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The petroleum industry is an enormous global enterprise. It is estimated that the world consumes some 30 billion barrels of oil per year. Drilling, transporting, refining and transporting petroleum through pipelines and other shipping methods drives the economies of many countries. Renewable fuel sources may seem like small potatoes when compared with such massive fossil fuel production and infrastructure, but some companies are making a go of it, and customers and the oil industry are taking notice.

In the U.S., a number of companies are producing biofuels from plant sources. Yet another niche within renewable fuels involves companies who take waste vegetative matter and other discarded materials and convert them into second generation biofuels. Producing fuel from renewable sources also can mean incentives from state and federal government entities offering renewable fuel certificates for blends containing fossil fuel alternatives.

In November 2015, Wilmington, Delaware-based Ensyn announced it had been granted a key regulatory approval from the U.S. Environmental Protection Agency (EPA) for its renewable gasoline product RFGasoline, meaning both the company’s RFGasoline and its RFDiesel now had approval, pursuant to Title 40 CFR Part 79 promogulated under the Clean Air Act, which is required in order to market the fuels in the U.S.

The company describes its RFGasoline as “a drop-in gasoline transportation fuel” which is created by processing Ensyn’s renewable crude, Renewable Fuel Oil (RFO), with customary petroleum feedstocks in conventional petroleum refinery”—a process it calls “RFO coprocessing.”

AT THE ROOT

Ensyn’s RFO is produced by processing nonfood solid biomass, including wood residues, using the company’s patented core technology, Rapid Thermal Processing (RTP)—a thermal conversion process the company says is characterized by moderate temperatures and atmospheric pressure.

Ensyn’s website, www.ensyn.com, provides a step-by-step description of its closed-loop RTP technology. First, the biomass enters a feed preparation system. The biomass material is then dried and sized using heat and energy captured from the RTP process. The prepared feedstock is then metered into the conversion unit, where the material is broken down into pyrolytic vapor by a rapidly flowing stream of hot sand.

Pyrolytic vapor travels to the bio-oil collection system while the separated sand and charcoal enter the sand reheater. The charcoal is combusted in a bubbling bed to reheat the sand. Flue gas carries ash overhead to a collection system. Clean, hot sand is transferred from the sand reheater back to the conversion unit. The energy in the hot flue gas is directed to the biomass preparation system, while the vapor is quickly quenched in the bio-oil collection system. The condensed product is drawn off continuously and any remaining noncondensable gas is recycled to the conversion unit to provide the lift that drives and completes the closed-loop process.

The weight percent yields from processing the biomass are approximately 65 to 80 percent liquid, with 12 to 16 percent each of char and combustible gas, according to the company. Ensyn says the precise liquid yield depends on the feedstock that is being processed. Char and gas also can be used as fuel sources for plant operations or for export to other facilities.

According to Ensyn’s website, “The RTP technology has multiple proven applications and has been demonstrated commercially in a number of industrial sectors.” Not only have liquids been used for renewable fuel, they have been a source of numerous chemical products, more than 30 of which have been commercialized, says the company.

ADVANCING AND EXPANDING

Ensyn and its partners have been combusting RFO for industrial heating purposes for many years. More than 20 million gallons have been combusted commercially in boilers and furnaces in Canada and the U.S.

Ensyn completed an enhancement of its RFO production plant in Renfrew, Ontario, in 2014, converting it from a renewable chemicals and heating fuels plant to a dedicated fuels facility producing RFO. The 3-million-gallon-per-year production plant is Ensyn’s first facility dedicated to the production of RFO.

Initial term contracts for RFO produced in the Ontario facility have been signed with two hospitals in New Hampshire and Youngstown Thermal, the district heating facility in Youngstown, Ohio.

In addition to the Ontario facility, Ensyn says it has built and commissioned more than 15 production units incorporating its RTP conversion technology since 1989, including five commercial facilities in operation in Wisconsin producing specialty chemicals and heating fuels.

The company says, “At the core of each of these applications is the same platform RTP technology that has been in use for the last two decades,” adding, “Ensyn is now applying this same technology as it expands production capacity in North America and internationally for the production of advanced cellulosic biofuels.”

BREAKING THROUGH

Through an alliance with Honeywell UOP, Ensyn is developing and commercializing RFO coprocessing. The two companies have formed Envergent Technologies for the technology licensing, engineering services and supply of equipment.

Veronica May, vice president and general manager of Honeywell UOP’s renewable energy and chemicals business, says, “With Part 79 regulatory approvals now in hand for both RFDiesel and RFGasoline, Ensyn and Honeywell UOP can accelerate the commercial introduction of RFO coprocessing,”

Ensyn says it is advancing its RFO Coprocessing business “with UOP and an array of first-class, global industry leaders,” many of them involved in the Part 79 registration process.

The liquid RFO feedstock was produced at one of Ensyn’s commercial facilities and shipped to Brazil. Using Petrobras FCC coprocessing technology, 400 gallons of coprocessed gasoline were produced in a collaboration between Petrobras and the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). The gasoline fraction was shipped to a global oil company in the U.S. for initial evaluation and preparation for the Part 79 test.

The final RFGasoline product was then shipped to Southwest Research Institute (SwRI) in San Antonio, Texas, where independent Part 79 testing was conducted.

“This approval is another key step in the commercialization of our refinery coprocessing business,” stated Dr. Robert Graham, Ensyn chairman. “Refiners can now proceed with commercial deployment of RFO coprocessing and sell both key products, renewable gasoline and renewable diesel, into U.S. commerce. Ensyn and Honeywell UOP can now expedite offtake negotiations with refiners while Ensyn and its project partners proceed with expansion of RFO production capacity in order to meet demand.”

The author is editor of Renewable Energy from Waste and can be reached at ksmith@gie.net.