Subjects -> CHEMISTRY (Total: 997 journals)
    - ANALYTICAL CHEMISTRY (59 journals)
    - CHEMISTRY (723 journals)
    - CRYSTALLOGRAPHY (22 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (45 journals)
    - ORGANIC CHEMISTRY (49 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (723 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 20)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 34)
ACS Applied Polymer Materials     Hybrid Journal   (Followers: 9)
ACS Catalysis     Hybrid Journal   (Followers: 71)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 26)
ACS Combinatorial Science     Hybrid Journal   (Followers: 24)
ACS Macro Letters     Hybrid Journal   (Followers: 32)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 50)
ACS Nano     Hybrid Journal   (Followers: 432)
ACS Photonics     Hybrid Journal   (Followers: 19)
ACS Symposium Series     Full-text available via subscription   (Followers: 4)
ACS Synthetic Biology     Hybrid Journal   (Followers: 35)
Acta Chemica Iasi     Open Access   (Followers: 8)
Acta Chimica Slovaca     Open Access   (Followers: 4)
Acta Chimica Slovenica     Open Access   (Followers: 2)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access   (Followers: 1)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 9)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 9)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 11)
Adsorption Science & Technology     Open Access   (Followers: 9)
Advanced Electronic Materials     Hybrid Journal   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 76)
Advanced Journal of Chemistry, Section A     Open Access   (Followers: 17)
Advanced Journal of Chemistry, Section B     Open Access   (Followers: 16)
Advanced Science Focus     Free   (Followers: 7)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 4)
Advanced Therapeutics     Hybrid Journal   (Followers: 1)
Advances in Chemical Engineering and Science     Open Access   (Followers: 98)
Advances in Chemical Science     Open Access   (Followers: 41)
Advances in Chemistry     Open Access   (Followers: 35)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 22)
Advances in Drug Research     Full-text available via subscription   (Followers: 27)
Advances in Environmental Chemistry     Open Access   (Followers: 10)
Advances in Enzyme Research     Open Access   (Followers: 12)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 19)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 35)
Advances in Nanoparticles     Open Access   (Followers: 20)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Polymer Science     Hybrid Journal   (Followers: 51)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 21)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 7)
Advances in Science and Technology     Full-text available via subscription   (Followers: 17)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 5)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 3)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 4)
Alchemy : Jurnal Penelitian Kimia     Open Access   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 70)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 23)
American Journal of Chemistry     Open Access   (Followers: 39)
American Journal of Plant Physiology     Open Access   (Followers: 14)
American Mineralogist     Hybrid Journal   (Followers: 16)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 40)
Angewandte Chemie     Hybrid Journal   (Followers: 220)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 326)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 4)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 6)
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: 13)
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: 12)
Applied Spectroscopy     Full-text available via subscription   (Followers: 28)
Applied Surface Science     Hybrid Journal   (Followers: 35)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Applied Chemistry Research     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemical Sciences     Open Access   (Followers: 1)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 8)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 6)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 462)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
Bioinspired Materials     Open Access   (Followers: 6)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 3)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 4)
Biomacromolecules     Hybrid Journal   (Followers: 25)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 11)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 209)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 90)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 19)
Biosensors     Open Access   (Followers: 3)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
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: 26)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 4)
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: 13)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 76)
Catalysis for Sustainable Energy     Open Access   (Followers: 11)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 12)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 16)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 3)
ChemCatChem     Hybrid Journal   (Followers: 9)
Chemical and Engineering News     Free   (Followers: 24)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 86)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 27)
Chemical Physics Letters : X     Open Access   (Followers: 4)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 25)
Chemical Reviews     Hybrid Journal   (Followers: 254)
Chemical Science     Open Access   (Followers: 38)
Chemical Science International Journal     Open Access   (Followers: 1)
Chemical Technology     Open Access   (Followers: 58)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
ChemInform     Hybrid Journal   (Followers: 9)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 31)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 217)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 20)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 24)
Chemistry Central Journal     Open Access   (Followers: 5)
Chemistry Education Research and Practice     Free   (Followers: 7)
Chemistry Education Review     Open Access   (Followers: 6)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 48)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 326)
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)
ChemistrySelect     Hybrid Journal  
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
ChemNanoMat     Hybrid Journal   (Followers: 1)
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access   (Followers: 1)
ChemPhotoChem     Hybrid Journal  
ChemPhysChem     Hybrid Journal   (Followers: 13)
ChemPlusChem     Hybrid Journal   (Followers: 2)
Chempublish Journal     Open Access   (Followers: 1)
ChemSystemsChem     Hybrid Journal   (Followers: 2)
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: 13)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Ciencia     Open Access   (Followers: 1)
Clay Minerals     Hybrid Journal   (Followers: 9)
Cogent Chemistry     Open Access   (Followers: 3)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 12)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
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)
Communications Materials     Open Access   (Followers: 3)
Composite Interfaces     Hybrid Journal   (Followers: 10)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)

        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: 11  
 
  Partially Free Journal Partially Free Journal
ISSN (Print) 2190-6815 - ISSN (Online) 2190-6823
Published by Springer-Verlag Homepage  [2626 journals]
  • Synergistic effect of ultrasonic and microwave pretreatment on improved
           biohydrogen generation from palm oil mill effluent
    • Abstract: Abstract This study aims to investigate the effect of the ultrasonic, microwave, and combined ultrasonic-microwave pretreatment of palm oil mill effluent (POME) sludge before fermentation to analyze hydrogen (H2) production and chemical oxygen demand (COD) removal efficiency in batch fermentation. Experimental results showed that the pretreatment of sludge (ultrasonication, microwave, and ultrasonication-microwave pretreatment) had positively influence the H2 production and COD removal efficiency during fermentation as compared to control one (without any pretreatment). Combined ultrasonication-microwave pretreatment of POME sludge was shown to be more effective for increasing both H2 production and COD removal from POME with the highest cumulative H2 and COD removal efficiency of 4080 mL H2/L-POME and 75.56%, respectively. The improvement observed for cumulative H2 production and COD removal was 12.14% and 21.42%, respectively, compared to the control one. These observations concluded that the POME sludge pretreatment with ultrasonication-microwave irradiation could be an effective strategy for improved treatment of POME with simultaneous production of H2.
      PubDate: 2021-01-12
       
  • Machine learning prediction of higher heating value of biomass
    • Abstract: Abstract Recently, biomass sources are important for energy applications. There is need for analyzing of the biomass model based on different components such as carbon, ash, and moisture content since the biomass sources are important for energy applications. In this paper, an extreme learning machine (ELM) is used to estimate efficiency. ELM was implemented for single-layer feed-forward neural network (SLFN) architectures. Because biomass modeling could be a very challenging task for conventional mathematical, it is suitable to apply machine learning models which could overcome nonlinearities of the process. The main attempt in this study was to develop a machine learning model for prediction of the higher heating values of biomass based on proximate analysis. According the prediction accuracy (coefficient of determination and root mean square error) of the higher heating value of the biomass, the inputs’ influence was determined on the higher heating value. According to the obtained results, fixed carbon has less moderate coefficient, ash has less correlation coefficient, and volatile matter has the most correlation coefficient. Therefore, the volatile matter percentage weight has the highest relevance on the higher heating value of the biomass. On the contrary, the ash has the smallest relevance on the higher heating value of the biomass based on machine learning approach.
      PubDate: 2021-01-12
       
  • Simultaneous production of astaxanthin and lipids from Chlorella
           sorokiniana in the presence of reactive oxygen species: a biorefinery
           approach
    • Abstract: The current study aimed to investigate the concurrent production of astaxanthin and lipids using Chlorella sorokiniana under mixotrophic conditions in an external loop airlift photobioreactor (ELAPB). Supplementation of Fe2+ into the media in the red phase (stress phase) induced the astaxanthin production. The maximum yield of 154.36 mg L−1 was obtained by the end of the red phase, which is equivalent to 3.4% of the dry biomass weight. The role of reactive oxygen species in the formation of astaxanthin, which protects the microalgal cells from different oxidative stress, has been elucidated. Apart from astaxanthin, unsaturated fatty acids (81.34%) were also produced with excellent biodiesel properties. Unsaturated fatty acids viz., palmitoleic acid (16:1), have resulted in high yields (22.85%), followed by linoleic acid (18:2), 28.27%; oleic acid (C18:1), 14.38%; and eicosapentaenoic acid (20:5), 4.49%. Hence, the simultaneous production of high value-added products, viz., astaxanthin, and lipids makes the whole process economically viable and environmentally sustainable and elevates the commercial potential during scale-up. The astaxanthin radical scavenging activity was also assessed by H2O2 assay, and the maximum scavenging activity was determined as 91%. The study confers the potential advantages of algal cultivation for high-value commercial product synthesis towards additional revenue generation and development of an efficient microalgae-based biorefinery process. Graphical abstract
      PubDate: 2021-01-12
       
  • Optimization of steam explosion parameters for improved biotechnological
           use of wheat straw
    • Abstract: Abstract Using lignocellulosic raw materials as substrate for biotechnological applications has been a focus of research during the last two decades. They contain sugars, which can be used in industrial fermentation processes, in from of polysaccharides (cellulose, hemicellulose). Wheat straw, one representative of lignocellulosic materials, is sustainably and abundantly available, especially in Europe and North America. However, wheat straw, just like any other lignocellulosic material, needs to be pretreated in one way or the other in order to generate sufficient quantities of monosaccharides. One widely used pretreatment for lignocellulosic material is steam explosion combined with enzymatic hydrolysis. In this study, the effects of steam exploding wheat straw in combination with water are presented. By impregnation with water, saccharide yields from subsequent enzymatic hydrolysis increased from 18.8 to 22.6 g L−1 for glucose and 13.8 to 16.4 g L−1 for xylose, respectively. Moreover, the basic steam explosion parameters residence time and temperature were optimized in ranges from 5 to 20 min and 180–200 °C. This further optimization increased the maximum saccharide yield to 41.2 g L−1 for glucose (200 °C, 15 min) and 18.9 g L−1 for xylose (190 °C, 10 min). Finally, the growth of the intensively investigated biotechnological production host Yarrowia lipolytica on hydrolysates derived from different steam explosion parameters was evaluated. Y. lipolytica grew well in media containing up to 90% wheat straw hydrolysate as sole carbon source, demonstrating the potential as substrate for biotechnological processes.
      PubDate: 2021-01-12
       
  • Fiber characterization of old corrugated container bleached pulp with
           laccase and glycine pretreatment
    • Abstract: Abstract In response to deal with the increasingly serious environmental problems and shortage of fiber raw materials, biological enzyme pretreatment is an effective way to replace a large number of chemical additives to improve the properties of waste paper fibers. Fiber characterization of old corrugated container bleached pulp with laccase and glycine (Lac/Gly) pretreatment was investigated by means of Fourier transform infrared spectroscopy (FTIR), headspace gas chromatography (HSGC), fiber quality measurements (FQA), X-ray diffraction method (XRD), and atomic force microscope (AFM). Results showed that, compared with the control pulp, the whiteness and brightness of the Lac/Gly-treated pulp increased by 16.17% and 7.41%, respectively. And the FTIR showed that Lac/Gly pretreatment promotes the effective removal of lignin by hydrogen peroxide (H2O2) bleaching. The content of carboxyl groups in pulp increased remarkably by 21.92%. The paper physical analysis showed that the paper strength properties have improved remarkably. The fiber quality analyses indicated that the fiber length, coarseness, and curl index changed a little. The XRD analysis showed that the crystallinity decreased by 5.83% due to Lac/Gly treatment. The AFM analysis showed that through Lac/Gly treatment, the lignin and extracts over the fiber surface are decreased significantly.
      PubDate: 2021-01-11
       
  • Convective drying of Moringa oleifera seeds: kinetics modelling and
           effects on oil yield from different extraction techniques
    • Abstract: Abstract This work shows the convective drying kinetics of moringa seeds (Moringa oleifera L) at different drying temperatures 40, 50, 60, 70, and 80 °C and the effect drying on the extracted oil yield. Four simplified models were fitted to the kinetics data, and a phenomenological mathematical model (PMM) was developed to describe the process. The simplified model that better represented the experimental data was Verma, with a global relative mean error of 1.31%. The PMM with the use of an equilibrium boundary condition at the surface produced better results than those obtained when considering the convective condition, indicating that the effects of external mass transfer resistance are neglected. The moringa oil was extracted from all dried seeds conditions using different extraction techniques, such as Soxhlet technique, ultrasound-assisted, and mechanical extraction; and the maximum oil yield obtained for dry seeds was 43.06%, 31.53%, and 24.93% respectively. All drying temperatures of the moringa seed do not show influence the oil yield obtained in each extraction method used.
      PubDate: 2021-01-11
       
  • Valorizing municipal organic waste to produce biodiesel, biogas, organic
           
    • Abstract: Economically viable alternatives for utilizing municipal solid waste are still a major challenge for society, especially in less developed countries. A potential pathway is using the organic fraction of municipal solid waste (OFMSW) to produce energy, biofuels, organic fertilizers, and value-added chemical compounds. We evaluated an integrated biorefinery structure for the treatment of used cooking oil, pruning biomass, and organic and food residues to produce biodiesel, biogas, organic compost, 1,3-propanediol, and electrical energy at the campus of the Federal University of Pernambuco, which was considered a case study to represent a small city of Northeastern Brazil. A pilot transesterification plant, a biodigestion unit, and a compost unit were installed to process 3.3 tons daily of OFMSW produced. Additionally, research was carried out to produce 1,3-propanediol on a laboratory scale from residual glycerol. The quality of the biodiesel generated from the used cooking oil met national technical standards and the conversion of residual oil into biodiesel reached 93%. The average biogas production was 0.584 ± 0.176 Nm3 kgVS−1, with an average methane production of 50% generating up to 44 MWh of electricity per year. The organic compost produced met the quality requirements of organic fertilizers, such as maturation and nutrient contents. Glycerol treatment increased the yield of 1,3-propanediol production. Our findings demonstrate that the integrated biorefinery will lead to a reduction of US$ 80,000 in the costs of OFMSW management. More importantly, this approach generates incentives for circular economy initiatives in small municipalities in Brazil and other less developed countries. Graphical abstract
      PubDate: 2021-01-11
       
  • Metal nanoparticle mixtures to improve the biogas yield of cattle manure
    • Abstract: Abstract Metal nanoparticle elements such as Fe, Ni, and Co are promising in improving the performance and stability of anaerobic digestion. However, the impact of nanoparticle mixtures of Fe, Ni, and Co on biogas production from anaerobic digestion of cattle manure still needs further studies. Therefore, this study investigated the effect of the most effective concentrations of nanoparticle additives on biogas and CH4 production and H2S mitigation during anaerobic digestion of cattle manure. The nanoparticle additive concentrations were selected from the findings of previous studies and were 30 mg/L Fe, 2 mg/L Ni, and 1 mg/L Co at four combinations. Biogas production increased by 14.61% upon the use of nanoparticle mixtures of 30 mg/L Fe and 2 mg/L Ni compared with control (cattle manure-only). Furthermore, the addition of nanoparticle mixtures of 30 mg/L Fe, 2 mg/L, and 1 mg/L Co increased CH4 production by 19.30% compared with control. Moreover, H2S production decreased by 35.10% in the presence of nanoparticles mixture of 30 mg/L Fe, 2 mg/L, and 1 mg/L Co in comparison with control. Modified Gompertz and logistic function models were used to determine the kinetic constant of the reaction. The modified Gompertz model has the better predicting ability for cattle manure anaerobic digestion.
      PubDate: 2021-01-11
       
  • A mathematical model for optimizing a biofuel supply chain with
           outsourcing decisions under the carbon trading mechanism
    • Abstract: Abstract Carbon trading is a market-based mechanism for controlling carbon emissions by providing economic incentives to reduce emissions. In recent years, there has been an increasing interest in modeling supply chain networks under this scheme; however, to date, only a limited number of researchers have investigated the implication of this mechanism for biofuel supply chains. The optimization model presented in this paper examines a trade-off between the cost of trading carbon credits and costs associated with outsourcing of the biomass pretreatment process when carbon emissions exceed the predetermined carbon cap in a biofuel supply chain. To demonstrate the applicability of the model, we analyzed challenges in supplying different sources of biomass to two biorefinery plants and shipping the produced biofuels to multiple demand zones. The results showed that carbon emission reductions have a relatively nonlinear pattern when the carbon credit price increases linearly. Furthermore, we presented significant managerial and policy insights on the impact of different carbon emission caps on total costs and total emissions. Moreover, we analyzed the cost adjustment between trading carbon credits and outsourcing decisions for different carbon cap settings. This paper ends with suggestions for further development of the presented model for future researches.
      PubDate: 2021-01-10
       
  • Biochemical characteristics of a novel ethanol-tolerant xylanase from
           Bacillus subtilis subsp. subtilis JJBS250 and its applicability in
           saccharification of rice straw
    • Abstract: Abstract The present study reports the partial purification and characterisation of a novel xylanase from Bacillus subtilis subsp. subtilis JJBS250 followed by its applicability in the saccharification of rice straw. Bacterial xylanase was partially purified by gel filtration chromatography using Sephadax G-50 matrix that displayed optimal activity at 60 °C and pH 7.0 with half-life values of 1420 and 718 min at 60 °C and 80 °C, respectively. Bacterial xylanase showed high tolerance to ethanol with Km and Vmax values of 1.62 mg/ml and 23.92 U/ml, respectively, for beechwood xylan. Maximum amount of reducing sugars was obtained from sodium carbonate pretreated rice straw (151.65 mg/g substrate) as compared to untreated biomass (90.49 mg/g substrate) using 20 U/g enzyme dose at 60 °C and pH 7.0 after 48 h. Furthermore, the saccharification of pretreated rice straw was improved by synergistic action of bacterial and fungal xylanases. Analysis of rice straw using scanning electron microscopy (SEM), x-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy clearly showed the morphological changes and delignification in rice straw after pretreatment. Bacterial xylanase exhibiting novel properties including ethanol tolerance and high thermostability is highly suitable for the production of second generation biofuels in simultaneous saccharification and fermentation process using lignocellulosic substrates.
      PubDate: 2021-01-09
       
  • Enzymatic deinking of office waste printed paper: optimization via
           response surface methodology
    • Abstract: Abstract In traditional deinking process, large amounts of chemicals are required which makes these methods expensive and polluting. Also, application of sustainable material implies the use of green processes to reduce waste and pollution. Green enzymatic deinking processes are alternatives to those technologies that have negative effects on the environment. In this work, we applied response surface methodology for deinking the electrophotography-printed paper based on a systematic experimental pattern. The individual and interactive effects of enzymatic deinking parameters including time, temperature, and enzyme dosage on the handsheet properties were investigated. Different analyses were carried out to determine the best process conditions of enzymatic deinking to optimize the handsheet properties (i.e., tensile, burst, whiteness, and brightness). The obtained responses of an oven-dried fiber at 45 min, 43 °C and the enzyme concentration of 1 mg/15 g were 12.44, 0.65, 72.20, and 87 for tensile strength, burst strength, whiteness, and brightness, respectively. Measuring the optical density of the deinked handset after printing showed that the printability of the deinked paper is in the desired range.
      PubDate: 2021-01-09
       
  • Role of organosolv pretreatment on enzymatic hydrolysis of mustard biomass
           for increased saccharification
    • Abstract: Abstract This study focusses mainly on assessing the effectiveness of acetone organosolv process as a pretreatment strategy on mustard (Brassica juncea) biomass. We used aqueous acetone as the solvent and sulfuric acid as a catalyst for ease of cellulosic saccharification. The acetone organosolv pretreatment of mustard straw and stalk (MSS) biomass was investigated for the effect of acetone concentration (SC), acid catalyst concentration (AC), and treatment duration (t) using a full factorial design of the experiment and subsequent Pareto analysis of their effects. The 23 full factorials design contained 12 runs, each of which was deployed to pretreat weighed amount of MSS biomass. Each of the different products of these 12 runs was further saccharified using cellulase enzyme produced by Trichoderma reesei. Among the variables, the time has a pronounced effect during pretreatment on glucose yield. Since the increase in time from 30 to 90 min caused an increase of 3.39 g/L in glucose concentration, the increase in acid catalyst concentration from 0.2 to 0.4% caused an increment of 0.7 g/L in glucose content, while the rise in acetone concentration from 50 to 80% caused an increment of 0.44 g/L in glucose concentration. The reducing sugars generated after hydrolysis of MSS biomass can be utilised for the production of bioethanol by Saccharomyces cerevisiae. The FTIR data and SEM studies of untreated and treated MSS biomass were performed to indicate the pretreatment of the MSS biomass. Therefore, after pretreatment MSS biomass can be an alternative substrate for bioethanol production. This study is an attempt to promote the valorization of widely available MSS biomass for bioethanol production by using a statistically optimized process.
      PubDate: 2021-01-08
       
  • Bioremediation of hexavalent chromium-contaminated wastewater by Bacillus
           thuringiensis and Staphylococcus capitis isolated from tannery sediment
    • Abstract: The widespread use of hexavalent chromium Cr(VI) in the leather industry causes substantial environmental problems when effluents are left untreated. Therefore, the present work attempts to assess the ability of Bacillus thuringiensis (V45) and Staphylococcus capitis (S21), isolated from tannery industry sediment, to detoxify Cr(VI) by reducing the oxidation state. Initially, the minimum tolerance of chromium by both bacteria was found up to 1000 μg/mL. V45 could tolerate Cr(VI) (520 μg/mL), and S21 could also tolerate hexavalent Cr(VI) (340 μg/mL). Similarly, both bacteria were able to tolerate other metals such as Hg2+ (40 μg/mL), Cu2+ (30 μg/mL), Ni2+ (60 μg/mL), Zn2+ (40 μg/mL), and Pb2+ (30 μg/mL). V45 and S21 could decrease Cr(VI) at a primary concentration of 50 μg/mL up to 86.42% and 97.34%, respectively. In optimization experiments, the best temperature to decrease Cr(VI) was shown to be 35 °C with pH 7 for 96 h. The occurrence of Cu2+ and Na+ slightly increased during the decrease of hexavalent Cr(VI) by V45, while the isolate S21 exhibited the same effects with Cu2+, Mn2+, and Na+. The carboxylate and amino conjugates in the biomass are intricate in the bioreduction of Cr(VI), as confirmed by FTIR spectroscopy. In addition, SEM imagery revealed the accumulation of Cr(VI) around both types of bacterial cells. The occurrence of other elements was evident from SEM-EDS spectroscopy. This study demonstrated the ability of native bacterial populations (V45 and S21) in tannery sediment to reduce Cr(VI) compounds. Graphical abstract
      PubDate: 2021-01-08
       
  • Acid-catalyzed fractionation of almond shells in
           γ-valerolactone/water
    • Abstract: Abstract The fractionation of almond shells, an agro-industry residue available in some Mediterranean climate regions, was investigated using acid-catalyzed hydrolysis in γ-valerolactone (GVL)/water. A set of non-isothermal experiments at nominal temperatures of 120, 140, and 160 °C and sulfuric acid concentrations from 25 to 75 mM were developed using a constant 80% w/w GVL in water concentration and a reaction time of up to 120 min. GVL was an efficient medium and promoted solubilization of both lignin and hemicellulose, even at low temperature during the initial period of reactor heating, while cellulose conversion was limited. A temperature of 160 °C gave the highest extraction of lignin and hemicellulose, but recovery of hemicellulose carbohydrates was better below 140 °C. Sulfuric acid concentrations above 45 mM promoted excessive dehydration of xylose and glucose to furans and humins, which were recovered with lignin. A model was developed to describe the kinetics of lignin and hemicellulose solubilization. It distinguished three fractions of different reactivity in each polymer (lignin or hemicellulose): fast-reacting, slow-reacting, and unreactive. The amount of each fraction was correlated with acid concentration and reaction temperature. Activation energies and the other parameters in the model were obtained numerically by least-squares optimization using the data from the non-isothermal experiments. Activation energies for the fast-reacting and slow-reacting fractions of hemicellulose were 142 and 39.7 kJ mol−1, and for those of lignin 134 and 71.7 kJ mol−1, respectively. Acid concentration had a larger influence than temperature on establishing the amounts of slow-reacting hemicellulose and lignin, whereas temperature was the dominant variable concerning the fractions of non-reacting polymers.
      PubDate: 2021-01-08
       
  • Graphene oxide–coated pyrolysed biochar from waste sawdust and its
           application for treatment of cadmium-containing solution: batch, fixed-bed
           column, regeneration, and mathematical modelling
    • Abstract: Abstract Cadmium being a heavy metal, which is also a known pollutant, had a wide variety of usage in many industries like electro-plating industries, phosphate fertilizers, batteries, mining, stabilizers, pigments, and alloys. In this study, sawdust was used to produce the nanocoated adsorbent. Sawdust is non-hazardous low-cost waste materials and easily available. Thermally activated biochar was produced from sawdust and coated with graphene oxide nanomaterials in two different methods, and the synthesized nanocomposite was used to remove cadmium present in solution. Batch study was performed to optimize different parameters for better removal. Experiments were performed and the best condition optimized for removal of cadmium was found to be pH 7.5 and temperature 35 °C or 308.15 K, with 1 g/L adsorbent dose, and within 2 h, i.e. 120 min, above 55.68 mg/g removal capacity was attained with initial metal concentration of 50 mg/L. The modified saw dust composite was more effective in removal of cadmium than the normal sawdust-based composites. The characterization of the nanocomposite was done to know the internal structure of the composite. The continuous fixed-bed column study was performed, and the study followed Admas–Bohart model. The batch and column study results showed that this nanocoated composite can be an alternative for the treatment of pollutant present in the solution. The regeneration of the composite showed a sustainable use of the composite for the treatment of pollutant.
      PubDate: 2021-01-08
       
  • Synergistic effect of acidity balance and hydrothermal pretreatment
           severity on alkali extraction of hemicelluloses from corn stalk
    • Abstract: Abstract The current hemicelluloses extraction methods have problems such as low extraction ratio and quality. In the previous study, a new pH pre-corrected hydrothermal pretreatment has been proved effective in improving enzymatic hydrolysis of cellulose while retaining higher hemicelluloses without degradation. In this investigation, the synergistic effect of alkali loading and hydrothermal pretreatment severity on hemicelluloses preservation was studied. After pretreatment, the hemicelluloses were extracted with alkali. The results show that hemicelluloses extracted with 10% (w/v) NaOH after pH pre-corrected hydrothermal pretreatment at the severity of 2.0 contained no cellulose. At this condition, the ratios of hemicelluloses dissolution and recovery were the highest. The extracted hemicelluloses had the lowest color value, branch degree, and polydispersity.
      PubDate: 2021-01-08
       
  • Euphorbia tirucalli stem bark and phylloclades’ oil quality variability
           and implication for energy use
    • Abstract: Abstract Liquid biofuels have emerged as a worldwide alternative fuel with potential to replace fossil fuels. Due to their wide availability as derivatives of organic materials from plants, they have attracted much attention and investment in developing countries including Tanzania, as alternative sources of energy. This study examined effects of oil quality from stem barks and phylloclades of Euphorbia tirucalli trees of different girth sizes (viz., 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, and 80 cm) from semi-arid, coastal, and southern highlands in Dodoma, Dar es Salaam, and Mbeya Southern highland, agro-ecological zones in Tanzania. Using Soxhlet extraction method, oils were extracted from E. tirucalli stem barks with different girth sizes while oils from phylloclades were extracted from matured apical phylloclades collected from shoots of E. tirucalli trees from which the stem bark samples had been collected. Oil yields were determined by measuring the weight of oil (g) by the total weight of sample extracts used (20 g), and the average oil yield on each sample was determined. Oil quality was evaluated as oxidative stability index (OSI), acid values (AVs), and percent free fatty acids (%FFAs). Their results were then compared with the European Union (EU) oil quality standard specifications prescribed in EN 14214 of 6 h, 0.5 mg KOH/g, max and 0.020 maximum wt% limits, respectively. Differences in the quality of E. tirucalli (stem bark and phylloclades) oil were analyzed statistically with paired-sample t test (two-tailed) using the SPSS 15.0 software package. Results showed that the difference in OSIs from stem barks were not significantly higher (3–5 h) than phylloclades (3–4 h) at the p > 0.5 level. Also, the difference in AVs and %FFAs from the stem barks (7.6–7.4 mg KOH and 3.8–3.6%) was not significantly lower than those from the phylloclades (8.4–8.1 mg KOH and 4.3–4.0%) respectively. The quality of oil from stem bark and phylloclades samples at different stem girth sizes semi-arid agro-ecological zone was not significantly higher than from southern highland and coastal agro-ecological zones, respectively. Thus, there were no significant differences in the quality of E. tirucalli oil (stem bark and phylloclades) among stem girth sizes in different agro-ecological zones. The AVs and %FFAs of oils from stem bark and phylloclades were higher than the recommended standards, while the OSIs were below the biofuel standard limit. High AVs and %FFAs reduced oil quality by producing considerably low OSIs values than recommended standards. Finally, the study concluded that E. tirucalli oil requires purification to reduce levels of AV and %FFA contents so that the oil becomes suitable for application as liquid biofuel for energy generations.
      PubDate: 2021-01-08
       
  • Synthesis and kinetics study of trimethylolpropane fatty acid triester
           from oleic acid methyl ester as potential biolubricant
    • Abstract: Abstract The use of trimethylolpropane triesters as biodegradable lubricant base oil substitute mineral oils could significantly reduce the environmental pollution. In the present work, a commercial oleic acid (72% C18) was utilized as a precursor for the manufacture of trimethylolpropane triesters (TMPTE) through a two-step transesterification process. Oleic acid methyl ester (OME) produced from the first step was subsequently interacted with trimethylolpropane (TMP) using sodium methylate to produce TMPTE. The effect of the operating parameters, temperatures (90 °C, 100 °C, 110 °C, 120 °C, and 130 °C), molar ratio of OME to TMP (3:1, 4:1, 5:1, and 7:1), vacuum pressure (20, 50, 100, and 200 mbar), and catalyst amount (0.5, 0.7, 0.9, and 1.1(w/w)) was investigated. Under the selected reaction conditions (temperature 120 °C, oleic acid methyl ester to trimethylolpropane molar ratio 4:1, catalyst amount 0.9%w/w, vacuum pressure 20 mbar and reaction time 2 h), the final product composition was approximately 85.47% TMPTE, 10.80% TMPDE, 1.40%TMP ME, and 2.33% OME. The kinetics/mathematical model explains the chemical kinetics of transesterification of oleic acid methyl esters (OME) with trimethylolpropane (TMP) to produce biolubricant which has been investigated at temperature 120 °C. To support forward reaction, the excess amount of OME was increased by 10:1 (OME/TMP). The kinetic model suggested for the transesterification process of OME with TMP in this work based on three reversible series-parallel reaction mechanisms. The kinetics equations were solved using LINGO PROGRAM. A harmony between the experimental data and theoretically estimated values was achieved.
      PubDate: 2021-01-08
       
  • Editorial to the special thematic issue “Advances in Thermo-chemical
           Gasification of Biomass and Syngas Applications” with selected
           contributions from the “International Conference on Polygeneration
           Strategies 2019” (ICPS19)
    • PubDate: 2021-01-07
       
  • Material flow of cellulose in rice straw to ethanol and lignin recovery by
           NaOH pretreatment coupled with acid washing
    • Abstract: Abstract Agricultural residues could become feedstocks for biobased products as they are renewable, carbon neutral, and do not compete with food. In India, > 130 MT rice straw is available annually for alternate uses. Exploiting this abundant biomass for biochemical production will pave way for bio-based economy. Rice straw is highly recalcitrant due to lignin-carbohydrate complex and high ash. For production of value added products, the cellulose fraction is very important and also lignin can be used. However, for overall economic efficiency, it is imperative to separate and recover these fractions maximally from biomass and convert them into high value products at high titers and efficiency. Biomass has to be deconstructed to access these fractions. An improvised pretreatment with sodium hydroxide (NaOH) coupled with acidified water wash enabled high retrieval of cellulose and lignin. More than 80% of cellulose present in raw rice straw was recovered in pretreated solids and lignin (> 65%) recovered from acidification of alkali prehydrolysates/wash waters. Enzymatic hydrolysis of solids with commercial cellulases resulted in 80–100% glucan conversion at 6% and 3% loading respectively yielding ~ 5.5% and 3.3% sugar syrups which can be fermented to value added chemicals. Saccharomyces cerevisiae LN fermented hydrolysates with 77–97% efficiency producing 0.508 gg−1 and 0.403 gg−1ethanol within 24 h consuming all glucose while xylose was unutilized. Material calculations showed that this process converted 63% of cellulose present in rice straw to ethanol potentially yielding 135 L ethanol and ~ 100 Kg lignin per ton of rice straw with limited water use.
      PubDate: 2021-01-07
       
 
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