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  Subjects -> CHEMISTRY (Total: 909 journals)
    - ANALYTICAL CHEMISTRY (56 journals)
    - CHEMISTRY (643 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (47 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (643 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 14)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 31)
ACS Catalysis     Hybrid Journal   (Followers: 53)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 23)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 28)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 44)
ACS Nano     Hybrid Journal   (Followers: 328)
ACS Photonics     Hybrid Journal   (Followers: 15)
ACS Symposium Series     Full-text available via subscription  
ACS Synthetic Biology     Hybrid Journal   (Followers: 25)
Acta Chemica Iasi     Open Access   (Followers: 6)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 62)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 77)
Advances in Chemical Science     Open Access   (Followers: 21)
Advances in Chemistry     Open Access   (Followers: 27)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 7)
Advances in Enzyme Research     Open Access   (Followers: 11)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 27)
Advances in Nanoparticles     Open Access   (Followers: 17)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 17)
Advances in Polymer Science     Hybrid Journal   (Followers: 45)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 4)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 8)
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: 3)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 69)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 34)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 15)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 37)
Angewandte Chemie     Hybrid Journal   (Followers: 186)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 274)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
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: 15)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 26)
Applied Surface Science     Hybrid Journal   (Followers: 34)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access  
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 4)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 382)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 7)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 24)
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: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 142)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 93)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 20)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     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: 25)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 25)
Carbon     Hybrid Journal   (Followers: 70)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 10)
Catalysis Science and Technology     Hybrid Journal   (Followers: 10)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 13)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 2)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 75)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 28)
Chemical Physics Letters : X     Open Access  
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 22)
Chemical Reviews     Hybrid Journal   (Followers: 219)
Chemical Science     Open Access   (Followers: 29)
Chemical Technology     Open Access   (Followers: 36)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 57)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 33)
Chemistry & Industry     Full-text available via subscription   (Followers: 9)
Chemistry - A European Journal     Hybrid Journal   (Followers: 184)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 46)
Chemistry of Materials     Hybrid Journal   (Followers: 281)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 21)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Cogent Chemistry     Open Access   (Followers: 2)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 23)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 13)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 7)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 8)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 6)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 14)
Current Research in Chemistry     Open Access   (Followers: 9)
Current Science     Open Access   (Followers: 77)
Current Topics in Medicinal Chemistry     Hybrid Journal   (Followers: 9)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 2)
Dalton Transactions     Full-text available via subscription   (Followers: 26)

        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  [2351 journals]
  • Characterization of products obtained from hydrothermal liquefaction of
           biomass ( Anchusa azurea ) compared to other thermochemical conversion
           methods
    • Abstract: In this study, biomass was converted into new products with catalyst (H3BO3, Na2CO3, Al2O3) and without catalyst at 300, 325, and 350 °C by the hydrothermal liquefaction method. The products obtained were analyzed by GC-MS, FT-IR, SEM, elemental analysis, and 1H NMR methods. Based on the trials, the highest liquid product yield (total bio-oil) was determined as 29.69% in the trial without catalyst at 350 °C. The higher heating value (HHV) has been calculated by Dulong’s formula, and the HHV values of all the (light bio-oil, heavy bio-oil, and solid residue) were determined to be higher than the HHV value of the feedstock. The highest HHV value was obtained from heavy bio-oil as 31.32 MJ/kg with the catalyst at 350 °C. This HHV value is higher than the HHV value attained by the pyrolysis and supercritical liquefaction method. The products obtained generally consisted of monoaromatics, polyaromatics, oxygen compounds, and aliphatics. Based on the results of the elemental analysis, HHV values varying between 16.22 and 31.78 MJ/kg were found for all products.
      PubDate: 2019-06-01
       
  • Valorization of waste Indigofera tinctoria L. biomass generated from
           indigo dye extraction process—potential towards biofuels and compost
    • Abstract: The current study focuses on the valorization potential of Indigofera tinctoria L. waste biomass recovered from the indigo dye production process for biofuel and compost. In order to compare the potential of after dye extracted biomass (ADB) with before dye extracted biomass (BDB), different physical (proximate analysis, calorific value, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD)), chemical (ultimate analysis, inorganic elemental analysis, Fourier transform infrared spectroscopy (FTIR)), and compositional characterization (cellulose, hemicellulose, lignin, and extractive content) were performed. With C/N ratio of 19.66 and high mineral contents (P = 1513.47 and K = 5672.63 ppm), ADB showed favorable potential for compost. Additionally, the ultimate composition (C = 44.23%, H = 6.62%, N = 2.25%, and O = 37.94%) and lignocellulosic composition (cellulose = 41.15%, hemicellulose = 28.9%) of ADB indicated comparable methane (498.94 L/kg VS) and ethanol (281.9 L/Mg) potential. Considering the overall biomass potential, an integrated approach has been suggested to utilize ADB for biofuels (biogas and bioethanol) and compost production. This approach may enhance the eco-sustainability by substituting the current energy and fertilizer need in Indigofera biomass cultivation and indigo dye production processes with a predicted energy equivalent of 3709.68 MJ (from biogas) or 1131.56 MJ (from bioethanol) per 240 kg dry weight of ADB. Graphical abstract ᅟ
      PubDate: 2019-06-01
       
  • Effect of process conditions on the properties of castor oil maleate and
           styrene copolymer produced by bulk polymerization
    • Abstract: This work evaluated the influence of process conditions on the chemical characteristics and yield of polymers based on castor oil. Castor oil maleate and styrene copolymers (MACO-Sty) were produced by bulk polymerization using benzoyl peroxide (BPO) and cobalt naphthenate as free radical initiators and reaction accelerators, respectively. The effects of temperature (100 to 140 °C), molar ratio between styrene and castor oil maleate (2:1 to 4:1), BPO concentration (0.10 to 0.20 wt%), and cobalt naphthenate concentration (0.10 to 0.20 wt%) were evaluated on the number average molecular weight (Mn), weight average molecular weight (Mw), dispersity (Đ), molar fraction of styrene in the copolymer, reaction yield, and viscosity of the copolymer. A wide range of molecular weights (Mw from 15,809 to 38,656) could be produced, with dispersity ranging from 2.0 to 4.8, and high yields into copolymers (> 80%). The physical characteristics ranged from resins of low viscosity (1.583 Pa s) to solid polymers.
      PubDate: 2019-06-01
       
  • Production and optimization of NaCl-activated carbon from mango seed using
           response surface methodology
    • Abstract: Granular activated carbon (AC) produced from mango seed husk through chemical activation with NaCl has potential application in adsorption cooling system. The study investigated the relationship among process parameters and effects on physicochemical and functional properties of AC. Production conditions were optimized using response surface methodology for impregnation ratio (0.25, 0.5, and 0.75), soaking time (2 h, 4 h, and 6 h), and activation temperature (400 °C, 450 °C, and 500 °C). Surface area, ash content, and bulk density were response variables. The AC was produced with comparable quality to commercial AC. Impregnation ratio, soaking time, and carbonization temperature, but not their interaction, had significant effects (p < 0.05) on AC surface area, ash content, and bulk density. Optimum production conditions for soaking time, impregnation ratio, and carbonization temperature were 4 h, 0.25, and 500 °C, respectively, which gave BET surface area, ash content, and bulk density of 415 m2 g−1, 6.92%, and 243 kg m−3, respectively.
      PubDate: 2019-06-01
       
  • Extraction and characterization of lignin from olive pomace: a comparison
           study among ionic liquid, sulfuric acid, and alkaline treatments
    • Abstract: Olive pomace is a phytotoxic by-product in the olive oil production. Lignin is a biopolymer present in the olive pomace in remarkable percentages, which has a great variety of potential industrial uses. The extraction of lignin using the ionic liquid triethylammonium hydrogen sulfate resulted in recovery yields as high as 40% of the available lignin in the dry olive pomace. This percentage was obtained after optimizing conditions such as temperature, extraction time, and water content in the ionic liquid. This is the first time such a high percentage of extraction has been achieved when evaluating this type of feedstock. For comparison, two other extraction methods (sulfuric acid and alkaline treatments) were used to assess their extracting performances. Lignin was quantified after developing a rapid, robust, and reliable method by Fourier transform infrared spectroscopy (purity of 101 ± 16%) and characterized by proton nuclear magnetic resonance and gel permeation chromatography. The assay total phenolic content (TPC) revealed high content of phenolic groups (212 ± 26.9 mg of gallic acid equivalents per g of lignin). The high purity and TPC conferred on the extracted lignin a potentially high antioxidant activity. In addition, a 67-fold scale-up extraction of initial mass loading was performed obtaining same results as in the lower scale. Thus, the extraction of lignin using this methodology is expected to mitigate the disposal of the olive pomace and provide certain revenue to the oil mill. Graphical abstract
      PubDate: 2019-06-01
       
  • A comparative investigation of H 2 O 2 -involved pretreatments on
           lignocellulosic biomass for enzymatic hydrolysis
    • Abstract: An effective pretreatment to improve cellulose accessibility and facilitate glucose release is crucial in a cellulosic ethanol biorefinery. This work comparatively assessed four H2O2-involved pretreatments, i.e., concentrated H3PO4 plus H2O2 (PHP), H2O2–CH3COOH (HPAC), alkaline-H2O2 (AHP), and Fenton chemistry (FC), for their pretreatment performances on wheat straw, poplar, and birch biomass. Substrate characteristics before and after pretreatment were assessed using SEM, XRD, and LSCM. The hydrolytic potentials of the pretreated substrates were compared by Simons’ stain and cellulose–glucose conversion assessment. The results showed that acidic H2O2-involved pretreatments (PHP and HPAC) were more efficient in biomass delignification compared to AHP and FC. PHP pretreatment is more promising for cellulosic ethanol production due to its corresponding high glucose yield (368.0 mg g−1) after enzymatic hydrolysis.
      PubDate: 2019-06-01
       
  • Kinetic modelling and techno-economic analysis of biodiesel production
           from Calophyllum inophyllum oil
    • Abstract: Calophyllum inophyllum oil, a non-edible renewable resource, was used for the production of biodiesel. In the present study, kinetic analysis was done for the biodiesel production from C. inophyllum oil using alkali and enzymatic method, a non-edible renewable resource with methanol to identify the rate equation and estimate model kinetic parameters. The present model was validated, and the experimental and predicted values were compared. The first-order rate equation represents an alkali transesterification reaction’s kinetic mathematical model under chosen experimental conditions for the estimated parameters. The enzymatic transesterification was carried out at 500 rpm for 8 h in room temperature produced a yield of 97% of FAME (fatty acid methyl ester) for the reaction with 6:1 methanol to oil in molar ratio. The sequential cleavage of fatty acid and reaction with methanol by the enzyme were assumptions used in developing the kinetic model. The transesterification of C. inophyllum oil was simulated with Aspen Plus (V 8.6, Aspen Tech., Inc.). The simulation and economically viable estimation for the comparison of a ceaseless biodiesel production from C. inophyllum oil are formed on the basis of the kinetics of chemical transesterification (base-catalyzed methanolysis) and enzymatic transesterification reactions. The base-catalyzed transesterification requires nearly seven times higher than the enzymatic transesterification Also, the simulation demonstrated that the base-catalyzed transesterification required additional number of process equipment units when related to the enzymatic process. Graphical abstract ᅟ
      PubDate: 2019-06-01
       
  • Selective hemicellulose hydrolysis of Scots pine sawdust
    • Abstract: The depletion of fossil resources is driving forward the search for new and alternative renewable feedstocks in the production of renewable chemicals, which could replace the petroleum-based ones. One such feedstock is pine (Pinus sylvestris) sawdust, which is generated enormous amounts in Finnish sawmills yearly. However, prior to the utilization in high-value applications, it needs to be fractionated into its constituents. In this work, the objective was to produce monomeric hemicellulose sugars from pine sawdust without degrading cellulose or lignin simultaneously. The influence of the reaction temperature and time, as well as acid type and concentration, was studied. Based on the results, the temperature was the main distinguishing feature between cellulose and hemicellulose hydrolysis. Promising results were achieved with acid mixtures consisting of 0.5% sulfuric acid and 5.5 or 10% formic acid. At 120 °C with the reaction time of 2 h, the mixtures produced hemicellulose sugars with the yields of 62%. These yields were comparable to the yields achieved in similar conditions with 1.5% sulfuric acid or 40% formic acid. Therefore, by using an acid mixture, the concentration of a single acid could be reduced significantly. The solid fractions remaining after the hydrolysis consisted mainly of cellulose and lignin, which verified the selectivity of the hemicellulose hydrolysis. Also, the fractionation of the remaining solids confirmed that the utilization of all the sawdust components is feasible.
      PubDate: 2019-06-01
       
  • Characterization and use of southern cattail for biorefining-based
           production of furfural
    • Abstract: In this work, we assessed the potential of southern cattail (Typha domingensis) as a lignocellulosic material for producing furfural in some regions. Also, we modeled and optimized the process involving autohydrolysis of the raw material, and its subsequent separation by liquid–liquid extraction and simple distillation. The process is based on biorefining principles and aimed at preserving the integrity of other polymer fractions of the raw material for subsequent use. The autohydrolysis liquor and furfural were characterized by Fourier-transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy, and high pressure liquid chromatography (HPLC). Also, a central composite factor design was used to model and optimize the autohydrolysis/liquid–liquid extraction process for conversion of hemicellulosic materials into furfural. Based on the results, southern cattail is a suitable material for extracting hemicellulose to be converted into furfural while preserving other fractions of use for other purposes. The optimum operating ranges for the autohydrolysis conditions were found to be 177–189 °C and 30–45 min. Under such conditions, 20–25% of all xylan in the raw material was converted into furfural with little simultaneous production of degradation products. Furfural in the autohydrolysis liquor was separated virtually quantitatively by extraction with chloroform and subsequent simple distillation.
      PubDate: 2019-06-01
       
  • Acidic hydrolysis performance and hydrolyzed lipid characterizations of
           wet Spirulina platensis
    • Abstract: Acidic hydrolysis process of wet microalgae is a worthy technique to reduce the processes and energy of the production. To aim the alternative fuel as a biofuel feedstock from wet microalgae, the Spirulina platensis containing high moisture, 88–95 wt%, was representative in this research. Microalgae cell disruption by acidic hydrolysis was investigated using various concentrations of sulfuric acid with the hydrolysis temperature in the range of 25–100 °C and hydrolysis time in the range of 30–120 min. The acid-hydrolyzed lipid was extracted from the mixture by solvent extraction using n-hexane. The maximum lipid concentration from acidic hydrolysis was 17.15 wt% that obtained at hydrolysis temperature of 100 °C for 60 min and then extracted with 700 mL of hexane for 30 min. The physical and chemical analyses of the lipid and microalgae solid residue were examined. According to the research results, the higher heating values of hydrolyzed lipid were found in the range of 32–40 MJ/kg and their main chemical components were hexadecane, heptadecane, and palmitic acid. The boiling point ranges of the hydrolyzed lipid were mainly indicated in the fractions of light and heavy gas oils which may be generated in term of biofuel feedstock for automobile fuels.
      PubDate: 2019-06-01
       
  • Efficient metal-free conversion of glucose to 5-hydroxymethylfurfural
           using a boronic acid
    • Abstract: 5-Hydroxymethylfurfural (HMF), which can be synthesized from hexose sugars without rearrangement of their carbon framework, is a key platform chemical that is readily convertible into fuels and chemicals that are now derived from petroleum. Methods to convert glucose, which is readily accessible from cellulose, to HMF typically rely on toxic heavy metals or harsh acidic conditions and often give low yields or low selectivity. Here, we report on a mild, efficient, and metal-free process that uses an organocatalyst, 2-carboxyphenylboronic acid, along with small amounts of chloride ion to effect the selective transformation of glucose to HMF.
      PubDate: 2019-06-01
       
  • Tofu-derived nitrogen-doped mesoporous carbon materials as metal-free
           catalyst for oxygen reduction reaction
    • Abstract: Nitrogen dope mesoporous carbon materials are widely used in the designing of oxygen reduction reaction (ORR) catalysts. How to prepare nitrogen-doped carbons (NC) with broad mass transfer path and preserve abundant ORR active nitrogen functionalities is still a great challenge. Here, nitrogen-doped mesoporous carbon materials are obtained through simply pyrolysis a mixture of renewable biomass (tofu) and ZnCl2. Owing to the effective chemical activation effect during carbonization, the optimal NC could present high porosity (high surface area of 1062 m2 g−1, large pore volume of 0.97 cm3 g−1) and high nitrogen content (7.74 wt%). Benefit from the rich of nitrogen functionalities to create abundant active sites and the well-developed mesoporous structure (high mesopore area 825 m2 g−1 and dual mesopore system with mesopore in both 3 nm and 30 nm) to guarantee fast mass transport and electron transfer, the obtained NC could serve as fine metal-free ORR catalyst, accelerating oxygen reduction reaction via high efficient 4e− oxygen reduction pathway. And more important, NC showed higher stability than commercial Pt/C (20 wt%), which highlight its great potential in the designing of electrocatalyst.
      PubDate: 2019-06-01
       
  • Combined pretreatments of eucalyptus sawdust for ethanol production within
           a biorefinery approach
    • Abstract: Eucalyptus sawdust is a residue from the pulp and timber industries which can be used as a raw material in a biorefinery. In this work, two consecutive treatment steps were applied to eucalyptus sawdust from a pulp mill, as a fractionation strategy, to recover and preserve lignocellulosic components while enhancing enzyme accessibility to cellulose. The first treatment step assayed was autohydrolysis (170 °C, 40 min). It was followed by (a) mechanical refining (3000 rpm, 0.5 mm), (b) kraft pulping (155 °C, 90–140 min, alkali charge 2.1–3.4%), or (c) soda pulping (155 °C, 90 min, alkali charge 2.4–4.0% NaOH). The remaining solid fractions were enzymatically hydrolyzed using 25 FPU/g of Cellic CTec 2 from Novozymes and a solid content of 13%. The efficiency of the enzymatic hydrolysis was higher than 70% in the case of an additional kraft or soda pulping while only autohydrolysis led to efficiencies lower than 60%. The best hydrolysis parameters and lignin and xylose recovery yields were obtained for autohydrolysis followed for a kraft pulping (cellulose conversion up to 71%, cellulose hydrolysis 95% at 48 h, lignin and xylose recovery 99 and 85%, respectively). The treated solid that reached the highest enzymatic yields was fermented using Saccharomyces cerevisiae in a 3.5-L reactor. The highest bioethanol yield was found for the autohydrolysis-treated solids followed by soda pulping, reaching a value of 250 L of ethanol per tonne of sawdust. Under this condition of combined treatments, 300 kg lignin/t sawdust and 120 kg xylose/t sawdust can be obtained.
      PubDate: 2019-06-01
       
  • Hydrothermal pretreatment with sulfonated bentonite catalyst enhances
           potassium removal and bioconversion of oil palm empty fruit bunch to sugar
           and biohydrogen
    • Abstract: Oil palm empty fruit bunch (EFB), a rich of polysaccharide and element as potassium, is being recognized as one of the most potential kinds of lignocellulosic biomass for bioenergy and biochemical production. In this study, EFB was subjected to hydrothermal pretreatment in the absence (HT) and presence of a sulfonated bentonite catalyst (HTcat). The effect of pretreatment on enzymatic hydrolysis and anaerobic digestion was investigated. The hydrothermal pretreatments were conducted at 160–200 °C for 5–25 min, while the effect of catalytic HTcat pretreatment of EFB was studied at 180–200 °C for 25 min. The results showed that temperature and catalyst in HTcat pretreatment were the main factors that could enhance both production of glucose and biohydrogen up to 1.04–1.14- and 3.32–4.36-fold, respectively, compared with those pretreated by HT at 180–200 °C for 25 min without catalyst. The catalyst specifically enhanced hemicellulose and lignin removal from EFB. During HT pretreatment, disruption of EFB cell wall also facilitated over 70% potassium dissolution from EFB to the liquid residue at 160–190 °C for 25 min, while poorer dissolution of potassium was found at 200 °C without or with catalyst addition. The HT pretreatment successfully improved the removal of potassium from EFB and its bioconversion yield. However, the potassium forms a sticky compound with other elements and soluble organic compound, and further study is required for the valorization of the potassium and liquid residue.
      PubDate: 2019-06-01
       
  • Influence of biochar application on growth of Oryza sativa and its
           associated soil microbial ecology
    • Abstract: In this study, biochar was produced from three biomass feedstocks such as fruits of Cassia fistula and Caesalpinia sp. and barks of Eucalyptus globulus. The samples of the obtained biochar were characterized for pH, physiochemical properties, surface morphology, and surface functional groups. The obtained biochar samples were further studied with/without the combination of urea for their plant growth enhancement properties including the germination studies and effect on shoot and root growth of rice plants. Biochar produced from C. fistula fruits at 1.5% concentration increased the plant shoot height 18% higher than the control plants. Eucalyptus sp. barks’ biochar application at 0.5% concentration also increased the plant shoot height 12% longer than the control. However, the biochar produced from Caesalpinia sp. did not increase the shoot length. Yet, a generalized increase in root length was observed with the application of biochar. The combined application of nitrogen fertilizer (urea) and biochar together reverted the effect of biochar on the shoot length increase. Phospholipid-derived fatty acid (PLFA) characterization of soil revealed that soil biota shifts when soil was supplemented with the biochar. The bacterial community increased and a loss of fungal community was observed with the application of biochar.
      PubDate: 2019-06-01
       
  • From concept to practice: manufacturing of bio-lubricants from renewable
           resources
    • Abstract: The annual global oil market is about 40 million tons, including vegetable oil-based lubricants, and modified esters currently account for only about 10–15%. Half of these lubricants are getting into the atmosphere, water, and soil. That is why environmentally friendly lubricants present a rapidly expanding branch of industrial lubricants, which will become increasingly important over the next century. The aim of this work is to make a comparative analysis of fats. Animal fats and fish oil which are inappropriate for food industry were selected for the investigation purposes. The base and ferment hydrolysis were made in order to separate free fatty acids from selected fats. The produced esters, animal fats, and fish oil were studied by evaluation of their physicochemical properties. As a result, octyl esters which were produced from animal fats and fish oil are ascribed to 22, fish fats to 32, and animal fats to 46 classes.
      PubDate: 2019-06-01
       
  • Impact of time on yield and properties of biocrude during downstream
           processing of product mixture derived from hydrothermal liquefaction of
           microalga
    • Abstract: This paper is a study on effects of separation procedures on yield and characteristics of biocrude derived from hydrothermal liquefaction (HTL) of Tetraselmis sp. microalgae. The algae was grown and cultivated in outdoor open raceway ponds. The HTL experiments were performed using 1 l custom built high pressure–temperature reactor with inbuilt magnetic stirrer. HTL experimental studies were conducted at reaction temperature of 350 °C and 15 min holding time using alga solids loading of 16 w/v%. HTL product mixture diluted with dichloromethane (ratio 1:1) was allowed to stand for 1 h, 3 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h and 15 h at room temperature. The result showed that varying stand times for product mixture separation influenced yields in biocrude, solid residue and dissolved aqueous solids. Biocrude yields were in the range of 30 wt% to 56 wt% characterised with higher heating value of ~ 35 to 37 MJ/kg and hydrogen to carbon atomic ratios of 1.56 to 1.95. Maximum yield of biocrude was obtained after 9 h stand time for product mixture and dichloromethane (PM–DCM) mixture. Although, varying PM–DCM mixture stand times showed variation in product yields, there was no clear trend in distribution of elemental contents. Majority of alkali metals distributed in aqueous phase and solid residue, which could be used as nutrients, an alternative to conventional fertiliser.
      PubDate: 2019-06-01
       
  • Energy performance comparisons and enhancements in the sugar cane industry
    • Abstract: In this study, energy-related operational parameters for modern and traditional (conventional) sugar mills are analyzed, with the goals of identifying improvements in energy efficiency and potential for surplus electricity export. Results show that the power-to-heat ratio of modern and traditional mills is clearly distinct, lying in the ranges of 0.3–0.5 and 0.04–0.07, respectively. Modifications under consideration for the traditional mills include the following upgrades: electric drives and higher capacity back-pressure turbine (case 1); high-pressure boiler, condensing extraction steam turbine and electric drives (case 2); and improvements in case 2 plus bagasse drying (case 3). The thermodynamic impact of these modifications shows that more power is generated as the modification becomes more advanced. Case 1 exhibits a modest increase in cogeneration efficiency (4%) as compared to the base case, while the cogeneration efficiency increase is more marked for cases 2 and 3 (21% and 31%, respectively). Surplus power was studied in a regional context, where it was found that the contribution of 19 retrofitted sugar mills in nine Brazilian regions could supply 30% or more power as compared to current installed power capacity. The economic analysis showed that levelized cost of electricity (LCOE) was lowest for case 1 (11 USD/MWh) and highest for cases 2 and 3 (58 USD/kWh).
      PubDate: 2019-06-01
       
  • Biofuel consisting of wheat straw–poplar wood blends: thermogravimetric
           studies and combustion characteristic indexes estimation
    • Abstract: Renewable energies can play an important role reversing the current fossil fuels dependence. Among these, biomass is finding more uses consolidating itself as the energy of the future. Current trend is focused on the manufacture of new blends able to achieve a better use of this biomass. The aim of this paper was to assess the potential as fuel of a series of blends consisting of wheat straw and poplar wood fertilized in organic way. Different poplar clones were fertilized with two organic amendments derived from sewage plants. Thus, the effect of clones and fertilization on the thermal behavior of the blends was studied. For this purpose, fuel and thermogravimetric analysis as well as combustion characteristic indexes were used. Results denoted acceptable fuel analysis values. Thermogravimetric profiles showed three mass losses related to volatiles (550 K and 650 K) and char (700 K) liberation. The greatest mass release for blends occurred for the first stage. In particular, the blend consisting of AF8 poplar clone without fertilizer together with straw was the one that experienced this greater release. In the same way, thermal indexes warned of better thermal behavior when fertilizer was not applied; being, again, the blend mentioned above, the one that achieved the best indexes values. Thus, fertilization decreased the thermal performance of wheat straw–poplar wood blends.
      PubDate: 2019-06-01
       
  • Optimization of process parameters and estimation of kinetic parameters
           for lactic acid production by Lactobacillus casei MTCC 1423
    • Abstract: Central composite rotatable design was employed for the optimization of process parameters for maximizing the production of lactic acid (LA) by Lactobacillus (Lb.) casei MTCC 1423 from sugarcane molasses. The optimized conditions obtained were sugar concentration 190 g/L, CSL content 2.75% (v/v), pH 6.75, incubation temperature 38 °C, and incubation time 59.5 h with predicted 119.45 g/L maximal LA production. Validation experiments using these optimized condition has resulted in 120.23 ± 2.21 g/L lactic acid production. A Monod model and kinetic model proposed by Luedeking and Piret were considered to obtain kinetic parameters of relevance. Maximum specific growth rate (μmax.), Monod’s constant (Ks) and substrate inhibition constant (Ki) were determined as 0.7163 ± 0.0058 (h−1), 0.6203 ± 0.0013 (g/L), and 362.75 ± 0.76 (g/L), respectively. Maximum biomass concentration 14.98 ± 0.32 g/L (cell dry weight, CDW) under the optimized condition was found. The growth cell yield, YX/S (g/g) and product yield, YP/S (g/g) were determined as 0.3289 ± 0.0012 (g/g) and 0.9194 ± 0.0078 (g/g), respectively under the optimized conditions. Under the optimized condition obtained, growth (α) and non-growth associated constant (β) values were found as 0.4231 ± 0.0194 (gLA/gcells) and 0.1517 ± 0.0022 (gLA/gcells-h), respectively, demonstrating (since α/β > 1.0) that lactic acid production by Lb. casei MTCC 1423 was more contributed by growth associated segment as compared to non-growth associated segment and was directly proportional to concentration not depending on their growth. Kinetic parameter values at optimized conditions for sugar consumption, γ, η, and maintenance factor, m were obtained as 3.492 ± 0.0061 (gLA/gcells), 0.1663 ± 0.00528 (gsugar/gcells-h), and 0.00142 ± 0.0022 (gsugar/gcells-h), respectively.
      PubDate: 2019-06-01
       
 
 
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