Those in the U.S. petrochemicals industry that rely on aromatics have seen minimal benefits from surging North American shale-gas and tight-oil production.

In fact, aromatics output could become structurally short on the back of the switch to ethane feedstock for ethylene production, despite current price stability, according to Brian Ames, president of Dow Chemical’s olefins, aromatics and alternatives division.

The U.S. is typically net-short aromatics, such as toluene and benzene—chemical feedstocks for end-products along the styrenics chain like foam cups; phenol, a known feedstock of bisphenol A; and acetone. Aromatics can also be used as an octane booster in gasoline blending.

“What we’ve found is that because the U.S. is a net importer [of aromatics], the price structure here needs to be high enough to attract the imports from other parts of the world. We see that continuing, but there are a lot of dynamics here,” Ames said at a Hart Energy-sponsored event.

And since shale gas is rich in NGLs such as butane, ethane, methane and propane, those markets have been among the greatest benefactors of North America’s unconventional energy development. For example, ethane is converted to ethylene, so any ethylene-derived chemical like ethylene oxide and polyethylene stand to profit as well.

“Benzene and the aromatics are supplied equally from both oil refineries, as well as from ethylene crackers, so we have to be cognizant of what’s going on with the refining industry as well in the case of aromatics,” Ames said. “And what we’re finding is that there is potential for reduced production of aromatics from ethane crackers, as well as reduced production of aromatics from the refineries because of some of the changes going on with the crude and refinery feedslates.”

Dow, for one, has announced several projects in accordance with its strategy to capture key feedstocks like ethylene and propylene by reinvesting in the U.S. petrochemical industry.

Current key investments for the company include:

• Restart ethane cracker at Dow Chemical’s St. Charles operations near Hahnville, Louisiana. The cracker successfully started last December;

• Improve ethane-feedstock flexibility for an ethylene cracker at the company’s operations in Plaquemine, Louisiana, in 2015; • Construct a new, world-scale ethyleneproduction plant on the Gulf Coast for start-up in 2017;

• Construct a new, world-scale, on-purpose propylene-production facility at the Dow Texas site in Freeport, for start-up in 2015; and

• Construct several new, specialty-material production units on the Gulf Coast, aligned to the company’s highvalue Performance Plastics franchise.

Most petrochemical projects announced in 2011 with the advent of shale gas are expected to be online around the 2017- 2018 timeframe.

Tight-oil feedslates also yield fewer aromatics. The U.S. currently imports aromatics primarily from Asia and Europe to meet demand.

“So far we haven’t seen a big impact [on the U.S. aromatics market], because the price structure here has been set up high enough to attract imports from other parts of the world and so we’d expect that would continue,” Ames said.

Ultimately, there may be more aromatics imports, “but the effect on the economics is not that significant,” he added.

In contrast, since the U.S. exports aromatics and olefin derivative styrene—with a chemical composition of 30% ethylene and 70% benzene—even that market would benefit from lower ethylene prices, according to Ames.

“I think they [styrenics] will become more advantaged, because the ethylene portion will be cheaper for integrated producers,” he said. “The benzene cost is likely to remain pretty similar to the way it has been the last decade because the price structure here is set up in a way to attract those imports. So I think it’s net-favorable."