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The simultaneous saccharification and co-fermentation (SSCF) kinetic model described in the companion paper can predict batch and fed batch fermentations well at solids concentrations up to 62.4 g/L cellulose paper sludge but not in batch fermentation at 82.0 g/L cellulose paper sludge. Four hypotheses for the discrepancy between observation and model prediction at high solids concentration were examined: ethanol inhibition, enzyme deactivation, inhibition by non-metabolizable compounds present in paper sludge, and mass transfer limitation. The results show that mass transfer limitation was responsible for the discrepancy between model and experimental data. The model can predict the value of high paper sludge SSCF in the fermentation period with no mass transfer limitation. The model predicted that maximum ethanol production of fed-batch fermentation was achieved when it was run as close to batch mode as possible with the initial solids loading below the mass transfer limitation threshold. A method for measuring final enzyme activity at the end of fermentation was also developed in this study.

A kinetic model was developed to predict batch simultaneous saccharification and co-fermentation (SSCF) of paper sludge by the xylose-utilizing yeast Saccharomyces cerevisiae RWB222 and the commercial cellulase preparation Spezyme CP. The model accounts for cellulose and xylan enzymatic hydrolysis and competitive uptake of glucose and xylose. Experimental results show that glucan and xylan enzymatic hydrolysis are highly correlated, and that the low concentrations of xylose encountered during SSCF do not have a significant inhibitory effect on enzymatic hydrolysis. Ethanol is found to not only inhibit the specific growth rate, but also to accelerate cell death. Glucose and xylose uptake rates were found to be competitively inhibitory, but this did not have a large impact during SSCF because the sugar concentrations are low. The model was used to evaluate which constants had the greatest impact on ethanol titer for a fixed substrate loading, enzyme loading, and fermentation time. The cellulose adsorption capacity and cellulose hydrolysis rate constants were found to have the greatest impact among enzymatic hydrolysis related constants, and ethanol yield and maximum ethanol tolerance had the greatest impact among fermentation related constants.

The commercial production of ethanol from cellulose by simultaneous saccharification and fermentation (SSF) is prevented in part by the high cost of fungal cellulase enzymes. Intermittent exposure of SSF processes to ultrasonic energy under selected conditions (5 FPU of cellulase/g of substrate; 15 min of exposure/240 min cycle during the latter half of SSF) was found to increase ethanol production from mixed waste office paper by approximately 20%, producing 36.6 g/L ethanol after 96 h (70% of the maximum theoretical yield). Without ultrasound, 10 FPU of cellulase/g of substrate was required to achieve similar results. Continuous exposure of the organism to ultrasonic energy was bacteriostatic and decreased ethanol production but may be useful for the controlling bacterial growth in other processes.

Paper membranes made from vulcanized cellulose were used for the pervaporation (PV) of aqueous solutions containing methanol, ethanol, and isopropanol. It was noted that the vulcanized cellulose paper membranes (VCPM) could effectively separate alcohol and water from the mixture solutions. To observe the effect of the separation of alcohol aqueous mixtures, the permeation behavior of water and alcohol was examined by means of the separation factor and the permeation flux. The values of the permeation flux in the ethanol/water mixtures were found to vary from 6.2 kg/m2h to 2.1 kg/m2h, as the concentration of ethanol increased from 8 to 87 wt %, and the separation factor (α) changed from α = 2.6 to 6.6, respectively. This showed that the VCPM enhanced the separation of water and alcohol. The highest value observed for the permeation flux was 11 kg/m2h at 87 wt % of methanol concentration and the separation factor at this condition was 4.1. It was shown also that an efficient separation was obtained in the isopropanol/water mixture with a separation factor of 16.6. The contact angles of alcohol/water droplets on the VCPM were measured as well as the wettability of the membrane. There was a tendency of decrease for the contact angle, as the alcohol concentration decreased. This suggested that the solvent wettability decreased in high alcohol concentrations. It was concluded that a high permeabilitty of water through the VCPM resulted in the separation of alcohols and water in the PV process. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Innovative neutralizing and strengthening treatments for aged acidic paper have been developed, based on the use of supercritical carbon dioxide (CO2SCF) as solvent system. After treatment with the non toxic neutralizing agent CaCO3 in CO2SCF, acidic papers exhibited a pH increase of water extracts, the creation of an alkaline reserve and a decrease in the rate of artificial aging, while mechanical tensile properties of aged acidic papers improved after treatment with catechol both simply dissolved in ethanol or in CO2SCF in the presence of ethanol as co-solvent.

BACKGROUND During winemaking, after extraction from the skins, anthocyanins and tannins adsorb onto the pulp flesh cell walls. This study aims to quantify the amounts adsorbed and their impact on wine composition, the impact of variety and ethanol on adsorption, and whether the presence of anthocyanins plays a role and impacts tannin adsorption. RESULTS Anthocyanin and tannin fractions obtained by mimicking winemaking conditions were mixed with fresh flesh cell walls of two varieties: Carignan and Grenache. Adsorption isotherms were measured. Adsorption of tannins was higher with Carignan than with Grenache and decreased when the ethanol content increased. In comparison, anthocyanins were adsorbed in small amounts, and their mixing with tannins had no impact on their adsorption. The differences were related to differences in pulp cell wall composition, particularly in terms of extensins and arabinans. CONCLUSION Adsorption of tannins, which can reach 50% of the initial amount, depends on the pulp cell wall composition. This needs to be further investigated. This article is protected by copyright. All rights reserved.

Upgrading of ethanol to n‐butanol through dehydrogenation coupling has received increasing attention due to the wide application of n‐butanol. But the enhancement of ethanol dehydrogenation and followed coupling to produce high selectivity to n‐butanol is still highly desired. Our previous work has reported an acid‐base‐Ag synergistic catalysis, with Ag particles supported on Mg and Al‐containing layered double oxides (Ag/MgAl‐LDO). Here, Ag‐LDO interfaces have been manipulated for dehydrogenation coupling of ethanol to n‐butanol by tailoring the size of Ag particles and the interactions between Ag and LDO. It has been revealed that increasing the population of surface Ag sites at Ag‐LDO interfaces promotes not only the dehydrogenation of ethanol to acetaldehyde but also the subsequent aldol condensation of generated acetaldehyde. A selectivity of up to 76 % to n‐butanol with an ethanol conversion of 44 % has been achieved on Ag/LDO with abundant interfacial Ag sites, much superior to the state‐of‐the‐art catalysts., Synergistic Catalysis: Upgrading of ethanol to n‐butanol through dehydrogenation coupling provides a sustainable way for n‐butanol production. But high selectivity to n‐butanol is still desirable. In this work, Ag‐LDO interfaces have been manipulated for dehydrogenation coupling of ethanol to n‐butanol by tailoring the size of Ag particles and the interactions between Ag and LDO. Increasing the population of interfacial Ag sites promotes not only the dehydrogenation of ethanol to acetaldehyde but also the subsequent aldol condensation. A selectivity of up to 76 % to n‐butanol with an ethanol conversion of 44 % has been achieved on Ag/LDO with abundant interfacial Ag sites.

As ethanol production continues to rise around the world, and wastewater discharge requirements for phosphorus become more stringent, it is important that phosphorus removal technologies are evaluated on ethanol wastewater streams. In this study, five coagulating agents with distinct characteristics were evaluated for their soluble reactive phosphate (SRP) removal performance on both a synthetic wastewater sample and a wastewater sample collected from a corn ethanol manufacturer. All coagulants demonstrated a positive correlation between coagulant dose and percent removal of SRP on both samples. Alum and ferric chloride produced the highest SRP removal efficiencies on both the ethanol and synthetic wastewater, indicating that prepolymerized, high-basicity coagulants (e.g., aluminum chlorohydrate, poly-aluminum ferric chloride) are less effective for SRP removal than nonpolymerized coagulants. The background matrix analysis combined with the pH studies revealed that the high alkalinity in the ethanol wastewater has a substantial inhibitory effect on SRP removal capacity that supersedes pH effects. These experimental results suggest that the Al-Al and Al-OH bonds in the heavily hydroxylated and polymerized structure of high-basicity coagulants are very rigid, which could prevent inner-sphere complexation and drive a less effective outer-sphere interaction, thus hindering SRP removal efficiency. PRACTITIONER POINTS: Five different coagulants are evaluated for reactive phosphate removal from wastewater. Alum and ferric chloride show higher removal efficiency than prepolymerized and high-basicity coagulants. Optimal removal pH increases with increasing coagulant basicity.

An exceptionally mild and efficient method was developed for the preparation of (hetero)aryl‐AuI‐L complexes using ethanol or water as the reaction medium at room temperature and Ar‐B(triol)K boronates as the transmetalation partner. The reaction does not need an exogeneous base or other additives, and quantitative yields can be achieved through a simple filtration as the only required purification method, which obviates considerable waste associated with alternative workup methods. A broad reaction scope was demonstrated with respect to both the L and (hetero)aryl ligands on product Au complexes. Despite the polar reaction medium, large polycyclic aromatic hydrocarbon units can be incorporated on the Au complexes in very good to excellent yields. The approach was demonstrated for the chemoselective manipulation of orthogonally protected aryl boronates to afford a new class of N‐heterocyclic carbene‐Au‐aryl complexes. A mechanistic rationale was proposed., Triols and triturations! High‐yield synthesis of diverse aryl‐AuI complexes is achieved under mild conditions in green solvents (ethanol or water) by harnessing the unique properties of aryl‐B(triol)K boronates. The method permits transmetalation from aryl‐B(triol)K boronates while preserving aryl‐B(pin) boronates on the substrate. Pure products are obtained through a simple filtration.

Poly(2‐oxazoline)s (POxs) with 2,2′‐iminodiacetate (IDA) end groups were investigated as inhibitors for laccase. The polymers with the IDA end groups are reversible, competitive inhibitors for this enzyme. The IC50 values were found to be in a range of 1–3 mm. Compared with IDA alone, the activity was increased by a factor of more than 30; thus indicating that attaching a polymer chain to an inhibitor can already improve the activity of the former. The enzyme activity drops to practically zero upon increasing the concentration of the most active telechelic inhibitor, IDA‐PEtOx30‐IDA (PEtOx: poly(2‐ethyl‐2‐oxazoline)), from 5 to 8 mm. This unusual behavior was investigated by means of dynamic light scattering, which showed specific aggregation above 5 mm. Furthermore, the laccase could be stabilized in the presence of POx‐IDA, upon addition at a concentration of 20 mm and higher. Whereas laccase becomes completely inactive at room temperature after one week, the stabilized laccase is fully active for at least a month in aqueous solution., Bulking up: Poly(2‐oxazoline)s (POx) with iminodiacetate (IDA) end groups competitively inhibit the enzyme laccase. A telechelic IDA‐POx‐IDA derivative shifts the inhibition mechanism at higher concentrations to become a dead‐end inhibitor. Simultaneously, the polymers stabilize the enzyme to preserve its activity, even for 28 days at room temperature.

Key points Oculomotor behaviours are commonly used to evaluate sensorimotor disruption due to ethanol (EtOH).The current study demonstrates the dose‐dependent impairment in oculomotor and ocular behaviours across a range of ultra‐low BACs (

The combination of bioethanol production and carbon capture and storage technologies (BECCS) is considered an indispensable method for the achievement of the targets set by the Paris agreement. In Croatia, a first‐of‐its‐kind biorefinery project is currently underway that aims to integrate a second‐generation ethanol plant into an existing fossil refinery. The goal is to replace the fossil fuel production by second‐generation ethanol production using miscanthus. In the ethanol fermentation, CO2 is emitted in highly concentrated form and this can be directly compressed, injected and stored in exploited oil reservoirs. This study presents an assessment of the greenhouse gas (GHG) reduction potential of miscanthus ethanol produced in combination with CCS technology, based on data from the planning process of this biorefinery project. The GHG reduction potential is evaluated as part of a full environmental life cycle assessment. This is of particular relevance as a lignocellulosic ethanol industry is currently emerging in the European Union (EU) and LCAs of BECCS systems have, so far, often omitted environmental impacts other than GHG emissions. Overall, the ethanol to be produced in this planned biorefinery project would clearly achieve the EU's global warming potential (GWP) reduction target for biofuels. Depending on the accounting approach applied for the biological carbon storage, reduction potentials between 104% and 138% relative to the fossil comparator are likely. In addition, ethanol can reduce risks to resource availability. As such, the results generated from data based on the intended biorefinery project support the two major rationales for biofuel use. However, these reductions could come at the expense of human health and ecosystem quality impacts associated with the combustion of lignin and biogas. In order to prevent potential environmental trade‐offs, it will be imperative to monitor and manage these emissions from residue combustion, as they represent significant drivers of the overall environmental impacts.

An efficient ionic liquids (ILs) recycle technology will increase the economic viability of lignocellulosic biorefinery. The availability of recycling 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) for rice straw (RS) pretreatment was conducted. The kosmotropic salt K3 PO4 (TKP) solution was used as anti-solvent for cellulose precipitation and forming a three-phase system consisting of biomass, ILs-rich and salt-rich phases. The upper ILs phase and the bottom TKP phase were recycled without additional purification, which significantly simplifies the process for recovering ILs. Subsequently, the RS pretreated with multiple reusing ILs (RPRS) were investigated by components analysis, structure evolution, enzymatic hydrolysis and fermentation experiments. The results showed that unpurified reusing ILs led to further delignification and improvement of enzyme accessibility of the pretreated RS. The reducing sugar yield of RS pretreated with 8th reusing IL (8th RPRS) could still reach 98.9%, and the ethanol and succinic acid concentrations achieved 91.9 g/L and 29.3 g/L by simultaneous saccharification and co-fermentation (SScF). The present study demonstrated that the ILs recovered by phase-separation process could be used for RS pretreatment, and achieving high titer ethanol fermentation. This article is protected by copyright. All rights reserved.

Wines produced from grapes cultivated in cool climate areas are characterized by high levels of organic acids. One method to correct this is malolactic fermentation (MLF). The aim of this study was to determine the effectiveness of different strains of Oenococcus oeni bacteria (Viniflora CH11, Viniflora CH16, Viniflora CH35, Viniflora Oenos, SIHA LACT Oeno) during the biological acidity reduction process. Red wine from Rondo and Regent cultivars was obtained by ethanol fermentation of the pulp, at 20 °C for 14 days. The profile of organic acids was examined with a particular focus on changes in the content of l-malic and l-lactic acids. Additionally, the impact on profile and quantity of phenolic compounds and antioxidant capacity was measured. The results showed that MLF had a positive influence on content of organic acids through the reduction of l-malic acid content with a simultaneous increase of the amount of l-lactic acid. The best effect was obtained with the CH11 and CH35 bacterial strains. The biological acidity reduction process had no significant (P > 0.05) impact on phenolic content or antioxidant capacity. However, the wine making process (ethanol fermentation, maturation) contributed to the reduction of polyphenols and in consequence lower antioxidant capacity of the final tested wines. PRACTICAL APPLICATION: The present study provides useful information on the impact of different Oenococcus oeni bacterial strains on MLF in red wines, reduction of l-malic to l-lactic acid, and stability of phenolic compounds during MLF and the maturation period. Also, this article provides information about phenolic compounds and antioxidant capacity during malolactic fermentation and maturity of red wines made from hybrids of Vitis vinifera such as Rondo and Regent cultivars.

Background and purpose Alcohol exposure in utero may lead to a wide range of long-lasting morphological and behavioural deficiencies known as fetal alcohol spectrum disorders (FASD), associated with a higher risk of later developing neuropsychiatric disorders. However, little is known about the long-term consequences of cocaine use and abuse in individuals with FASD. This study aimed to investigate the effects of maternal binge alcohol drinking during prenatal and postnatal periods on cocaine reward-related behaviours in adult offspring. Experimental approach Pregnant C57BL/6 female mice were exposed to an experimental protocol of binge alcohol consumption (drinking-in-the-dark test) from gestation to weaning. Male offspring were subsequently left undisturbed until reaching adulthood and were tested for cocaine-induced motivational responses (conditioned place preference, behavioural sensitization and operant self-administration). Protein expression of dopamine- and glutamate-related molecules was assessed following cocaine-induced reinstatement. Key results The results show that prenatal and postnatal alcohol exposure enhanced the preference for the cocaine-paired chamber in the conditioned place preference test. Furthermore, early alcohol-exposed mice displayed attenuated cocaine-induced behavioural sensitization but also higher cocaine self-administration. Furthermore, alterations in glutamatergic excitability (GluA1/GluA2 ratio) and ΔFosB expression were found in the prefrontal cortex and the striatum of alcohol-exposed mice after cocaine-primed reinstatement. Conclusion and implications Our findings demonstrate that maternal binge-like alcohol consumption during gestation and lactation alters sensitivity to the reinforcing effects of cocaine in adult offspring mice. Together, such data suggest that prenatal and postnatal alcohol exposure may underlie an enhanced susceptibility of alcohol-exposed offspring to develop drug addiction later in adulthood.

BACKGROUND: The organosolv process promotes biomass delignification at relatively high temperatures using a wide variety of organic solvent solutions. Nevertheless, previous studies on organosolv processes have not dealt with the use of ethyl lactate as organic solvent. Thus the aim of the present contribution was to determine and to validate if the use of ethyl lactate has a positive influence on lignin recovery for organosolv processes whose feedstock is the solid waste from a wheat straw‐based biorefinery. The effect of operating conditions (temperature and time) on lignin recovery was also studied. RESULTS: A mixed design of experiments was proposed as the strategy to maximize lignin recovery. The mathematical model derived from a multiple linear regression applied to the mixed design results indicates that 190 °C and a non‐aqueous solution containing ethyl lactate and ethanol (81.2% w/w ethyl lactate) could provide a maximum lignin recovery of 75.9% w/w. This theoretical maximum was validated. Thus the proposed model adequately describes the behavior of lignin recovery. Moreover, Fourier transform infrared (FTIR) characterization of the resultant lignin suggested that its structure is a function of the organic solvent solution used during the organosolv process. CONCLUSION: The evidence from this study indicates that lignin recovery from the solid waste of a wheat straw‐based biorefinery in an organosolv process depends on temperature and ethyl lactate presence in the reaction medium. These findings enhance the understanding of organosolv processes and could be applied if eventual lignin valorization is desired. © 2019 Society of Chemical Industry

In this study, the phenolic components, as well as the antioxidant and antimicrobial activities, of the ripe and unripe fruit of pawpaw (Asimina triloba [L.] Dunal) extracted using five different solvents (distilled water, 95% methanol, 80% methanol, 95% ethanol, and 80% ethanol) were analyzed. The total phenolic content and total flavonoid content were the highest in the 95% ethanol (149.50 mg CAE/g) and 80% ethanol (5.62 mg RE/g) extracts of the unripe fruit, respectively. Analysis of 17 phenolic compounds in pawpaw extracts revealed that epigallocatechin, epicatechin, and p-coumaric acid were the as major compounds, and the amounts of all components significantly decreased with the ripening (P < 0.05). In all antioxidant assays, the 95% ethanol extract of the unripe fruit showed the highest antioxidant activity (EC50 0.22 to 0.93 mg/mL). The pawpaw extracts were more sensitive against Corynebacterium xerosis and Clostridium perfringens. In particular, the 95% ethanol extract of the ripe fruit notably inhibited C. xerosis growth, with minimum inhibitory concentration of 1.56 mg/mL. These results showed that the unripe fruit of pawpaw has abundant phenolic compounds and superior antioxidant activity, and that the 95% ethanol extract of the ripe fruit shows strong inhibitory activity against various microorganisms. Therefore, pawpaw fruit can be utilized as an attractive source of nutrients and therapeutic agents. PRACTICAL APPLICATION: In this study, we identified that the unripe fruit of pawpaw is rich in phenolic compounds and shows strong antioxidant activities. The 95% ethanol extract of the ripe fruit showed strong high inhibitory effect against various microorganisms. These results suggest that pawpaw fruit can serve as a source of antioxidants and delay the aging process. In addition, the fruit could also potentially be utilized as a potential antimicrobial agent.

Lignocellulosic biomass is one of the potential feedstocks to produce second-generation cellulosic ethanol and biochemicals. To enhance the enzymatic digestibility of lignocellulosic biomass for efficient enzymatic saccharification, a variety of pretreatment methods have been studied. Among these, organosolv pretreatment using ethanol is a promising pretreatment method owing to its inherent advantages, such as low solvent cost, lack of toxicity, the ability to retain most cellulose fraction in substrates for enzymatic hydrolysis, coproduction of high-purity lignin and hemicellulosic sugars, easy solvent recovery, and reuse. In this review, the research progress regarding different types of ethanol organosolv pretreatment processes has been summarized in terms of methods, substrate properties, reaction mechanisms, delignification kinetic as well as the impact of pretreatment methods on the enzymatic digestibility. Attempts are also made to provide insights into the complete utilization of lignocellulosic biomass to achieve high potential revenues. Though some ethanol organosolv processes have been studied or are being developed towards commercialization, ethanol organosolv pretreatment is still facing some challenges. Finally, the direction for future work is given to develop a proper ethanol organosolv pretreatment for commercialization.

The aim of this study was to investigate the extraction of oil from macauba pulp using ethanol and isopropanol as pressurized solvents. Experiments were carried out in a semi-continuous extractor system at various temperatures (40, 60, and 80 °C) maintaining the pressure fixed at 10 000 kPa and the solvent flow at 3 mL/min and also using conventional extraction (in a Soxhlet). For both methods assessed, higher yields were obtained with the use of ethanol as the solvent. In the pressurized liquid extraction (PLE), an increase in temperature from 40 to 60 °C provided higher yields at 72 min of extraction, which was not influenced by the extraction carried out at 80 °C. This temperature effect was also observed in the extraction kinetics data. The maximum yields obtained by PLE were 44.78% and 37.12% with ethanol and isopropanol, respectively, which represents ∼77% of the yield obtained by conventional extraction. Oleic and palmitic acids are the main fatty acids identified in macauba pulp oil, representing ∼88% of the fatty acids composition, which was not influenced by the extraction method and solvent used. PLE with ethanol provides oils with higher levels of β-carotene. The flavonoid content was higher with the use of isopropanol; however, it was not influenced by the method used. This article is protected by copyright. All rights reserved

Mitigating the effect of fermentation inhibitors in bioethanol plants can have a great positive impact on the economy of this industry. Liquid-liquid extraction (LLE) using ethyl acetate is able to remove fermentation inhibitors-chiefly, acetic acid-from an aqueous solution used to produce bioethanol. The fermentation broth resulting from LLE has higher performance for ethanol yield and its production rate. Previous techno-economic analyses focused on second-generation biofuel production did not address the impact of removing the fermentation inhibitors on the economic performance of the biorefinery. A comprehensive analysis of applying a separation system to mitigate the fermentation inhibition effect and to provide an analysis on the economic impact of removal of acetic acid from corn stover hydrolysate on the overall revenue of the biorefinery is necessary. This study examines the pros and cons associated with implementing LLE column along with the solvent recovery system into a commercial scale bioethanol plant. Using details from the NREL-developed model of corn stover biorefinery, the capital costs associated with the equipment and the operating cost for the use of solvent were estimated and the results were compared with the profit gain due to higher ethanol production. Results indicate that the additional capital will add 1% to the total capital and manufacturing cost will increase by 5.9%. The benefit arises from the higher ethanol production rate and yield as a consequence of inhibitor extraction and results in a $0.35 per gallon reduction in the minimum ethanol selling price (MESP). © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:971-977, 2016.

1,1,1,2-tetrachloroethane was given subcutaneously to mice (1.2–2.0 g/kg) and the excretion was followed for 3 days. About half of the dose (21–62 %) was expired unchanged. The part metabolized was excreted mainly as trichloro-ethanol (17–49 % of the dose), and to a lesser extent as trichloroacetic acid (1–7 %). The metabolites were identified by paper chromatography, gas chromatography and mass spectrometry and the Fujiwara reaction was used for the quantitative determination of trichloroacetic acid and of trichloroethanol after oxidation to this acid. It is suggested that the initial metabolic reaction is a hydrolytic fission of a carbon-chlorine bond with the formation of trichloroethanol. Trichloroethanol was the precursor of trichloroacetic acid.

Economical production of second generation ethanol from Ponderosa pine is of interest due to widespread mountain pine beetle infestation in the western United States and Canada. The conversion process is limited by low glucose and high inhibitor concentrations resulting from conventional low-solids dilute acid pretreatment and enzymatic hydrolysis. Inhibited fermentations require larger fermentors (due to reduced volumetric productivity) and low sugars lead to low ethanol titers, increasing distillation costs. In this work, multiple effect evaporation (MEE) and nanofiltration (NF) were evaluated to concentrate the hydrolysate from 30 g/l to 100, 150, or 200 g/l glucose. To ferment this high gravity, inhibitor containing stream, traditional batch fermentation was compared with continuous stirred tank fermentation (CSTF) and continuous fermentation with cell recycle (CSTF-CR). Equivalent annual operating cost (EAOC = amortized capital + yearly operating expenses) was used to compare these potential improvements for a local-scale 5 MGY ethanol production facility. Hydrolysate concentration via evaporation increased EAOC over the base process due to the capital and energy intensive nature of evaporating a very dilute sugar stream; however, concentration via NF decreased EAOC for several of the cases (by 2 to 15%). NF concentration to 100 g/l glucose with a CSTF-CR was the most economical option, reducing EAOC by $0.15 per gallon ethanol produced. Sensitivity analyses on NF options showed that EAOC improvement over the base case could still be realized for even higher solids removal requirements (up to two times higher centrifuge requirement for the best case) or decreased NF performance. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:946–956, 2015

An accurate determination of the thermal properties of biomass is particularly important when studying biomaterials for the second-generation ethanol industry. This study presents the thermograms of aqueous solutions of banana flower stalks obtained using differential scanning calorimetry. The samples were prepared using a detailed procedure to obtain normalized specific heat values as a function of temperature, pH, and biomass concentration. The specific heat capacity data were fitted using empirical first-order equations with an algorithm for nonlinear regression, followed by a statistical analysis. All the models applied in modeling of the specific heat capacity showed statistically significant goodness of fit ( Radj2 > 0.996) for all the parameters in the selected expressions. The results obtained in this research can provide information for the modeling, design, and control of the unit operations involved in the second-generation ethanol industry. © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1221–1228, 2015

Labelled tetrachloroethane was synthesized by addition of chlorine to 14C-acetylene. The product (0.51 μci/mg) was injected intraperitoneally into female albino mice (dose 0.21–0.32 g/kg) and the elimination of radioactivity was followed for 3 days. Half of the dose (45–61 %) was expired as carbon dioxide and 28 % (range 23–34) of the activity was excreted with the urine. About 16 % of the dose still remained in the animal and less than 4 % was expired unchanged. By paper chromatography and isotope dilution analysis, the urine was found to contain dichloroacetic acid, trichloroacetic acid, trichloroethanol, oxalic acid and small amounts of glyoxylic acid and urea. Half of the urinary activity was not accounted for. On simultaneous injection of benzoate considerable amounts of labelled hippuric acid, about 20 % of the dose, were excreted. It is suggested that the metabolism of tetrachloroethane takes place mainly via a stagewise hydrolytic fission of carbon-chlorine bonds and oxidation to give first dichloroacetic acid and then glyoxylic acid. With part of the tetrachloroethane, a non-enzymic dehydrochlorination occurs with the formation of trichloro-ethylene which was also found in the breath. It is suggested that trichloroethylene is the precursor of the trichloroethanol and trichloroacetic acid found in urine.

Rice straw is one of the most abundant lignocellulosic waste materials worldwide, and it can serve as feedstock for bioethanol production. In this study, ethanol was produced from rice straw by simultaneous saccharification and fermentation (SSF) of the whole pretreated slurry with high solid load. Pretreatment of rice straw using 0.5% (w/w) H2SO4 was performed to increase the efficiency of enzymatic saccharification. Enzymatic saccharification and SSF of the whole pretreated slurry were subsequently performed to evaluate the inhibitory effect on enzymatic saccharification and the final ethanol yield. The result showed that pretreatment was the key for achieving high ethanol yield of the whole pretreated slurry. Rice straw pretreated at 170°C with a solid load of 15% exhibited efficient enzymatic saccharification. By the result of ethanol yields, no inhibitory effect was found when the whole pretreated slurry was subjected to SSF. The ethanol yield of SSF of the whole pretreated slurry was enhanced to 77.3%, compared with the glucose recovery efficiency of enzymatic saccharification of the washed pretreated rice straw, which was 74.4%. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 582–588, 2015