re-injected to the wells, and 8% of them are disposed of through evaporation pits. Not only will the exposed pits affect aquifers, but it may also pose a danger to animals and birds that mistake the pits for water holes (O’Rourke, Connolly).

Radiation is also emitted from the both solid and liquid drilling waste.  It is normal and common that radioactive materials on soils and rocks formations. Oil extraction involved drilling rocks underground; this may expose or concentrate naturally-occurring radioactive material (NORM) such as uranium, thorium, and radium (U.S. Environmental Protection Agency). NORM-contaminated waste may put the waste disposal workers and nearby residents at risk. People may inhale the radioactive dust during extraction.

Crude oil is transported to refinery before it become useful. Oil will be heated up to at least 650 degrees Celsius. End products with different molecular weights will be separated through fractional distillation. The major synthetic rubber materials, styrene and butadiene, are considered as by-products of the refining process. Sulfur can also be derived from crude oil as a by-product, but it is derived from a different method than styrene and butadiene.

Oil refineries require thousands of gallons of water per day for production and cooling process. Water used as cooling agent does not really come into contact with the process material and so has very little contamination (Australia Institute of Petroleum). These water will either be recirculate in the refineries to keep cooling the distillation process, or discharge to the nearby water such as rivers, lakes, and seas. Although these cooling water will not contaminate the nearby water, it changes the water temperature in the surrounding. Not only does the change in water temperature change the oxygen environment, it also poses a danger to aquatic organisms (Pollution Issue).  

Treated process water, including rainwater falling on the refinery site and process water that actually come into contact with the process streams, is discharged to the sewerage system (Australia Institute of Petroleum). Since these water physically come into the contact with oily materials and chemical vapors, they can no longer be reuse inside refineries.

Air emission during the refining process will also impact the environment. Burning oil produces hydrocarbon vapors, nitrogen oxides, sulfur oxides, carbon dioxide, methane, mercury compounds, etc. (U.S. Environmental Protection Agency). Methane is a source of greenhouse gas, which causes global warming. Different means are used within the refineries in order to reduce the effects to human and environment, and prevent gases to escape to the atmosphere. A visible example is the tall smokestack. Gases are released up high to the sky to minimize the effect to life on the ground. Floating roofs is another example to reduce gas emission. Floating roofs are installed in tanks to prevent evaporation and so that there is no space for vapor to gather in the tanks (Australia Institute of Petroleum). 

1-3, butadiene is a by-production produced from oil refining. Most of the 1,3-Butadiene manufactured is used in the production of synthetic rubber, which is one of the major raw materials for synthetic rubber eraser. 1,3 butadiene can be release in two forms. If it is released in form of liquid, the disposal of it to the water can create moderate acute (short-term) toxicity to aquatic life. It has slight chronic (long-term) toxicity to aquatic life (Australia Government). Since it is not expected to accumulate in marine life, therefore it will not affect human due to the food chain.

The hydrogen sulfide created produced during refining process can be converted to elemental sulfur, which is an essential element for vulcanization of rubber. Claus process is a gas desulfurizing process to recover sulfur in sulfur recovery plants. Once the process completed and the reaction products (elemental sulfur) are cool, sulfur can be transported in either a molten or solid state (Australia Institute of Petroleum) for further production.  

Solid wastes and resides from refineries that cannot be reprocessed are disposed of in disposed of in EPA (US Environmental Protection Agency)-approved facilities off-site, or chemically treated on-site to form inert materials which can be disposed to land-fill within the refinery (Australia Institute of Petroleum).

There are different types of synthetic rubbers. Styrene-butadiene rubber is the one used for eraser production. In the manufacture of SBR, the main monomer, butadiene, is a gas at normal temperatures, but it can liquefied under pressure and is usually handled under this form. The other monomer, styrene, is a liquid (International Institute of Synthetic Rubber Producers, 48). War materials are added to the reactor along with catalyst, which starts & stops the chemical reaction. The unreacted butadiene & styrene are recovered and pumped back to store. They can be reuse to the second batch of production. Liquid SBR is then shipped to the eraser factory.

SBR mixed with pigments, vegetable oil, pumice, sulfur, and other ingredients that modify the properties of the final product (madehow). A lot of heat is used to mix the ingredients into the form of paste. The paste is now eraser in liquid form. There are two major ways to shape the eraser. First, extruder is a machine that shapes the erasers into a rectangular form. “Inside the machine, the eraser mixture is shaped to form thick strands, and carefully heated” (STAEDTLER Mars GmbH & Co.KG). The injection molding process is another way to shape the erasers. “The mixture, in the form of a warm liquid, is forced into molds and allowed to cool into a solid” (madehow). The eraser sheets or strands are ready to be cut after cooling down.

A large volume of water is used in the process of cooling down. I cannot find not sufficient information to tell whether the water is discharged or recycled within the factory. Most of the eraser manufactures do not release information on this.

The SBR residue (SBR-r) can be used as an economical alternative filler in nitrile rubber (Baeta, Zattera, Oliveira, and Oliveira). The rubber content of the residue can be reused in different rubber production. The defected erasers form the production can be recycled and reused in the next batch (How It's Made - Eraser).

Except the waste produced related to the machines, there are not much waste produced directly from the mixing to cutting of erasers. Some known waste from making erase includes gases release from burning fossil fuel to provide electricity. Reducing carbon dioxide emission in all processes is one of the goals of STADTLER (Eraser company) in the environmental protection aspect (Staedtler). “The pumice content of the eraser causes the blade goes blunt, the blade therefore have to be changed every four hours” (STAEDTLER Mars GmbH & Co.KG). The blades are also example of associated wastes produced from eraser manufacturing.

Plastic and paper are used in the packaging of eraser, and then erasers will be shipped to retailers all over the world.

Erasers are shipped to different parts of the world by trucks, ships, and airplanes. Greenhouse gases are released to the atmosphere from burning of fossil fuel in transportation and distribution.

Once the erasers reach customers’ hand, eraser dusts are the only waste produced on users’ end. Since eraser dusts are so small, they are usually dumped to the landfill with other household trash. There is no practice to recycle synthetic rubber eraser since it is hard to collect the residue of eraser.

Although only a small amount of waste is produced from a user’s hand, much more of them are produced from the raw material extraction, production, transportation, and distribution. Eraser help cleaning pencil marks on paper, but all the wastes produced before reaching to users’ hand are much more than pencil marks. It is ironic that a cleaning tool is not that clean.

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