Quantifying the economic competitiveness of cellulosic biofuel pathways under uncertainty and regional sensitivity

The revised Renewable Fuel Standard requires the annual blending of 16 billion gallons of cellulosic biofuel by 2022 from zero gallons in 2009. The necessary capacity investments have been underwhelming to date, however, and little is known about the likely composition of the future cellulosic biofuel industry as a result. This dissertation develops a framework for identifying and analyzing the industry\u27s likely future composition while also providing a possible explanation for why investment in cellulosic biofuels capacity has been low to date. The results of this dissertation indicate that few cellulosic biofuel pathways will be economically competitive with petroleum on an unsubsidized basis. Of five cellulosic biofuel pathways considered under 20-year price forecasts with volatility, only two achieve positive mean 20-year net present value (NPV) probabilities. Furthermore, recent exploitation of U.S. shale gas reserves and the subsequent fall in U.S. natural gas prices have negatively impacted the economic competitiveness of all but two of the cellulosic biofuel pathways considered; only two of the five pathways achieve substantially higher 20-year NPVs under a post-shale gas economic scenario relative to a pre-shale gas scenario. The economic competitiveness of cellulosic biofuel pathways with petroleum is reduced further when considered under price uncertainty in combination with realistic financial assumptions. This dissertation calculates pathway-specific costs of capital for five cellulosic biofuel pathway scenarios. The analysis finds that the large majority of the scenarios incur costs of capital that are substantially higher than those commonly assumed in the literature. Employment of these costs of capital in a comparative TEA greatly reduces the mean 20-year NPVs for each pathway while increasing their 10-year probabilities of default to above 80% for all five scenarios. Finally, this dissertation quantifies the economic competitiveness of six cellulosic biofuel pathways being commercialized in eight different U.S. states under price uncertainty, utilization of pathway-specific costs of capital, and region-specific economic factors. 10-year probabilities of default in excess of 60% are calculated for all eight location scenarios considered, with default probabilities in excess of 98% calculated for seven of the eight. Negative mean 20-year NPVs are calculated for seven of the eight location scenarios

Learning and Memory in the Port Jackson Shark, Heterodontus portusjacksoni

Basic understanding of the fundamental principles and mechanisms involved in learning is lacking for elasmobranch fishes. Our aim in this study was to experimentally investigate the learning and memory capacity of juvenile Port Jackson sharks, Heterodontus portusjacksoni. Sharks (N = 30) were conditioned over a 19-day period to associate an underwater LED light or stream of air-bubbles [conditioned stimulus (CS)] with a food reward [unconditioned stimulus (US)], using three procedures (delay, trace and control). During experiments, the CS signalled at a random time between 180 and 300 s for 30 s (six times per day). For the delay the US overlapped in time with the CS, for the trace the US delivered 10 s after the CS and for our control the US was delivered at random time between 180 and 300 s after the CS. H. portusjacksoni sharks trained in all procedures improved consistently in their time to obtain food, indicative of Pavlovian learning. Importantly, the number of sharks in the feeding area 5 s prior to CS onset did not change over time for any procedures. However, significantly more sharks were present 5 s after CS onset for delay for both air-bubble and light CS. Sharks trained in the delay and trace procedures using air-bubbles as the CS also displayed significantly more anticipatory behaviours, such as turning towards the CS and biting. Sharks trained with the light CS did not exhibit such behaviours; however, trace procedural sharks did show a significant improvement in moving towards the CS at its onset. At 20 and 40 days after the end of the conditioning experiments, some sharks were presented the CS without reward. Two sharks trained in the delay procedure using air-bubbles as the CS exhibited biting behaviours: one at 20 and the other at 40 days. This study demonstrates that H. portusjacksoni have the capacity to learn a classical conditioning procedure relatively quickly (30 trials during 5 days) and associate two time-separated events and retention of learnt associations for at least 24 h and possibly up to 40 days

Techno-economic analysis of biomass to transportation fuels and electricity via fast pyrolysis and hydroprocessing

A previous Iowa State University (ISU) analysis published in 2010 investigated the technical and economic feasibility of the fast pyrolysis and hydroprocessing of biomass, and concluded that the pathway could produce cellulosic biofuels for a minimum fuel selling price (MFSP) of $2.11/gal. The 2010 ISU study was largely theoretical in that no commercial-scale fast pyrolysis facilities were being constructed at the time of publication. The present analysis expands upon the 2010 ISU study by performing an updated techno-economic analysis of the fast pyrolysis and hydroprocessing pathway. Recent advances in pathway technology and commercialization and new parameters suggested by the recent literature are accounted for. The MFSP for a 2000 MTPD facility employing fast pyrolysis and hydroprocessing to convert corn stover to gasoline and diesel fuel is calculated to quantify the economic feasibility of the pathway. The present analysis determines the MFSP of gasoline and diesel fuel produced via fast pyrolysis and hydroprocessing to be$2.57/gal. This result indicates that the pathway could be competitive with petroleum, although not as competitive as suggested by the 2010 ISU study. The present analysis also demonstrates the sensitivity of the result to process assumptions

Technoeconomic Sensitivity of Biobased Hydrocarbon Production via Fast Pyrolysis to Government Incentive Programs

Fast pyrolysis and upgrading is a promising thermochemical pathway that produces pyrolysis oil that can be upgraded via hydroprocessing into hydrocarbon-based transportation fuels (drop-in biofuels). The internal rate of return (IRR) of a fast pyrolysis and upgrading facility is a function of feedstock cost and projected revenues. We calculate the IRR of a fast pyrolysis and upgrading facility under six different policy scenarios: (1)a baseline scenario in which the facility receives no government support; (2)a scenario in which cap-and-trade (H.R. 2454) is enacted with both carbon price and offsets; (3)a scenario in which the Volumetric Ethanol Excise Tax Credit (VEETC) is modified to include drop-in biofuels; (4)a scenario in which the VEETC is replaced with a variable VEETC; (5)the revised Renewable Fuel Standard (RFS2); and (6)the Cellulosic Biofuel Producer Tax Credit (CBPTC). Combinations of these policy scenarios are also analyzed. We find that the policies responsible for increasing the value of pyrolysis products increase facility IRR the most, whereas policies minimizing facility tax burden have an only marginal effect on IRR

Comparative techno-economic analysis of biohydrogen production via bio-oil gasification and bio-oil reforming

This paper evaluates the economic feasibility of biohydrogen production via two bio-oil processing pathways: bio-oil gasification and bio-oil reforming. Both pathways employ fast pyrolysis to produce bio-oil from biomass stock. The two pathways are modeled using Aspen Plus® for a 2000 t d-1 facility. Equipment sizing and cost calculations are based on Aspen Economic Evaluation® software. Biohydrogen production capacity at the facility is 147 t d-1 for the bio-oil gasification pathway and 160 t d-1 for the bio-oil reforming pathway. The biomass-to-fuel energy efficiencies are 47% and 84% for the bio-oil gasification and bio-oil reforming pathways, respectively. Total capital investment (TCI) is 435 million dollars for the bio-oil gasification pathway and is 333 million dollars for the bio-oil reforming pathway. Internal rates of return (IRR) are 8.4% and 18.6% for facilities employing the bio-oil gasification and bio-oil reforming pathways, respectively. Sensitivity analysis demonstrates that biohydrogen price, biohydrogen yield, fixed capital investment (FCI), bio-oil yield, and biomass cost have the greatest impacts on facility IRR. Monte-Carlo analysis shows that bio-oil reforming is more economically attractive than bio-oil gasification for biohydrogen production

Techno-economic analysis of fast pyrolysis and upgrading facilities employing two depolymerization pathways

We evaluate the economic feasibility of fast pyrolysis and upgrading facilities 11 employing either of two depolymerization pathways: two-stage hydrotreating 12 followed by a FCC (fluid catalytic cracking) stage or single-stage hydrotreating 13 followed by a hydrocracking stage. In the hydrotreating/FCC pathway, two options 14 are available as the hydrogen source for hydrotreating: merchant hydrogen or 15 hydrogen from natural gas reforming. The primary products of the hydrotreating/FCC 16 pathway are commodity chemicals whereas the primary products for the 17 hydrotreating/hydrocracking pathway are transportation fuels and hydrogen. The two 18 pathways are modeled using Aspen Plus® for a 2000 metric tons/day facility. 19 Equipment sizing and cost calculations are based on Aspen Economic Evaluation® 20 software. 21 The fast pyrolysis bio-oil yield is assumed to be 65% of biomass. We calculate the 22 internal rate of return (IRR) for each pathway as a function of feedstock cost, fixed 23 capital investment (FCI), hydrogen and catalyst costs, and facility revenues. The 24 results show that a facility employing the hydrotreating/FCC pathway with hydrogen 25 production via natural gas reforming option generates the highest IRR of 13.3%. 26 Sensitivity analysis demonstrates that product yield, FCI, and biomass cost have the 27 greatest impacts on facility IRR. Monte-Carlo analysis shows that two-stage hydrotreating and FCC of the aqueous phase bio-oil with hydrogen produced via 1 natural gas reforming has a relatively low risk for project investment

Techno-economic analysis of biobased chemicals production via integrated catalytic processing

We evaluate the economic feasibility of a fast pyrolysis facility producing biobased commodity chemicals based on various manifestations of Integrated Catalytic Processing (ICP). Five scenarios are analyzed: fluid catalytic cracking (FCC) of whole pyrolysis oil (WPO); one-stage hydrotreating and FCC of WPO; FCC of the aqueous phase of pyrolysis oil (APPO); one-stage hydrotreating and FCC of the APPO; and two-stage hydrotreating followed by FCC of the APPO. We calculate the internal rate of return (IRR) for each scenario as functions of the costs of feedstock, hydrogen, and catalyst, and projected revenues for the facility. The assumed feedstock cost is $83/MT for mixed wood. The assumed hydrogen cost is$3/kg. Catalyst costs are based on December 2010 prices and projected revenues are based on August 2010 petrochemical prices. The analysis indicates that a facility employing FCC of WPO or APPO without hydrotreating is unable to generate a positive IRR. Employment of two-stage hydrotreating significantly increases the facility IRR, although IRRs in excess of 10% are only attained when higher pyrolysis oil yields (70 wt%) are assumed