BUTADIENE AND BUTYLENES (C, OLEFINS)

The United States has been short of butadiene capacity for some time and has been importing this raw material from Europe. The reason for this is that the United States has been making its ethylene primarily from natural gas liquids and thus has not been getting enough C, olefins as coproducts. In Europe, on the other hand, ethylene has been made in large volume by cracking of heavy oil fractions, from which propylene, butylenes, and butadiene are recovered as coproducts. Further, in Europe there is virtually no market for alkylate gasoline, whereas in the United States chemical uses for the C, hydrocarbons have been competing against their use in gasoline.

In the United States, C, hydrocarbons are derived mainly from oil refinery gases generated during the processes of crude distillation, catalytic cracking, and catalytic reforming. Most of the C, fraction is butylenes; only a small portion is butadiene.

Therefore, the C, fraction is processed to remove the butadiene and then catalytically dehydrogenated to convert the butylenes to butadiene. Some 70 percent of the butylenes are so treated; the rest go into a range of products including solvents and chemical intermediates as well as butyl rubber and polybutene plastics and resins.

About 80 percent of the 3.7 billion pounds of butadiene produced in the United States in 1973 went into synthetic rubber-mostly for tires. The rest went into nylon and a range of copolymers with styrene or acrylonitrile and styrene.

In the United States, the synthetic rubber market is tied to cars, for tires mostly but also for other parts as well. Over-all, this market is fairly static, particularly when compared to high-growth areas such as polyethylene and polypropylene. A number of specialty rubbers show promise of modest growth.

Hence, U.S. butadiene consumption has been growing at a comparatively modest (for petrochemicals) rate of 3-4 percent per year and is not expected to deviate significantly from this rate. Current industry outlook is for expansions in butadiene production associated with ethylene capacity via heavy oil fraction cracking to keep pace with demand growth, thus keeping the United States in a modest domestic deficit position filled from imports from Europe, which will also be expanding ethylene/butadiene capacity similarly.

This year, Europe and Japan, with their feedstock shortages associated with last winter's oil embargo, are reluctant to increase their butadiene exports to the United States, making butadiene temporarily tight and prices high.

Production and consumption data for butadiene are summarized in tables 5 and 6.

TABLE 3.-U.S. propylene chemical consumption

BUTADIENE AND BUTYLENES (C, OLEFINS)

The United States has been short of butadiene capacity for some time and has been importing this raw material from Europe. The reason for this is that the United States has been making its ethylene primarily from natural gas liquids and thus has not been getting enough C, olefins as coproducts. In Europe, on the other hand, ethylene has been made in large volume by cracking of heavy oil fractions, from which propylene, butylenes, and butadiene are recovered as coproducts. Further, in Europe there is virtually no market for alkylate gasoline, whereas in the United States chemical uses for the C, hydrocarbons have been competing against their use in gasoline.

In the United States, C, hydrocarbons are derived mainly from oil refinery gases generated during the processes of crude distillation, catalytic cracking, and catalytic reforming. Most of the C4 fraction is butylenes; only a small portion is butadiene.

Therefore, the C, fraction is processed to remove the butadiene and then catalytically dehydrogenated to convert the butylenes to butadiene. Some 70 percent of the butylenes are so treated; the rest go into a range of products including solvents and chemical intermediates as well as butyl rubber and polybutene plastics and resins.

About 80 percent of the 3.7 billion pounds of butadiene produced in the United States in 1973 went into synthetic rubber-mostly for tires. The rest went into nylon and a range of copolymers with styrene or acrylonitrile and styrene.

In the United States, the synthetic rubber market is tied to cars, for tires mostly but also for other parts as well. Over-all, this market is fairly static, particularly when compared to high-growth areas such as polyethylene and polypropylene. A number of specialty rubbers show promise of modest growth.

Hence, U.S. butadiene consumption has been growing at a comparatively modest (for petrochemicals) rate of 3-4 percent per year and is not expected to deviate significantly from this rate. Current industry outlook is for expansions in butadiene production associated with ethylene capacity via heavy oil fraction cracking to keep pace with demand growth, thus keeping the United States in a modest domestic deficit position filled from imports from Europe, which will also be expanding ethylene/butadiene capacity similarly.

This year, Europe and Japan, with their feedstock shortages associated with last winter's oil embargo, are reluctant to increase their butadiene exports to the United States, making butadiene temporarily tight and prices high.

Production and consumption data for butadiene are summarized in tables 5 and 6.