Dynamotive Produces Renewable Gasoline and Diesel from Biomass in Three-Stage Process: Pyrolysis, Hydroreforming, Hydrotreating
Dynamotive Energy Systems Corporation has successfully produced renewable gasoline and diesel from biomass at its research facility in Waterloo Ontario through a novel two-stage upgrading process of its pyrolysis oil, BioOil.
The BINGO (Biomass INto GasOil) process involves pyrolysis of lignocellulosic biomass to produce a primary liquid fuel, BioOil, which is then hydroreformed to a Stage 1 gas-oil equivalent liquid fuel that can either be directly utilized in blends with hydrocarbon fuels for industrial stationary power and heating applications or be further upgraded to transportation grade liquid hydrocarbon fuels (gasoline/diesel) in a Stage 2 hydrotreating process. (Earlier post.)
The first stage of hydro-reforming, carried out at 330 °C and ~1,800 psi (12.4 MPa), of the biooil stabilizes the liquid; renders it miscible with hydrocarbon liquids; causes phase separation of the water in the biooil; lowers its viscosity and corrosivity; and drops the oxygen content from ~50% in the raw biooil to around 10%.
Designated UBA, the reformed bio-oil product has a HHV of 39.5 MJ/kg. The HHV of the original biooil is ~16 MJ/kg while that of hydrogen is ~121 MJ/kg.
Since UBA still contains ~10% oxygen it is not a pure hydrocarbon and needs further treatment to convert it to motor fuel grade products. Among the technologies commercially available are FCC (catalytic cracking) and hydrotreatment/hydrocracking. UBA can blend freely with most hydrocarbon fuels in concentrations up at least 50%.
For a proof-of-concept, Dynamotive hydrotreated UBA over a commercial catalyst at 350°C and ~1,700 psi (11.7 MPa). The resulting liquid product, designated UBB, had a HHV of ~45 MJ/kg—comparable to that of diesel—with oxygen content of approximately 1%. Commercial hydrotreating catalysts are available that can steer the product towards diesel/gasoline/jet fuel etc. at somewhat higher severity conditions. The overall yield of UBB from bio-oil is 38%.
The major by-product from lignocellulosic biomass pyrolysis is Biochar which has emerging value for soil productivity enhancement and carbon sequestration. Dynamotive markets its Biochar under the trade name CQuest.
Based on initial test and analysis, the Company currently estimates that it can deliver advanced (second generation) fuels from biomass at a cost of less than $2 per gallon of ethanol-equivalent fuel in facilities processing about 70,000 tonnes of biomass per annum (current scale of its 200 metric tonne per day plant).
Dynamotive’s pyrolysis process converts roughly 85% of the total biomass feed into useful solid (char) and liquid (BioOil) fuels. The balance is utilized to provide energy to the process. Dynamotive estimates that the net overall yield of hydrocarbon liquids from wheat straw would be 29% UBA or 24% UBB.
As far as we can determine this would be the highest yield of hydrocarbon liquids from whole biomass ever reported. It far exceeds the 14% biomass to diesel reported for the Bioliq BTL process; even when account is taken of the likelihood that yields of motor fuels—as opposed to unspecified hydrocarbons—in the final step will be somewhat lower on account of the higher severity hydrotreatment that would be required.—“A preliminary look at the economics of a new biomass conversion process by Dynamotive”
Dynamotive projects that a plant processing under 70,000 tonnes of biomass a year would produce approximately 4,500,000 gallons of renewable gas-oil at less than $2 per gallon. The scale factor enables distributed production—i.e., plants can be developed in diverse locations closer to feedstock.
The two stage process also allows for the opportunity to further upgrade the stage 1 renewable gasoil into diesel and gasoline fuels at a centralized facility or the development of a fully integrated plant if production logistics and economics merit it. This provides for flexibility in development and application.
Given the plant scale, the investment required is comparatively low. Approximately $33 million will deliver a 15-year production capacity of approximately 67 million gallons of renewable transportation grade hydrocarbon fuels.
Dynamotive’s pyrolysis platform is available today, with plants of 130 Mt and 200 Mt per day completed. The upgrading process uses conventional hydrotreatment equipment and process conditions allowing for rapid implementation at pilot and commercial scale. Dynamotive plans to build an upgrading pilot plant later this year.
In October, the US Department of Energy awarded UOP LLC a $1.5 million grant to develop economically viable technology to stabilize pyrolysis oil from second generation biomass feedstocks for use as a renewable fuel source. The UOP award is one of five made by the DOE in this area. (Earlier post.) UOP is also investigating a pyrolysis pathway as a component for its work on renewable JP-8 aviation fuel, an element of which is funded by DARPA. (Earlier post.)