Biobased Ethylene

Commercial plans for a biobased ethylene source to manufacture polyethylene have been published by Dow Chemical Company for a process based in Brazil. In a report by Kevin Bullis published by MIT Technology Review on July 25, 2011, plans for the construction of a 240-million-liter ethanol plant using sugarcane as feedstock has been proposed by Dow as a joint venture with Mitsui. This ethanol-based ethylene would be used to manufacture 350,000 metric tons of polyethylene. This would be in addition to a 200,000-ton sugarcane-to-polyethylene plant operated by Brazil-based Braskem. However, for this ethanol-based ethylene and polyethylene facility to be successful, the ethylene costs must be competitive with ethylene produced from naphtha, which will mostly likely remain the high-cost ethylene source. 

The polyethylene industry should not discount the future importance of biobased ethylene and such statements should be avoided. Technological innovations could even result in cost advantages of ethylene from ethanol as compared to ethane-cracking, which requires extremely large capital investments for construction of a world-class ethylene manufacturing plant. 

Another example of algae-based research was announced in July 2009, when ExxonMobil announced a joint venture with Synthetic Genomics Inc. to investigate the synthesis of biofuel from natural and engineered strains of algae [30]. 

Richardson, Saudi feedstock problems worsen, 2010 Report, www.icis.com. 

Chevron-Phillips Chemical Company press release, Bloomberg News, Dec. 15,2011. 

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In 2009, Coca Cola introduced the PlantBottle , which is made from partially biobased PET. The same material is now being used by Heinz. PET, as has been explained, is most often made by polymerizing ethylene glycol and terephthalic acid. Biobased ethylene glycol is now available. When it is used to make PET, the resulting polymer has about 30% biobased content. Coca Cola and others are working on economically viable routes to produce terephthalic acid from biobased sources, which would permit 100% biobased PET [8,9]. 

By ethoxylation of natural fatty alcohols from vegetable oils with biobased ethylene oxide fiolly biobased nonionic fatty alcohol polyglycol ether surfactants can be manufaaured... 

Biobased ethylene can be produced from biobased ethanol. The ethanol can be fermented from sugars found in organic sources like corn, sugarcane, potatoes, etc. The two common sources of bioethanol are from corn in the United States or sugarcane in Brazil. Bioethanol is converted to ethene with an aluminum oxide catalyst. The ethene is polymerized to polyethylene. Figure 5.1 lists the molecular formula of ethanol, ethane, and polyethylene. 

Platform chemicals are compounds that serve as building blocks for numerous chemical intermediates and end products. An example is ethylene, which serves as the feedstock for derivatives such as acetaldehyde, ethylene dichloride, ethylene oxide, polyethylene, vinyl acetate, and ethyl acetate. Biobased chemicals such as succinic acid, 3-hydroxypropionic acid (3-HP), and butanol also have the potential to be converted into multiple derivatives, some of which are commodity chemicals and others that are higher-value chemicals. 

Braskem, a Brazilian company, began producing biobased polyethylene on a commercial scale in 2010 [7]. The starting material is sugar cane. Conventional fermentation methods are used to produce ethanol from sugar. Ethanol is then dehydrated to ethylene. This ethylene can then be used to produce polyethylene, exactly as is done with ethylene from petrochemical sources. The resulting polyethylene is identical in performance to conventional polyethylene, and of course is not biodegradable. 

Braskem is also planning to introduce biobased polypropylene. The same basic idea can be used to produce any plastics that are derived from ethylene, from any source of sugar or starch. Of course, cost remains a major barrier. 

A classical example for a biobased polymer, which can be made from renewable bioproducts, is polyethylene (PE), which is nowadays produced exclusively by the catalyzed polymerization of ethylene coming directly from the steam cracker, a 100% petrochemical process. Ethylene, however, can also be produced via ethanol coming from glucose fermentation. This is a typical bio process. 

In addition to bio-based polyesters such as poly(lactic acid) (PLA), polyhydroxyalkanoates (PHAs), and poly(ethylene furanoate) (PEE), all based upon biomass-derived building blocks that have a structure different from today s commercial petrochemical-based polyesters, biobased polyesters can be developed having an identical structure to well-known petrochemical based polyesters. A very important class of such drop-in type bio-based polyesters are represented by polyesters based upon either isophthalic acid or terephthalic acid, such as PET,... 

Traditional plastics can be made from agricultural products, including PET, PBT, nylon 6, nylon 10, and acrylics. The largest interest has occurred with the biobased PET botde. Currently, Coca-Cola introduced a biobased PET bottle, for example. Plant Bottle, with 30% biobased and 70% petroleum based (After Dasani Test 2009). PET botdes are made typically from 30% mono-ethylene glycol (MEG) and 70% terephthalic acid. The MEG can be made with biobased sources and the terephthalic acid is made from petroleum sources. The production capacity of the 30% bio-PET bottle is 452,000 tons. Coca-Cola plans to launch a 100% PET bottle in the future (Race to 100% bio-PET). 

Conversion after separation, biorefinery process streams are subjected to chemical, thermal or biochemical conversions. The output of this operation is a portfolio of biobased fuels and chemicals. Of the three primary operations, conversion is the least well developed for the biorefinery. While the petrochemical industry can describe many high yield, selective conversions of their primary building blocks (ethylene, propylene, benzene and so on) only a scant number of biorefinery conversions, comparable in efficiency and breadth to the existing chemical industry, are available. 

Ethanol from sugars or starch is used in large quantities either as a fuel or fuel additive, or increasingly as a raw material for the production of (green) ethylene and polyethylene (PE). The principle of the dehydration of ethanol to ethylene can also be applied to other biobased alcohols, thus giving access to bioolefins and biohydrocarbons [11]. 

Table 11. Key Life Cycle Indicators for Biobased PDO and Ethylene Oxide-...

Acrylated oleic methyl ester (AOME) biobased elastomer/ MMT + Methyl methacrylate (MMA)/ ethylene glycol dimethacrylate (EGDMA)... 

Aliphatic polyesters like poly(e-caprolactone), poly(butylene succinate), and poly (hydroxyalkanoate)s are widely used. An aromatic polyester of poly(ethylene terephthalate) is much more utilized practically. Poly(lactic acid) (PLA) is an aliphatic polyester and has recently attracted major attention. So far, PLA has been a leading polymer produced from biobased resources. High molecular weight PLA is already produced in various ways and used as a green plastic for electronic products, automobile parts, and in biomedical applications [27-40]. 

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