Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels. Thermochemical Research Pathways with In Situ and Ex Situ Upgrading of Fast Pyrolysis Vapors

Abstract

The dry basis elemental composition of the feedstock, shown in Table 2, is identical to previous NREL and PNNL design reports [20,21]. The composition was originally assumed to come from pulpwood. Recent feedstock logistics work at the Idaho National Laboratory (INL) suggests that the use of blended material may be required to meet a cost target of $80/dry U.S. ton while still meeting these specifications [22]. For the purpose of this report, it is assumed that any blended material provided to meet this feedstock elemental composition will not adversely affect fast pyrolysis conversion efficiencies. Ongoing studies being conducted jointly by INL, NREL, and PNNL will provide experimental evidence of the impact of blended feedstocks on fast pyrolysis and gasification processes. Future TEA will be modified to reflect conversion impacts inferred from such studies.This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. not considered in this design in order to focus on the core technology of in situ and ex situ fast pyrolysis vapor upgrading. Aspen Plus ModelAn Aspen Plus Version 7.2 simulation was used as the basis for this report. Since the products in pyrolysis are numerous and varied, only selected model compounds were used to represent the product slate. Additional hydrocarbon species were added to represent hydroprocessing products. Many of the desired molecular species in the desired boiling ranges for light and heavy fractions did not exist in Aspen Plus databanks and physical property parameters needed to be estimated. The biomass feedstock, ash, char, and coke were modeled as non-conventional components. Appendix F provides information about compounds selected to represent the process. The Peng-Robinson with Boston-Mathias modifications (PR-BM) equation of state was used throughout most of the process simulation. The ASME 1967 steam table correlations (STEAM-TA) were used for the steam cycle calculations. Combustor/Regenerator Temperature, °C (°F) 650 (1,202) 720 (1,328) 650 (1,202) Pressure, psia (bar) 117 (8.1) 117 (8.1) 113 (7.8) Excess air (%) 20 20 20 Solids temperature before transfer to reactor, °C (°F) 650 (1,202) 720 (1,328) 341 (645) No. of cyclones per combustor 2 2 2 Area 200 Equipment Cost EstimationsCapital costs for the equipment in this area were estimated by Harris Group. A previously developed spreadsheet tool for gasifier costs was leveraged for this exercise. Cost estimates from this tool were compared with order of magnitude estimates from technology vendors and documented in Appendix I of Worley et al.

Biomass catalytic pyrolysis: process design and economic analysis

“…The total estimated plant cost, including OSBL, is estimated at 78.55 MM US$. This is the cost for the 500 MT/D dry biomass BCP plant and it is in general agreement with the adjusted cost of a BCP plant recently reported by PNNL and NREL people.…”

Formate‐assisted pyrolysis of biomass: an economic and modeling analysis

“…The current laboratory mass yields (on the dry feedstock basis) of bio‐oil, char, ash, and non‐condensable gases are 23%, 33.7%, 19%, and 0.3%, respectively . It must be noted that mass yields of bio‐oil produced via FAsP are lower than that of bio‐oil made via fast pyrolysis and catalytic fast pyrolysis . The simulation results indicate that 0.42 metric tons of CO is necessary to regenerate one metric ton of calcium formate.…”

“…Of this CO requirement, 0.29 metric tons of CO is provided by steam reforming of non‐condensable gases. For the complete deoxygenation of bio‐oil, 8.5 kg of hydrogen is consumed per 100 kg of RGD fuel as compared to the 8.8 kg and 13.1 kg of hydrogen consumption for upgrading bio‐oil produced via catalytic pyrolysis and fast pyrolysis to 100 kg of RGD fuel, respectively . The hydrogen generated from the steam reforming of non‐condensable gases is sufficient to meet the 100% H 2 demand.…”

A review of thermochemical upgrading of pyrolysis bio‐oil: Techno‐economic analysis, life cycle assessment, and technology readiness

“…Active research and development has been carried out at laboratory scale and through chemical process models, TEA and LCA for in situ and ex situ catalytic pyrolysis processes, as described by Dutta et al (). For in situ and ex situ catalytic pyrolysis, scale, MFSP, GHG emissions, oxygen content, and TRL are very similar, but catalyst deactivation is faster in ex situ catalytic pyrolysis.…”

“…Prior literature has reviewed findings from biomass thermochemical conversion TEAs (Brown, ) and TEA together with LCA (Patel, Zhang, & Kumar, ). However, in recent years, much additional research has emerged specifically on the conversion and upgrading of bio‐oils produced from fast pyrolysis of biomass (Bridgwater, ; de Miguel Mercader, ; Dutta et al, ; Elkasabi, Mullen, & Boateng, ; Fatih Demirbas, ; Fisk et al, ; Hangtao, Xiaoning, Qiang, & Changqing, ; Ko et al, ; Snowden‐Swan & Male, ; Stefanidis, Kalogiannis, Iliopoulou, Lappas, & Pilavachi, ; Tran, Uemura, Chowdhury, & Ramli, ). Therefore, this review focuses on understanding the key benefits, differences, and trade‐offs among select pyrolysis bio‐oil upgrading methods under investigation at laboratory and pilot scales, whose potential for scale‐up has been evaluated using LCA and TEA methods.…”