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The economic feasibility of the lignocellulosic biomass refinery requires the valorization of lignin in addition to its polysaccharide fraction. One promising approach is the combination of chemical methods for lignin fractionation and depolymerization with microbial funneling of the resulting phenolic monomers into valuable chemicals. In this work, we explored the integration of γ-valerolactone (GVL) for biomass pretreatment, catalytic hydrogenolysis for lignin depolymerization, and microbial funneling to 2-pyrone-4,6-dicarboxylic acid (PDC) by the engineered bacterium Novosphingobium aromaticivorans strain PDC. We first investigated the microbial PDC production feasibility from common phenolic compounds previously identified in lignin hydrogenolysis products. Next, we studied the PDC production potential from maple, poplar, sorghum, and switchgrass using the proposed integrated pipeline and, finally, we performed a technoeconomic analysis (TEA) of the system to identify parameters that affect its economic feasibility. We found that N. aromaticivorans strain PDC is able to produce PDC from phenolic compounds with propanol, methyl, or methyl ester sidechains. Using Pd/C as a catalyst for hydrogenolysis to favor the production of these phenolics from lignin extracted with the GVL process, we obtained microbial PDC production yields of 88, 139, 103, and 79 g PDC per kg lignin from maple, poplar, sorghum, and switchgrass, respectively. Using these yields, we estimated a baseline minimum selling price of $12.10 per kg of purified PDC, and identified options to further improve the integrated pipeline. [ABSTRACT FROM AUTHOR]

5-Hydroxymethyl furfural (HMF) is a platform chemical, which can be derived from lignocellulosic biomass, and used for production of liquid fuels and polymers. We demonstrate a process for production of HMF using sequential enzymatic and catalytic reactions of glucose to synthesize HMF, and simulated-moving-bed (SMB) separation to purify HMF. The adsorption thermodynamic parameters of glucose, fructose, and HMF on a commercial chromatography resin are experimentally determined for modeling the SMB-based HMF production process. The experimental data are used to develop a rigorous process model and then estimate the cost of production. Chromatographic separation of HMF has 16% lower operating costs compared to an extraction-based process and has a minimum selling price of approximately $1478 per ton. We demonstrate that the HMF process can be integrated with the high fructose corn syrup (HFCS) process, and we performed analyses considering two systems including construction of a new integrated facility and retrofitting an existing HFCS facility to produce HMF. Our analyses suggest that the latter approach is a promising short-term low-risk strategy to advance the HMF production technology to commercial scale. [ABSTRACT FROM AUTHOR]

We report a process to produce a versatile platform chemical from biomass-derived fructose for organic dye, polymer, and liquid fuel industries. An aldol-condensed chemical (HAH) is synthesized as a platform chemical from fructose by catalytic reactions in acetone/water solvent with non-noble metal catalysts (e.g., HCl, NaOH). Then, selective reactions (e.g., etherification, reduction, dimerization) of the functional groups, such as enone and hydroxyl groups, in the HAH molecule enable applications in organic dyes and polyether precursors. High yields of target products, such as 5-(hydroxymethyl) furfural (HMF) (85.9% from fructose) and HAH (86.3% from HMF) are achieved by sequential dehydration and aldol-condensation with a simple purification process (>99% HAH purity). The use of non-noble metal catalysts, the high yield of each reaction, and the simple purification of the target product allow for beneficial economics of the process. Techno-economic analysis indicates that the process produces HAH at minimum selling price (MSP) of $1958 per ton. The MSP of HAH product allows the economic viability of applications in organic dye and polyether markets by replacing its counterparts, such as anthraquinone ($3200-$3900 per ton) and bisphenol-A ($1360-$1720 per ton). [ABSTRACT FROM AUTHOR]

Catalytic strategies for the synthesis of 1,5-pentanediol (PDO) with 69% yield from hemicellulose and the synthesis of 1,6-hexanediol (HDO) with 28% yield from cellulose are presented. Fractionation of lignocellulosic biomass (white birch wood chips) in gamma-valerolactone (GVL)/H2O generates a pure cellulose solid and a liquid stream containing hemicellulose and lignin, which is further dehydrated to furfural with 85% yield. Furfural is converted to PDO with sequential dehydration, hydration, ring-opening tautomerization, and hydrogenation reactions. Acid-catalyzed cellulose dehydration in tetrahydrofuran (THF)/H2O produces a mixture of levoglucosenone (LGO) and 5-hydroxymethylfurfural (HMF), which are converted with hydrogen to tetrahydrofuran-dimethanol (THFDM). HDO is then obtained from hydrogenolysis of THFDM. Techno-economic analysis demonstrates that this approach can produce HDO and PDO at a minimum selling price of $4090 per ton. [ABSTRACT FROM AUTHOR]

We demonstrate a process to produce levoglucosenone (LGO) and 5-hydroxymethylfurfural (HMF) from cellulose in up to 65% carbon yield using sulfuric acid as catalyst and a solvent consisting of a mixture of tetrahydrofuran (THF) with water. In pure THF, LGO is the major product of cellulose dehydration, passing through levoglucosan as an intermediate. Increasing the water content (up to 5 wt%) results in HMF as the major product. HMF is formed both by glucose dehydration and direct dehydration of LGA. The maximum combined yield of LGO and HMF (∼65 carbon%) is achieved in the presence of 1–2.5 wt% H2O, such that comparable amounts of these two co-products are formed. THF gave the highest total yields of LGO and HMF among the solvents investigated in this study (i.e., THF, diglyme, tetraglyme, gamma-valerolactone (GVL), cyclopentyl methyl ether (CPME), 1,4-dioxane, and dimethyl sulfoxide (DMSO)). Furthermore, the rate of LGO and HMF degradation in THF was lower than in the other solvents. LGO/HMF yields increased with increased strength of the acid catalyst (H2SO4 ＞ H3PO4 ＞ HCOOH), and HMF was produced more selectively than LGO in the presence of hydrochloric acid. Techno-economic analysis for LGO and HMF production from cellulose shows that the lowest LGO/HMF production costs are less than $3.00 per kg and occur at a cellulose loading and water content of 2–3% and 1.5–2.5% respectively. [ABSTRACT FROM AUTHOR]

Concentrating solar power (CSP) with thermal energy storage has the potential for grid-scale dispatchable power generation. Thermochemical energy storage (TCES), that is, the reversible conversion of solar-thermal energy to chemical energy, has high energy density and low heat loss over long periods. To systematically analyze and compare candidate reactions for TCES, we design an integrated process and develop a general process model for CSP plants with TCES systems. We illustrate our model applicability by using ammonia and methane systems with two gas storage options. The analysis allows us to identify critical issues as well as key targets for fluid phase TCES systems. Gas storage is identified as the main cost driver and compressor electricity consumption as the main energy driver. The impacts of reaction temperature, operating pressure and plant characteristics are also studied. [ABSTRACT FROM AUTHOR]

γ-Valerolactone (GVL) is a biomass-derived solvent which completely solubilizes all fractions of lignocellulosic biomass, leading to the recovery of polysaccharides (cellulose and hemicellulose) as soluble carbohydrates at high yields (＞70%) without the use of expensive reagents, like enzymes and ionic liquids. Biological upgrading of carbohydrates to biofuels or bio-based chemicals requires that the carbohydrates are separated from GVL. We demonstrate that an engineered solvent system consisting of GVL, water and an organic co-solvent is mono-phasic at the temperatures used for biomass fractionation (e.g., 160 °C) and is bi-phasic at lower temperatures (e.g., room temperature). The advantage of using this engineered solvent system is that the carbohydrates are spontaneously separated from organic solvent components into an aqueous hydrolysate stream, thereby avoiding the need for expensive and potentially hazardous separation processes, such as operation at elevated pressures required for separation using liquid CO2. We also show that the organic co-solvent can be selected from an array of organic components, leading to a trade-off between the efficacy of carbohydrate separation and the ‘greenness’ of the solvent. We show further that toluene is a promising co-solvent component, and techno-economic analyses of the process, wherein toluene is used as a co-solvent, lead to a minimum selling price of ethanol of $3.10 per gallon of gasoline equivalent. [ABSTRACT FROM AUTHOR]

We develop and evaluate an integrated catalytic conversion strategy, which utilizes both the hemicellulose and cellulose fractions of lignocellulosic biomass to produce liquid hydrocarbon fuels (butene oligomers). In this strategy, the cellulose and hemicellulose fractions are simultaneously converted to levulinic acid (LA), using LA-derived γ-valerolactone (GVL) as a solvent. The LA is then converted to GVL, which is subsequently converted to butene, and then to butene oligomers. To generate the integrated strategy, we develop separation subsystems to achieve experimentally optimized feed concentrations for the catalytic conversion steps. Importantly, to minimize the utility requirements of the overall process, we perform heat integration, which allows us to satisfy all heating requirements from combustion of biomass residues, which are also used to produce steam for electricity generation. In addition, we develop an alternative design in which there is no electricity generation, study alternative feedstocks, and perform sensitivity analyses. Our technoeconomic analysis shows that the integrated strategy using hybrid poplar feedstock leads to a minimum selling price of $4.01 per gallon of gasoline equivalent for butene oligomers if biomass residues are sold as low quality fuel. [ABSTRACT FROM AUTHOR]

Levulinic acid (LA) is a valuable platform chemical upon which biorefining strategies for the production of chemicals, fuels and power can be established. Herein, we report the results of process synthesis and technoeconomic analysis studies for the conversion of lignocellulose derived LA to liquid fuels through the intermediate formation of levulinate esters. In this strategy, esterification of levulinic and formic acids with alkenes (i.e., butene) produces hydrophobic esters, which extract the unconverted LA from the aqueous sulfuric acid solution. Following the γ-valerolactone (GVL) production from LA and levulinate esters, GVL is converted to butene, hence providing the butene required for esterification and butene oligomers. The minimum selling price of butene oligomers from a 1365 dry tons per day of loblolly pine processing facility is calculated to be $4.92 per gallon of gasoline equivalent. Our analysis shows that the biomass feedstock price is the main cost driver. [ABSTRACT FROM AUTHOR]

Levulinic acid derived from ligno-cellulosic biomass has the potential to be utilized as a platform intermediate molecule in the production of renewable liquid fuels for the transportation sector. Herein we report a catalytic process for the conversion of levulinic acid to γ-valerolactone (GVL) using a RuRe/C catalyst that is significantly more active than a traditional Ru/C catalyst. The bimetallic catalyst is active for the reduction of levulinic acid and simultaneous decomposition of formic acid with good stability in the presence of sulfuric acid, the homogeneous catalyst commonly used in the production of levulinic acid from carbohydrates. Results from techno-economic analyses show that the integration of this new process with catalytic decarboxylation of GVL to butene followed by alkene oligomerization could provide a cost-effective route for the conversion of ligno-cellulosic biomass to liquid hydrocarbon fuels. [ABSTRACT FROM AUTHOR]