Ethylene Production from Oil, Gas and Coal-Derived Feedstock

摘要

Ethylene and the associated olefins, propylene and butadiene, are the basic feedstock for the petrochemicals industry. World-wide ethylene production is around 40 million metric tons a year, valued at some 20 billion dollars. The wide range of products from these olefins suggests that the markets for these products, and hence demand for olefins, will increase. Ethylene is now almost exclusively produced by the cracking (pyrolysis) of a wide range of hydrocarbon feedstocks, namely ethane, LPG, naphtha and gas-oil (middle distillate). In the long-term, with declining availability of these hydrocarbons, ethylene from coal could become a possible alternative. Ethylene can also be produced by the dehydration of ethanol (ethyl alcohol) produced by fermentation. This report compares the cost of producing ethylene by cracking natural gas or oil-derived feedstocks, with dehydration of methanol. The report also comments on the future prospects of using coal as raw material for ethylene production, via methanol. The economics of the route to ethylene via methanol depend both on the cost of methanol from the basic feedstock, natural gas or coal, and on the value placed on methanol as a fuel. To show how coal and naphtha compete as a feedstock for ethylene, the report gives graphs showing the preferred feedstock for any given set of coal and naphtha prices. There are other possible ways of making ethylene from coal which are considered briefly. 34 references, 10 figures, 15 tables. (ERA citation 09:038056)