Search

Ethanol produced from lignocellulosic biomass is a renewable alternative to diminishing petroleum-based liquid fuels. In this study, the feasibility of ethanol production from waste paper using the separate hydrolysis and fermentation (SHF) was investigated. Two types of waste paper materials, newspaper and office paper, were evaluated for their potential to be used as a renewable feedstock for the production of fermentable sugars via enzymatic hydrolysis of their cellulose fractions. Hydrolysis step was conducted with a mixture of cellulolytic enzymes produced locally by Trichoderma reesei Rut-C30 (cellulase-overproducing mutant) and Aspergillus niger F38 cultures. Surfactant pretreatment effect on waste paper enzymatic digestibility was studied and Triton X-100 at 0.5 % (w w(-1)) has improved the digestibility of newspaper about 45 %. The effects of three factors (dry matter quantity, phosphoric acid pretreatment and hydrolysis time) on the extent of saccharification were also assessed and quantified by using a methodical approach based on response surface methodology. Under optimal hydrolysis conditions, maximum degrees of saccharification of newspaper and office paper were 67 and 92 %, respectively. Sugars released from waste paper were subsequently converted into ethanol (0.38 g ethanol g(-1) sugar) with Saccharomyces cerevisiae CTM-30101.

Paper sludge is an attractive biomass source for the conversion to ethanol due to its low cost and the lack of severe pretreatment required. Four sludges from pulp and paper operations including both virgin kraft (VK) and recycled and deinking (RD) paper mills were analyzed. A fractionation process using a laboratory screen was utilized to produce a fiber-rich stream for enzymatic hydrolysis. This process removed 82-98 % of the ash with fiber yields from 39 to 69 %. Even though sludges in both non-fractionated and fractionated scenarios were pH-adjusted, total sugar conversion was still improved by 12-27 % by fractionation with 4.5 times less acid required for pH adjustment. Fermentation of the fractionated sludges showed very high ethanol yields. Acid insoluble clay adsorbs 3-5 mg enzyme per gram of clay depending on enzyme dosage. Acid soluble CaCO3 adsorbs about half of the enzyme compared to clay. Fractionation efficiency was also evaluated by testing different size mesh screen openings (100 to 500 mesh). The 400-mesh screen presented the best fiber yield, ash removal and ash fractionation ratio for both VK and RD sludges. The ash-rich streams have a lower C/N ratio than the original sludge which improves its suitability as soil amendment.

This study optimized the simultaneous saccharification and citric acid (CA) production from banana pseudostem (BP). Thereafter, kinetic assessment of Aspergillus brasiliensis growth and CA production were determined for the optimum conditions using fresh water (SSF

Made available in DSpace on 2018-11-26T17:06:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-11-01 project Energy and Mobility for Sustainable Regions - EMSURE Primary sludge, from different pulp and paper mills, was used as feedstock in simultaneous saccharification and fermentation (SSF) processes to produce ethanol. SSF was carried out with Saccharomyces cerevisiae ATCC 26602 yeast and NS 22192 enzymatic extract using 150 g L-1 of carbohydrates (CH) from primary sludge. The effect of sterilization, reduction of enzyme dosage and fed-batch vs. batch conditions were studied. The removal of sterilization can be considered since no contamination or atypical by-products were observed, although SSF efficiency slightly decreased. The reduction of the enzyme dosage from 35 to 15 FPU g(CH)(-1) was successful. Despite of initial mixing difficulties, batch SSF enabled higher ethanol concentration (41.7 g L-1), conversion yield (48.9%) and productivity (0.78 g L-1 h(-1)), compared to the fed-batch process at the same conditions of low enzyme dosage of 5 FPU g(CH)(-1) and high solids content of 21.7%, rarely found in literature. Published by Elsevier Ltd. Univ Coimbra, Fac Sci & Technol, CIEPQPF, Dept Chem Engn, Polo 2,Rua Silvio Lima, P-3030790 Coimbra, Portugal Sao Paulo State Univ, Dept Engn & Food Technol, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil Sao Paulo State Univ, Dept Engn & Food Technol, Rua Cristovao Colombo 2265, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil project Energy and Mobility for Sustainable Regions - EMSURE: CENTRO-07-0224-FEDER-002004

This work evaluates the environmental performance of using pulp and paper sludge as feedstock for the production of second generation ethanol. An ethanol plant for converting 5400 tons of dry sludge/year was modelled and evaluated using a cradle-to-gate life cycle assessment approach. The sludge is a burden for pulp and paper mills that is mainly disposed in landfilling. The studied system allows for the valorisation of the waste, which due to its high polysaccharide content is a valuable feedstock for bioethanol production. Eleven impact categories were analysed and the results showed that enzymatic hydrolysis and neutralisation of the CaCO3 are the environmental hotspots of the system contributing up to 85% to the overall impacts. Two optimisation scenarios were evaluated: (1) using a reduced HCl amount in the neutralisation stage and (2) co-fermentation of xylose and glucose, for maximal ethanol yield. Both scenarios displayed significant environmental impact improvements.

Bioethanol seems very potential to be an alternative energy substituting the fossil-based energy due to its renewable sources. Any sources containing carbohydrate (poly or mono) may be fermented into ethanol (bioethanol). This study aims to investigate the optimum conditions in the fermentation of used paper HVS hydrolysate to yield ethanol. The used paper HVS hydrolysate, produced from the hydrolysis of used paper HVS, was initially treated with a so-called detoxification stage to remove compounds hindering the fermentation process. The detoxification stage employed adsorptive separation with the aid of carbon (charcoal) activated with KOH and K2CO3 solution. The fermentation varied the types of microbes or yeast (i.e. Saccharomyces cerevisiae, Rhizopus oligosporus) and its concentration. Within the ranges of studied parameters, the optimum conditions to yield highest level of ethanol (0.436%) were activated carbon with KOH, yeast of Saccharomyces cerevisiae, and concentration of 3 g yeast/70 mL hydrolysate.

Herein, we report the first example of a paper-based screen-printed biosensor for the detection of ethanol in beer samples. Common office paper was adopted to fabricate the analytical device. The properties of this paper-based screen-printed electrode (SPE) were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy, and they were compared with the well-established polyester-based SPEs as well. Paper demonstrated similar properties when compared with polyester, highlighting suitability towards its utilization in sensor development, with the advantages of low cost and simple disposal by incineration. A nanocomposite formed by Carbon Black (CB) and Prussian Blue nanoparticles (PBNPs), namely CB/PBNPs, was utilized as an electrocatalyst to detect the hydrogen peroxide generated by the enzymatic reaction between alcohol oxidase (AOx) and ethanol. After optimizing the analytical parameters, such as pH, enzyme, concentration, and working potential, the developed biosensor allowed a facile quantification of ethanol up to 10 mM (0.058 %vol), with a sensitivity of 9.13 μA/mM cm2 (1574 μA/%vol cm2) and a detection limit equal to 0.52 mM (0.003%vol). These satisfactory performances rendered the realized paper-based biosensor reliable over the analysis of ethanol contained in four different types of beers, including Pilsner, Weiss, Lager, and alcohol-free. The proposed manufacturing approach offers an affordable and sustainable tool for food quality control and for the realization of different electrochemical sensors and biosensors as well.

The feasibility of cellulase recycling in the scope of bioethanol production from recycled paper sludge (RPS), an inexpensive byproduct with around 39% of carbohydrates, is analyzed. RPS was easily converted and fermented by enzymes and cells, respectively. Final enzyme partition between solid and liquid phases was investigated, the solid-bound enzymes being efficiently recovered by alkaline washing. RPS hydrolysis and fermentation was conducted over four rounds, recycling the cellulases present in both fractions. A great overall enzyme stability was observed: 71, 64 and 100% of the initial Cel7A, Cel7B and -glucosidase activities, respectively, were recovered. Even with only 30% of fresh enzymes added on the subsequent rounds, solid conversions of 92, 83 and 71% were achieved for the round 2, 3 and 4, respectively. This strategy enabled an enzyme saving around 53-60%, while can equally contribute to a 40% reduction in RPS disposal costs., The authors acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). The financial support of FCT through GlycoCBMs Project PTDC/AGR-FOR/3090/2012–FCOMP-01-0124-FEDER-027948 and the PhD grant to DG (SFRH/BD/88623/2012) is equally acknowledged. The authors also thank RENOVA (Portugal) for kindly providing the recycled paper sludge.

For transformers in service, aging markers from cellulose in oil such as furans, water, methanol and acids are measured for diagnostic purposes. The content of these indicators, measured in oil, may therefore vary with load, temperature, solid and liquid insulation aging, as well as marker stability and evaporative loss. Correction factors estimating the level of the aging marker to a reference temperature would make the diagnostic more relevant. In this study, correction factors for temperature differences have been estimated for different aging markers in insulation systems impregnated with either mineral oil or synthetic ester. In the case of mineral oil based systems, we observe correction factors for water, methanol and furans in line with previously reported findings. On the other hand, for the synthetic ester system, novel correction factors for water and methanol are suggested while for furans, no temperature dependence was observed.

We developed a convenient method by coupling frontal elution paper chromatography with desorption corona beam ionization mass spectrometry (DCBI-MS) for rapid determination of chlorphenamine added in herbal medicines or dietary supplements. In this method, the ethanol extract of the herbal products was spotted directly onto an isosceles triangular filter paper sheet, and then the paper sheet was developed under strong elution condition with the sample zone migrating at the solvent front. The analyte was finally condensed at the V-shaped tip which could then be placed under the visible plasma beam of DCBI for ionization. The overall procedure took less than 5 min. The frontal elution paper chromatography on a triangular plate used in this work improved the signal intensity of chlorphenamine by 30-fold due to the analyte condensing at the tip and the reduction of the background suppression. Furthermore, the paper sheet also functioned as a filter in the analysis of solid or powder samples, which can increase the analytical throughput by omitting the step of centrifugation. The proposed method in current study was successfully applied in the determination of chlorphenamine in herbal medicines. Chlorphenamine was detected in four of the twelve types of herbal medicines examined in this study. The limit of detection was 200 ng/mL (2.0 ng absolute) in full-scan positive-ion mode and the linear range was from 5.0 μg/mL to 50 μg/mL with satisfactory linear coefficient (R(2) (the square of the correlation coefficient)=0.895). Good reproducibility was achieved with relative standard deviations (RSDs) less than 15.0% and the recoveries of chlorphenamine ranged from 84.3 to 90.6%.

In this study, a facile and effective route to prepare hybrid photocatalysts (paper-TiO

Pulping and papermaking of Leucaena diversifolia by soda-anthraquinone-ethanol was studied using an experimental design in order to investigate the effects of cooking variables: temperature, time, soda concentration, ethanol concentration and wash-disintegrate temperature on the pulp yield and the physico-chemical characteristics of paper sheets (tensile index, burst index, tear index and brightness). Previously, in order to assess the potential of plants of this raw material grown over short periods, its results were compared with those of other leucaena varieties and the best crop among three grown for 1–3 years was selected. The results were evaluated using the response surface methodology with a view to identifying the most suitable operating conditions. In accordance with biomass production and the features of the raw materials and cellulose pulp obtained, the L. diversifolia grown for 2 years was found to be the most suitable choice for obtaining pulp and paper among the five leucaena varieties examined. Suitable physical characteristics of paper sheets (tensile index, burst and tear index) and acceptable yield pulping and brightness could be obtained by operating at medium temperature, active alkali concentration, pulping time, ethanol concentration and wash-disintegrate temperature.

A new analytical platform based on the use of thin-layer chromatography (TLC) coupled with paper-based analytical device (PAD) was developed for the determination of total capsaicinoids in chilli samples. This newly developed TLC-PAD is simple and low-cost without any requirement of special instrument or skillful person. The analysis consisted of two steps, i.e., extraction of capsaicinoids from chilli samples by using ethanol as solvent and separation of capsaicinoids by thin-layer chromatography (TLC) and elution of capsaicinoids from the TLC plate with in situ colorimetric detection of capsaicinoids on the PAD. For colorimetric detection, Folin-Ciocalteu reagent was used to detect phenolic functional group of capsaicinoids yielding the blue color. The blue color on the PAD was imaged by a scanner followed by evaluation of its grayscale intensity value by ImageJ program. This newly developed TLC-PAD method provided a linear range from 50 to 1000 mg L−1 capsaicinoids with the limit of detection as low as 50 mg L−1 capsaicinoids. The proposed method was applied to determine capsaicinoids in dried chilli and seasoning powder samples and the results were in good agreement with those obtained by HPLC method.

Primary sludge from a Portuguese pulp and paper mill, containing 60% of carbohydrates, and unbleached pulp (as reference material), with 93% of carbohydrates, were used to produce ethanol by simultaneous saccharification and fermentation (SSF). SSF was performed in batch or fed-batch conditions without the need of a pretreatment. Cellic® CTec2 was the cellulolytic enzymatic complex used and Saccharomyces cerevisiae (baker's yeast or ATCC 26602 strain) or the thermotolerant yeast Kluyveromyces marxianus NCYC 1426 were employed. Primary sludge was successfully converted to ethanol and the best results in SSF efficiency were obtained with S. cerevisiae. An ethanol concentration of 22.7 g L−1 was produced using a content of 50 g L−1 of carbohydrates from primary sludge, in batch conditions, with a global conversion yield of 81% and a production rate of 0.94 g L−1 h−1. Fed-batch operation enabled higher solids content (total carbohydrate concentration of 200 g L−1, equivalent to a consistency of 33%) a...

Great part of the History of mankind is registered in the form of documents or works of art on paper support. Paper can be deteriorated due to physical, chemical and biological agents. Within microorganisms, fungi are the major paper biodeteriogens. Throughout history, several toxic methods have been used to prevent and stop fungal deterioration on paper based materials. More recently, a growing concern about environmental and health issues has led to the research on new antifungal alternatives, with lower toxicity. However, the existent antifungal methods and compounds still have drawbacks in terms of efficacy, health hazards, damaging effects on paper, or lack of thorough testing. In this context, the present thesis focused on testing and developing accessible antifungal treatments with low toxicity, which could prevent the long term paper deterioration. The selection of antifungal compounds was made taking into account the results from a literature review on antifungals used on paper conservation, a survey to paper conservators, and a review of antifungals used in cosmetics and pharmaceutical industries, having as a basic premise their low toxicity. Aspergillus niger, Chaetomium globosum, Cladosporium cladosporioides, Penicillium chrysogenum and Penicillium corylophilum were selected as test fungal species. Fungal growth on paper was evaluated by measuring colonization areas and biomass dry weight determination. A formulation containing parabens and calcium propionate (PBs+CP) presented the best antifungal activity on paper samples, followed by a formulation containing clotrimazole and calcium hydroxide nanoparticles (CLT+NPs), and ultimately 70% ethanol (70%EtOH). Before application on cultural heritage materials, conservation treatments have to be thoroughly tested to assess if they can cause any damage on the treated materials in the short and long term. The effects of the tested formulations on paper were evaluated in terms of pH, colourimetry, folding endurance and molecular alterations, using moist heat artificial ageing. Besides plain paper, paper previously biodeteriorated by A. niger was tested in order to evaluate the potential of each compound to prevent further deterioration caused by fungal metabolites. The obtained results on biodeteriorated samples illustrate how tremendously damaging the products excreted by fungi can be in the long term. PBs+CP formulation was the only one capable of preventing long term acidification, loss of folding endurance, and discoloration caused by fungal metabolites, but on the other hand, on plain samples, this formulation caused paper discoloration. CLT+NPs formulation significantly prevented the acidification and loss of folding endurance, although causing a minor discoloration on paper at a long term. 70%EtOH had a mild positive impact in the chemical stabilization of paper and did not cause any paper discoloration. The information provided in this thesis contributes to a deeper understanding on safer options for preventing and treating paper deterioration by fungi and opens the way for further research in this challenging field of heritage conservation.

We propose a novel approach to continuous bioprocessing of gases. A miniaturized, coated-paper strip, high gas fraction, biocomposite absorber has been developed using slowly shaken horizontal anaerobic tubes. Concentrated Clostridium ljungdahlii OTA1 was used as a model system. These gas absorbers demonstrate elevated CO mass transfer with low power input, reduced liquid requirements, elevated substrate consumption, and increased product secretion compared to shaken suspended cells. Concentrated OTA1 cell paste was coated by extrusion onto chromatography paper. The immobilized system shows high, constant reactivity immediately upon rehydration. Cell adhesion was by adsorption to the cellulose fibers; visualized by SEM. The C. ljungdahlii OTA1 coated paper mounted above the liquid level absorbs CO and H2 from a model syngas secreting acetate with minimal ethanol. At 100 rpm shaking speed (7.7 Wm(-3) ) the optimal cell loading is 6.5 gDCW m(-2) to maintain high CO absorbing reactivity without the cells coming off of the paper into the liquid phase. Reducing the medium volume from 10 mL to 4 mL (15% of tube volume) did not decrease CO reactivity. The reduced liquid volume increased secreted product concentration by 80%. The specific CO consumption by paper biocomposites was higher at all shaking frequencies100 rpm than suspended cells under identical incubation conditions. At 25 rpm the biocomposite outperforms suspended cells for CO absorption by 2.5-fold, with an estimated power reduction of 97% over the power input at 100 rpm. The estimated minimum kL a for miniaturized biocomposite gas-absorbers is ∼100 h(-1) , 10 to 10(4) less power input than other syngas fermentation systems reported in the literature at similar kL a. Specific consumption rates in a biocomposite were ∼14 mmol gDCW-1 h(-1) . This work intensified CO absorption and reactivity by 14-fold to 94 mmol CO m(-2) h(-1) over previous C. ljungdahlii OTA1 work by our group. Specific acetate production rates were 23 mM h(-1) or 46 mmol m(-2) h(-1) . The specific rates and apparent kL a scaled linearly with biocomposite coating area. Biotechnol. Bioeng. 2016;113: 1913-1923. © 2016 Wiley Periodicals, Inc.

The objective of this work was to investigate the influence of hydrogen bonds between fibres on static and dynamic strength properties of paper. A commercial bleached pinewood kraft pulp was soaked in water, refined in a PFI, and used to form paper webs in different solvents, such as water, methanol, ethanol, n-propanol and n-butanol, to determine the effect of their dipole moment on static and dynamic strength properties of resulting paper sheets. Paper which was formed in water, being the solvent of the highest dipole moment among the tested ones, showed the highest breaking length and tear resistance. When paper webs were formed in n-butanol, which was the least polar among the solvents, these parameters were reduced by around 75%. These results provide evidence of the importance of water in paper web formation and strong impact of hydrogen bonds between fibres on strength properties of paper.

Based on the Fick’s law, model about the migration of silver-loaded zeolite on antibacterial kraft paper was built, and migration of antibacterial agent in distilled water, 65 % ethanol and 4 % acetic acid at 2 h、24 h、96 h、240 h、480h、720h and 960 h under 40 °C were detected by AAS. The predicted and experimental results were compared using MATLAB software. The results are shown that the turns of migration in different foodstuff are that 65 % ethanol>4 % acetic acid>distilled water, while silver ion is not detected in olive oil and N-hexane. The migration in distilled water, 65 % ethanol and 4 % acetic acid can be well fitted with the predicted model, and the migration in 4 % acetic acid is similar with the model’s result in certain period of time, and migration of antibacterial agent from papers to food stimulants in different effective migration coefficient, depth of paper and time can be greatly predicted with.

This work examined the simultaneous saccharification and fermentation (SSF) process for the biological conversion of pulp & paper sludge (PPS) and monosodium glutamate waste liquor (MGWL) into ethanol using Saccharomyces cerevisiae CICC 1001 in batch condition. At the SSF conditions of sterilization, pH 6.0, 6% TS (total solid), and adding nutrient solution, the highest ethanol yield of 42.5 g L−1 was obtained at the enzyme loading of 40 A.U. (activity unit) g−1 VSfed (volatile solid); only if the pH value was changed to 4.5, the ethanol yield reduced by 47%; only if the TS concentration was changed to 3%, the ethanol yield decreased by 11%; only if the substrates were not sterilized, 5% decrease occurred to the ethanol production; only if no nutrient solution was added to the reactor, 97% reduction of ethanol yield happened; the extent of influence of the impact factors ranked in the order of nutrient solution > pH > TS concentration > sterilization. The Fourier Transform Infrared (FTIR) spectra of substrates after SSF further verified the results of process performances. Therefore, this SSF of PPS and MGWL reduced the residue streams and land-filling costs while benefiting in ethanol production.

The characterization of cellulases is complex and has gained increasing importance due to the application of cellulases in finishing of textile fibres and the conversion of lignocellulose into second generation ethanol. Usually two or three different substrates such as filter paper Whatman No. 1, carboxymethylcellulose and avicel are used to characterize total, endo (EG) and exoglucanase (ExG) activity, respectively, and assays are carried out without any mechanical agitation. Unfortunately, the different activities obtained are not directly comparable and do not reflect cellulase behaviour in industrial applications, mainly due to physic-chemical differences between the substrates and the adopted procedures. In this study the pH profiles of three different cellulase preparations from Hypocrea jecorina (former Trichoderma reesei) have been characterized with modified filter paper assays which permitted the distinction between EG and ExG activities using a single insoluble substrate. Furthermore, the influ...

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.

Screening of peptides to find the ligands that bind to specific targets is an important step in drug discovery. These high-throughput screens require large number of structural variants of peptides to be synthesized and tested. This chapter describes the generation of arrays of peptides on Teflon-patterned sheets of paper. First, the protocol describes the patterning of paper with a Teflon solution to produce arrays with solvophobic barriers that are able to confine organic solvents. Next, we describe the parallel syntheses of 96 peptides on Teflon-patterned arrays using the SPOT synthesis method.

This work is aimed at a selection of yeast strains suitable for simultaneous saccharification and fermentation of waste paper. The waste paper, as a lignocellulosic material, represents an unconventional source for the production of ethanol which is a promising alternative fuel. The yeast strains Saccharomyces cerevisiae and Pichia kudriavzevii produced the highest amounts of ethanol at 30 °C and were also resistant at 40 °C during the first 92 h of fermentation. These two strains were immobilized by entrapment into poly(vinyl alcohol) hydrogel lens-shaped particles LentiKats®. The immobilized S. cerevisiae was a better ethanol producer and retained higher metabolic activity in repeated batch fermentations than P. kudriavzevii. The immobilized S. cerevisiae was also suitable for a long-term storage, with 23% decrease in the ethanol production ability after 1-year storage of yeast cells.

The hydrolytic kinetics of mixtures of cotton gin waste (CGW) and recycled paper sludge (RPS) at various initial enzyme concentrations of Spezyme™ AO3117 was investigated. The experiments showed that the concentrations of reducing sugars and the conversions of the mixtures increased with increasing initial enzyme concentration. The reducing sugar concentration and conversion of the mixture of 75% CGW and 25% RPS were higher than those of the mixture of 80% CGW and 20% RPS. The conversion of the former can reach 73.8% after a 72-h hydrolysis at the initial enzyme loading of 17.4 Filter Paper Unit (FPU)/g substrate. A three-parameter kinetic model based on enzyme deactivation and its analytical expression were derived. Using nonlinear regression, the parameters of the model were determined for the experimental data of hydrolytic kinetics of the mixtures. Based on this kinetic model of hydrolysis, two profit rate models, representing two kinds of operating modes with and without feedstock recycling, were developed. Using the profit rate models, the optimal enzyme loading and hydrolytic time can be predicted for the maximum profit rate in ethanol production according to the costs of enzyme and operation, enzyme loading, and ethanol market price. Simulated results from the models based on the experimental data of hydrolysis of the mixture of 75% CGW and 25% RPS showed that use of a high substrate concentration and an operating mode with feedstock recycle can greatly increase the profit rate in ethanol production. The results also demonstrated that the hydrolysis at a low enzyme loading is economically required for systematic optimization of ethanol production.

Ethanol production from the steam-exploded mixture of 75% cotton gin waste and 25% recycled paper sludge in various conditions was investigated by semi-simultaneous saccharification and fermentation (SSSF) consisting of a pre-hydrolysis and a simultaneous saccharification and fermentation (SSF). Four cases were studied: 24-h pre-hydrolysis + 48-h SSF (SSSF 24), 12-h pre-hydrolysis + 60-h SSF (SSSF 12), 72-h SSF, and 48-h hydrolysis + 24-h fermentation (SHF). The ethanol concentration, yield, and productivity of SSSF 24 were higher than those of the other operations. A model of SSF was used to simulate the data for four components in SSF. The analysis of the reaction rates of cellobiose, glucose, cell, and ethanol using the model and the parameters from the experiments showed that there was a transition point of the rate-controlling step at which the cell growth control in the initial 2 h was changed to the cellobiose reaction control in later period during ethanol production of SSF from the mixture.

High-solid paper sludge was investigated for its potential to produce renewable biofuel. As a pretreatment method without consuming a large amount of energy, mechanical grinding for a comparatively short time followed by chemical swelling was used for optimal enzyme saccharification and ethanol production from paper sludge. Chemical swelling by phosphoric acid was more favorable than ball mill grinding. However, sequential pretreatment system using ball milling for 2 min and then phosphoric acid swelling for 1 h enhanced the enzyme saccharification rate and the reducing sugar productivity, 84.1% and 28.1 mg/g/h, respectively. The simultaneous saccharification and fermentation (SSF) from the sequential pretreatment system resulted to 81.5% ethanol conversion rate, the productivity being 1.27 g/L/h compared to untreated raw paper sludge which gave 54.3% ethanol conversion rate and 0.424 g/L/h productivity. Our work shows that consecutive mechanical grinding and chemical swelling are effective pretreatment methods for the enhancement of enzyme saccharification and efficient ethanol production from paper sludge.

Paper sludge (PS) from the paper and pulp industry consists primarily of cellulose and ash and has significant potential for ethanol production. Thirty-seven PS samples from 11 South African paper and pulp mills exhibited large variation in chemical composition and resulting ethanol production. Simultaneous saccharification and fermentation (SSF) of PS in fed-batch culture was investigated at high solid loadings and low enzyme dosages. Water holding capacity and viscosity of the PS influenced ethanol production at elevated solid loadings of PS. High viscosity of PS from virgin pulp mills restricted the solid loading to 18% (w/w) at an enzyme dosage of 20 FPU/gram dry PS (gdPS), whereas an optimal solid loading of 27% (w/w) was achieved with corrugated recycle mill PS at 11 FPU/gdPS. Ethanol concentration and yield of virgin pulp and corrugated recycle PS were 34.2g/L at 66.9% and 45.5 g/L at 78.2%, respectively.

Paper mill sludge (PS), a solid waste from pulp and paper industry, was investigated as a feedstock for acetone-butanol-ethanol (ABE) production by simultaneous saccharification and fermentation (SSF). ABE fermentation of paper sludge by Clostridium acetobutylicum required partial removal of ash in PS to enhance its enzymatic digestibility. Enzymatic hydrolysis was found to be a rate-limiting step in the SSF. A total of 16.4-18.0g/L of ABE solvents were produced in the SSF of de-ashed PS with solid loading of 6.3-7.4% and enzyme loading of 10-15FPU/g-glucan, and the final solvent yield reached 0.27g/g sugars. No pretreatment and pH control were needed in ABE fermentation of paper sludge, which makes it an attractive feedstock for butanol production. The results suggested utilization of paper sludge should not only consider the benefits of buffering effect of CaCO3 in fermentation, but also take into account its inhibitory effect on enzymatic hydrolysis.

Waste paper can serve as a feedstock for ethanol production due to being rich in cellulose and not requiring energy-intensive thermophysical pretreatment. In this study, an efficient process was developed to convert waste paper to ethanol. To accelerate enzymatic saccharification, pH of waste paper slurry was adjusted to 4.5-5.0 with H2SO4. Presaccharification and simultaneous saccharification and fermentation (PSSF) with enzyme loading of 40 FPU/g waste paper achieved an ethanol yield of 91.8% and productivity of 0.53g/(Lh) with an ethanol concentration of 32g/L. Fed-batch PSSF was used to decrease enzyme loading to 13 FPU/g waste paper by feeding two separate batches of waste paper slurry. Feeding with 20% w/w waste paper slurry increased ethanol concentration to 41.8g/L while ethanol yield decreased to 83.8%. To improve the ethanol yield, presaccharification was done prior to feeding and resulted in a higher ethanol concentration of 45.3g/L, a yield of 90.8%, and productivity of 0.54g/(Lh). Ethanol fermentation recovered 33.2% of the energy in waste paper as ethanol. The biochemical methane potential of the stillage eluted from ethanol fermentation was 270.5mL/g VTS and 73.0% of the energy in the stillage was recovered as methane. Integrating ethanol fermentation with methane fermentation, recovered a total of 80.4% of the energy in waste paper as ethanol and methane.

Bacterial cellulose (BC) synthesized by Gluconacetobacter sucrofermentans CECT 7291 seems to be a good option for the restoration of degraded paper. In this work BC layers are cultivated and purified by two different methods an alkaline treatment when the culture media contains ethanol and a thermal treatment if the media is free from ethanol. The main goal of these tests was the characterization of BC layers measured in terms of tear and burst indexes, optical properties, SEM, X-ray diffraction, FTIR, degree of polymerization, static and dynamic contact angles, and mercury intrusion porosimetry. The BC layers were also evaluated in the same terms after an aging treatment. Results showed that BC has got high crystallinity index, low internal porosity, good mechanical properties and high stability over time, especially when purified by the alkaline treatment. These features make BC an adequate candidate for degraded paper reinforcement. © 2014 Elsevier Ltd.

As the economic demand for vegetable oils increases, there is a need for improved recovery from source seeds to offset the rising demand. In many cases, the choice of extraction solvent has become a major concern owing to the different yield performance of different solvents. In most cases, ethanol has often been preferred. This is as a result of combined factors of lack of proper knowledge of several other commercially available alternatives and possibly, the technical and economic advantage it offers. This work, therefore, presents a comparative experimental investigation of two solvents (n-hexane and ethanol) performed at the Department of Chemical/Petrochemical Engineering Laboratory, Rivers State University, Port Harcourt, Nigeria, using a sohxlet extractor. This study primarily focuses on the technical advantage of using n-hexane for seed oil extraction over the conventional ethanol using a two-stage experimental procedure was used – a seed oil extraction stage and a solvent recovery sage. In each stage, the coconut seed sample were subjected to the same experimental conditions and the yield performance is comparatively analyzed. The results of this investigation show that the n-hexane is a better solvent for the extraction of the sample coconut oilseed. The variation of solvent yield with temperature, extraction time and solvent concentration were plotted and analyzed in order to estimate and also forecast the effect of the parameters on solvent yield and also establish an optimal condition for optimal solvent yield. As part of the scope of this work, key recommendations are provided to ensure optimal solvent yield for coconut oil extraction.

During past decades, the considerable efforts have been made to utilize lignocellulose as biomass feedstock for the optimal production of bio-ethanol as an alternative source of fuel. In this work, the effective bioconversion of paper sludge to ethanol was investigated by using Zymomonas mobilis NBRC 13756. Major components of the raw paper sludge were carbohydrates and ash. Fermentation utilizing strains of Z. mobilis instead of traditional yeasts and the use of simultaneous saccharification and fermentation (SSF) process have been proposed due to their high ethanol yields with cost-effectiveness. Free cells of Z. mobilis resulted in no ethanol production even after 24 h of incubation because cells’ growth was inhibited by metal ions contained in the paper sludge. The application of SSF with Ca-alginate-immobilized cells of Z. mobilis was performed and 18 g/L of ethanol was obtained after 48 h of incubation at an initial paper sludge concentration of 200 g/L. In addition, the repeated batch fermentation of Ca-alginate-immobilized Z. mobilis cells was attempted for producing ethanol up to run 4. Our work suggests that Ca-alginate-immobilized cells of Z. mobilis could effectively produce ethanol from paper sludge not only under the batch fermentation but also under the repeated batch fermentation.

Active layers of electrocatalysts were prepared by ion beam assisted deposition (IBAD) of platinum and one of rare earth metals (Ce, Gd, Dy, Yb) on the carbon based Toray Carbon Fiber Paper TGP-H-060 T (TorayCFP) and AVCarb® Carbon Fiber Paper Р50 (AVCarbCFP) catalysts carriers with the aim of electrocatalysts production for direct methanol and ethanol oxidation fuel cells (DMFC, DEFC) with polymer membrane electrolyte. Formation of layers in IBAD mode, by means of the deposition of metal and mixing of precipitating layer with the substrate by accelerated (U = 5 kV) ions of the same metal, was carried out. In this process, a neutral fraction of metal vapor and ionized plasma of vacuum pulsed electric arc discharge were used. According to scanning electron microscopy, electron probe microanalysis, X-ray fluorescence analysis and Rutherford backscattering spectrometry investigations atoms of deposited metals, carbon substrates, and oxygen as impurity enter into the composition of layers. The thickness of the prepared catalytic layers is ~30 nm; content of platinum atoms in the layers – ~2×1016 cm–2, or much less than 0.05 mgPt/cm2. Properties of the prepared electrocatalysts were investigated by cyclic voltammetry in 1M CH3OH + 0.5M H2SO4 and 1M C2H5OH + 0.5M H2SO4 solutions. It was established that the prepared electrocatalysts show activity in the processes of electrochemical oxidation of methanol and ethanol. The inclusion of the rare earth metal in the composition of formed layers enhances the activity of electrocatalysts in a multistage process of oxidation of alcohols. Moreover the activity of prepared electrocatalysts in the oxidation of more complex molecules of ethanol is higher than the activity in oxidation reaction of methanol. The advantages of proposed IBAD method are as follows: possibility of forming a cohesive catalytically active layer on a carbon substrate at low platinum consumption; one stage of deposition of each of metals a comparison against multistage traditional chemical methods of catalysts preparation. Figure 1