In the midst of continuing economic travails across Europe, the largest petroleum refiner in Italy is placing a bet on biofuels. The Italian energy company Eni S.p.A. will retrofit one of its diesel refineries in Venice to produce renewable diesel, using a system designed by the Illinois-based Honeywell company UOP. The switch will eventually ecompass Eni’s entire operation in Venice and, if the project is a success, it could serve as a model for putting underused fossil fuel facilities back to work in the new green economy right here in the U.S.A.
Converting a Diesel Refinery to Renewable Diesel
Honeywell calls the new process UOP/Eni Ecofining, since it was developed jointly by UOP and Eni. Converting an existing refinery to Ecofining is fairly straightforward. The process does not require unusual extremes of heat or pressure and the resulting product, Green Diesel, is chemically identical to its petroleum counterpart.
“The process for producing green diesel operates in mild conditions and integrates well within existing petroleum refineries,” according to UOP.
The two-step process can use oils from conventional biofuel crops like soy and palm, but in practice UOP and Eni have already moved on to next-generation, non-edible oils such as algae oil. Also notably included are inedible animal tallow (waste from meat processors) and waste grease, which otherwise present thorny disposal issues.
How Ecofining Works
To simplify the procedure down to the bones (you can find complete details at UOP’s Green Diesel pages) — first the feedstock is pressurized and mixed with hydrogen, then sent to a catalytic reactor where it is deoxygenated. This part of the process yields propane, water, and carbon dioxide as byproducts.
After the byproducts are removed, the resulting diesel gets another dose of hydrogen gas and is sent to a second reactor for further processing.
The final distillation steps yield more byproducts including additional propane. Leftover hydrogen is also recaptured and sent back to the two reactors.
As for the Green Diesel product itself, because it is chemically identical to petroleum, it can be used as a drop-in substitute, without any modifications to the vehicle or its engine, or to the fueling infrastructure.
UOP also claims that Green Diesel provides better performance than conventional biodiesel, especially in cold weather.
Ecofining in the U.S.A.
Ecofining is already making inroads in the U.S. market, with the announcement last spring of a new Ecofining facility in Louisiana, built by the Chicago-based biofuel company Emerald Biofuels.
That’s great as far as new refinery construction goes, but of much greater interest to environmental advocates in the U.S. is the potential for switching existing petroleum refineries to biofuel, since that could pull the rug out from under the controversial Keystone XL Pipeline.
The Keystone XL project would not necessarily provide more oil to the U.S. market. Its purpose is to convey tar sands oil from Canada to the global market, through Gulf Coast refineries.
So far, the Obama Administration has resisted approving the pipeline on environmental grounds. Keystone advocates have muddied the issue by arguing that the “shovel-ready” project will create badly needed construction jobs, and it will preserve jobs in the refining sector.
However, the emergence of conversion-friendly biorefining alternatives like Ecofining pretty much eliminates that argument. After all, if the creation and preservation of energy jobs is what it’s all about, there’s plenty of work to go around.
Image Credit: Ecofining, courtesy of UOP
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.