There are several economic benefits to placing gas-to-liquids (GTL) units within existing refineries, the vice president of process technology at contracting firm Fluor said on Wednesday.

Speaking at the GTL Technology Forum, Paul Koppel outlined the economic problems with many current GTL proposals and explained how increased synergies can help push the projects forward.

“Most project developers are new organizations that don’t have a track record,” he said. “Many of the technologies are new and unproven commercially. Bankers don’t look kindly on that. 

“So who will take the risk?”

By working in tandem with existing refineries, some of that risk can be mitigated, Koppel said. Benefits to placing a GTL unit inside a refinery include the possibility of using excess syngas capacity, the potential availability of CO2, the use of a hydrocracker for upgrading, and the availability of existing utilities, offsites and services.

“If syngas production, a hydrocracker and services are available, total investment cost can be reduced by 75 percent,” Koppel said.

“Even if syngas is unavailable, you can still reduce cost by about 45 percent, we’ve found.”

The tradeoff would be that the feedstock natural gas is indexed to the Henry Hub price, which currently averages near $4/MMBtu, rather than natural gas in remote areas, which runs from $0-$2/MMBtu, Koppel explained. However, the synergies in other areas could offer the appearance of a more broad economic stability.

One reason to promote this solution, he said, is that Fluor has found co-processing waste CO2 in GTL plants can boost yields and improve utilization rates.

By putting in CO2 and operating at the right conditions, Koppel said that CO2 can serve as an appropriate substitute for steam in the GTL process.

“With the addition of CO2, you can get a hydrogen-to-CO ratio of about 2, which is exactly where you want to be,” Koppel said. “That’s the ratio required for Fischer-Tropsch and methanol synthesis, and it minimizes the syngas adjustment.”

For the purpose of co-processing, the waste CO2 can be extracted from pipelines, refineries, ammonia plants and flue gas. 

Once the process begins, Fluor works with MIDREX on a natural gas reforming process, which allows for high a CO2 addition rate and a low steam-to-carbon ratio.

“That allows you to save energy and reduce water use,” Koppel said.

The downside to this process is higher compression costs, however.

“There is no perfect solution,” he said. “There’s always a trade-off.”

On the whole, Koppel said he was fairly optimistic on the future of GTL. Fluor’s experience includes involvement in most of the big GTL projects that have been built around the globe, including the Sasol I, II and III programs in South Africa; Sasol in Lake Charles, Louisiana; Shell Bintulu in Malaysia; and Mossgas in South Africa.

“The challenge the industry has is how we move ahead,” Koppel said. “Overall, it is a good technology and something we really need.”