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The catalytic relevance of different surface functionalities present on hydrotalcite‐derived Mg−Al mixed metal oxides (MgAlO) are investigated in the context of ethanol upgrade to n‐butanol. The catalyst structure and active sites were altered through changes in the Mg/Al ratio and introduction of additional redox metal oxide functionalities. After performing a series of catalytic activity tests, operando FTIR characterization, TGA measurements and in situ active center titration; qualitative and quantitative relationships between catalyst structure and catalytic performance are obtained. We found the Mg−Al mixed metal oxides system can catalyze the ethanol to n‐butanol process through a Guerbet reaction pathway, though the process is kinetically limited. By introducing redox active metal oxides to the catalyst formulation, such as MoO3 or V2O5, this problem can be partially solved, but at a cost of losing a significant fraction of high‐strength basic centers which are the most catalytically relevant function in the system, as they control enolate formation rates leading to the C−C coupling step required for n‐butanol formation. [ABSTRACT FROM AUTHOR]

The primary aim of this research study was to examine the effectiveness and environmental consequences of using Delonix regia biodiesel (DRB) in combination with butanol (BUT), exhaust gas recirculation (EGR), and diesel fuel (D) on a direct injection compression ignition engine operating at a constant speed. This study involved the formulation of five distinct biodiesel blends, namely DRB10% + D90%, DRB20% + D80%, DRB10% + BUT10% + D80%, DRB10% + BUT20% + D70%, and DRB20% + D80% + EGR10%. The inclusion of n‐butanol in a biodiesel blend serves to tackle the problem of inadequate combustion in fuel blends by alleviating the oxygen deficiency that occurs during the combustion process. The findings of the study revealed that the combination of DRB at 10%, BUT at 20%, and D at 70% produced in a significant reduction in specific fuel consumption (SFC) by 11.19% and brake thermal efficiency by 2.62%. Additionally, this combination led to a decrease in exhaust emissions of CO and Smoke, with the exception of HC and NOx, when compared to the use of diesel fuel. The control of HC and NOx emissions can be achieved through the implementation of an exhaust gas recirculation system. The results of this investigation suggest that Delonix regia biodiesel, in combination with a 20% concentration of n‐butanol, has potential as a viable alternative fuel choice that may be utilized without necessitating any engine modifications. [ABSTRACT FROM AUTHOR]

Present study involves the investigation of the esterification kinetics between butyric acid and n‐butanol. This reaction was conducted in a batch reactor, utilizing homogeneous methanesulfonic acid (MSA) catalyst. Response surface methodology (RSM) was conducted prior to the kinetic study using "Design Expert; version‐11.0" for finding the causal factors influencing the conversion of butyric acid. Most important factors identified with their limits against conversions (during optimization of the process using RSM) were taken up to critically analyze the effect of them on butyric acid conversion. Concentration and activity‐based model of the process were proposed assuming second order reversible reaction scheme using homogeneous MSA catalyst. During the study of non‐ideal behavior of the system, UNIFAC model was adapted for assessing the activity coefficients of species present in equilibrated liquid phase. Experimental data were used to evaluate kinetic and thermodynamic parameters such as rate constants, activation energy, enthalpy, and entropy of the system. The endothermic nature of esterification was confirmed by positive value of enthalpy obtained. The effect of various levels of causal variables like temperature (60–90°C), catalyst concentration (0.5–1.5 wt.%), and molar ratio of n‐butanol to butyric acid (1–3) on conversion kinetics of butyric acid was investigated during transient and equilibrium phase of the reaction. It has been observed that molar ratio of butanol to butyric acid has the highest influence on the conversion. The rate equation derived offered a kinetic and thermodynamic framework to the generated data. It also exhibits a notable degree of conformity of predicted data to the experimental ones and effectively characterizes the system across different reaction temperatures, reactant molar ratio, and catalyst concentration. [ABSTRACT FROM AUTHOR]

The permeability–selectivity trade‐off of membrane is a major challenge limiting the development of pervaporation (PV) technology. Rational design of high‐performance mixed matrix membranes (MMMs) has the potential to break off the trade‐off. Herein, a solvent‐assisted linker exchange‐based strategy is reported to introduce fluoroalkyl into metal–organic framework‐808 (MOF‐808). The pore size of fluorinated MOF‐808 can be adjusted with fluoroalkyl of different chain length (like trifluoromethyl and pentafluoropropyl). Then, the fluorinated MOF‐808/polyether block amide (PEBA) MMMs are prepared for the PV of n‐butanol/water. Compared with pristine PEBA membrane, 20 wt% 3F‐MOF‐808(P)/PEBA MMMs (3F = ‐CF3 group; P = postmodification method) exhibit 69% increase in permeation flux and 33% increase in separation factor in the PV of 2.5 wt% n‐butanol aqueous solutions at 70 °C. Based on Grand Canonical Monte Carlo and molecular dynamics simulations, fluorinated MOF‐808 shows better butanol affinity (pull effect) and stronger water repulsion ability (push effect). And the "push–pull effect" between fluorinated MOF‐808 with butanol/water is helpful to enhance the PV performance of MMMs. The application of "push–pull effect" provides a new strategy for the rational design of high‐performance MMMs, which is of great significance for the in‐depth research and application of PV technology. [ABSTRACT FROM AUTHOR]

The esterification reaction of n‐butanol and acetic acid has been performed in batch reactor in the presence of different homogeneous acid catalyst, namely sulfuric acid, nitric acid, and para toluene sulfonic acid (p‐TSA). The objective of present research work is to investigate kinetic behavior of esterification reaction over the temperature range of 60°C–80°C. The effect of reaction parameter such as catalyst loading varied from 1% to 5% v/v and acid to alcohol molar ratio of 1:1, 1:3, and 1:5 has been observed. A pseudo homogeneous kinetic model has been applied. Kinetic parameters such as equilibrium constant, reaction rate constant, enthalpy, activation energy, and entropy were calculated by the experimental data for different acid catalyst system. It was observed that sulfuric acid gives higher conversion 73% than p‐TSA 68.5% and nitric acid 66.25% at temperature of 80°C, 1:1 molar ratio and 3% catalyst concentration. The activation energy was estimated 36448.49, 23324.31 and 19060.156 J/mol K for three different catalyst sulfuric acid, nitric acid and p‐TSA respectively. The enthalpy and entropy of the esterification reaction of acetic acid with n‐butanol over three different catalysts has been calculated (Enthalpy: 25.788 KJ/mol, 12.256 KJ/mol, 28.320 KJ/mol, Entropy: 88.1 J/mol K, 45.298 J/mol K, 91.44 J/mol K) and found enthalpy is having positive value that shows reaction is endothermic. [ABSTRACT FROM AUTHOR]

At present, there are still few gas sensors for detecting n‐butanol at room temperature. It is worth noting that detecting target gas at room temperature is beneficial to reduce energy consumption and prolong the lifetime of sensors. In this work, different molar ratios Au nanoparticles modified SnO2 derived from Sn‐MOF hollow cubes (Au‐SnO2) are synthesized by the coprecipitation method. The Au‐SnO2 has higher specific surface area than pure SnO2, which is conducive to improving gas sensing. The 0.7% Au‐SnO2 exhibit excellent sensing performances of 240% toward 100 ppm n‐butanol and the actual detection interval is 200 ppb–500 ppm under the room temperature. Meanwhile, DFT calculations reveal that Au‐SnO2 gas sensor has wonderful selectivity to n‐butanol at room temperature. The enhancement of n‐butanol sensing performance is also related to the "catalytic sensitization" effect and the "electron sensitization" effect triggered driven by Au NPs. It is hoped this Au‐SnO2 sensing material with such great gas response, selectivity and low detection limit will help detect n‐butanol at room temperature to lower energy consumption. [ABSTRACT FROM AUTHOR]

Under high ambient pressure (5 MPa) and different injection pressures (90, 120, and 150 MPa), a high‐speed imaging technique was carried out to comparatively investigate the macroscopic spray characteristics of diesel with three different types of blended fuel in a constant volume chamber. The oxygenated fuels were n‐butanol (B), pine oil (P), and 2,5‐dimethylfuran (DMF). All their blending ratio with diesel were 20%. Results showed that less viscosity could be improved the spray characteristics of the fuel in the range of experimental conditions. Then, the tested fuels had a longer penetration and a greater spray area with increasing the injection pressure from 90 to 150 MPa. On the other hand, the percentage increases in the mean spray cone angle of D100, B20, P20, and DMF20 were 3%, 4.4%, 2.4%, and 2.9%, respectively. At the same experimental condition, the spray penetrations of DMF20 and P20 were larger than that of D100, but the spray penetration of B20 was basically similar to D100. Besides, the performance of the spray cone angle and spray area were D100 < B20 < P20 < DMF20. In addition, the comprehensive influence was that blending oxygenated fuels would be a benefit for developing fuel atomization and the air–fuel mixture of conventional diesel fuel. [ABSTRACT FROM AUTHOR]

The nanocrystalline HZSM‐5 was synthesized by supercritical hydrothermal synthesis for the first time and investigated in catalytic esterification of pyromellitic dianhydride(PMD)and n‐butanol to tetrabutyl pyromellitate(TBPM). The HZSM‐5 prepared by conventional hydrothermal synthesis was also examined for comparison. The catalysts were studied using XRD, N2 adsorption, NH3‐TPD, Pyridine‐adsorption FT‐IR, SEM,[27] Al MAS NMRandCHNS analysis. According to the results of characterization, the supercritical hydrothermal condition was helpful to reduce the size of crystal particles and improve the crystallinity of HZSM‐5, and shorten the crystallization time. The surface area, especially external surface area, and pore volume were increased, and the total acidity was increased. The strong acid sites were transformed into the weak acid sites, and the strength of weak and strong acid was weakened. The amount of framework tetrahedral Al species and Brönsted acid sites were increased. Therefore, the formation of coke was retarded, and thePMD conversion, the TBPM selectivity and the catalytic stability were obviously improved. [ABSTRACT FROM AUTHOR]

Probiotics are greatly exploited for use as biocatalysts to synthesize γ‐aminobutyric acid (GABA). However, the permeability barrier of the cell envelope is considered to be one of the major hindrances in the effective production of GABA. The objective of this study was to evaluate the GABA producing ability of the permeabilized Enterococcus faecium NCIM 5593 cells. n‐butanol treated cells for 10 minutes showed highest activity in comparison to the other solvents and/or detergents used. The optimization of process conditions for better Glutamate decarboxylase (GAD) activity revealed the optimum points to be n‐butanol concentration (10%), cell concentration (60 g L‐1), gutamate (8 g L‐1), temperature (37°C) and pH (5). The predicted Michaelis–Menten model fitted well with the experimental results with a deviation of 0.16 and 0.05 for permeabilized and non‐ permeabilized cells, respectively. Kinetic data revealed that permeabilized cells (Vmax: 0.59 ± 0.02 g Lh‐1; Km = 2.76 ± 0.07 g L‐1) showed higher affinity for glutamate than non‐permeabilized cells (Vmax: 0.18 ± 0.01 g Lh‐1; Km = 4.65 ± 0.09 g L‐1) as evidenced by Vmax and Km values. GABA produced using permeabilized cells were purified using ion‐exchange chromatography and purified GABA (purity; 98.26%) was subjected for structural characterization studies using MS and NMR. Overall, the approach of using n‐butanol as a solvent to improve cell permeability to enhance GAD activity showed a greater promise as a whole cell biocatalysts and the same could be employed for batch operations to decrease the cost of industrial GABA production. [ABSTRACT FROM AUTHOR]

A recently developed and efficient absorption contactor was evaluated, using alternative physical absorption liquids that are more economical, environmentally friendly, easier to recycle, untested and have lower energy requirements compared to commercial absorption solutions for capturing carbon dioxide. For this purpose, CO2 was captured using n‐butanol and ethyl acetate in an originally designed structured packed column. Mass transfer coefficients were determined at different gas and liquid velocities. The results are correlated in terms of dimensionless numbers, such as ShL = 0.01283ReG1.4ReLScL1/3, with a regression coefficient of 0.992. [ABSTRACT FROM AUTHOR]

The study includes the use of alcohols in conjunction with diesel as a binary fuel and biodiesel. In addition, this study was conducted on quaternary fuels (premium diesel, waste cooking biodiesel, n‐butanol, and bioethanol), including Fe3O4 (iron(III) oxide)‐doped reduced graphene oxide (rGO) nanocomposite to reduce the use of fossil fuels, their cost, and energy demand. It includes 10% bioethanol, 5%–20% n‐butanol, 25 ppm Fe3O4‐doped rGO nanocomposite, and 20% and 100% waste cooking biodiesel, all of which have been tested in a diesel engine to ensure that they are suitable for use. The findings were compared to those obtained with premium diesel, ranging from 50% to 100% at full engine load conditions. In comparison to 100% premium diesel fuel, the fuel blend (Blend G) had 37.50% brake thermal efficiency and 0.46% (brake‐specific energy consumption), as well as lower rates of 316.2% carbon monoxide, 198.80% hydrocarbon, and 80.01% smoke with 28.10% higher oxides of nitrogen (NOx). Adding 20% n‐butanol to premium diesel, as well as waste cooking biodiesel, bioethanol, and Fe3O4‐doped rGO nanocomposite fuel blends, was used in this study to improve the performance of the diesel engine and reduce some of the NOx emissions. In the near future, these fuel blends may be a viable alternative combination for the diesel engine. [ABSTRACT FROM AUTHOR]

The chief objective of this study is to utilize non‐edible, carbon‐rich oil derived from Prunus domestica seeds as blended fuel. The combustion efficiency of derived blends shall further be enhanced by blending higher alcohol into biodiesel/diesel blends. This work details the impact of effectively utilizing waste and non‐edible oil to replace fossil fuels partially. In this study, the P. domestica is trans‐esterified to methyl ester and blended with diesel at 20%. Further to enhance the ignition nature, butanol, higher alcohol, is blended to P. domestica biodiesel/diesel blends at 5% and 10%. The ignition pattern of the modified fuels is extensively studied and compared with diesel in a stationary research diesel engine. This study involves four fuel samples, namely, neat P. domestica methyl ester and is termed PDME. 20% of PDME is blended with 80% diesel is referred to as PDME20. 20% of PDME with 5% n‐butanol and 75% diesel is termed PDME20Bu5D75, 20% of PDME with 10% n‐butanol and 70% diesel is termed as PDME20Bu10D70 and diesel. Addition of PDME and butanol at different blends found miscible with diesel. PDME and butanol provided a suitable time for reaction and mixing, complete combustion, higher O2 content, and rich fuel‐air mixture, resulting in lower emissions than diesel. Further, butanol aided better atomization, effective combustion and resulted in higher efficiency with lower fuel consumption. Adding butanol also lowered the viscosity and improved the mixing process, and produced better in‐cylinder pressure and heat release rate. [ABSTRACT FROM AUTHOR]

In this paper, we describe multiple scenarios to assess the techno‐economic results of producing hydrocarbon fuels from corn stover‐derived ethanol and the impact of co‐producing higher‐value, ethanol‐derived n‐butanol and 1,3‐butadiene to improve economic feasibility. In our baseline process, the stover‐derived lignin is burned for its energy content to raise process steam and electricity. We evaluated an alternative approach based on the same stover‐to‐ethanol process, but instead of burning residual lignin to produce heat and electricity, it was fed to a hydrothermal liquefaction process and converted into hydrocarbon fuel, while the ethanol from fermentation is used to make only butanol or butadiene. Our results indicate that the hydrothermal liquefaction pathways have significant cost advantages over the pathways that burn the lignin. For comparison purposes, two more scenarios were evaluated based on the assumption that ethanol was purchased at market prices and converted to butanol or butadiene exclusively. This comparison evaluates the economics for making higher‐valued chemicals which, in the absence of incentives, would be the most profitable approaches in our study. The results for these evaluations indicated that the ethanol‐to‐butanol economics were generally favorable and achieved or exceeded the 10% internal rate of return target. The butadiene process had less favorable economic performance in some years when the market price for butadiene was less than the selling price needed to achieve the internal rate of return. Economic incentives for low‐carbon chemicals and fuels were not considered in our analysis. © 2022 Battelle Memorial Institute. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

A n‐butanol reduced mechanism (60 species and 306 reactions) was developed using the direct relation graph with error propagation and isomer lumping methods. Sensitivity analysis (SA) was then performed to identify reactions that were sensitive to the ignition delay (ID) for the adjustments of the pre‐exponential factor to replicate the experimental ID times. As compared with the experimental measurements at initial temperatures of 343–1350 K, initial pressures of 0.02–80 bar, and equivalence ratios of 0.5–2.0, the maximum deviation for the predictions by the n‐butanol reduced mechanism was at 37.75% for the ID times, 8 cm/s for the laminar flame speed, and a factor of three for both the species concentration profiles under jet‐stirred reactor and premixed laminar flame. Furthermore, a maximum deviation of 2.5 crank angle degrees in combustion phasing was obtained when the reduced mechanism was benchmarked against the detailed mechanism under homogeneous charge compression ignition (HCCI) conditions at initial temperature of 413 K, initial pressure of 1 bar, and equivalence ratios of 0.5–2.0. Despite these deviations, the low temperature IDs and the laminar flame speed predicted by the present reduced mechanism were in better agreement to the experimental measurements than the existing n‐butanol reduced mechanisms of comparable sizes. Hence, this collectively indicates that improvements were made to the present reduced mechanism, particularly for the low‐temperature reactions. The n‐butanol reduced mechanism was also compared with gasoline and diesel surrogates under 0D HCCI simulations. The results indicate that the combustion characteristics of n‐butanol is closer to gasoline than to diesel. This suggests that n‐butanol could safely replace gasoline fuel in neat form while it is more suitable to be blended with diesel fuel to maintain engine performance and prevent any adverse effects on the engine. [ABSTRACT FROM AUTHOR]

Cellulosic n‐butanol from renewable lignocellulosic biomass has gained increased interest. Previously, we have engineered Clostridium cellulovorans, a cellulolytic acidogen, to overexpress the bifunctional butyraldehyde/butanol dehydrogenase gene adhE2 from C. acetobutylicum for n‐butanol production from crystalline cellulose. However, butanol production by this engineered strain had a relatively low yield of approximately 0.22 g/g cellulose due to the coproduction of ethanol and acids. We hypothesized that strengthening the carbon flux through the central butyryl‐CoA biosynthesis pathway and increasing intracellular NADH availability in C. cellulovorans adhE2 would enhance n‐butanol production. In this study, thiolase (thlACA) from C. acetobutylicum and 3‐hydroxybutyryl‐CoA dehydrogenase (hbdCT) from C. tyrobutyricum were overexpressed in C. cellulovorans adhE2 to increase the flux from acetyl‐CoA to butyryl‐CoA. In addition, ferredoxin‐NAD(P)+ oxidoreductase (fnr), which can regenerate the intracellular NAD(P)H and thus increase butanol biosynthesis, was also overexpressed. Metabolic flux analyses showed that mutants overexpressing these genes had a significantly increased carbon flux toward butyryl‐CoA, which resulted in increased production of butyrate and butanol. The addition of methyl viologen as an electron carrier in batch fermentation further directed more carbon flux towards n‐butanol biosynthesis due to increased reducing equivalent or NADH. The engineered strain C. cellulovorans adhE2‐fnrCA‐thlACA‐hbdCT produced n‐butanol from cellulose at a 50% higher yield (0.34 g/g), the highest ever obtained in batch fermentation by any known bacterial strain. The engineered C. cellulovorans is thus a promising host for n‐butanol production from cellulosic biomass in consolidated bioprocessing. [ABSTRACT FROM AUTHOR]

Ethanol to n‐butanol conversion is a process that can increase the carbon number of alcohols by coupling. There is increasing interest in the mechanisms for n‐butanol production in a simple step through the effective use of bifunctional acid–base catalysts. In this context, commercial hydroxyapatite (HAP) and two synthetized model supported catalysts, Ca/Al2O3 and Ca‐P/Al2O3, were used in bioethanol condensation. Characterization and acid–base sites were considered, and Fourier‐transform infrared (FTIR) spectroscopy and diffuse reflectance infrared Fourier‐transform spectroscopy–mass spectrometry (DRIFT‐MS) reactivity tests were performed in situ, as a first approximation to design a sustainable catalytic process rationally, and with the aim of understanding the process at the catalytic surface. The results indicated that the reactions occur at a large range of temperatures (200–450 °C). Hydroxyapatite and Ca/Al2O3 have similar basic sites (low and medium) and Ca‐P/Al2O3 presented the strongest Brönsted and Lewis combined acid sites. Three major reactions were identified: non‐oxidative dehydrogenation, aldol condensation, and intermolecular reduction, associated with the basic‐acid sites Ca‐O‐Ca/Ca‐O‐P/Ca‐O‐Al. Side reactions also occur involving different acid sites related to Lewis alumina centers favoring ethylene or diethyl‐ether production. © 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd [ABSTRACT FROM AUTHOR]

In this Letter, new chrysanthemum‐shaped micrometre calcium carbonate was prepared by using CaCl2 aqueous solution + NH3H2O + CTAB + n‐butanol + n‐hexane inverse microemulsion system. Scanning electron microscope, X‐ray powder diffraction, and Fourier transform infrared spectroscopy were used to characterise the morphology and structure of the micron calcium carbonate. Further, the formation mechanism of chrysanthemum‐shaped micron calcium carbonate was discussed. [ABSTRACT FROM AUTHOR]

Alcohol has a potential health risk to human health, so it is important to realise the rapid detection of alcohols. Based on this, the nano Na2Mg(CO3)2 was prepared by a simple hydrothermal method to establish a cataluminescence (CTL) gas sensor for alcohols. The Na2Mg(CO3)2with highly purified quality was characterised by scanning electron microscope, energy dispersive spectroscopy and the powder X‐ray diffraction. The results show that the nano Na2Mg(CO3)2 is a peony‐like substance with a large surface area, which will be beneficial to produce ultra‐weak chemiluminescence reaction between the detector and the material. The peony‐like Na2Mg(CO3)2 has good CTL response to alcohols (methanol, ethanol, n‐propanol and n‐butanol), showing high selectivity. The response time of Na2Mg(CO3)2 for four alcohols is between 1 and 2 s, which indicate that the material has the advantage of rapid response. The limit of detection of four alcohols defined as 3 N/S is about 7.91, 4.75, 6.69 and 8.10 mg/l, respectively. The optimum reaction conditions of the gas sensor based on nano Na2Mg(CO3)2 are mild and this nanomaterial can be used for alcohol detection. [ABSTRACT FROM AUTHOR]

Ethanol Guerbet condensation is an environmentally friendly process for preparing biofuel such as n‐butanol and alcohols with more than 4 carbon atoms. In this work, a multifunctional catalyst Ni/TiO2 was prepared by an excess impregnation method and its catalytic performance for ethanol Guerbet condensation was evaluated. The selectivity of C4‐C8 alcohols reached up to almost 70% (41.4% of n‐butanol) at nearly half conversion of ethanol at 210 °C and 10 h. Based on GC‐MS analysis results, the products in ethanol Guerbet condensation were identified and a reaction network was established. The presence of acetaldehyde and 2‐crotonaldehyde in the reaction products verified that Ni/TiO2‐catalyzed ethanol condensation followed the traditional dehydrogenation‐condensation‐hydrogenation reaction mechanism. [ABSTRACT FROM AUTHOR]

BACKGROUND Cadaverine is a natural polyamine that can replace fossil‐derived hexamethylene diamine to produce bio‐based polyamide. Despite huge developments in cadaverine bioproduction, an econo"mically attractive purification process is a highly important part of the production of high‐purity cadaverine. RESULTS: This study utilized l‐lysine hydrochloride as a substrate for the production of high‐purity cadaverine via a litre‐scale integrated process incorporating fermentation, bioproduction, deprotonation, extraction and rectification. First, 8.24 U mg–1 lysine decarboxylase activity and 205 g L–1 cadaverine with a yield of 91.61% were achieved through the fermentation of low‐cost industrial culture by engineered Escherichia coli and the bioproduction of cadaverine by lysine decarboxylase. Secondly, four integrated purification methods – deprotonation‐evaporation, pH adjustment‐deprotonation‐evaporation, deprotonation‐extraction‐evaporation and deprotonation‐extraction‐rectification – were explored, and the conditions of each unit operation in the chosen method (deprotonation‐extraction‐rectification) were optimized. Then the optimized method was applied to a 2‐L purification system, resulting in 99% purity of cadaverine with a yield of 87.47%. Furthermore, the n‐butanol recovery ratio reached 91.25%, effectively avoiding the waste of resources and environmental pollution, and thus reducing purification costs. CONCLUSION: The proposed experimental approach proves that this integrated process leads to the production of high‐purity cadaverine. In the 2‐L‐scale integrated process, 358.64 g cadaverine of 99% purity was produced at a cost of US$3.99 (US$1.11 per 100 g), which is far below its market price (US$784.71 per 100 g). This integrated process provides a potential way for the industrial‐scale production of bio‐based cadaverine. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A literature review and health effects evaluation were conducted for n‐butanol, a chemical that occurs naturally in some foods, which is an intermediate in the production of butyl esters and can be used as a gasoline additive or blend. Studies evaluating n‐butyl acetate were included in the review as n‐butyl acetate is rapidly converted to n‐butanol following multiple routes of exposure. The primary n‐butanol health effects identified were developmental and nervous system endpoints. In conducting the literature review and evaluating study findings, the following observations were made: (1) developmental findings were consistently identified; (2) neurodevelopmental findings were inconsistent; (3) evidence for nervous system effects was weak; (4) comparing internal doses from oral and inhalation exposures using physiologically based pharmacokinetic models introduces uncertainties; and (5) a lack of mechanistic information for n‐butanol resulted in the reliance on mechanistic data for ethanol, which may or may not be applicable to n‐butanol. This paper presents findings from a literature review on the health effects of n‐butanol and proposes research to help reduce uncertainty that exists due to database limitations. A literature review and health effects evaluation were conducted for n‐butanol, a chemical occurring naturally in some foods, which is an intermediate in the production of butyl esters and can be used as a gasoline additive or blend. The primary n‐butanol health effects identified were developmental and nervous system endpoints. This paper presents findings from a literature review on the health effects of n‐butanol, discusses health assessment issues and proposes research to help reduce uncertainty that exists due to database limitations. [ABSTRACT FROM AUTHOR]

The polydimethylsiloxane (PDMS) membrane commonly used for separation of biobutanol from fermentation broth fails to meet demand owing to its discontinuous and polluting thermal fabrication. Now, an UV‐induced polymerization strategy is proposed to realize the ultrafast and continuous fabrication of the PDMS membrane. UV‐crosslinking of synthesized methacrylate‐functionalized PDMS (MA‐PDMS) is complete within 30 s. The crosslinking rate is three orders of magnitude larger than the conventional thermal crosslinking. The MA‐PDMS membrane shows a versatile potential for liquid and gas separations, especially featuring an excellent pervaporation performance for n‐butanol. Filler aggregation, the major bottleneck for the development of high‐performance mixed matrix membranes (MMMs), is overcome, because the UV polymerization strategy demonstrates a freezing effect towards fillers in polymer, resulting in an extremely high‐loading silicalite‐1/MA‐PDMS MMM with uniform particle distribution. [ABSTRACT FROM AUTHOR]

A new type of multi‐metal oxide gas‐sensing material, CoSnO3 was synthesized by a simple hydrothermal method, in which CoSn(OH)6 was used as a precursor, and it was calcined into amorphous CoSnO3. The CoSnO3 nanoparticles were characterized by means of XRD, FE‐SEM, TEM and N2 adsorption‐desorption analysis. The average size of the CoSnO3 nanoparticles was of 90 nm. The sensor based on the CoSnO3 nanoparticles showed good gas‐sensing performances to n‐butanol. The highest response was about 23 to 100 ppm n‐butanol at 200 °C. Moreover, CoSnO3 nanoparticles exhibits promising candidate material for fast, sensitive and selective detection of n‐butanol. [ABSTRACT FROM AUTHOR]

Three kinds of polyhedral α‐Fe2O3 nanoparticles enclosed by different facets including oblique parallel hexahedrons (op‐hexahedral NPs), cracked oblique parallel hexahedrons (cop‐hexahedral NPs), and octadecahedral nanoparticles (octadecahedral NPs), were successfully prepared by simply changing only one reaction parameter in the hydrothermal process. The structural and morphological of the products were systematically studied using various characterizations including X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), revealing that the three kinds of α‐Fe2O3 nanoparticles were enclosed by {104}, {110}/{104}, and {102}/{012}/{104} crystal planes, respectively. The exposed facets and shape of the nanocrystals were found to be affected by the adding amount of ethylene glycol in the solvent. The gas‐sensing properties and mechanism of the α‐Fe2O3 samples were studied and analyzed, which indicated that the sensitivity of the three samples followed the order of octadecahedral NPs > cop‐hexahedral NPs > op‐hexahedral NPs due to the combined effects of specific surface area and oxygen defects in the nanocrystals. [ABSTRACT FROM AUTHOR]

The production of biobutanol is hindered by the product's toxicity to the bacteria, which limits the productivity of the process. In situ product recovery of butanol can improve the productivity by removing the source of inhibition. This paper reviews in situ product recovery techniques applied to the acetone butanol ethanol fermentation in a stirred tank reactor. Methods of in situ recovery include gas stripping, vacuum fermentation, pervaporation, liquid-liquid extraction, perstraction, and adsorption, all of which have been investigated for the acetone, butanol, and ethanol fermentation. All techniques have shown an improvement in substrate utilization, yield, productivity or both. Different fermentation modes favored different techniques. For batch processing gas stripping and pervaporation were most favorable, but in fed-batch fermentations gas stripping and adsorption were most promising. During continuous processing perstraction appeared to offer the best improvement. The use of hybrid techniques can increase the final product concentration beyond that of single-stage techniques. Therefore, the selection of an in situ product recovery technique would require comparable information on the energy demand and economics of the process. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:563-579, 2017 [ABSTRACT FROM AUTHOR]

The partition of n-butanol in Winsor type III (W-III) microemulsions was investigated in this work. Three kinds of anionic surfactants (sodium dodecyl sulfate (SDS), sodium dodecyl sulfonate (DSS), and sodium dodecyl benzene sulfonate (SDBS)) and two kinds of anionic/cationic surfactant mixtures (SDS/octadecyl trimethyl ammonium chloride (OTAC) mixtures and DSS/OTAC mixtures) were studied. Internal standard gas chromatography was employed in n-butanol content analysis. The results showed that no water exists in the excess oil (EO) phase and no oil exists in the excess water (EW) phase. For the W-III microemulsions obtained by salinity scanning, relatively constant n-butanol content in the EO (11-12 v%) and EW (1-4 v%) was found under different salinities. Accurate measurement of n-butanol content in each phase is important for those systems having low solubilization ability. For the W-III microemulsions prepared using SDS/OTAC surfactant mixture, the percentage of n-butanol distributed into the interfacial layer decreased while the fraction of n-butanol in the interfacial layer first increased sharply and then tended to be stable with the addition of n-butanol. For the different optimum W-III microemulsion systems tested, most of the surfactant-to-alcohol molar ratio data are near 1:3, but obvious deviation could be observed for some data. On the basis of the accurate measurement of n-butanol content in the EO and EW phases, the standard free energy, Δ G ( T = 298.15 K) of n-butanol transferring from the EO phase to the interfacial region was calculated. The results show negative Δ G values. For microemulsions with the same components, n-butanol content is an important factor influencing the Δ G value, and a high absolute value of Δ G leads to high solubilization ability. [ABSTRACT FROM AUTHOR]

Alcohols extensively used in internal combustion engines are important renewable and sustainable energy resources from environmental and economical perspectives. Besides, bio production of alcohols decreases consumption of fossil-based fuels. Although there are many studies with regards to the use of lower alcohols such as methanol and ethanol in internal combustion engines, there are a limited number of investigations with higher alcohols. Higher alcohols such as propanol, n-butanol, and 1-pentanol are part of the next generation of biofuels, given they provide better fuel properties than lower alcohols. Biodiesel-higher alcohol blends can be used in diesel engines without any engine modification but need to be tested under various engine conditions with long periods in order to evaluate their impacts on engine performance and environmental pollutants. The objective of this study was to evaluate the effect of using propanol, n-butanol, and 1-pentanol in waste oil methyl ester (B100) on engine performance and exhaust emissions of a diesel engine running at different loads (0, 3, 6, and 9 kW) with a fixed engine speed (1800 rpm). Test fuel blends were prepared by adding propanol, n-butanol, and 1-pentanol (10 vol.%) into waste oil methyl ester to achieve blends of B90Pr10, B90nB10, and B90Pn10, respectively. According to engine performance and exhaust emissions results, the addition of propanol, n-butanol, and 1-pentanol to B100 had the effect of increasing brake specific fuel consumption and exhaust gas temperatures. The brake thermal efficiency (BTE) decreased for B90Pr10 and B90nB10, while B90Pn10 showed a slight increase in BTE as compared with B100. When compared with B100, B90Pr10, B90nB10, and B90Pn10 decreased carbon monoxide emissions at lower loads while it increased slightly at 9 kW load. The decrement in oxides of nitrogen emission was observed at whole loads for B90Pr10, B90nB10, and B90Pn10 compared with B100. When considering all loads, B90Pn10 presented the best mean hydrocarbon emission with a reduction of 45.41%. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We aimed to isolate aerobic butanol-producing microorganisms from environmental samples as potential platform strains for butanol production. Soil samples collected were subjected to a semi-high-throughput screening strategy. A microorganism capable of producing butanol in high concentrations under aerobic conditions was isolated and identified as Bacillus species by 16S rDNA analysis. The growth and butanol production under both aerobic and anaerobic conditions of the isolated Bacillus sp. 15, together with a different composition of by-products, suggest different metabolic networks from the obligate anaerobes Clostridia. At 1 L scale fermentation with 0.2 L/Min of ariflow, butanol titer reached up to 10.38 g/L in a batch culture. The fermentation process of the isolate also occurred in two phases and the acidic condition is critical for butanol production. The butanol concentration was further improved to 12.3 g/L with minimized by-products using a microaerobic condition. With the above-mentioned distinct features, the isolated Bacillus sp. 15 is a suitable platform strain for further process development and metabolic engineering for butanol production. [ABSTRACT FROM AUTHOR]

A simple solvent-free preparation method was used to synthesize sulphated zirconia catalyst with various amounts of nickel promoter. This research investigated the effect of nickel addition to sulphated zirconia on the catalyst performance in esterification of acetic acid (a bio-oil model) with n-butanol. The results show that the addition of nickel contributed to the increase of sulphur content that bonded with nickel, the increase of thermal stability of the catalysts, and the formation of additional sulphate groups, and thus resulted in better catalytic performance compared to sulphated zirconia without nickel. More nickel being added resulted in a significant increase of acetic acid conversion; with 0.05 mol/mol nickel amount, the conversion was 97.93 %. This result represents a dramatic increase of about 2 and 3 times compared to the conversions of non-nickel sulphated zirconia catalyst and non-catalyst reactions, respectively. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (NPs) supported on hydrotalcite (Au/HT) are highly active and selective catalysts for the continuous, gas-phase, non-oxidative dehydrogenation of bioderived C2-C4 alcohols. A sharp increase in turn over frequency (TOF) is noted when the size of Au NPs is less than 5 nm relating to the strong synergy between metallic Au NPs and the acid-base groups on the support surface. It is shown that catalytic activity depends critically on Au NP size, support composition, and support pretreatments. A reaction pathway elucidated from kinetic isotope effects suggests that the abstraction of β-H by Au NPs (C−H activation) is the rate-determining step in the dehydrogenation of bioderived C2-C4 alcohols. [ABSTRACT FROM AUTHOR]

Background The relationship between olfactory function, rhinencephalon and forebrain changes in Kallmann syndrome (KS) have not been adequately investigated. We evaluated a large cohort of male KS patients using Sniffin' Sticks and MRI in order to study olfactory bulb (OB) volume, olfactory sulcus (OS) depth, cortical thickness close to the OS, and olfactory phenotype. Methods Olfaction was assessed administering Sniffin' Sticks®, in 38 KS patients and 17 controls (by means of Screening 12 test®). All subjects underwent magnetic resonance imaging (MRI) to study OB volume, sulcus depth, and cortical thickness. Results Compared to controls, KS patients showed smaller OB volume ( p<0.0001), reduced sulcus depth ( p<0.0001), and thicker cortex in the region close to the OS ( p<0.0001). Anosmic KS patients had smaller OB than controls and hyposmic KS patients; there was no difference between hyposmic KS patients and controls. OB volume correlated with Sniffin' Sticks score ( r = 0.64; p < 0.001), OS depth ( p<0.0001) and, inversely, with cortical thickness changes ( p<0.0001). Sniffin' Sticks showed an inverse correlation with cortical thickness ( r = −0.5; p<0.0001) and a trend toward a statistically significant correlation with OS depth. Conclusion The present study provides further evidence of the strict relationship between olfaction and OB volume. The strong correlation between OB volume and the overlying cortical changes highlights the key role of rhinencephalon in forebrain embryogenesis. [ABSTRACT FROM AUTHOR]

ABSTRACT n-Butanol has been widely used and its residue exists extensively in the environment. It could lead to conformational and functional changes of trypsin by forming a complex with it. Docking method and spectrographic technique were employed to the study of the complex of trypsin and n-butanol. The fluorescence results indicated that n-butanol can form a complex with trypsin and change the distance between tryptophan and fluorescence quenchers. The conformational changes of trypsin were proved by UV-visible absorption and synchronous fluorescence spectroscopy indicating that n-butanol had little effect on the conformation of trypsin at a low concentration while denatured and coagulated the trypsin at a high concentration. The binding site was displayed by molecular modeling, which gave information about distances and binding forces between n-butanol and trypsin. The results were in accordance with spectroscopic experiments. Besides, enzyme activity assay gave the dose-response relationship of n-butanol with trypsin. [ABSTRACT FROM AUTHOR]

ABSTRACT Butanol biosynthesis through aldehyde/alcohol dehydrogenase ( adhE2) is usually limited by NADH availability, resulting in low butanol titer, yield, and productivity. To alleviate this limitation and improve n-butanol production by Clostridium tyrobutyricum Δ ack- adhE2 overexpressing adhE2, the NADH availability was increased by using methyl viologen (MV) as an artificial electron carrier to divert electrons from ferredoxin normally used for H2 production. In the batch fermentation with the addition of 500 μM MV, H2, acetate, and butyrate production was reduced by more than 80-90%, while butanol production increased more than 40% to 14.5 g/L. Metabolic flux analysis revealed that butanol production increased in the fermentation with MV because of increased NADH availability as a result of reduced H2 production. Furthermore, continuous butanol production of ∼55 g/L with a high yield of ∼0.33 g/g glucose and extremely low ethanol, acetate, and butyrate production was obtained in fed-batch fermentation with gas stripping for in situ butanol recovery. This study demonstrated a stable and reliable process for high-yield and high-titer n-butanol production by metabolically engineered C. tyrobutyricum by applying MV as an electron carrier to increase butanol biosynthesis. Biotechnol. Bioeng. 2015;112: 705-715. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The ( S)-3-hydroxybutyryl-CoA dehydrogenase PaaH1 from Ralstonia eutropha ( RePaaH1) is an enzyme used in the biosynthesis of n-butanol from acetyl-CoA by the reduction of acetoacetyl-CoA to ( S)-3-hydroxybutyryl-CoA. The RePaaH1 protein was crystallized using the hanging-drop vapour-diffusion method in the presence of 1.4 M ammonium sulfate, 0.1 M sodium cacodylate pH 6.0, 0.2 M sodium chloride at 295 K. X-ray diffraction data were collected to a maximum resolution of 2.6 Å on a synchrotron beamline. The crystal belonged to space group P3221, with unit-cell parameters a = b = 135.4, c = 97.2 Å. With three molecules per asymmetric unit, the crystal volume per unit protein weight ( VM) is 2.68 Å3 Da−1, which corresponds to a solvent content of approximately 54.1%. The structure was solved by the single-wavelength anomalous dispersion method and refinement of the structure is in progress. [ABSTRACT FROM AUTHOR]

SUMMARY Simultaneous injection of n-butanol and gasoline through a new system of two injectors directing the sprays towards the back of the intake valve in a spark-ignition engine was tried in lieu of injecting a blend of these fuels through a single injector. This system avoids the problem of phase separation, which is generally faced during the use of alcohol-gasoline blends. Experiments were conducted on a spark-ignition engine with this dual injection system using a fuel ratio of 1:1 (B50S) on the mass basis. High-speed photographs indicated that the sprays from the injectors did not interfere till they reached the intake valve. Comparisons were made with pre-blended butanol-gasoline (B50) and neat (100%) gasoline at the best spark timing. All injection and spark parameters were controlled using a real time engine controller. Neat n-butanol (B100) was superior only near full throttle with improved efficiency of the engine of about 1.2% (absolute). Heat release rates were observed to be higher and more advanced with B100 at wide open throttle. However, a reverse of this trend was observed at the throttle position of 15%. NO emission was also lower by 30% with B100 at wide open throttle as compared with gasoline. However, a small increase in carbon monoxide (CO) levels was observed because of lower post combustion temperatures as compared with gasoline and B50S. Simultaneous injection reduced hydrocarbon (HC) emissions by 13% to 50% as compared with B50 (blended fuel). HC emissions with gasoline and B50S were similar. Nitric oxide (NO) emission was lower with B50S as compared with gasoline; however it was higher than B50 because of better combustion. On the whole, the developed dual injection system was superior to the conventional method of blending in terms of performance, emissions and ability to change the fuel ratio as needed. B50S is suitable at all throttle positions, whereas B100 shows benefits at full throttle conditions. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

( S)-3-Hydroxybutyryl-CoA dehydrogenase from Clostridium butyricum ( CbHBD) is an enzyme that catalyzes the second step in the biosynthesis of n-butanol from acetyl-CoA by the reduction of acetoacetyl-CoA to 3-hydroxybutyryl-CoA. The CbHBD protein was crystallized using the hanging-drop vapour-diffusion method in the presence of 2 M ammonium sulfate, 0.1 M CAPS pH 10.5, 0.2 M lithium sulfate at 295 K. X-ray diffraction data were collected to a maximum resolution of 2.3 Å on a synchrotron beamline. The crystal belonged to space group R3, with unit-cell parameters a = b = 148.5, c = 201.6 Å. With four molecules per asymmetric unit, the crystal volume per unit protein weight ( VM) is 3.52 Å3 Da−1, which corresponds to a solvent content of approximately 65.04%. The structure was solved by the molecular-replacement method and refinement of the structure is in progress. [ABSTRACT FROM AUTHOR]

Enhanced extraction of 2,3-butanediol by adding salt into solvent n-butanol has been studied in this paper. Ternary phase diagrams for 2,3-butanediol + water + salt have been determined. The influences of phase ratio, type of salts and salt content on distribution coefficient and selectivity have also been investigated systematically. With phase ratio of 0.75 (w/w) and salt content of K2HPO4 of 25% (w/w), the distribution coefficient, separation factors and recovery yield in a single extraction process by n-butanol can reach 5.2%, 34% and 80%, respectively. Salt addition can greatly enlarge the two phase region and enhance extraction simultaneously in this system. [ABSTRACT FROM AUTHOR]

In the context of the global objective of shifting from petroleum to a biomass-based economy, the research on fermentative strategies to produce alternative biofuels and chemicals has become a predominant field of study. Microorganisms, because of their substrate versatility and metabolic efficiency, are promising to partially support our increasing needs for materials and fuels, opening up scenarios for the use of alternative sources, including wastes. Butanol is a very attractive molecule since it can be seen both as a chemical platform and as a fuel. Today, it is principally derived from petroleum, but it also represents the final product of a microbial fermentation. Although Clostridia are the natural and traditional organisms employed in butanol production, systematic approaches to improve production and resistance traits are currently impeded by a lack of characterization and genetic tools. This is the main reason why, besides their optimizations, a significant and growing amount of research is centered on the engineering of alternative robust cell factories capable of elevated production, possibly combined with higher tolerance. Here, we review the most recent advances in n-butanol production in non-Clostridial microbial hosts, including not only other prokaryotic but also eukaryotic microorganisms, which might eventually be seen as second-generation hosts. [ABSTRACT FROM AUTHOR]

Composite membranes were prepared by incorporating ZSM-5 zeolite into poly(ether-block-amide) (PEBA) membranes. These composite membranes were characterized by TGA, XRD, and SEM. The results showed that the zeolite could distribute well in the polymer matrix. And when the zeolite content reached 10%, the agglomeration of zeolite in the membranes was found. The composite membranes were used to the pervaporative separation of n-butanol aqueous solution. The effect of zeolite content on pervaporation performance was investigated. With the contribution of preferential adsorption and diffusion of n-butanol in the polymer matrix and zeolite channel, the 5% ZSM-5-PEBA membrane showed enhanced selectivity and flux. The effects of liquid temperature and concentration on separation performance were also investigated. All the composite membranes demonstrated increasing separation factor and permeation flux with increasing temperature and concentration. Incorporation of ZSM-5 could decrease the activation energy of n-butanol flux of the composite membrane. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

This review provides a technical description of the range of commercial products that can be accessed from n-butanol, with specific emphasis on n-butanol derived from renewable sources (biobutanol). n-Butanol itself and primary derivatives in which the oxygen functionality of the molecule is retained (butyraldehyde and butyric acid) have mainstream applications in the solvent, polymer, fuel oxygenate, and/or specialty chemical markets, while butanol dehydration products (butenes and butadiene) present additional opportunities in the hydrocarbon fuel and synthetic elastomers markets. The volume and value of these markets are noted and specific applications of first- and second-generation n-butanol derivatives are discussed. Selected technologies for the conversion of butenes into other valuable olefins are described and current biobutanol producers and technology providers are identified and profiled. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

The alcoholn-butanol has been recommended for use as a standard odorant by various groups for the training or standardization of breath odour judges and sensory evaluation panels. The objective of this study is to assess the use ofn-butanol as a suitable odorant for organoleptic training of breath judges.One judge with full smell acuity was trained in the method of organoleptic assessment using odorant solutions of main chemical classes (acids, amines, indole and sulphides) with the exception of alcohols. The subject was proficient in scoring odorant solutions, standard gas mixtures and human breath using the Rosenberg 0–5 organoleptic scale. A wide range ofn-butanol solutions were prepared from 0 to 90 000 ppm and dispensed as replicate 12-ml volumes in Universal bottles (24 ml) leaving a headspace of 12 ml. Sets of odorants were prepared, labelled by code, randomized and presented to the judge in a completely blind fashion. The judge scored each concentration. This process was repeated on 32 occasions over a period of 12 weeks. Mean values of data for each determination for each concentration series were plotted against the log concentrations of odorant. Linear regression slope analysis was used to measure slope, the 95% CI of slope and the scatter of points (R2 value). Headspace concentrations of odorant were determined using gas chromatography (GC) analysis.Then-butanol regression slope gave a highR2 value (0.971) and low scatter. However, the data did not correspond to other published work using an ASTM method where the range of recommended butanol concentrations was insufficient at both the high and low ends to determine the top and threshold. Moreover, headspace analysis using GC confirmed the published gas concentrations to be in error by a factor of 100. It was also observed that high concentrations of odorants were irritant causing desensitization if used for prolonged periods.The published method had erroneous headspace calculations listed andn-butanol could not be recommended as a training odorant because of its irritancy. [ABSTRACT FROM AUTHOR]

The mitigation of end‐product inhibition during the biosynthesis of n‐butanol is demonstrated for an in‐situ product recovery (ISPR) system employing a poly(ionic liquid) (PIL) absorbent. The thermodynamic affinity of poly(vinyldodecylimidazolium bromide) [P(VC12ImBr)] for n‐butanol, acetone and ethanol versus water was measured at conditions experienced in a typical acetone‐ethanol‐butanol (ABE) fermentation. In addition to providing a high n‐butanol partition coefficient (PC = 6.5) and selectivity (αBuOH/water = 46), P(VC12ImBr) is shown to be biocompatible with Saccharomyces cerevisiae and Clostridium acetobutylicum. Furthermore, the diffusivity of n‐butanol in a hydrated PIL provides absorption rates that support ISPR applications. Using a 5 wt% PIL phase fraction relative to the aqueous phase mass, P(VC12ImBr) improved the volumetric productivity of a batch ABE ISPR process by 31% relative to a control fermentation. The concentration of n‐butanol in the P(VC12ImBr) phase was sufficient to increase the alcohol concentration from 1.5 wt% in the fermentation medium to 25 wt% in the saturated PIL, thereby facilitating downstream n‐butanol recovery. [ABSTRACT FROM AUTHOR]

This work presents a detailed review and comparative analysis of the process design and economics of n-butanol production using corn grain and corn stover. This includes reviewing the most recent n-butanol technologies; demonstrating the impact of key parameters (e.g. plant capacity, raw material pricing, yield) on the overall n-butanol process economics; and comparing how cellulosic biomass conversion technologies and challenges differ from traditional sugar-based n-butanol conversion technology. A major challenge of n-butanol production is the low n-butanol yield (compared to ethanol), resulting in higher production costs. However, recent research efforts have achieved significant yield improvements using a combination of genetic engineering, fermentation techniques, and integrated process development using continuous fermentation with online stripping to remove n-butanol during fermentation. This study presents the advances in n-butanol research for both sugar-based (corn) and cellulosic (corn stover) feedstocks, and also provides a comparison of overall process technologies and process economics. In addition, the results of a sensitivity analysis comparing various technologies, sugar yields, and coproduct distributions are discussed in order to provide research guidance. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]