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Second-generation biomass (BM) can be produced in amounts that meet worldwide fuel demands. However, BM favors parallel and undesirable reactions in its transformation chain. We circumvent this problem by first modifying BM by ketalization, giving a user-friendly liquid we named BP (bio-petroleum). This study converted a representative compound of BP, DX (1,2:3,5-di-O-isopropylidene-α-D-xylofuranose), mixed with n-hexane by beta zeolites and catalysts containing beta zeolite. Beta zeolite showed low coke and high liquid product yields in converting this mixture (having 30 wt. % DX) into hydrocarbons in a fixed-bed reactor at 500 °C with a space velocity of 16 h−1 (0.3 catalyst/feed). Its performance was further improved by steam treatment (lowering the coke yield by lowering the acid site density) or incorporation into a catalyst (improving DX participation due to the active sites in the matrix). Further, by changing the conversion process from a fixed bed to a fluidized cracking unit, a much larger amount of the deactivated catalyst could be used (catalyst/feed = 3), remarkably reducing oxygenates and fully converting DX. Additionally, the green hydrocarbon efficiency (olefin, aromatics, furans, and cyclo-alkanes) of DX was approximately 77%. Hence, beta catalysts were shown to have a great potential to provide green fuels for future bio-refineries. [ABSTRACT FROM AUTHOR]

Catalytic fast pyrolysis of sunflower seed shells was performed using a two‐stage fixed bed reactor to produce partially deoxygenated bio‐oils. Ketonization and aldol condensation reactions were performed in a dual bed reactor using a CeO2 catalyst followed by a bifunctional Cu/Ni/ZrO2 catalyst. An ethanol‐saturated N2 stream was supplied to increase the H/C ratio of the pyrolysis intermediates. The oxygen content decreased from 23 to 13 wt % over the CeO2 fixed‐bed due to the almost complete conversion of methoxy phenols and the formation of ketones and alkyl‐substituted phenols. The Cu/Ni/ZrO2 catalyst in the presence of ethanol vapor increased the fraction of alkanes in the condensed product and favored the formation of larger ketones and higher molecular weight species. Miscibility tests showed that the partially upgraded bio‐oil could be homogeneously blended with fossil fuel oil in a 1:4 mass ratio. The oily fraction of the non‐catalytic pyrolysis bioliquid (oxygen content up to 23 wt %) was also partially miscible with the petroleum‐derived fuel. [ABSTRACT FROM AUTHOR]

Anaerobic digestion of lignocellulosic biomass faces changes such as biomass floating and effluent discharge. To overcome these challenges, a unique removable cartridge anaerobic digester was built and tested using corn stover as the feedstock. Three operating methods differing in the number of cartridges and days of rotation were tested. The first method used three cartridges, with each cartridge being rotated every 7 days. The second and third methods employed four cartridges, with cartridges being rotated every 7 and 9–10 days, respectively. The retention time for methods 1, 2, and 3 was 21, 28, and 38 days, respectively. After observation spanning 1 year, it was found that the cartridge digester was capable of generating a stable amount of biogas for energy without biomass floating or effluent discharging issues. The average daily methane yield from each method was 7.57, 7.11, and 6.82 L/day/kg-VS, and the cumulative methane yield was 158.95, 199.04, and 259.00 L/kg-VS, respectively. Ammonium nitrogen and pH values were in normal ranges throughout the experiment. This study provided new knowledge in operating and optimizing this cartridge digester, which may be broadly used for the anaerobic digestion of lignocellulosic biomass in the near future. [ABSTRACT FROM AUTHOR]

Biofuel consists of non-fossil fuel derived from the organic biomass of renewable resources, including plants, animals, microorganisms, and waste. Energy derived from biofuel is known as bioenergy. The reserve of fossil fuels is now limited and continuing to decrease, while at the same time demand for energy is increasing. In order to overcome this scarcity, it is vital for human beings to transfer their dependency on fossil fuels to alternative types of fuel, including biofuels, which are effective methods of fulfilling present and future demands. The current review therefore focusses on second-generation lignocellulosic biofuels obtained from non-edible plant biomass (i.e., cellulose, lignin, hemi-celluloses, non-food material) in a more sustainable manner. The conversion of lignocellulosic feedstock is an important step during biofuel production. It is, however, important to note that, as a result of various technical restrictions, biofuel production is not presently cost efficient, thus leading to the need for improvement in the methods employed. There remain a number of challenges for the process of biofuel production, including cost effectiveness and the limitations of various technologies employed. This leads to a vital need for ongoing and enhanced research and development, to ensure market level availability of lignocellulosic biofuel. [ABSTRACT FROM AUTHOR]

With the increased availability of low‐cost natural gas, the co‐conversion of natural gas and biomass‐to‐liquid fuels has attracted attention from industry due to its potential for improving liquid fuel yields while lowering greenhouse gas emissions. This study provides an understanding of Fischer–Tropsch kinetics, improvements in processing strategies for hydrocarbon production, and of its impact on cost for the co‐conversion of natural gas and biomass‐to‐transportation fuels. Studies that investigate the effect of Fischer–Tropsch reaction kinetics on techno‐economic analysis can be used to develop process models that consider reaction stoichiometry and account for the effect of the paraffin‐to‐olefin ratio. We consider two processing scenarios: (1) one that does not employ a hydrocracker, and (2) the other where a hydrocracker serves as an integral part of the process scheme. Our analysis shows that co‐processing natural gas not only facilitates the economic benefits of converting biomass‐to‐liquid fuels but also facilitates flexibility in process integration. The resulting minimum fuel selling price ranged from $2.47–$3.47/GGE (gallon gasoline equivalent) without the hydrocracker and ranged from $2.17–$3.60/GGE with the inclusion of the hydrocracker, for a 50 million GGE hydrocarbon fuel production facility and for varying blending ratios for biomass from 0–100% with natural gas. The hydrocracker helps to increase the production of diesel and jet fuels substantially, with carbon efficiencies of 50% attained for a chain growth probability of 0.87. The cost penalty comes from the capital expenses of the hydrocracker, and the expense may not be offset with hydrocarbon yield improvement. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: US Department of Energy research aimed at co‐optimizing fuels and engine performance identified several bioblendstocks that can improve fuel economy including an aromatic‐rich hydrocarbon derived from woody biomass. This work supports an analysis of its large‐scale deployment implying a production target of approximately 15 billion liters of bioblendstock for the supply of 57 billion liters of high‐octane fuel by 2050. It simulates potential transition pathways to lignocellulosic feedstock market structures capable of supplying a mature biorefining industry at this scale. In the present absence of biorefineries, transitions are modeled via nonbiofuel feedstock markets, so‐called companion markets. The resource distribution across several demand industries is simulated to determine biomass availability and price dynamics over time. Results indicate that the wood supply base is mainly influenced by traditional markets including housing and pulp and paper. The selected companion market of wood pellet combustion for heat and electricity generation is found to positively stimulate biomass mobilization, especially in the initial absence of biorefineries. Eventually, biorefineries are found to be able to out‐compete the companion market. As such, they directly benefit from the processing (i.e., pelleting) capacity established to produce commodity‐type intermediates for the companion market. We conclude that the amount of bioblendstock produced is directly related to the size of the companion market (and its pelleting capacity). An initially larger companion market generates up to 20 million dry tonnes of additional feedstock, equivalent to 27 commercial‐scale biorefineries, or an additional production of 5 billion liters by 2050. Distinguishing between industry‐specific feedstock preferences based on average biomass quality characteristics, this analysis goes beyond past research efforts that assume automatic fungibility across different feedstocks. Improving engine performance is a key driver for the promotion of low‐carbon fuels derived from bioblendstocks. This analysis portrays feedstock market transition pathways for their large‐scale deployment. [ABSTRACT FROM AUTHOR]

This paper presents a comparative techno-economic analysis ( TEA) of five conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with a specific focus on pathways utilizing oxygenated intermediates. The four emerging pathways of interest are compared with one conventional pathway (Fischer-Tropsch) for the production of the hydrocarbon blendstocks. The processing steps of the four emerging pathways include biomass-to-syngas via indirect gasification, syngas clean-up, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation. Conversion of biomass-derived syngas to oxygenated intermediates occurs via three different pathways, producing: (i) mixed alcohols over a MoS2 catalyst, (ii) mixed oxygenates (a mixture of C2+ oxygenated compounds, predominantly ethanol, acetic acid, acetaldehyde, ethyl acetate) using an Rh-based catalyst, and (iii) ethanol from syngas fermentation. This is followed by the conversion of oxygenates/alcohols to fuel-range olefins in two approaches: (i) mixed alcohols/ethanol to 1-butanol rich mixture via Guerbet reaction, followed by alcohol dehydration, oligomerization, and hydrogenation, and (ii) mixed oxygenates/ethanol to isobutene rich mixture and followed by oligomerization and hydrogenation. The design features a processing capacity of 2000 tonnes/day (2205 short tons) of dry biomass. The minimum fuel selling prices ( MFSPs) for the four developing pathways range from $3.40 to $5.04 per gasoline-gallon equivalent ( GGE), in 2011 US dollars. Sensitivity studies show that MFSPs can be improved with co-product credits and are comparable to the commercial Fischer-Tropsch benchmark ($3.58/ GGE). Overall, this comparative TEA study documents potential economics for the developmental biofuel pathways via mixed oxygenates. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

This work describes in detail one potential conversion process for the production of high-octane gasoline blendstock via indirect liquefaction of biomass. The processing steps of this pathway include the conversion of biomass to synthesis gas via indirect gasification, gas clean-up via reforming of tars and other hydrocarbons, catalytic conversion of syngas to methanol, methanol dehydration to dimethyl ether ( DME), and the homologation of DME over a zeolite catalyst to high-octane gasoline-range hydrocarbon products. The current process configuration has similarities to conventional methanol-to-gasoline ( MTG) technologies, but there are key distinctions, specifically regarding the product slate, catalysts, and reactor conditions. A techno-economic analysis is performed to investigate the production of high-octane gasoline blendstock. The design features a processing daily capacity of 2000 tonnes (2205 short tons) of dry biomass. The process yields 271 liters of liquid fuel per dry tonne of biomass (65 gal/dry ton), for an annual fuel production rate of 178 million liters (47 MM gal) at 90% on-stream time. The estimated total capital investment for an nth-plant is $438 million. The resulting minimum fuel selling price ( MFSP) is $0.86 per liter or $3.25 per gallon in 2011 US dollars. A rigorous sensitivity analysis captures uncertainties in costs and plant performance. Sustainability metrics for the conversion process are quantified and assessed. The potential premium value of the high-octane gasoline blendstock is examined and found to be at least as competitive as fossil-derived blendstocks. A simple blending strategy is proposed to demonstrate the potential for blending the biomass-derived blendstock with petroleum-derived intermediates. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

A thermochemical processing route from biomass residues to light olefins (ethylene and propylene) is assessed by means of process simulation and cost analysis. A two-step process chain is proposed where (1) biomass residues are first converted to synthetic methanol in a gasification plant situated close to feedstock resources and (2) the produced methanol is transported to a steam cracking site where it is further converted in a methanol to olefins (MTO) plant. Possibilities for heat and product integration as well as equipment sharing with a steam cracking plant are discussed. Overall mass yields from dry biomass to light olefins range from 169 to 203 kg/t. Based on cursory capital cost estimates, the maximum methanol purchase price for such integrated MTO plants is estimated to be in the range of 420-450 €/t. [ABSTRACT FROM AUTHOR]

The Biomass Scenario Model ( BSM) is a system-dynamics simulation model intended to explore the potential for rapid expansion of the biofuels industry. The model is not predictive - it uses scenario assumptions based on various types of data to simulate industry development, emphasizing how incentives and technological learning-by-doing might accelerate industry growth. The BSM simulates major sectors of the biofuels industry, including feedstock production and logistics, conversion, distribution, and end uses, as well as interactions among sectors. The model represents conversion of biomass to biofuels as a set of technology pathways, each of which has allowable feedstocks, capital and operating costs, allowable products, and other defined characteristics. This study and the BSM address bioenergy modeling analytic needs that were identified in recent literature reviews. Simulations indicate that investments are most effective at expanding biofuels production through learning-by-doing when they are coordinated with respect to timing, pathway, and target sector within the biofuels industry. Effectiveness metrics include timing and magnitude of increased production, incentive cost and cost effectiveness, and avoidance of windfall profits. Investment costs and optimal investment targets have inherent risks and uncertainties, such as the relative value of investment in more-mature versus less mature pathways. These can be explored through scenarios, but cannot be precisely predicted. Dynamic competition, including competition for cellulosic feedstocks and ethanol market shares, intensifies during times of rapid growth. Ethanol production increases rapidly, even up to Renewable Fuel Standards-targeted volumes of biofuel, in simulations that allow higher blending proportions of ethanol in gasoline-fueled vehicles. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts, Biorefining published by John Wiley & Sons, Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The kinetics of methane steam reforming were studied on a Ni/Mg/K/AlO catalyst that was developed for conditioning of biomass-derived syngas. Reactions were conducted in a packed-bed reactor while the concentrations of reactants (methane and steam) and products (hydrogen, carbon monoxide, and carbon dioxide) were varied at atmospheric pressure, with the effects of temperature (525-700 °C) and residence time also being investigated. A power law rate model was developed using nonlinear regression to provide a predictive capability for the rate of methane conversion over this catalyst, to be used for reactor design and technoeconomic analysis of process designs. In order to provide some mechanistic insight, and to compare this catalyst to other non-promoted Ni/AlO catalysts reported in the literature, a reaction mechanism consisting of five elementary steps, using a Langmuir-Hinshelwood type approach, was also considered. These five steps included: (i) CH adsorption, (ii) HO adsorption, (iii) surface reaction of adsorbed CH and HO to form CO and H, (iv) CO desorption, and (v) H desorption. Nonlinear regression was then used to fit each of the rate laws to the experimental data. From these results, the model that assumed CH adsorption to be the rate determining step provided the best fit of the experimental data. This finding is consistent with literature studies on non-promoted Ni/AlO catalysts, in which methane adsorption has been proposed to be the rate determining step during catalytic methane steam reforming. Both the power rate laws and the rate law assuming CH adsorption to be the rate determining step can be used as predictive tools for determining methane conversion for a given set of process conditions. Additionally, a rate expression that assumed the rate was only a function of methane partial pressure was considered, namely, $$rate = k*P_{{CH_{4} }}$$ , where $$k = k_{0} *e^{{^{{ - {\text{Ea}}/{\text{RT}}}} }}$$ , with P in units of Torr. This first-order-methane rate expression fit the data well, yielding an apparent activation energy over this catalyst of E = 93 kJ/mol and the pre-exponential rate constant of k = 7.67 × 10 mol/(g-cat s Torr CH). [ABSTRACT FROM AUTHOR]

This techno-economic study investigates the production of ethanol and a higher alcohols coproduct by conversion of lignocelluosic biomass to syngas via indirect gasification followed by gas-to-liquids synthesis over a precommercial heterogeneous catalyst. The design specifies a processing capacity of 2,205 dry U.S. tons (2,000 dry metric tonnes) of woody biomass per day and incorporates 2012 research targets from NREL and other sources for technologies that will facilitate the future commercial production of cost-competitive ethanol. Major processes include indirect steam gasification, syngas cleanup, and catalytic synthesis of mixed alcohols, and ancillary processes include feed handling and drying, alcohol separation, steam and power generation, cooling water, and other operations support utilities. The design and analysis is based on research at NREL, other national laboratories, and The Dow Chemical Company, and it incorporates commercial technologies, process modeling using Aspen Plus software, equipment cost estimation, and discounted cash flow analysis. The design considers the economics of ethanol production assuming successful achievement of internal research targets and nth-plant costs and financing. The design yields 83.8 gallons of ethanol and 10.1 gallons of higher-molecular-weight alcohols per U.S. ton of biomass feedstock. A rigorous sensitivity analysis captures uncertainties in costs and plant performance. © 2012 American Institute of Chemical Engineers Environ Prog, 2012 [ABSTRACT FROM AUTHOR]

Increasing demand for renewable feedstock-based biofuels is driving the interest and rapid development of processes to produce fuels and chemicals from biomass-generated syngas. Biomass is gasified to produce syngas that can be converted via thermochemical routes to fuels and chemicals such as alcohols, olefins, and fuel grade hydrocarbons. An alternate route to produce liquid products from syngas is through gas fermentation, a hybrid thermochemical/ biochemical process. Biomass gasification, thermochemical syngas conversion routes, and gas fermentation are described including a comparison for converting biomass to ethanol via thecurrent thermochemical route versus gas fermentation. © 2012 American Institute of Chemical Engineers Environ Prog, 2012 [ABSTRACT FROM AUTHOR]

Biofuel produced from biomass pyrolysis is a good example of a highly complex mixture. Detailed understanding of its composition is a prerequisite for optimizing transformation processes and further upgrading conditions. The major challenge in understanding the composition of biofuel derived from biomass is the wide range of compounds with high diversity in polarity and abundance that can be present. In this work, a comprehensive analysis using mass spectrometry is reported. Different operation conditions are studied by utilizing multiple ionization methods (positive mode atmospheric pressure photo ionization (APPI), atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) and negative mode ESI) and applying different resolving power set-ups (120 k, 240 k, 480 k and 960 k) and scan techniques (full scan and spectral stitching method) to study the complexity of a pyrolysis biofuel. Using a mass resolution of 960 k and the spectral stitching scan technique gives a total of 21,703 assigned compositions for one ionization technique alone. The number of total compositions is significantly expanded by the combination of different ionization methods. [ABSTRACT FROM AUTHOR]

In this review, we focus on the literature that described the various unit operations in a process design flowsheet of biorefineries. We begin by establishing the accepted definitions of a biorefinery, go on to describe how to categorize biorefineries, and finally review the literature on biorefinery process designs by listing the unit operation in each process design. Distinguishing biorefineries based on feedstock, the types of processing units, and the products emanating from the biorefinery are discussed. [ABSTRACT FROM AUTHOR]

This study explores the hydrothermal liquefaction (HTL) of wood chips to biocrude followed by upgrading to diluents, which are used to transport bitumen through pipelines. In this study, we considered a 2000 dry t day−1 plant capacity with two scenarios. The first scenario uses hydrogen for upgrading from the on-site hydrogen production plant (i.e., the hydrogen production scenario) and the other relies on procuring hydrogen from an external source (i.e., the hydrogen purchase scenario). We developed a data-intensive process model for HTL and used it to estimate plant capital costs. Project investment costs for the hydrogen production and hydrogen purchase scenarios are 559.67 and 429.13 M $, respectively. The product values (PV) of the diluent from the two scenarios are 0.98 ± 0.03 and 0.79 ± 0.03 $ L−1, respectively, at a 95% confidence interval. The sensitivity analysis shows that diluent yield and internal rate of return (IRR) have the highest impact on the PV of the diluent, followed by capital cost and biomass cost. The optimum plant size at which the cost of production is lowest is 4000 dry t day−1 for PVs of 0.82 $ L−1 and 0.68 $ L−1 for the hydrogen production and purchase scenarios, respectively. This study offers insights into the techno-economic feasibility of producing diluents from HTL. The results of the study could help in the production of diluents for bitumen transportation for the oil sands industry and help reduce the overall greenhouse gas (GHG) footprint of the oil and gas sector. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]