Ethanol sugar cane-derived

Such a country is Brazil. Burdened under a massive balance of payments deficit due mainly to a lack of any petroleum reserves, Brazilians have been looking to other fuel sources for some time. Already some Brazilian gasoline contains a substantial percentage of ethanol derived from biomass fermentation (principally sugar cane bagasse and molasses). 

There are continuing efforts to develop cost-effective processes for fuel alcohol production, although the economics are often dependent on the availability of subsidized feedstocks to compete with traditional fuels derived from oil. The pretreatment and fermentation of such feedstocks, derived from corn, sugar cane, and even municipal waste, yields a dilute aqueous solution of ethanol which must be separated from a complex mixture of waste materials and then concentrated by distillation to remove water. Both batch and continuous production processes have been developed, with the requirement for effective bioseparations during both the pretreatment and ethanol recovery parts of the process. 

The ethylene glycol in the composition of this PET is derived from sugar cane, by way of the synthesis process described earlier for ethylene (Figrtre 6.5), followed by two stages of chemical transformation - first into ethylene oxide and then into ethylene glycol. As we saw earlier, the bio-ethanol pathway does not completely... 

Ethylene for the manufacture of polyethylene is derived from cracking various components of petroleum oil such as the gasoline fraction, gas oil, or from hydrocarbons such as ethane. While petroleum remains the predominant source of the monomer at the present time, it can also be produced using biomass. In fact ethylene has been commercially derived from molasses, a by-product of sugar cane industry, via the dehydration of ethanol. 

Competition between NR and bio-based SR (SR made from biosourced feedstock) should not be underestimated. For example in 2012, LANXESS is planning to produce the world s first SR, i.e. ethylene propylene diene monomer (EPDM) rubber (under the brand name of Keltan Eco) from ethylene derived from sugar cane at its Triunfo plant in Brazil. The ethanol is dehydrated into ethylene and polymerized to produce EPDM rubber." Besides, bio-based SR is suggested to be the bio-based feedstock of poly(butadiene) rubber for tyre industries. 

The world s 140 million metric tons of annual ethylene capacity almost exclusively employs steam cracking of hydrocarbon feedstocks [5]. The majority of the feedstocks come from petroleum refining, such as by cracking of naphtha, but some producers use liquefied natural gas as a feedstock. In Brazil, where sugar cane is plentiful, Braskem has built a 200,000 metric ton per year ethylene plant based upon the dehydration of sugar-derived ethanol [6]. In the United States, natural gas liquids, a mixture of ethane, propane, butane, and other hydrocarbons, are available from shale deposits. The ethane is separated and cracked to make ethylene. Depending on the cost of oil and natural gas, this can be an economic advantage. In 2012, about 70% of United States ethylene production was from ethane [7]. 

The data (and their sources) used to calculate the carbon contents, vq, and the conversion efficiency factors, cv, and the calculations themselves, are given in Appendix 2. As tq we use 0.61, 0.44 and 0.43 for rapeseed, maize, and sugar cane, respectively. We derive values of cv = 0.58 for rapeseed bio-diesel, cv = 0.37 for maize bio-ethanol, and cv = 0.30 for sugar cane ethanol production. 

Despite the efficiency of the manufacture of ethanol from petrochemical feedstocks, much of the world s production is based on a fermentation process. Over the past 75 years in the United States, where the total annual production now stands at just under 4 million tonnes, the source of this basic chemical feedstock has swung away from fermentation to petrochemistry and back again (Table 6.1). The carbon source for the fermentation is glucose derived from starch (see Section 6.6). An even larger quantity, about 9.5 million tonnes, is produced each year in Brazil from cane sugar. Nowadays the prime consumer is the motor car. 

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