Comparison of co-refining of fast pyrolysis oil from Salix via catalytic cracking and hydroprocessing

• Lignocellulosic biomass from energy crops, i.e., short rotation coppice willows such as Salix spp., can be used as feedstock for production of transportation biofuels. Biomass conversion via fast pyrolysis followed by co-refining with fossil oil in existing refinery infrastructure could enable a fast introduction of large-scale production of biofuels. In this study, Salix was first liquefied using ablative fast pyrolysis in a pilot scale unit. The resulting pyrolysis oil, rich in oxygenates, was thereafter co-refined in 20 wt% ratio with fossil feedstock using two separate technologies, a fluidized catalytic cracking (FCC) laboratory unit and a continuous slurry hydroprocessing pilot plant. In the FCC route, the pyrolysis oil was cracked at 798 K using a commercial FCC catalyst at atmospheric pressure, while in the hydroprocessing route, the oil was processed at 693 K and a hydrogen pressure of 15 MPa in the presence of an unsupported molybdenum sulfide catalyst. Both routes resulted in significant deoxygenation (97 wt% versus 93 wt%). It is feasible to co-refine pyrolysis oil using both methods, the main difference being that the hydroprocessing results in a significantly higher biogenic carbon yield from the pyrolysis oil to liquid and gaseous hydrocarbon products (92 wt%) but would in turn require input of H2. In the cracking route, besides the liquid product, a significant part of the biogenic carbon ends up as gas and as coke on the catalyst. The choice of route depends, among other factors, on the available amount of bio-oil and refining infrastructures. © 2023 The Authors

Ämnesord

LANTBRUKSVETENSKAPER  -- Annan lantbruksvetenskap -- Förnyelsebar bioenergi (hsv//swe)

AGRICULTURAL SCIENCES  -- Other Agricultural Sciences -- Renewable Bioenergy Research (hsv//eng)

Nyckelord

Biofuels

Co-refining

Fast pyrolysis

Fluidized catalytic cracking

Hydroprocessing

Salix

Atmospheric pressure

Bioconversion

Carbon

Catalysts

Crops

Feedstocks

Fluidization

Fluidized beds

Molybdenum compounds

Pilot plants

Refining

Sulfur compounds

Biogenics

Fast pyrolysis oil

Fluidized catalytic crackings

Lignocellulosic biomass

Pyrolysis oil

]+ catalyst

biofuel

catalyst

cracking (fracture)

pyrolysis

refining industry

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)