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This study investigates the sensitivity of greenhouse gas (GHG) emissions and the minimum fuel selling price for a 2000 metric ton day−1 integrated pyrolysis‐bioenergy‐biochar platform with respect to the biorefinery location and biomass types. The regional techno‐economic and life‐cycle analysis is evaluated in three US counties using representative crops: rice in Glenn County (California), corn in Hamilton County (Iowa), and peanuts in Jackson County (Florida). We evaluate the biochar selling price considering crop yield increases of 0.6%, 2.9%, and 10% after biochar application over 20 years in Glenn County, Hamilton County, and Jackson County, respectively. The biochar prices are calculated under low and high commodity prices to determine upper and lower bounds. Jackson County has the most economically beneficial scenario with an average minimum fuel selling price (MFSP) of $1.55 gal−1 of biofuel produced whereas Hamilton County has the highest average MFSP of $3.82 gal−1. The life‐cycle analysis shows that woody biomass has a strong potential to produce carbon‐negative energy compared to grass and straw. Of the 304 cases scenarios considered for this platform, 64% could produce biofuel with negative GHG emissions, which would meet the Renewable Fuel Standard (RFS) target for cellulosic biofuels. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Abstract: High‐value chemicals from lignin could increase the profitability of lignocellulosic biorefineries. Besides lignin from the paper and pulp industry, ethanol plants produce lignin as a waste; thus, the objective of this work is to evaluate the techno‐economics of integrating hydrothermal liquefaction of lignin to produce biochemicals within ethanol biorefineries. This paper evaluates a 2000 metric tonne per day (MTPD) corn‐stover biorefinery producing 61 MMgal/yr. of ethanol and different yields of lignin‐derived biochemicals. A minimum ethanol selling price (MESP) of $1.03 ± 0.19 per gallon was computed considering the production of lignin‐derived catechol, phenol, cresols, acetic acid, formic acid, furfural, and acetaldehyde. The most influential factors on MESP identified are fixed capital investment, internal rate of return (IRR), feedstock price, cresols, catechol, and acetic acid prices. In terms of costs, the total purchased equipment cost is $114.5 MM, total installed cost (TIC) is $345.7 MM, and total capital investment is $624.5 MM. However, ethanol biorefineries adopting this lignin‐to‐chemicals strategy could still face higher levels of price uncertainty. The hydrothermal liquefaction process for the production of lignin‐derived chemicals is in the early stages of development; thus more laboratory and pilot‐scale research is needed to establish its potential for commercialization. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Biochar properties can vary widely depending on feedstock and processing conditions, which can make meaningful comparisons between biochars difficult. Clear trends can be observed in slow pyrolysis biochar properties over a 300-800°C range of highest treatment temperatures (HTT). These trends, however, are much less consistent for biochars made under slightly oxidizing conditions, such as in gasification and internally-heated kiln carbonization processes. In this study, slow pyrolysis biochars were produced from corn stover under either pure nitrogen or nitrogen + 5% oxygen atmospheres over a 200-800°C HTT range. For the biochars made at 300 and 400°C, the presence of oxygen in the reaction environment resulted in biochars with properties similar to those of biochars produced at higher HTTs in pure nitrogen. Addition of oxygen has only minor effects on biochar bulk oxygen content or abundance of surface oxygenated functionalities. Thermogravimetric analysis with mass spectroscopy (TGA-MS) indicated that the apparent increase in HTT for chars made in the O2 environment at 300 and 400°C resulted in the removal of methyl and higher alkyl functionalities in the biomass feedstock. Advanced solid state 13C nuclear magnetic resonance spectroscopy (NMR) methods to quantify carbon functional group abundance and aromaticity supported this observation. Overall, addition of oxygen to the pyrolysis atmosphere will increase pyrolysis process severity but will not create oxygenated groups on biochar surfaces as biochar aging does. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 696-707, 2017 [ABSTRACT FROM AUTHOR]

The development of catalytic transformations and processes is essential to utilize bio-oil and lignin derivatives. Metal nanoparticles (M-NPs) stabilized in ionic liquids (ILs) are promising for the catalytic hydrotreatment of bio-oil because the properties of the catalyst system can be customized by combining the appropriate IL and metal nanoparticles. Herein, we demonstrate an experimental approach to stabilize lignin-derived phenolics isolated from bio-oil with ruthenium NPs stabilized by an ionic copolymer in 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]). The mild hydrotreatment of phenolic oligomers (POs) was performed with the synthesized M-NP catalyst at 100 °C for 6 h. Hydrotreatment of the POs resulted in enhanced thermal stability of the POs by as much as a factor of three, as determined by the aging index and by reducing reactive functionalities, which was also confirmed by NMR spectroscopy and GC analysis. The results support our hypothesis that M-NPs stabilized in ILs can effectively stabilize POs under mild conditions, which could be applicable to any lignin-derived phenolic. [ABSTRACT FROM AUTHOR]

The growth of the bioeconomy has recently been slowed by over production of petroleum and natural gas from unconventional domestic reserves, which has reduced demand for biofuels. In the longer term, liquid transportation fuels, both petroleum- and bio-based, are threatened by electrification of the transportation sector, which will benefit from the use of low-cost natural gas to generate electricity for battery electric vehicles. Low-cost natural gas in the USA is attractive for other applications as well, including the production of certain petrochemicals. On the other hand, natural gas is not suitable for producing many high molecular weight petrochemicals. Cost-competitive biorenewable versions of these products will need to be commercialized if petroleum is to be displaced without causing substantial economic distortions. This article reviews the available bio-based pathways and the current state of research on their technical and, where available, economic feasibility. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Microgram-scale reactors combined with gas chromatography (GC) coupled to mass spectrometry (MS) or flame ionization detection (FID) are used widely in pyrolysis research. Whether these devices meet the expected fast heating rates and short vapor residence times of fast pyrolysis have not been verified. In this study, experiments and simulations are used to investigate heat and mass transfer in a furnace-based micropyrolyzer. Surprisingly, heating rates obtained from the temperature history of sample cups in the reactor were modest compared to the greater than 1000 K s−1 heating rates sometimes assumed for such reactors. The heating rate at 773 K, employed commonly in fast pyrolysis, was only 180 K s−1. The highest rate observed was 494 K s−1 at a furnace temperature of 1268 K, which is well above typical pyrolysis temperatures. The mass transfer of volatilized samples was studied using both an optically accessible furnace and computational fluid dynamics. The standard sample cups used with these micropyrolyzers impede the escape of vapors. The use of shallow perforated cups overcame this mass transfer limitation to lead to levoglucosan yields ≈10 % higher than usually reported for the pyrolysis of cellulose. [ABSTRACT FROM AUTHOR]

This paper describes a novel integrated biorefinery based on fast pyrolysis and subsequent bio-oil upgrading to produce three product portfolios: hydrocarbon biofuels (gasoline and diesel), bio-based products (bioasphalt, calcium acetate, and dextrose), and hydrocarbon chemicals (aromatics, olefins, and fuel oil). Based on the economic assumptions and historical market prices of the products, we calculate internal rates of return ( IRRs) of the biorefinery (2000 dry metric tons per day) over 30 years to evaluate its performance. Given the historical low, average, and high prices of the products, a total of 27 scenarios are explored and the maximum IRR for each scenario is determined. Results indicate that upgrading bio-oil to bio-based products yields the maximum IRR of 67.9% if bio-based products can be marketed at a historical high price level (between $257 and $1491 per metric ton) and an IRR of 42.5% at an average price level (between $240 and $950 per metric ton). Under some market conditions, the biorefinery should produce hydrocarbon chemicals or biofuels to increase the IRR. We also estimate the IRR probability distribution using Monte Carlo simulation by -incorporating distributions of product prices and bio-oil fractions allocated for three product portfolios. Average IRRs of −3.9% for biofuels, 42.7% for bio-based products, and 17.3% for hydrocarbon chemicals are observed with standard deviations of 24.4%, 24.1%, and 6.5%, respectively. The integrated -biorefinery exhibits an IRR distribution of 16.2% ± 16.4% suggesting that the integrated biorefinery could balance the economic disadvantages and benefits from individual product portfolio to achieve profitable IRRs. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

The production of aromatic hydrocarbons from cellulose by zeolite-catalyzed fast pyrolysis involves a complex reaction network sensitive to the zeolite structure, crystallinity, elemental composition, porosity, and acidity. The interplay of these parameters under the reaction conditions represents a major roadblock that has hampered significant improvement in catalyst design for over a decade. Here, we studied commercial and laboratory-synthesized ZSM-5 zeolites and combined data from 10 complementary characterization techniques in an attempt to identify parameters common to high-performance catalysts. Crystallinity and framework aluminum site accessibility were found to be critical to achieve high aromatic yields. These findings enabled us to synthesize a ZSM-5 catalyst with enhanced activity, which offers the highest aromatic hydrocarbon yield reported to date. [ABSTRACT FROM AUTHOR]

We report on the quantitative analysis of free radicals in bio-oils produced from pyrolysis of cellulose, organosolv lignin, and corn stover by EPR spectroscopy. Also, we investigated their potential role in condensed-phase polymerization. Bio-oils produced from lignin and cellulose show clear evidence of homolytic cleavage reactions during pyrolysis that produce free radicals. The concentration of free radicals in lignin bio-oil was 7.5×1020 spin g−1, which was 375 and 138 times higher than free-radical concentrations in bio-oil from cellulose and corn stover. Pyrolytic lignin had the highest concentration in free radicals, which could be a combination of carbon-centered (benzyl radicals) and oxygen-centered (phenoxy radicals) organic species because they are delocalized in a π system. Free-radical concentrations did not change during accelerated aging tests despite increases in molecular weight of bio-oils, suggesting that free radicals in condensed bio-oils are stable. [ABSTRACT FROM AUTHOR]

Dried distillers grains with solubles ( DDGS) are potential feedstocks for the production of hydrocarbon fuels and chemicals from catalytic pyrolysis. This study evaluates the economic feasibility of a 2000-metric-ton-corn-per-day integrated biorefinery with an add-on facility processing corn DDGS to hydrocarbons. In addition to ethanol, the integrated facility would produce a wide range of hydrocarbons, including aromatics, olefins, and synthetic gasoline and diesel. The hydrocarbon products command a substantially higher market value than that of the pre-processed DDGS: $109 million per year vs. $78 million per year. The add-on DDGS conversion facility contributes an extra $152 million of capital investment compared with the stand-alone corn ethanol production scenario. The operating costs for the integrated scenario are also higher than for the stand-alone scenario, mainly due to increases in utilities, labor costs, and capital depreciation. The minimum fuel selling price ( MFSP) for the integrated scenario is $2.27/gallon, which is comparable to the MFSP of $2.18/gallon for the stand-alone scenario. Sensitivity analysis shows that the feedstock cost, hydrocarbon yield, and fixed capital investment have the greatest impacts on the MFSP. With the benefit of products diversity, the proposed integrated corn biorefinery may be competitive with conventional stand-alone ethanol production. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Industry statistics indicate that technology-learning rates can dramatically reduce both feedstock and biofuel production costs. Both the Brazilian sugarcane ethanol and the United States corn ethanol industries exhibit drastic historical cost reductions that can be attributed to learning factors. Thus, the purpose of this paper is to estimate the potential impact of industry learning rates on the emerging advanced biofuel industry in the United States. Results from this study indicate that increasing biorefinery capital and feedstock learning rates could significantly reduce the optimal size and production costs of biorefineries. This analysis compares predictions of learning-based economies of scale, S-Curve, and Stanford-B models. The Stanford-B model predicts biofuel cost reductions of 55 to 73% compared to base case estimates. For example, optimal costs for Fischer-Tropsch diesel decrease from $4.42/gallon to $2.00/gallon. The optimal capacities range from small-scale (grain ethanol and fast pyrolysis) producing 16 million gallons per year to large-scale gasification facilities with 210 million gallons per year capacity. Sensitivity analysis shows that improving capital and feedstock delivery learning rates has a stronger impact on reducing costs than increasing industry experience suggesting that there is an economic incentive to invest in strategies that increase the learning rate for advanced biofuel production. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Fast pyrolysis of biomass to produce a bio-oil followed by catalytic upgrading is a widely studied approach for the potential production of fuels from biomass. Because of the complexity of the bio-oil, most upgrading strategies focus on removing oxygen from the entire mixture to produce fuels. Here we report a novel method for the production of the specialty chemical, gluconic acid, from the pyrolysis of biomass. Through a combination of sequential condensation of pyrolysis vapors and water extraction, a solution rich in levoglucosan is obtained that accounts for over 30 % of the carbon in the bio-oil produced from red oak. A simple filtration step yields a stream of high-purity levoglucosan. This stream of levoglucosan is then hydrolyzed and partially oxidized to yield gluconic acid with high purity and selectivity. This combination of cost-effective pyrolysis coupled with simple separation and upgrading could enable a variety of new product markets for chemicals from biomass. [ABSTRACT FROM AUTHOR]

This study explores the separate recovery of sugars and phenolic oligomers produced during fast pyrolysis with the effective removal of contaminants from the separated pyrolytic sugars to produce a substrate suitable for fermentation without hydrolysis. The first two stages from a unique recovery system capture 'heavy ends', mostly water-soluble sugars and water-insoluble phenolic oligomers. The differences in water solubility can be exploited to recover a sugar-rich aqueous phase and a phenolic-rich raffinate. Over 93 wt % of the sugars is removed in two water washes. These sugars contain contaminants such as low-molecular-weight acids, furans, and phenols that could inhibit successful fermentation. Detoxification methods were used to remove these contaminants from pyrolytic sugars. The optimal candidate is NaOH overliming, which results in maximum growth measurements with the use of ethanol-producing Escherichia coli. [ABSTRACT FROM AUTHOR]

In contrast to a few years ago, when cellulosic ethanol via enzymatic hydrolysis was the only widely recognized technology for commercially producing cellulosic biofuels, a diversity of approaches are currently under commercial development. While no commercial-scale (≥20 million gallons per year) cellulosic biofuel facilities are operating at present, at least ten biorefinery projects employing six different pathways are expected to begin operations by 2014. These biorefineries will employ the following pathways: (i) catalytic pyrolysis and hydrotreating to hydrocarbons; (ii) gasification and Fischer-Tropsch synthesis to hydrocarbons; (iii) gasification and methanol-to-gasoline synthesis; (iv) dilute acid hydrolysis, fermentation to acetic acid, and chemical synthesis to ethanol; (v) enzymatic hydrolysis to ethanol; and (vi) consolidated bioprocessing (single-step enzyme production, hydrolysis, and fermentation) to ethanol. This review provides an overview of the six pathway technologies, comprehensive descriptions of each of the ten biorefinery projects, and a discussion of the current direction of cellulosic biofuel commercialization efforts and its implications for the revised Renewable Fuel Standard. © 2013 Society of Chemical Industry and John Wiley & Sons Ltd [ABSTRACT FROM AUTHOR]

Depolymerization of cellulose offers the prospect of inexpensive sugars from biomass. Breaking the glycosidic bonds of cellulose to liberate glucose has usually been pursued by acid or enzymatic hydrolysis although a purely thermal depolymerization route to sugars is also possible. Fast pyrolysis of pure cellulose yields primarily the anhydrosugar levoglucosan (LG) whereas the presence of naturally occurring alkali and alkaline earth metals (AAEMs) in biomass strongly catalyzes ring-breaking reactions that favor formation of light oxygenates. Here, we show a method of significantly increasing the yield of sugars from biomass by purely thermal means through infusion of certain mineral acids (phosphoric and sulfuric acid) into the biomass to convert the AAEMs into thermally stable salts (particularly potassium sulfates and phosphates). These salts not only passivate AAEMs that normally catalyze fragmentation of pyranose rings, but also buffer the system at pH levels that favor glycosidic bond breakage. It appears that AAEM passivation contributes to 80 % of the enhancement in LG yield while the buffering effect of the acid salts contributes to the balance of the enhancement. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the cost of producing hydrogen by two types of biomass gasifiers: a conventional air-blown fluidized-bed gasifier and a thermally ballasted fluidized-bed gasifier developed at Iowa State University. The ballasted gasifier is an indirectly heated gasifier that uses a single reactor for both combustion and pyrolysis. Heat accumulated in high-temperature phase-change material during the combustion phase is released during the pyrolysis phase to generate producer gas. Experimental data from pilot-scale air-blown and ballasted gasification tests have been used as a basis for this study. Experimental data has been scaled up to calculate the cost and feasibility associated with 50 Mg of hydrogen per day production plants. Air-blown gasification yields for total direct cost, total capital cost, and the annual operating cost were $19.20, $43.21 and $38.65 million, respectively. The cost estimate of a system producing 50 Mg/day of hydrogen via air-blown gasification is projected to be $2.23/kg H2. The total direct cost, total capital cost and the annual operating cost for ballasted gasification were $30.17 $67.80, and $52.11 million, respectively. The hydrogen production cost for ballasted gasification showed $3.01/kg H2. This is 35% higher than that of air-blown gasification. A sensitivity analysis was performed to help to assist economic feasibility which includes variables for labor, capital charges, biomass costs, and hydrogen yields. The cost of biomass was found to be the most influential contribution to hydrogen production costs. As a result, a detailed analysis based on a state-by-state model is used to demonstrate the effect of biomass cost on hydrogen production cost. This model also predicts the potential number of 50 Mg of H2/day plants that might be built in each state based on potential switchgrass supply. © 2012 Society of Chemical Industry and John Wiley & Sons Ltd [ABSTRACT FROM AUTHOR]

The article presents a study on the use of fast pyrolysis instead of slow pyrolysis biochars as soil amendments. Three corn (Zea mays L.) stover quick pyrolysis biochars prepared with the use of various reactor conditions were physically and chemically characterized to identify their extent of pyrolysis. Quantitative solid-state carbon (C) nuclear magnetic resonance spectroscopy and elemental analysis revealed variation in aromatic C and oxygen (O) functional groups, mainly associated with carbohydrates which could be used to identify extent of pyrolysis.

In fast pyrolysis of cellulose, levoglucosan is often reported as the most abundant primary decomposition product. Char, the solid residue of pyrolysis is thought to catalyze secondary reactions that decompose levoglucosan into water and additional, secondary char. A CDS Analytical Pyroprobe 5200 was used to pyrolyze pure cellulose to levoglucosan and the generated vapors were passed through a temperature-controlled tubular reactor filled with material to be tested for catalytic activity and then to a GC-FID for analysis. Carbonaceous materials included as-received and acid-washed char derived from pyrolysis of red oak and, pure graphite. Acid-washed red oak char and pure graphite had little effect on levoglucosan decomposition compared with the empty tubular reactor for the range of tubular reactor temperatures studied (200-400°C). In contrast, unwashed red oak char significantly reduced the amount of levoglucosan when the tubular reactor was operated above 300°C. These results suggest that metals-which are removed through the procedure of acid washing-rather than the fixed carbon in the char, catalyze the decomposition of levoglucosan in the vapor phase. © 2012 American Institute of Chemical Engineers Environ Prog, 2012 [ABSTRACT FROM AUTHOR]

Well-defined and monodispersed rhodium nanoparticles as small as approximately 2 nm were encapsulated in situ and stabilized in a mesoporous silica nanoparticle (MSN) framework during the synthesis of the mesoporous material. Although both the activity and selectivity of MSN-encapsulated rhodium nanoparticles in CO hydrogenation could be improved by the addition of manganese oxide as expected, the carbon selectivity for C2 oxygenates (including ethanol and acetaldehyde) was unprecedentedly high at 74.5 % with a very small amount of methanol produced if rhodium nanoparticles were modified by manganese oxide with very close interaction. [ABSTRACT FROM AUTHOR]