Gasoline continued ethanol

But ethanol cannot be blended into gasoline at the refinery because it is hygroscopic and picks up traces of water in pipelines and storage tanks. Also, ethanol shipped away from the Midwest, where it is made by com fermentation, would add to the cost of gasoline. Gasohol may increase air pollution because gasoline containing ethanol evaporates more quickly. Studies and debate continue. 

In contrast to the Western economy, the Russia continued expansion of wood hydrolysis facilities, and about 40 such plants are presently in operation. All the Russian plants are based on dilute sulfuric acid in percolation towers. In the West interest in producing alcohols from wood was revitalized by the dramatic increase in the price of petroleum in the 1970s and the push to decrease oil imports by substituting gasohol, which is one part alcohol in nine parts gasoline, for 100 percent gasoline at gas pumps. Both ethanol and methanol can be used in gasohol blends. 

See alcohol, denatured alcohol, industrial biomass. Note Ethanol from fermentation of biomass and hydrolysis of cellulose is a significant alternate energy source, especially as an automotive fuel. Its use in gasoline will continue to increase. 

When the ethanol is not blended but used as such as fuel, hydrous ethanol (e.g. 95%) can be applied. In a cascade-type continuous set-up [27] a partial evaporation of the fermentation liquid was carried out and the ethanol-water mixture was passed over a H-ZSM5 zeolite (350 °C, 1 atm). As in the MTG (methanol to gasoline) [28, 29] process a mixture of alkanes (mainly C3-C5) and aromatics (mainly toluene, xylenes and C<)-compounds) was obtained. In this approach the ethanol-water separation is avoided the hydrocarbons and water are non-miscible and separate by gravity. Though its octane number is good there is no future in MTG-gasoline because of the trend to lower the aromatics content. 

Other chemical products, often referred to as connnodity chemicals, are required in large quantities. These are often intermediates in the manufacture of specialty chemicals and industrial and consumer products. These include ethylene, propylene, butadiene, methanol, ethanol, ethylene oxide, ethylene glycol, ammonia, nylon, and caprolactam (for carpets), together with solvents like benzene, toluene, phenol, methyl chloride, and tetrahydrofuran, and fuels like gasoline, kerosene, and diesel fuel. These are manufactured in large-scale processes that produce billions of pounds annually in continuous operation. Since they usually involve small well-defined molecules, the focus of the design is on the process to produce these chemicals from various raw materials. 

Methanol/syngas chemistry for acetic acid/anhydride could possibly be extended to some related intermediates, while Fischer-Tropsch products may fit in with detergent requirements (or provide a cracker feedstock). The Mobil methanol-to-gasoline process is potentially attractive for aromatic hydrocarbons. In view of the importance of polyethylene, the direct conversion of syngas or methanol to lower olefins has also received considerable attention, such that many current cracker-based routes could possibly continue. The possibility of fermentation ethanol re-emerging as an intermediate for chemicals is less clear. 

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