Life cycle greenhouse gas emissions of bio‐oil from two‐step torrefaction and fast pyrolysis of pine

Abstract

Life cycle assessment of bio‐oil from woody biomass through two pathways was carried out using a one‐step pathway that utilizes fast pyrolysis of pine and a two‐step pathway that incorporates a torrefaction step prior to fast pyrolysis. A two‐step pathway with torrefaction at a temperature of 330 °C and pyrolysis at 530 °C had a global warming potential of about 6 g CO2 equivalent per MJ of bio‐oil compared to about 39 g CO2 equivalent per MJ of bio‐oil for a one‐step pathway using an energy allocation‐based analysis. For a one‐step pathway, the size reduction step made the highest contribution of over 50% of the overall global warming potential. Greenhouse gas (GHG) savings of up to 80% compared to heavy fuel oil (HFO) were achieved for a two‐step pathway in comparison to a one‐step pathway due to savings in size reduction energy. The use of renewable energy sources produced internally to provide process heat either by first burning char and then condensables from torrefaction (oil) or vice versa resulted in similar global warming potential reduction in comparison to use of natural gas to provide process heat. The bio‐oil production pathways were found to be more sustainable in comparison to HFO due to relying chiefly on renewable biomass rather than fossil energy. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Production of Hydrocarbon Fuel Using Two-Step Torrefaction and Fast Pyrolysis of Pine. Part 2: Life-Cycle Carbon Footprint

“…In addition, for each torrefaction temperature, the lowest emissions were observed for scenario 3 which has the objectives of using renewable energy for process heat and maximizing bio-oil quality, with export of maximum char. In our previous study where we considered bio-oil as the final product for these one and two-step pathways, a similar trend of significant reduction in potential GHG emission but lower net GHG values were observed (about 36.3 gCO 2 eq/MJ of bio-oil for the one-step pathway) . In comparison with gasoline, percent reduction ranged from about 8% for scenario 2 of the two-step at torrefaction temperature of 290 °C to about 176% for scenario 3 at torrefaction temperature of 330 °C.…”

“…11 Winjobi et al in their assessment of the effect of torrefaction on the GHG emissions from the production of biooil from loblolly pine via fast pyrolysis achieved an 80% reduction in GHG relative to heavy fuel oil. 12 Iribarren et al in their assessment of hydrocarbon transportation fuel from fast pyrolysis of short-rotation poplar biomass achieved a GHG saving of 72% over conventional fossil fuel. 13 Hsu estimated about 75% reduction in GHG emissions for biofuel produced via fast pyrolysis and hydroprocessing of hybrid poplar over conventional fossil gasoline.…”

“…Steele et al in their assessment of pyrolysis bio-oil from whole southern pine achieved a 70% reduction in emission compared to residual fuel oil based on equivalent energy value . Winjobi et al in their assessment of the effect of torrefaction on the GHG emissions from the production of bio-oil from loblolly pine via fast pyrolysis achieved an 80% reduction in GHG relative to heavy fuel oil . Iribarren et al in their assessment of hydrocarbon transportation fuel from fast pyrolysis of short-rotation poplar biomass achieved a GHG saving of 72% over conventional fossil fuel .…”

Fuel property improvement and exhaust emission reduction, including noise emissions, using an oxygenated additive to waste plastic oil in a diesel engine

“…A study reports 15 that the life‐cycle analysis of woody biomass to bio‐oil using a two‐step torrefaction and pyrolysis process results in less environmental impact relative to the one‐step pyrolysis process. Nugroho and his co‐authors 16 investigated waste plastics, including PS, PP, polyethylene (PE) and polyethylene terephthalate (PET), aiming to obtain pyrolytic oil from it for application as fuel for a compression ignition engine.…”