Subjects -> CHEMISTRY (Total: 928 journals)
    - ANALYTICAL CHEMISTRY (59 journals)
    - CHEMISTRY (661 journals)
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    - INORGANIC CHEMISTRY (45 journals)
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    - PHYSICAL CHEMISTRY (65 journals)

CHEMISTRY (661 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
Accounts of Materials Research     Hybrid Journal   (Followers: 1)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 30)
ACS Applied Polymer Materials     Hybrid Journal   (Followers: 9)
ACS Catalysis     Hybrid Journal   (Followers: 51)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 23)
ACS Combinatorial Science     Hybrid Journal   (Followers: 21)
ACS Environmental Au     Open Access   (Followers: 11)
ACS Macro Letters     Hybrid Journal   (Followers: 25)
ACS Materials Letters     Open Access   (Followers: 3)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 41)
ACS Nano     Hybrid Journal   (Followers: 187)
ACS Photonics     Hybrid Journal   (Followers: 14)
ACS Symposium Series     Full-text available via subscription   (Followers: 3)
ACS Synthetic Biology     Hybrid Journal   (Followers: 31)
Acta Chemica Malaysia     Open Access  
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 2)
Acta Chromatographica     Full-text available via subscription   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 8)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 7)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 10)
Adsorption Science & Technology     Open Access   (Followers: 7)
Advanced Electronic Materials     Hybrid Journal   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 72)
Advanced Journal of Chemistry, Section A     Open Access   (Followers: 3)
Advanced Journal of Chemistry, Section B     Open Access   (Followers: 1)
Advanced Science Focus     Free   (Followers: 6)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 2)
Advanced Therapeutics     Hybrid Journal   (Followers: 1)
Advances in Chemical Engineering and Science     Open Access   (Followers: 111)
Advances in Chemical Science     Open Access   (Followers: 51)
Advances in Chemistry     Open Access   (Followers: 34)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 15)
Advances in Environmental Chemistry     Open Access   (Followers: 11)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 33)
Advances in Nanoparticles     Open Access   (Followers: 17)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Polymer Science     Hybrid Journal   (Followers: 51)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 18)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Sample Preparation     Open Access   (Followers: 9)
Advances in Science and Technology     Full-text available via subscription   (Followers: 16)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Chemical Education     Open Access   (Followers: 5)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 6)
Aggregate     Open Access   (Followers: 1)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 4)
Alchemy : Jurnal Penelitian Kimia     Open Access  
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 44)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 20)
American Journal of Chemistry     Open Access   (Followers: 37)
American Journal of Plant Physiology     Open Access   (Followers: 9)
Analyst     Hybrid Journal   (Followers: 35)
Analytical Science Advances     Open Access   (Followers: 1)
Angewandte Chemie     Hybrid Journal   (Followers: 144)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 236)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 6)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 4)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 5)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 1)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Surface Science     Hybrid Journal   (Followers: 31)
Arabian Journal of Chemistry     Open Access   (Followers: 4)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Applied Chemistry Research     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 2)
Asian Journal of Chemical Sciences     Open Access  
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access  
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 2)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 7)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Hybrid Journal   (Followers: 203)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 5)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 23)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 3)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 84)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 61)
Bioorganic Chemistry     Hybrid Journal   (Followers: 7)
Biopolymers     Hybrid Journal   (Followers: 15)
Biosensors     Open Access   (Followers: 3)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 3)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 5)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 1)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 11)
Canadian Mineralogist     Full-text available via subscription   (Followers: 5)
Carbohydrate Polymer Technologies and Applications     Open Access  
Carbohydrate Polymers     Hybrid Journal   (Followers: 9)
Carbohydrate Research     Hybrid Journal   (Followers: 23)
Carbon     Hybrid Journal   (Followers: 65)
Carbon Capture Science & Technology     Open Access  
Carbon Trends     Open Access   (Followers: 5)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 9)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysts     Open Access   (Followers: 11)
Cell Reports Physical Science     Open Access  
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
Chem     Hybrid Journal   (Followers: 1)
Chem Catalysis     Hybrid Journal  
ChemBioEng Reviews     Full-text available via subscription   (Followers: 3)
ChemCatChem     Hybrid Journal   (Followers: 7)
Chemical and Engineering News     Free   (Followers: 22)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Hybrid Journal   (Followers: 79)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 26)
Chemical Physics Impact     Full-text available via subscription  
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 4)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 178)
Chemical Science     Open Access   (Followers: 41)
Chemical Science International Journal     Open Access  
Chemical Technology     Open Access   (Followers: 75)
Chemical Thermodynamics and Thermal Analysis     Open Access   (Followers: 2)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 4)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 40)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 17)
ChemInform     Hybrid Journal   (Followers: 5)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Industry     Full-text available via subscription   (Followers: 6)
Chemistry - A European Journal     Hybrid Journal   (Followers: 119)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 19)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 18)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 6)
Chemistry Education Review     Open Access   (Followers: 1)
Chemistry in Education     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 42)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 166)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Hybrid Journal   (Followers: 20)
Chemistry-Didactics-Ecology-Metrology     Open Access  
ChemistryOpen     Open Access   (Followers: 1)
ChemistrySelect     Hybrid Journal  
Chemistry–Methods     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
ChemNanoMat     Hybrid Journal   (Followers: 1)
Chemoecology     Hybrid Journal   (Followers: 2)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 13)
Chemosensors     Open Access   (Followers: 1)
ChemPhotoChem     Hybrid Journal  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPhysMater     Full-text available via subscription  
ChemPlusChem     Hybrid Journal   (Followers: 2)
Chempublish Journal     Open Access  
ChemSystemsChem     Hybrid Journal   (Followers: 1)
ChemTexts     Hybrid Journal   (Followers: 1)
CHIMIA International Journal for Chemistry     Open Access   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 9)
Chromatographia     Hybrid Journal   (Followers: 21)
Chromatography     Open Access   (Followers: 2)
Chromatography Research International     Open Access   (Followers: 4)
Ciencia     Open Access  
Clay Minerals     Hybrid Journal   (Followers: 8)
Cogent Chemistry     Open Access   (Followers: 3)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 6)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 2)
Combustion Science and Technology     Hybrid Journal   (Followers: 26)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 1)
Communications Chemistry     Open Access   (Followers: 2)
Communications Materials     Open Access  
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comptes Rendus : Chimie     Open Access  
Comptes Rendus : Physique     Open Access   (Followers: 3)

        1 2 3 4 | Last

Similar Journals
Journal Cover
Biomass Conversion and Biorefinery
Journal Prestige (SJR): 0.493
Citation Impact (citeScore): 1
Number of Followers: 10  
 
  Partially Free Journal Partially Free Journal
ISSN (Print) 2190-6815 - ISSN (Online) 2190-6823
Published by Springer-Verlag Homepage  [2469 journals]
  • Editorial to thematic issue “Deep Eutectic Solvents in Biomass
           Conversion”

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      PubDate: 2022-07-01
       
  • Valorization of tomato pomace: extraction of value-added components by
           deep eutectic solvents and their application in the formulation of
           cosmetic emulsions

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      Abstract: Abstract Deep eutectic solvents (DESs) have been explored as an alternative to hazardous solvents to extract phenolic compounds. The aim of this work was estimate the performance of choline chloride-based DESs regarding the extraction of phenolic compounds of tomato pomace and determination of their antioxidant activity. “Green” choline chloride-based DESs coupled with ultrasound-assisted extraction were performed to extract. The solvents were choline chloride:1,2-propanediol (1:2 v/w):water (10% w/w) and choline chloride:lactic acid (1:2 v/w):water (10% w/w).The phytochemical constituents of tomato pomace extracts were verified with a combination of high-performance liquid chromatography coupled to diode-array detection and tandem mass spectrometry (HPLC–DAD-MS). The total antioxidant activity of the extracts was assessed using phosphomolybdenum (PM) method. The redox behavior of tomato pomace extracts was evaluated by means of cyclic voltammetry. The DES-based tomato pomace extracts were used as the antioxidant agent to develop a natural cosmetic formulation (colloidal solutions). The ζ-potential, colloidal stability, and the antioxidant, antimicrobial, and antifungal activity were studied. The antioxidant activity of the cosmetic emulsions has been studied by means of cyclic voltammetry. The tomato pomace extracts contain significant quantity of phenolic acids and flavanols (26–37% of the total compounds). Chlorogenic acid was detected as the main phenolic compound in tomato pomace extracts (ranging from 37.23 to 52.33 μg/g). The total antioxidant power of the extracts varies in the range at 408 to 511.18 μg/g extract. Choline chloride-based DESs have low values of oxidation potentials. Zeta-potential of obtained colloidal solutions (cosmetic formulation) varies from − 0.0102 to − 0.0594 mV indicating the moderate stability of obtained cosmetic emulsions. The following ranking of antioxidants was obtained: cosmetic emulsions with extract obtained by choline chloride:lactic acid deep eutectic solvent > cosmetic emulsions with extract obtained by choline chloride:1,2-propanediol deep eutectic solvent. Antibacterial and antifungal activity of the cosmetic emulsions with DES extracts relative to Gram-positive (Bacillus subtilis), Gram-negative (Escherichia coli), and Candida albicans wound pathogens were studied. Thus the DESs could serve as solvents to produce a phenolic-rich tomato extract could be readily applicable to cosmetic formulations.
      PubDate: 2022-07-01
       
  • Deep eutectic solvents for deacidification of waste biodiesel feedstocks:
           an experimental study

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      Abstract: Abstract The key challenge in reaching the goals set by Renewable Energy Directive is developing a sustainable, profitable, and environmentally acceptable biodiesel production process. In order to achieve balance between the above criteria, any use of high-quality edible oils as feedstocks needs to be avoided and utilization of waste feedstocks, such as used coffee grounds and waste animal fats, should be encouraged. The main drawback of these waste feedstocks is their high impurity content which usually requires an additional purification step. It is the purpose of this research to investigate the deacidification of three different waste biodiesel feedstocks by means of liquid-liquid extraction with deep eutectic solvents, in order to identify possible connections between solvent properties and extraction efficiency. Eight deep eutectic solvents were chosen to cover a wide range of different properties and the three used feedstocks varied in free fatty acid content. The relationship between solvent properties and extraction efficiency was determined by Spearman’s rank-order correlation. Strong, statistically significant positive correlation was found for solvent pH values, while a strong negative correlation was observed for polarities and molar volumes. The most effective solvent was potassium carbonate/ethylene glycol (1:10, mol.). Depending on the initial total acid number, solvent to feedstock mass ratios 0.1:1 and 0.25:1 were enough to reduce the acidity of waste animal fat below 2 mg of potassium hydroxide/g fat and the solvent was successfully reused up to four times.
      PubDate: 2022-07-01
       
  • L-proline-catalyzed Knoevenagel reaction promoted by choline
           chloride-based deep eutectic solvents

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      Abstract: Abstract Knoevenagel condensation of acetylacetone and aromatic aldehyde catalyzed by L-proline in the choline chloride-based deep eutectic solvents was achieved. High yields are up to 96.6%. Mild reaction conditions, enhanced rates, improved yields, recyclability of deep eutectic solvents containing L-proline, and reagents’ reactivity which is different from that in standard organic solvents are the remarkable features observed in deep eutectic solvents. The deep eutectic solvents containing catalyst was recycled in four subsequent runs with no decrease in activity.
      PubDate: 2022-07-01
       
  • Correction to: Nutrient recycling: from waste to crop

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      PubDate: 2022-07-01
       
  • Different design configurations of simultaneous saccharification and
           fermentation to enhance ethanol production from cashew apple bagasse
           pretreated with alkaline hydrogen peroxide applying the biorefinery
           concept

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      Abstract: Abstract Different strategies for simultaneous saccharification and fermentation (SSF) process were developed to enhance the productivity of ethanol by Kluyveromyces marxianus ATCC36907 as a part of biorefinery concept using cashew apple bagasse (CAB) as biomass. CAB was pretreated with 4.3% (v/v) alkaline hydrogen peroxide at pH 11.5 (CAB-AHP). Batch SSF conducted at 45 °C using 10% (w/v) CAB-AHP reported the highest concentration and ethanol yield. In the fed-batch SSF, the highest production (7.91 g ethanol/100gCAB) and ethanol yield (84.69%) were achieved using 10% (w/v) CAB-AHP initial solids load, 4% solid feeding at 24 h, and the feeding of enzymes only in the beginning of the process. The recycling of pretreatment inputs decreased 50% of the batch-SSF efficiencies, saving the consumption of water, H2O2, and NaOH in 66.67%, 48.44%, and 66.67%, respectively. Lignin was extracted from the hydrolysate with yield of 39.2%. Thus, the proposed biorefinery concept utilizes CAB to produce ethanol with high efficiency by fed-batch SSF, pretreatment input recycling, and the utilization of the extracted lignin for future applications.
      PubDate: 2022-07-01
       
  • The role of turmeric and bicnat on hydrogen production in porous tofu
           waste suspension electrolysis

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      Abstract: Abstract So far, tofu waste application as an electrocatalyst support requires carbonization. This study aims to evaluate porous tofu waste performance as an organic catalyst support without carbonization. The pre-treated tofu waste suspension by acidification using organic oxalic acid was electrolyzed in water solution. Elemental, phase, and morphology characterizations were also performed on tofu waste, supported by digital imaging of tofu waste revealing mesopores and macropores on its structure. The pore area size ranging from 43 to 935 nm2 has been activated by turmeric, thereby increasing the adsorption rate around tofu waste. Methoxyphenyl as an electron donor phenolic compound of turmeric behaves as an ORR agent. Bicnat addition, alkalizing liquid parts of tofu waste suspension, helps to loosen the bonds in water molecules. Pore activation by turmeric and bicnat carbonation synergetically destabilizes water molecule to increase hydrogen production 3-fold. This result is very favorable for converting waste into an alternative energy source.
      PubDate: 2022-07-01
       
  • «Green» synthesis and characterization of galactomannan sulfates
           obtained using sulfamic acid

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      Abstract: Abstract The “green” synthesis of galactomannan sulfates using a sulfamic acid–urea mixture has been studied for the first time. The effect of the time and temperature of the galactomannan sulfation process on the degree of substitution of galactomannan sulfates has been investigated. It is shown that, at a temperature of 70 °C with an increase in the process time up to 120 min, the degree of substitution increases up to 0.70. An increase in the process temperature up to 80 °C leads to the production of galactomannan sulfates with a degree of substitution of 1.67. With a further increase in the process temperature to 90 °C, the galactomannan structure is partially destructed, and the degree of substitution decreases. Embedding of the sulfate groups into the galactomannan structure has been confirmed by elemental analysis and Fourier-transform infrared spectroscopy. In addition, the initial and sulfated galactomannans have been characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and gel permeation chromatography. The thermal analysis shows that the initial galactomannan exhibits endothermic peaks at 254 and 294 °C and an exothermic peak at 315 °C, while sulfated galactomannan exhibits endothermic peaks at 209 and 275 °C and an exothermic peak at 281 °C. Using atomic force microscopy, it has been shown that the sulfated galactomannan film consists of spherical particles with an average diameter of 200–300 nm; according to the phase contrast data, it has the uniform composition without extraneous impurities.
      PubDate: 2022-07-01
       
  • Response surface methodology (RSM) for assessing the effects of
           pretreatment, feedstock, and enzyme complex association on cellulose
           hydrolysis

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      Abstract: The enzymatic hydrolysis of sugarcane bagasse cellulose (SBC) was performed after acid/peroxide-alkali (APA) pretreatment, soda/AQ pulping, and bleaching steps for producing glucose. Cellic® CTec3 (CT) and Celluclast®1.5L (CL) complexes were evaluated in both individual and mixed systems for observing their influence in cellulose conversion. Deconvolution of XRD patterns and SEM images proved the low crystallinity and high accessibility of SBC, thus being able to provide significantly higher glucose yield than the commercial cellulose with predominant Iβ polymorphism. The analysis of variance (ANOVA) and the response surface methodology (RSM), applied to a full factorial 24 design of experiments built for assessing the activity of CT and CL enzymes together in the hydrolytic system, were accurate in describing that the feedstock (SBC or commercial cellulose) and the treatment of cellulose are the factors with major effect on the saccharification efficiency (F = 744.12, p < 0.0001), thus predicting 53.71 g/L maximum glucose yield for the experimental conditions studied (near to the maximum yield reached, 55.77%) when using SBC, more than double the conversion reached for commercial cellulose, and showing the cooperative work of both complexes together for converting cellulose. Graphical abstract
      PubDate: 2022-07-01
       
  • Effect of prehydrolysis on pulping and bleaching of Acacia auriculiformis
           A. Cunn. ex Benth.

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      Abstract: Abstract Prehydrolysis prior to pulping shows a beneficial effect in subsequent delignification and bleaching. Prehydrolysis of Acacia auriculiformis produced higher pulp yield in soda and soda-anthraquinone processes at similar kappa number than non-prehydrolyzed kraft process. In D0EpD1 bleaching sequences, delignification (DoEp kappa) and bleachability were better for prehydrolyzed A. auriculiformis pulp in the pulping processes studied. The lignin from prehydrolyzed wood chips was characterized with lower molecular weight and slightly higher phenolic hydroxyl group. This suggested the depolymerization of lignin in prehydrolysis process.
      PubDate: 2022-07-01
       
  • Sustainable uses of cashew tree rejects: cashew apple bagasse and cashew
           gum

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      Abstract: Anacardium occidentale, more commonly known as cashew tree, is a tropical tree native from South America. The industrial use of the cashew is basically aimed at the processing of the nut and, minor extent, the use of the peduncle, generating high losses due to the large quantity of cashew apple bagasse that are discarded. Another cashew’s tree reject is the exudate, a yellowish-colored resin obtained by natural exudation or by incisions made on the stem of the cashew, which serves as raw material for the cashew gum production. In this context, the present work carries out a technological prospection in databases of patents and scientific articles mapping the cashew’s rejects applications, such as cashew apple bagasse and cashew gum as a byproduct. After the analysis of patents and scientific articles, it was possible to perceive that cashew apple bagasse presents a good potential, as an abundant and low-cost source of bioactive compounds, being an excellent raw material for functional food composition. In particular, many studies involving the cashew gum are in the area of medicine. Thus, the present study mapped the potentiality of the cashew rejects that can add environmental and social dimensions that are often overlooked in the context of small-scale agricultural production. Graphical abstract Statement of novelty This work identified the potential in agroindustrial cashew rejects in order to develop new sustainable perspectives for its use. Sustainable alternatives were also identified in the cashew production chain and new applications for the use of cashew apple bagasse and cashew exudate.
      PubDate: 2022-07-01
       
  • Alkaline hydrolysis of coconut pith: process optimization, enzymatic
           saccharification, and nitrobenzene oxidation of Kraft lignin

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      Abstract: The accumulation of pith in a coconut husk processing facility leads to disposal problems, fire hazards, and contamination of groundwater. The leachate contains phenolic compounds that percolate through the soil and contaminate groundwater. Monolignols (guaiacyl (G), syringyl (S), and p-hydroxyphenyl (H)) in soil and groundwater pose a threat to the land and water resources. This study focuses on minimizing waste accumulation by treating the accumulated pith with sodium hydroxide to recover lignin and sugar. Pith, which has about with 24% cellulose and 49% lignin, was used as a substrate for recovery of Kraft lignin (KL) and sugar. The operating condition for the recovery of KL was optimized using response surface methodology (RSM). Maximum KL recovery (~ 86%) was achieved with optimal biomass loading of 65 mg/ml, NaOH concentration 5.12% w/w, residence time 31 min, and temperature 121 °C. A glucose yield of 95% was obtained after 48 h of saccharification. The removal of the aromatic layer increased the crystallinity index (CrI) after hydrolysis from 65 to 81.7%. The S/G ratio of 0.49 indicated that the lignin structure of pith is a matrix with many branches, thus making the lignin matrix strong and rigid. Graphical abstract
      PubDate: 2022-07-01
       
  • Production of lignocellulolytic enzymatic complex using pretreated
           carnauba straw as carbon source and application on sugarcane bagasse
           hydrolysis

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      Abstract: Lignocellulolytic enzymes have a great biotechnological potential. Their commercial exploitation has been considerably increased in recent years. However, its industrial application in the conversion of lignocellulosic biomass to biofuels depends on the development of more economical processes and technologies for the lignocellulolytic enzyme production. In this study, the improvement of cellulases and xylanases by Trichoderma reesei CCT-2768 production induced by pretreated carnauba straw with alkaline hydrogen peroxide (A-HP) was performed and its crude extract produced was applied in the enzymatic hydrolysis of sugarcane bagasse. Herein, three conditions were carried out consisting of changing solid loading, pretreatment time, and hydrogen peroxide concentration. The FPase, CMCase, xylanase, and β-glucosidase activities of produced crude extracts were measured. Pretreated carnauba straw had a higher production of total cellulase (2.4 U/g dry substrate) and xylanase (172 U/g dry substrate) enzymes. The low cellulases (8.0 U/g dry substrate) and high xylanase charges (544 U/g dry substrate) present in the produced extract and applied into pretreated sugarcane bagasse hydrolysis allowed a hydrolysis efficiency of 86.96%. The in situ lignocellulolytic enzyme production can represent a relevant advance in the future in overall cost reducing enzymatic hydrolysis process of lignocellulosic materials. Graphical abstract
      PubDate: 2022-07-01
       
  • Semi-continuous desulfurization of natural gas in photobioreactor by green
           sulfur-oxidizing bacterial consortia isolated from hot spring

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      Abstract: Abstract Anoxygenic phototrophic bacteria are able to oxidize and remove hydrogen sulfide from natural sources by using inorganic substrates and light. In the present study, anoxygenic phototrophic bacteria were isolated from Vartoon hot spring (east of Isfahan Province, Iran) and used for removal of sulfide compounds from natural gas in a semi-continuous photobioreactor. Mat samples that obtained from the depth of spring were introduced into Winogradsky columns and kept in the presence of sunlight for 3–4 months until green and purple layers were composed. The layers were then transferred into mineral medium and incubated under anaerobic condition. The sequence of amplified 16S rDNA in green bacteria and an amplified sequence among the gene encoding photosynthetic reaction center in purple bacteria were used for molecular identification of bacteria. The bacterial growth based on the contents of bacteriochlorophylls and the extent of elemental sulfur production by the cells were measured after ethanol extraction. Molecular identification validated the presence of Chlorobium phaeobacteroides and Prosthecochloris vibrioformis from green sulfur bacteria in the consortium. The results indicated the most increase in bacteriochlorophylls c, d, and e content of mineral medium after bacterial growth. In addition, by releasing 62.4 mmol elemental sulfur, 79.30% increase was detected in sulfur content of the medium during 3 weeks. The consortium of sulfur-oxidizing phototrophic bacteria was potentially used for natural gas desulfurization in the semi-closed photobioreactor. This system is suggested as a replacement for chemoautotrophic systems in areas where there is sufficient access to sunlight.
      PubDate: 2022-07-01
       
  • Facile green synthesis of carbon quantum dots and biomass-derived
           activated carbon from banana peels: synthesis and investigation

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      Abstract: Abstract We introduce a simple, low-cost, and environment friendly method to obtain high-fluorescence carbon dots and activated carbon via a one-step hydrothermal process using banana peels. The dispersion of carbon dots generated strong, bright-blue photoluminescence (average diameter 3–6 nm), which could be further used in biosensing, electronics, and catalysis applications research. Moreover, the precipitation accumulated at the bottom of the hydrothermal process contained activated carbon with a highly porous structure and large specific surface area (294.6 m2 g−1), which could be used as a supercapacitor electrode. The three-electrode cell exhibited excellent capability and stability of the activated carbon as the working electrode in various aqueous electrolytes, with a high specific capacitance (199 F g−1) in an aqueous electrolyte (1-M KOH) and a high energy density of 54.15 Wh kg−1 at a current density of 0.5 A g−1. Thus, based on the excellent characteristics of the carbon dots and the strong electrochemical properties of the activated carbon as an electrode material, the banana peels, as an abundant bioresource, can provide two excellent produces.
      PubDate: 2022-07-01
       
  • Pyrolysis of olive cake with catalytic upgrading of volatile products

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      Abstract: Abstract SAPO-34 and 1 mol% MeSAPO-34 (metal-modified catalysts, Me = Ni, Fe) were synthesized and tested for the catalytic pyrolysis of olive cake at 500 °C under inert conditions. The characterization of the catalysts was performed using XRD, BET, SEM, EDX, FT-IR, and TGA. MeSAPO catalysts demonstrated a chabazite cubic structure identical to the parent catalyst, with lower surface areas and particle sizes, and less water retention. The use of catalysts increased gas yield from 39 to 66% and decreased the oil yield from 39 to 10%. Biochar yield was maintained around 25%, and the solid samples showed an increase in carbonization as shown in the SEM and EDX results. Liquid GC-MS analysis indicated that SAPO was more selective towards alkane and amine products, whereas metal-modified catalysts favored the production of alkenes, acids, and phenols. Similarly, the analysis of the gas samples revealed the presence of light olefins and light oxygenated compounds which varied with the type of catalyst used.
      PubDate: 2022-07-01
       
  • Biodiesel production by interesterification of rapeseed oil with methyl
           formate in presence of potassium alkoxides

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      Abstract: Abstract An alternative method for the biodiesel or fatty acid alkyl ester (FAAE) synthesis has been proposed—rapeseed oil interesterification with methyl formate. Reaction with methyl formate proceeds at a relatively low temperature (28 °C) instead of 55–65 °C necessary for triglyceride reactions with methanol and other monoesters. Similarly to transesterification with methanol, the product of the reaction with methyl formate consists of two layers. The main product the fatty acid methyl ester (FAME) is located in the top layer, but the process by-product formins forms the bottom layer. In this work, solutions of potassium alkoxides (methoxide, ethoxide, isopropoxide, tert-butoxide) in appropriate alcohols as homogeneous catalysts were used, adhering to the catalyst to oil molar ratio (COMR) 0.1 and methyl formate to oil molar ratio (MFOMR) 18. The FAAE content in the biodiesel layer in presence of all catalysts was 77–81 wt.%, which is lower than the level required by the EN14214 but significantly higher than the FAME content in reactions with methyl acetate under the same conditions. Fuel properties such as flash point, carbon residue, density, viscosity, and cold flow properties were investigated. For samples with MFOMR equal to or higher than 36 FAAE exceed 93% and the main characteristics of samples correspond to the EN14214 limits even without product purification.
      PubDate: 2022-07-01
       
  • Structural changes of waste biomass induced by alkaline treatment: the
           effect on crystallinity and thermal properties

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      Abstract: A low-cost waste biomass generated from a food industry, apricot shells, was subjected to alkali modification in order to compare morphology, crystalline structure and thermal stability of native and modified biomass, accompanied by their cellulose-rich fractions. The surface morphology and structure of compared samples were analysed by the scanning electron microscopy (SEM) and mercury porosimetry. Furthermore, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermal analysis (TG/DTA) were applied. The results have shown that after alkaline treatment, inter- and intra-particle porosity in the material rises, resulting in increase of the total surface area. The XRD diffractograms showed that crystallinity index increased together with crystallite size, suggesting that modified sample has more ordered crystalline structure than native sample (also confirmed by the FTIR analysis). Although the cellulose-rich fraction extracted from the alkali-modified sample showed higher thermal stability, the overall thermal analysis revealed that alkali-modified biomass has lower thermal stability than the native sample. This indicates that this type of modification will improve the fuel properties of this lignocellulosic biomass and imply its possible application in energy recovery process. Graphical abstract
      PubDate: 2022-07-01
       
  • A comparative study of hemicellulose isolation with hot water, alkaline,
           and delignification methods from tea leaf brewing waste

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      Abstract: Abstract Tea leaf brewing waste (TLBW) is a waste with high hemicellulose content. It is a valuable waste of the pharmaceutical and cosmetics industry especially the beverage industry. In this study, the extraction of hemicelluloses (HC) from tea leaf brewing waste using three different pretreatment methods were investigated. The isolation yield of the HC was determined depending on pretreatment methods and pretreatment parameters such as the isolation temperature (25–55 °C), alkaline concentration (NaOH, 5–20%), contact time (12–24 h), the oxidative component (H2O2), and the concentration of sodium chlorite (NaCIO2) in the solution (2–10%). It was observed that the yield of isolation of hemicellulose varied between about 1 and 36% on the basis of raw materials depending on the extraction parameters. The experimental results showed that the suitable conditions for isolation of hemicellulose by alkaline pretreatment method were 15% NaOH concentration, 12-h contact time, and 45 °C. As a result of the experiments performed with the most suitable conditions, approximately 96% of the total hemicellulose in the TLBW was isolated. The extraction yield of hemicellulose achieved by the delignification process was found to be lower about 3% compared with the alkaline methods. But, the hemicellulose color achieved by the delignification process was lighter in color than the alkaline method. The results of the FTIR and H-NMR analysis show that the purity of the hemicellulosic fraction, which was obtained using the delignification method, was higher than the alkaline method.
      PubDate: 2022-07-01
       
  • Catalytic fast pyrolysis of walnut shell with K/AC catalyst for the
           production of phenolic-rich bio-oil

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      Abstract: Abstract Potassium supported on commercial activated carbon (K/AC) catalysts were prepared and used for catalytic fast pyrolysis (CFP) of walnut shell to produce phenolic-rich bio-oil. Pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) and fixed-bed CFP tests were performed to reveal the influences of pyrolytic temperature, potassium loading and catalyst-to-biomass (C-to-B) ratio on the product distribution. The Py–GC/MS results showed that the K5.79/AC catalyst in which the potassium loading was 5.79% exhibited the maximal improvement on the yield of phenolic compounds. Pyrolytic temperature significantly affected the total phenolic yield, which achieved the maximum value at 450 °C whether with or without catalysts. Moreover, the C-to-B ratio also dramatically affected the yield of phenolic compounds. The total phenolic yield raised with increasing C-to-B ratio, whereas the excessive C-to-B ratio (higher than 3:1) would lead to an obvious decrease in total phenolic yield. Overall, the yield of total phenolic compounds achieved the maximum value of 145.65 mg/g (14.57 wt%) at 450 °C under C-to-B ratio of 3:1 in Py–GC/MS runs. Meanwhile, the lab-scale experiments obtained the maximal total phenolic yield of 135.13 mg/g (13.51 wt%) at 450 °C under C-to-B ratio of 1:3.
      PubDate: 2022-07-01
       
 
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