Estimating profitability of two biochar production scenarios: slow pyrolysis vs fast pyrolysis

Abstract

We estimate the profi tability of producing biochar from crop residue (corn stover) for two scenarios. The fi rst employs slow pyrolysis to generate biochar and pyrolysis gas and has the advantage of high yields of char (as much as 40 wt-%) but the disadvantage of producing a relatively low-value energy product (pyrolysis gas of modest heating value). The second scenario employs fast pyrolysis to maximize production of bio-oil with biochar and pyrolysis gas as lower-yielding coproducts. The fast pyrolysis scenario produces a substantially higher value energy product than slow pyrolysis but at the cost of higher capital investment.We calculate the internal rate of return (IRR) for each scenario as functions of cost of feedstock and projected revenues for the pyrolysis facility. The assumed price range for delivered biomass feedstock is $0 to $83 per metric ton.The assumed carbon offset value for biochar ranges from $20 per metric ton of biochar in 2015 to $60 in 2030.The slow pyrolysis scenario in 2015 is not profi table at an assumed feedstock cost of $83 per metric ton. The fast pyrolysis scenario in 2015 yields 15% IRR with the same feedstock cost because gasoline refi ned from the bio-oil provides revenues of $2.96 per gallon gasoline equivalent. By 2030, the value of biochar as a carbon offset is projected to increase to $60 per metric ton and the price of gasoline is expected to reach $3.70 per gallon, which would provide investors with an IRR of 26%.

Regional differences in the economic feasibility of advanced biorefineries: Fast pyrolysis and hydroprocessing

“…While several studies have either directly or indirectly quantified the feasibility of different aspects of the pathway under different scenarios, most techno-economic analyses (TEA) in the literature focus on factors such as feedstock supply logistics (Hess et al, 2009;Petrolia, 2008), biorefinery size (Islam and Ani, 2000;Wright et al, 2008), production of high-value products and co-products (Ahmad et al, 2010;Brown et al, 2011a;Brown et al, 2011b;French et al, 2010;Galinato et al, 2011;Wright et al, 2010a;Yoder et al, 2011), and product yield improvement (Ahmad et al, 2010;Akhtar and Amin, 2011;Carlson et al, 2011;Yoder et al, 2011). Only a handful of TEA studies have considered politico-economic factors.…”

“…McCarl et al (McCarl et al, 2009) quantify the economic feasibility of slow pyrolysis under a scenario in which char qualifies for GHG offset credits as part of a hypothetical carbon price program. Brown et al (Brown et al, 2011a) compare the 20-year internal rates of return (IRR) of slow pyrolysis and fast pyrolysis facilities under a scenario simulating the American Clean Energy and Security Act, in which petroleumbased transportation fuels become more expensive due to the implementation of a carbon price and biochar qualifies for GHG sequestration credits. Brown and Hu (Brown and Hu, 2011) quantify the economic feasibility of a fast pyrolysis and upgrading NOTICE: This is the author's versions of a work that was accepted for publication in Energy Policy.…”

“…Finally, pre-tax transportation fuel market values vary by ±10% depending on geographic region (API, 2012;EIA, 2012a). The economic feasibility of the fast pyrolysis and hydroprocessing pathway is sensitive to many of these factors individually (Brown et al, 2011a;Wright et al, 2010a), suggesting that it will also be sensitive to location, which affects all of these factors simultaneously. definition when lignocellulosic feedstock is utilized (Hsu, 2012).…”

“…This high-level scoping analysis employs a modified version of an existing process model of the pathway used in previous analyses (Brown and Hu, 2012;Brown et al, 2011a;Wright et al, 2010a) …”

Physico-Chemical Properties of Bio-Oils from Pyrolysis of Lignocellulosic Biomass with High and Slow Heating Rate

“…In order to decrease the dependence on fossil fuels and reduce CO 2 emissions there is an urgent need for energy conservation and use of renewable energy resources. A promising approach is to lower atmospheric CO 2 while producing energy from bio-oil and biochar which are two major products of biomass pyrolysis (Brown, Wright, & Brown, 2011). The worldwide petroleum consumption was recorded to 90 million barrels per day in 2012, however the consumption is expected for increase to 103 million barrels per day in 2025 .…”