Published March 2016
Butylenes are four-carbon monoolefins that are used in fuel and chemical applications. In 2015, the fuel market accounted for about 56% of the total world consumption of butylenes and chemical usage for about 44% of total consumption. This is relatively consistent for all regions. The major fuel application is in the manufacture of gasoline blending components, such as gasoline alkylate and methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE), which are used as octane improvers in fuel applications.
ETBE is used exclusively as an octane improver, while the vast majority of MTBE is used as an octane improver, with the remainder being consumed in the production of high-purity isobutylene. Isobutylene serves as a raw material for MTBE and ETBE, as well as for isooctane. Butylenes may also be blended directly into gasoline for volatility control. They are also marketed with propane and butanes as liquefied petroleum gas (LPG).
The following pie chart shows world consumption of butylenes:
Overall growth in consumption of butylenes is forecast to be about 2% annually during 2015–20, led by chemical usage at about 3% annually and fuel uses at just over 1% annually. Normal butylene usage in chemical applications is forecast to grow at about 6% annually during 2015–20.
Nearly all MTBE and all of the ETBE produced in the United States is exported to other countries as a gasoline octane improver. In 2015, fuel uses, led by butylene alkylates, accounted for about 53% of total consumption, while chemicals accounted for the remaining 47%. Overall growth is forecast at 4.0% annually during 2015–20.
Western European consumption of butylenes is forecast to decline at 0.3% annually during 2015–20. Fuel uses accounted for about 52% and chemical uses for 48% of consumption in 2015. Western Europe is the leading consumer of ETBE worldwide.
Japanese consumption of butylenes is expected to remain stagnant during 2015–20. Chemical applications account for about 65.5% and fuel uses for 34.5%, led by ETBE at 65.5%, but are forecast to grow at only 0.3% annually during 2015–20.
Chinese consumption of butylenes is forecast to grow at an average rate of almost 3% annually during 2015–20. Fuel uses accounted for about 65% of consumption, with growth forecast at 0.4% annually. Chemical uses accounted for about 35%, with growth forecast at 6.8% annually.
Overall, world capacity for butylenes is forecast to grow at 2.0% annually during 2015–20, led by growth of isobutylene at 3.0% per year; normal butylenes are expected to grow at a slower rate of 1.4% per year. Production from ethylene steam crackers (olefins plants) is projected to grow the fastest at about 3% annually during 2015–20, led by isobutylene at 3.5% and normal butylenes at almost 3%.
In North America, ethylene production will be based mainly on ethane, with little C4 produced. A large part of this is attributable to increased production of ethylene from shale gas operations, primarily in the United States.