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Synfuels International, Texas A&M Develop Portable GTL Process
In an interview, Ben R. Weber Jr., president of Dallas-based Synfuels International, Inc., told the Bulletin his field-scale technology converts gas at the wellhead into a gasoline-type product that could be used as fuel or shipped through existing infrastructure.
Designed specifically with the North Slope of Alaska in mind, Weber said such technology could substantially reduce the need for an expensive pipeline to the Lower 48 states by taking advantage of existing infrastructure such as marine tankers, rail and trucks, in addition to pipelines.
"We're not certain it could ever take the place of a pipeline ... but it could offer the alternative for some percentage to convert gas and ship it down existing infrastructure," he said.
Another region of the globe ripe for such technology is the Middle East, where massive gas reserves are effectively stranded for lack of processing and transportation infrastructure, Weber noted.
Converting gas to a liquid fuel has been possible for 70 years, typically using the Fischer-Tropsch process, but it has always been extremely cost prohibitive.
The new Synfuels process is simpler than existing technologies and does not use oxygen, except in power generation. The main byproduct of the conversion is water, which can be used for other industrial or agricultural purposes, Weber said.
The Synfuels process also differs from the conventional Fischer-Tropsch GTL process in economies of scale and production. Plants using the Synfuels process could vary in size from skid-mounted portable plants to permanent installations and would be a fraction of the size of a Fischer-Tropsch plant.
Weber said his units are capable of processing gas in 10, 25 and 50 mmcf per day increments. The latter is "the maximum size we would consider portable," he said.
Although a larger-sized fixed plant is conceivable, it's also possible to daisy chain the units to provide greater processing capacity. A 10 mmcf per day unit would cost on the order of $30 million (U.S.) to construct, producing a bbl of gasoline-type product for about $17.
Weber noted that those costs could vary substantially with large-scale production. "We think there's room to get those costs down lower," he explained.
The small size and portability of the units would enable petroleum companies to construct the plants almost anywhere, even at remote drilling sites. Consequently, Weber said gas could be produced in areas once considered impractical or uneconomic.
Depending on the catalysts used in the conversion process, the liquids have characteristics of C6s and C8s that can be further refined for specific uses. Weber confirmed one possible application is as a diluent for transporting heavy oil.
Weber also said the wellhead units could be used to liquefy solution gas as a cost-effective alternative to flaring, although he admitted "that wasn't the first purpose we had in mind."
The units are compatible with sour gas reserves, but additional scrubbers would be needed to remove sulphur and other impurities.
Although the liquefied gas could conceivably be converted back to a gaseous state, Weber stressed that the Synfuels process is not meant to be a substitute for liquefied natural gas (LNG), and would require further processing that may or may not be cost effective.
Each year, more than 15 tcf of stranded natural gas is burned, vented or re-injected into producing formations. If converted using the Synfuels process, the wasted gas could potentially yield an additional 2.5 billion bbls of petroleum equivalent per year, the company said in a news release.
The technology, conceived and developed in co-operation with Texas A&M; University and the Texas Engineering Experiment Station, has been under development for the past five years. S&B; Engineers and Constructors of Houston has been contracted to build and test a GTL pilot plant near the Texas A&M; campus.
Once commercialization is complete, sometime within the next 12-18 months, the consortium plans to licence the technology to worldwide manufacturers, Weber said.
