Ethylene renewable resources

Because oil and gas ate not renewable resources, at some point in time alternative feedstocks will become attractive however, this point appears to be fat in the future. Of the alternatives, only biomass is a renewable resource (see Fuels frombiomass). The only chemical produced from biomass in commercial quantities at the present time is ethanol by fermentation. The cost of ethanol from biomass is not yet competitive with synthetically produced ethanol from ethylene. Ethanol (qv) can be converted into a number of petrochemical derivatives and could become a significant source. 

Ethylene. Where ethylene is ia short supply and fermentation ethanol is made economically feasible, such as ia India and Bra2il, ethylene is manufactured by the vapor-phase dehydration of ethanol. The production of ethylene [74-85-1] from ethanol usiag naturally renewable resources is an active and useful alternative to the pyrolysis process based on nonrenewable petroleum. This route may make ethanol a significant raw material source for produciag other chemicals. 

Polyester chemistry is the same as studied by Carothers long ago, but polyester synthesis is still a very active field. New polymers have been very recently or will be soon commercially introduced PTT for fiber applications poly(ethylene naph-thalate) (PEN) for packaging and fiber applications and poly(lactic acid) (PLA), a biopolymer synthesized from renewable resources (corn syrup) introduced by Dow-Cargill for large-scale applications in textile industry and solid-state molding resins. Polyesters with unusual hyperbranched architecture also recently appeared and are claimed to find applications as crosstinkers, surfactants, or processing additives. 

Surfactants can be produced from both petrochemical resources and/or renewable, mostly oleochemical, feedstocks. Crude oil and natural gas make up the first class while palm oil (+kernel oil), tallow and coconut oil are the most relevant representatives of the group of renewable resources. Though the worldwide supplies of crude oil and natural gas are limited—estimated in 1996 at 131 X 1091 and 77 X 109 m3, respectively [28]—it is not expected that this will cause concern in the coming decades or even until the next century. In this respect it should be stressed that surfactant products only represent 1.5% of all petrochemical uses. Regarding the petrochemically derived raw materials, the main starting products comprise ethylene, n-paraffins and benzene obtained from crude oil by industrial processes such as distillation, cracking and adsorption/desorption. The primary products are subsequently converted to a series of intermediates like a-olefins, oxo-alcohols, primary alcohols, ethylene oxide and alkyl benzenes, which are then further modified to yield the desired surfactants. 

It should be pointed out that the raw materials for VAM and its related polymers (i.e. ethylene and acetic acid) are produced from fossil resources, mainly crude oil. It is possible to completely substitute the feedstock for these raw materials and switch to ethanol, which can be produced from renewable resources like sugar cane, com, or preferably straw and other non-food parts of plants. Having that in mind, the whole production of PVAc, that nowadays is based on traditional fossil resources, could be switched to a renewable, sustainable and C02-neutral production process based on bioethanol, as shown in Fig. 3. If the vinyl acetate circle can be closed by the important steps of biodegradation or hydrolysis and biodegradation of vinyl ester-based polymers back to carbon dioxide, then a tmly sustainable material circle can be established. 

Biopolymers and sustainable growth have been recently discussed by Singh (2). "Biopolymers" are defined as polymers made from "renewable" resources. However, not all biopolymers are biodegradable (2). For example, Dow and a Brazilian company called "Crystalsev" announced a joint venture in 2007 to manufacture LLDPE using ethylene produced from ethanol derived from sugarcane (22, 23). Though such LLDPE may be considered a biopolymer, it will not be any more biodegradable than LLDPE from petroleum-based ethylene. 

In total the planned bioethylene production capacity seems low compared to the annual ethylene production of 100 million tons (2000) but it is enough to show the capability of utilizing sucrose as feedstock for organic chemicals. The door towards the whole C2-chemistry being based on renewable resources is opened. 

By chemical recovery of polyester [poly(ethylene terephthalate) (PET)] (Chapter 16) and PU wastes, by alcoholysis or by aminolysis (Chapter 20), new polyols are obtained that can be used in rigid PU foam fabrication. The vegetable oil polyols, obtained by chemical transformation of the double bonds in vegetable oils in various hydroxyl groups are a very attractive route to obtain polyols from renewable resources (Chapter 17). 

Scientific Design Company, Inc. Ethylene Oxide/Ethyl-ene glycols Ethanol and oxygen Utilizes renewable resources to produce "green" glycol and EO 8 2009... 

The L- isomer is produced in humans and other mammals, whereas both the D- and L-enantiomers are produced in bacterial systems. Lactic acid can also be derived chemically from renewable resources such as ethanol or acetaldehyde or from chemicals coming from coal (e.g. acetylene) or oil (e.g. ethylene)... 

Gandini, A., Silvestte, A.J.D., Pascoal Neto, C. et al. (2009) The furan counterpart of poly(ethylene terephthalate) an alternative material based on renewable resources. Journal of Polymer Science Part A Polymer Chemistry, 47 (1), 295-298. 

Blends of starch with polar polymers containing hydroxyl groups, such as poly(vinyl alcohol), copolymers of ethylene and partially hydrolyzed vinyl acetate have been prepared since the 1970s, as described by Otey et al. [61, 68-72]. Since starch and other natural polymers are hydrophilic, water has been commonly used as a plasticizer for these materials. The possibility of using water as plasticizer makes it possible to add the polymer to be blended as an aqueous emulsion, as for example, in the case of natural rubber latex [112], poly(vinyl acetate) and other synthetic polymer lateces [71,113,114]. Blends of starch and biodegradable polymers and polymers from renewable resources have been reviewed recently due to their growing importance [82, 110, 111, 115, 116]. Table 15.3 gives some polymers commonly used in blends with starch. 

Poly(lactic acid) (PL A) is a renewable resource-based bioplastic with many advantages, compared to other synthetic polymers. PL A is eco-friendly, because, apart from being derived from renewable resources such as corn, wheat, or rice, it is recyclable and compostable [1, 2]. PLA is biocompatible, as it has been approved by the Food and Drug Administration (FDA) for direct contact with biological fluids [3] and has better thermal processability compared to other biopolymers such as poly(hydroxy alkanoate)s (PHAs), poly(ethylene glycol) (PEG), or poly(e-caprolactone) (PCL) [4]. Moreover, PLA requires 25-55% less energy to be produced than petroleum-based polymers, and estimations show that this can be further reduced by 10% [5]. 

However, not many people realize that polyethylene, another product that Commoner was very worried about, was originally produced in Britain by the fermentation of grain to produce alcohol and dehydration of alcohol to produce ethylene. It and many other common plastics including styrene and polyester can be produced by known chemical processes from renewable resources such as wheat, cellulose, starch, biomass, etc. through the following chemical reactions. 

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