Integrated Reactive Catalytic Fast Pyrolysis: Biocrude Production, Upgrading, and Coprocessing

Abstract

This study investigates hydrotreating biocrude produced by reactive catalytic fast pyrolysis (RCFP), a direct biomass liquefaction process that combines a robust hydrodeoxygenation catalyst for in situ pyrolysis with excess hydrogen at ambient (low) pressure. The RCFP process leverages advantages from catalytic fast pyrolysis (process simplicity and improved biocrude quality) and biomass hydropyrolysis (enhanced hydrodeoxygenation) to produce a thermally stable biocrude that can be upgraded in a single hydroprocessing step or coprocessed with petroleum refining intermediates to produce gasoline- and diesel-range hydrocarbons. RCFP biocrude (9.4 kg, 19.3 wt % oxygen, dry basis) was hydrotreated continuously for 144 h, in a pilot-scale hydroprocessing unit, at 138 barg (2000 psig) hydrogen pressure, 0.31 h–1 space velocity, and an average temperature of 300 °C. Blends of 10%, 15%, and 20% RCFP biocrude in light gas oil were also upgraded over a NiMo hydrotreating catalyst at 350 °C in hydrogen at 50–70 barg (725–1015 psig). The stand-alone hydrotreating results indicate that, even though there was no pressure drop increase indicative of reactor fouling, hydrotreating catalyst deactivation was evident as the product density increased from 0.852 to 0.955 kg/L after 144 h time-on-stream. Additionally, the oxygen content of the upgraded liquid product increased from 1.4 wt % to 5.5 wt % over the course of the experiment. In the coprocessing test, little or no catalyst deactivation was observed with the 10% RCFP blend on the basis of the density of the hydrotreated products. However, the hydrotreating catalyst activity was lower during upgrading of the 20% and 15% blends. On the basis of hydrodesulfurization of light gas oil, the relative activity of the hydrotreating catalyst decreased by 40% during the 1000 h coprocessing test. Fortunately, this level of deactivation measured at this small scale does not correlate to a prohibitively large deactivation rate at the industrial scale.

Petroleomics Approach to Investigate the Composition of Upgrading Products from Pyrolysis Bio-Oils as Determined by High-Field FT-ICR MS

“…Specifically, the density increased as a function of increasing catalyst deactivation. However, the catalyst was active even after 144 h. of time on stream Table presents the bulk elemental composition of the bio-oil feed (RCFP biocrude) and its hydrotreated effluents (RCFP-1–6).…”

“…Bio-oil, obtained from RCFP of loblolly pine, was hydrotreated continuously for 144 h under 2000 psi of H 2 . In total, 9.0 kg of bio-oil was fed into a pilot-scale hydroprocessing unit . Specifically, the RCFP biocrude (referred to as bio-oil feed) was hydrotreated continuously for 144 h in an RTI’s pilot-scale hydroprocessing unit at 2000 psi of hydrogen pressure and a liquid hourly space velocity (LHSV) of 0.35/h over a sulfide hydrotreating catalyst.…”

“…A total of 9.0 kg of feed was processed. Information about the catalyst is reported elsewhere . Six effluents were recovered at different time points: ∼36.5, 48.5, 72.5, 96.5, 124.5, and 143.5 h. Thus, the hydrotreated effluents could be used to access catalyst aging and were labeled RCFP-1–6.…”

“…Alternative fuels from biomass fast pyrolysis are promising “green” energy sources with the potential to offset carbon emissions . Indeed, fast pyrolysis of biomass has been the target of extensive scientific efforts since the oil crisis in the mid-1970s, with significant advances in catalyst development for hydrotreatment achieved in the past decade. − Thus, current biomass pyrolysis methods can produce liquid intermediates that can be upgraded to obtain hydrocarbon molecules with properties consistent with transportation fuels. − …”

Virtual Special Issue of Recent Advances in Biofuel Production via Co-refining Route

“…They reported higher biogenic carbon incorporation into fuel products when coprocessing CFP bio-oils compared to the FPBOs, and over 90% of carbon in CFP bio-oil was incorporated into liquid hydrocarbon products. Dayton et al 14 investigated hydrotreating biocrude produced by reactive catalytic fast pyrolysis (RCFP) as production of a thermally stable biocrude that could be upgraded in a single hydroprocessing step or coprocessed with petroleum refining intermediates to produce gasoline-and diesel-range hydrocarbons. In the co-processing test, little or no catalyst deactivation was observed with ≤10% RCFP blend based on the density of the hydrotreated products.…”