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Topic Editors

College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China
College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China
Prof. Dr. Shifeng Zhang
Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China
College of Materials Science and Technology, Nanjing Forestry University, Nanjing, China

Biomass for Energy, Chemicals and Materials

Abstract submission deadline
31 August 2025
Manuscript submission deadline
31 December 2025
Viewed by
13240

Topic Information

Dear Colleagues,

Biomass and its derived materials for energy, chemicals, and materials have attracted significant attention due to the combinations of biomass, energies, chemistry, and materials. In this field, the unique porous structures and chemical compositions of biomass can be used as a template, which is of great significance for the development of electrode materials with controllable geometry. At present, there are still challenges in the development of biomass and its derived carbon with regard to their pore formation, high value utilization, high carbon output, high energy density, high power density, and controllable nano-micro-structure, which are the main bottlenecks in the direction of electrochemical energy storage materials. It is worth noting that the doping of heteroatoms and extra redox also plays an important role in the performance of energy storage. This topic may require a clear understanding of the element composition of biomass and the inherent chemical and structural characteristics of biomass, as well as the mechanism by which organisms produce carbon materials during pyrolysis.

This topic is devoted to publishing original research papers, short communications, application notes, and critical reviews about the latest developments in the fields of the characterization of lignin, biomass and energy, chemicals, and materials. Contributions of particular interest including but not limited to the above are welcome.

Prof. Dr. Shaohua Jiang
Prof. Dr. Changlei Xia
Prof. Dr. Shifeng Zhang
Dr. Xiaoshuai Han
Topic Editors

Keywords

  • lignin
  • chemical characterization
  • chemical modification
  • de-polymerization
  • combustion
  • energy
  • biomass
  • hydrothermal liquefaction
  • bio-oils
  • bio-aromatic chemicals
  • synthesis
  • polymers
  • carbon fibers
  • composites

Participating Journals

Journal Name Impact Factor CiteScore Launched Year First Decision (median) APC
Biomass
biomass
- 2.9 2021 24.1 Days CHF 1000 Submit
Energies
energies
3.0 6.2 2008 17.5 Days CHF 2600 Submit
Materials
materials
3.1 5.8 2008 15.5 Days CHF 2600 Submit
Molecules
molecules
4.2 7.4 1996 15.1 Days CHF 2700 Submit
Nanomaterials
nanomaterials
4.4 8.5 2010 13.8 Days CHF 2900 Submit
Polymers
polymers
4.7 8.0 2009 14.5 Days CHF 2700 Submit

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Published Papers (15 papers)

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42 pages, 11308 KiB  
Review
Upgrading of Pyrolysis Bio-Oil by Catalytic Hydrodeoxygenation, a Review Focused on Catalysts, Model Molecules, Deactivation, and Reaction Routes
by Alejandra Carrasco Díaz, Lokmane Abdelouahed, Nicolas Brodu, Vicente Montes-Jiménez and Bechara Taouk
Molecules 2024, 29(18), 4325; https://doi.org/10.3390/molecules29184325 - 12 Sep 2024
Viewed by 294
Abstract
Biomass can be converted into energy/fuel by different techniques, such as pyrolysis, gasification, and others. In the case of pyrolysis, biomass can be converted into a crude bio-oil around 50–75% yield. However, the direct use of this crude bio-oil is impractical due to [...] Read more.
Biomass can be converted into energy/fuel by different techniques, such as pyrolysis, gasification, and others. In the case of pyrolysis, biomass can be converted into a crude bio-oil around 50–75% yield. However, the direct use of this crude bio-oil is impractical due to its high content of oxygenated compounds, which provide inferior properties compared to those of fossil-derived bio-oil, such as petroleum. Consequently, bio-oil needs to be upgraded by physical processes (filtration, emulsification, among others) and/or chemical processes (esterification, cracking, hydrodeoxygenation, among others). In contrast, hydrodeoxygenation (HDO) can effectively increase the calorific value and improve the acidity and viscosity of bio-oils through reaction pathways such as cracking, decarbonylation, decarboxylation, hydrocracking, hydrodeoxygenation, and hydrogenation, where catalysts play a crucial role. This article first focuses on the general aspects of biomass, subsequent bio-oil production, its properties, and the various methods of upgrading pyrolytic bio-oil to improve its calorific value, pH, viscosity, degree of deoxygenation (DOD), and other attributes. Secondly, particular emphasis is placed on the process of converting model molecules and bio-oil via HDO using catalysts based on nickel and nickel combined with other active elements. Through these phases, readers can gain a deeper understanding of the HDO process and the reaction mechanisms involved. Finally, the different equipment used to obtain an improved HDO product from bio-oil is discussed, providing valuable insights for the practical application of this reaction in pyrolysis bio-oil production. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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Figure 1
<p>Fossil fuels reserves from [<a href="#B5-molecules-29-04325" class="html-bibr">5</a>].</p>
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<p>Estimated contribution of renewables in global total energy consumption in 2021, (<b>a</b>) distribution of total energy consumption, (<b>b</b>) distribution of the renewable portion of global energy consumption, from Renewable Share of Total Final Energy Consumption 2021, adapted from [<a href="#B3-molecules-29-04325" class="html-bibr">3</a>,<a href="#B4-molecules-29-04325" class="html-bibr">4</a>,<a href="#B5-molecules-29-04325" class="html-bibr">5</a>].</p>
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<p>Classification of biomass feedstock in three generations, adapted from [<a href="#B9-molecules-29-04325" class="html-bibr">9</a>].</p>
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<p>Chemical composition of bio-oils from pyrolysis of two different feedstocks, beech wood and Flax shives, at 500 °C, adapted from [<a href="#B15-molecules-29-04325" class="html-bibr">15</a>,<a href="#B22-molecules-29-04325" class="html-bibr">22</a>].</p>
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<p>Upgrading methods of bio-oil, adapted from [<a href="#B21-molecules-29-04325" class="html-bibr">21</a>,<a href="#B24-molecules-29-04325" class="html-bibr">24</a>,<a href="#B25-molecules-29-04325" class="html-bibr">25</a>].</p>
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<p>Typical reactions involved in HDO, adapted from [<a href="#B36-molecules-29-04325" class="html-bibr">36</a>,<a href="#B58-molecules-29-04325" class="html-bibr">58</a>,<a href="#B63-molecules-29-04325" class="html-bibr">63</a>,<a href="#B64-molecules-29-04325" class="html-bibr">64</a>,<a href="#B65-molecules-29-04325" class="html-bibr">65</a>].</p>
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<p>A possible reaction mechanism for the HDO of phenol over MoS<sub>2</sub>, adapted from [<a href="#B77-molecules-29-04325" class="html-bibr">77</a>].</p>
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<p>Catalytic hydrodeoxygenation performance of m-cresol over an Ni<sub>2</sub>P/SiO<sub>2</sub> catalyst, adapted from [<a href="#B83-molecules-29-04325" class="html-bibr">83</a>].</p>
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<p>Proposed reaction pathway for HDO of guaiacol to hydrocarbons over Ni<sub>2</sub>P-based catalyst, adapted from [<a href="#B63-molecules-29-04325" class="html-bibr">63</a>,<a href="#B87-molecules-29-04325" class="html-bibr">87</a>].</p>
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<p>Possible reactions in the HDO of model molecules, adapted from [<a href="#B119-molecules-29-04325" class="html-bibr">119</a>].</p>
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<p>Reaction pathways and selectivity of aromatic products in the HDO of Guaiacol over Ni<sub>2</sub>P/SiO<sub>2</sub> at 300 °C, adapted from [<a href="#B120-molecules-29-04325" class="html-bibr">120</a>].</p>
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<p>Main reaction pathways of HDO of aldehydes and alcohols; R stands for alkyl groups, adapted from [<a href="#B124-molecules-29-04325" class="html-bibr">124</a>].</p>
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<p>Reaction pathways in the HDO of furfural according to [<a href="#B114-molecules-29-04325" class="html-bibr">114</a>]. FOL: furfuryl alcohol, MF: 2-methylfuran, THF: tetrahydrofuran, THMF: tetrahydro-2-methylfuran, THFOL: tetrahydrofurfuryl alcohol, adapted from [<a href="#B98-molecules-29-04325" class="html-bibr">98</a>].</p>
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<p>Proposed reaction scheme of the HDO of model compounds: 2-hexanone, 2-hexanol, 3-hexanone, and 3-hexanol over a NiMo/Al<sub>2</sub>O<sub>3</sub> catalyst, adapted from [<a href="#B127-molecules-29-04325" class="html-bibr">127</a>].</p>
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<p>General main reaction pathways of HDO of carboxylic acids; R stands for alkyl groups, adapted from [<a href="#B124-molecules-29-04325" class="html-bibr">124</a>].</p>
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<p>Proposed reaction network over Ni<sub>2</sub>P/Al<sub>2</sub>O<sub>3</sub> catalyst; the reaction steps are (1) Hydrogenolysis, (2) Hydrogenation, (3) Dehydration–hydrogenation, (4) Decarbonylation, (5) Decarboxylation, (6) Esterification, adapted from [<a href="#B131-molecules-29-04325" class="html-bibr">131</a>].</p>
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<p>Reaction pathways for the conversion of carbohydrates biomass-derived glucose into liquid alkanes, adapted from [<a href="#B133-molecules-29-04325" class="html-bibr">133</a>].</p>
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<p>Reaction pathways for the conversion of carbohydrates) formed by removal of oxygen atoms from hexoses (fructose), adapted from [<a href="#B134-molecules-29-04325" class="html-bibr">134</a>].</p>
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<p>Reaction scheme for the hydrodeoxygenation of phenolic compounds (phenol and m-cresol) for the Pd catalysts supported on various oxides, adapted from [<a href="#B137-molecules-29-04325" class="html-bibr">137</a>].</p>
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<p>Product distribution and major pathways of guaiacol and propionic acid transformations in HDO conditions: (1) Hydrogenolysis, (2) Hydrogenation, (3) Demethylation, (4) Demethoxylation, (5) Dehydration, (6) Etherification, (7) Esterification, adapted from [<a href="#B140-molecules-29-04325" class="html-bibr">140</a>].</p>
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<p>Major reaction pathways of eugenol and acetic acid, ethylene glycol, and furfural transformations during the HDO process, adapted from [<a href="#B141-molecules-29-04325" class="html-bibr">141</a>].</p>
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<p>Hydroprocessing castor oil by Ni-based bifunctional catalysts with variable acidity, adapted from [<a href="#B145-molecules-29-04325" class="html-bibr">145</a>].</p>
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<p>Main reaction pathways of bio-oil hydrotreatment over Ni<sub>2</sub>P/HZSM-5 catalysts, adapted from [<a href="#B64-molecules-29-04325" class="html-bibr">64</a>].</p>
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<p>TEM images of fresh and spent catalysts at different reaction temperatures, available from [<a href="#B151-molecules-29-04325" class="html-bibr">151</a>].</p>
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<p>Schematic diagram of the most common reactors used in the HDO; batch reactor (<b>a</b>) and continuous flow reactor (<b>b</b>), adapted from [<a href="#B159-molecules-29-04325" class="html-bibr">159</a>,<a href="#B161-molecules-29-04325" class="html-bibr">161</a>].</p>
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31 pages, 5843 KiB  
Review
Recent Advances in Characterization and Valorization of Lignin and Its Value-Added Products: Challenges and Future Perspectives
by Shehbaz Ali, Abida Rani, Mudasir A. Dar, Muther Mansoor Qaisrani, Muhammad Noman, Kamaraj Yoganathan, Muhammad Asad, Ashenafi Berhanu, Mukul Barwant and Daochen Zhu
Biomass 2024, 4(3), 947-977; https://doi.org/10.3390/biomass4030053 - 2 Sep 2024
Viewed by 1318
Abstract
Lignin, the earth’s second-most abundant biopolymer after cellulose, has long been relegated to low-value byproducts in the pulp and paper industry. However, recent advancements in valorization are transforming lignin into a sustainable and versatile feedstock for producing high-value biofuels, bioplastics, and specialty chemicals. [...] Read more.
Lignin, the earth’s second-most abundant biopolymer after cellulose, has long been relegated to low-value byproducts in the pulp and paper industry. However, recent advancements in valorization are transforming lignin into a sustainable and versatile feedstock for producing high-value biofuels, bioplastics, and specialty chemicals. This review explores the conversion of lignin’s complex structure, composed of syringyl (S), guaiacyl (G), and p-hydroxyphenyl (H) units, into value-added products. We critically assess various biochemical and analytical techniques employed for comprehensive lignin characterization. Additionally, we explore strategies for lignin upgrading and functionalization to enhance its suitability for advanced biomaterials. The review emphasizes key areas of lignin valorization, including catalytic depolymerization methods, along with the associated challenges and advancements. We discuss its potential as a feedstock for diverse products such as biofuels, bioplastics, carbon fibers, adhesives, and phenolic compounds. Furthermore, the review briefly explores lignin’s inherent properties as a UV protectant and antioxidant, alongside its potential for incorporation into polymer blends and composites. By presenting recent advancements and case studies from the literature, this review highlights the significant economic and environmental benefits of lignin valorization, including waste reduction, lower greenhouse gas emissions, and decreased reliance on non-renewable resources. Finally, we address future perspectives and challenges associated with achieving large-scale, techno-economically feasible, and environmentally sustainable lignin valorization. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Lignin and its interlinking with other chemical components particularly cellulose and hemicellulose contents of cell wall in plants.</p>
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<p>Chemical structures of key monolignols (coniferyl, <span class="html-italic">p</span>-coumaryl, and sinapyl alcohols) highlighting aromatic rings in lignin.</p>
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<p>Total number of articles published from 2000 to 20 June 2024 (<b>A</b>). A word-cloud analysis of the lignin valorization representing the most frequent fields of study (<b>B</b>). The data were sourced from the PubMed and Scopus databases using search items “Lignin valorization”, “Lignin biorefinery”, “Value-added products from lignin”, and “Bioplastics “in the title, abstract, or author keywords of the publications.</p>
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<p>Co-occurrence network analysis of author keywords with a word frequency of more than five times. The data come from a literature search with characterization and valorization of lignin using the full counting method. (<b>A</b>) The collaboration analysis of Lignin and its valorization strategies for value-added products. (<b>B</b>) The density visualization of lignin depicted by the full counting method highlights the latest developments in the research area.</p>
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<p>Thermal and chemical depolymerization of lignin: methods, products, and energy output.</p>
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<p>Catalyst depolymerization of lignin: methods, products, and energy output.</p>
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<p>An overview of the biological depolymerization of lignin into added-value chemicals and by biocatalysts.</p>
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20 pages, 5453 KiB  
Article
Influence of Synthesis Conditions on Catalytic Performance of Ni/CeO2 in Aqueous-Phase Hydrogenolysis of Glycerol without External Hydrogen Input
by Clara Jarauta-Córdoba, Lucía García, Joaquín Ruiz, Miriam Oliva and Jesús Arauzo
Molecules 2024, 29(16), 3797; https://doi.org/10.3390/molecules29163797 - 10 Aug 2024
Viewed by 465
Abstract
The aqueous-phase hydrogenolysis of glycerol was studied in Ni/CeO2 catalytic systems prepared by incipient wetness impregnation. The operating conditions were 34 bar, 227 ºC, 5 wt.% of glycerol, and a W/mglycerol = 20 g catalyst min/g glycerol without a hydrogen supply. [...] Read more.
The aqueous-phase hydrogenolysis of glycerol was studied in Ni/CeO2 catalytic systems prepared by incipient wetness impregnation. The operating conditions were 34 bar, 227 ºC, 5 wt.% of glycerol, and a W/mglycerol = 20 g catalyst min/g glycerol without a hydrogen supply. The effect of the catalyst preparation conditions on the catalytic activity and physicochemical properties of the catalysts was assessed, particularly the calcination temperature of the support, the calcination temperature of the catalyst, and the Ni content. The physicochemical properties of the catalysts were determined by N2 adsorption, H2-TPR, NH3-TPD, and XRD, among other techniques. A relevant increase in acidity was observed when increasing the nickel content up to 20 wt.%. The increase in the calcination temperatures of the supports and catalysts showed a detrimental effect on the specific surface area and acid properties of the catalysts, which were crucial to the selectivity of the reaction. These catalysts notably enhanced the yield of liquid products, achieving global glycerol conversion values ranging from 17.1 to 29.0% and carbon yield to liquids ranging from 12.6 to 24.0%. Acetol and 1,2-propanediol were the most abundant products obtained in the liquid stream. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Effect of (<b>a</b>) calcination temperature and (<b>b</b>) Ni content on pore volume distribution.</p>
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<p>XRD patterns of CeO<sub>2</sub> supports: (<b>a</b>) CeO<sub>2</sub>(500) and (<b>b</b>) CeO<sub>2</sub>(700).</p>
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<p>XRD diffractograms of calcined (<b>left</b>) and reduced (<b>right</b>) catalysts: (<b>a</b>) Ni10/CeO<sub>2</sub>(500)600, (<b>b</b>) Ni10/CeO<sub>2</sub>(500)700, (<b>c</b>) Ni10/CeO<sub>2</sub>(500)800, (<b>d</b>) Ni10/CeO<sub>2</sub>(700)700, and (<b>e</b>) Ni20/CeO<sub>2</sub>(500)700.</p>
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<p>H<sub>2</sub>-TPR profiles of CeO<sub>2</sub> supports (<b>left</b>): (<b>a</b>) CeO<sub>2</sub>(500) and (<b>b</b>) CeO<sub>2</sub>(700); H<sub>2</sub>-TPR profiles of Ni/CeO<sub>2</sub> catalysts (<b>right</b>): (<b>a</b>) Ni10/CeO<sub>2</sub>(500)600, (<b>b</b>) Ni10/CeO<sub>2</sub>(500)700, (<b>c</b>) Ni10/CeO<sub>2</sub>(500)800, (<b>d</b>) Ni10/CeO<sub>2</sub>(700)700, and (<b>e</b>) Ni20/CeO<sub>2</sub>(500)700.</p>
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<p>NH<sub>3</sub>-TPD profiles of CeO<sub>2</sub> supports (<b>left</b>): (<b>a</b>) CeO<sub>2</sub>(500) and (<b>b</b>) CeO<sub>2</sub>(700); NH<sub>3</sub>-TPD profiles of Ni/CeO<sub>2</sub> catalysts (<b>right</b>): (<b>a</b>) Ni10/CeO<sub>2</sub>(500)600, (<b>b</b>) Ni10/CeO<sub>2</sub>(500)700, (<b>c</b>) Ni10/CeO<sub>2</sub>(500)800, (<b>d</b>) Ni10/CeO<sub>2</sub>(700)700, and (<b>e</b>) Ni20/CeO<sub>2</sub>(500)700.</p>
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<p>Effect of specific surface on the catalytic acidity (expressed on a mass basis).</p>
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<p>Catalytic activity results.</p>
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<p>Variation of CCliq (%) from the third to the first hour of reaction.</p>
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<p>Reaction pathway: glycerol conversion to 1,2-PDO and EG.</p>
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<p>Acidity effects on the selectivity towards main products.</p>
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<p>XRD diffractograms of spent Ni/CeO<sub>2</sub> catalysts: (<b>a</b>) Ni10/CeO<sub>2</sub>(500)600, (<b>b</b>) Ni10/CeO<sub>2</sub>(500)700, (<b>c</b>) Ni10/CeO<sub>2</sub>(500)800, (<b>d</b>) Ni10/CeO<sub>2</sub>(700)700, and (<b>e</b>) Ni20/CeO<sub>2</sub>(500)700.</p>
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<p>SEM images: (<b>a</b>) calcined Ni10/CeO<sub>2</sub>(500)700, (<b>b</b>) used after reaction Ni10/CeO<sub>2</sub>(500)700, (<b>c</b>) calcined Ni10/CeO<sub>2</sub>(500)800, and (<b>d</b>) used after reaction Ni10/CeO<sub>2</sub>(500)800.</p>
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15 pages, 3526 KiB  
Article
Plasma Modification of Biomass-Based Starfish Catalysts for Efficient Biodiesel Synthesis
by Sungho Lee, Jeyoung Ha and Oi Lun Li
Nanomaterials 2024, 14(15), 1313; https://doi.org/10.3390/nano14151313 - 4 Aug 2024
Viewed by 802
Abstract
This study investigated biodiesel production via the transesterification of grapeseed oil with plasma-modified biomass-based catalysts originating from starfish. Dried starfish was first converted into magnesium and calcium oxide through heat treatment and then further modified by plasma engineering to improve the catalyst’s surface [...] Read more.
This study investigated biodiesel production via the transesterification of grapeseed oil with plasma-modified biomass-based catalysts originating from starfish. Dried starfish was first converted into magnesium and calcium oxide through heat treatment and then further modified by plasma engineering to improve the catalyst’s surface area and active sites via zinc addition. The Zn content was added via plasma engineering in the ratios of starfish (Mg0.1Ca0.9CO3): ZnO varying from 5:1, 10:1, to 20:1. The structure and morphology of the catalyst were confirmed through XRD, SEM, and XPS analysis. After the Zn addition and activation process, the surface area and the basicity of the synthesized catalysts were increased. The plasma-modified catalyst showed the highest basicity at the ratio of 10:1. Based on HPLC analyses, the optimized biodiesel yield in transesterification demonstrated 97.7% in fatty acid conversion, and its catalytic performance maintained 93.2% even after three repeated runs. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>The schematic of plasma modification via the plasma process.</p>
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<p>SEM image of (<b>a</b>) SF, (<b>b</b>) SF700, (<b>c</b>) SF900 (×3k), (<b>d</b>) SFZn1, (<b>e</b>) SFZn2, and (<b>f</b>) SFZn3 (×100k).</p>
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<p>XRD patterns of the prepared catalysts.</p>
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<p>XPS spectra of SF900: (<b>a</b>) Ca 2p, (<b>b</b>) Mg 1s, and (<b>c</b>) O 1s.</p>
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<p>XPS spectra of SFZn2: (<b>a</b>) Ca 2p, (<b>b</b>) Mg 1s, (<b>c</b>) Zn 2p, and (<b>d</b>) O 1s.</p>
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<p>Possible mechanisms of the transesterification reaction with catalysts.</p>
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<p>Biodiesel yield of grape seed oil via transesterification under 68 °C: (<b>a</b>) comparison with different reaction times of SFZn2, and (<b>b</b>) transesterification of each sample for 12 h.</p>
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<p>Biodiesel yield of grape seed oil of each catalyst in three consecutive runs (12 h, 68 °C).</p>
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18 pages, 924 KiB  
Article
The Effect of Technological Conditions on ABE Fermentation and Butanol Production of Rye Straw and the Composition of Volatile Compounds
by Wojciech Dziemianowicz, Katarzyna Kotarska and Anna Świerczyńska
Molecules 2024, 29(14), 3398; https://doi.org/10.3390/molecules29143398 - 19 Jul 2024
Viewed by 968
Abstract
The objective of this study was to evaluate the effect of pretreatment and different technological conditions on the course of ABE fermentation of rye straw (RS) and the composition of volatile compounds in the distillates obtained. The highest concentration of ABE and butanol [...] Read more.
The objective of this study was to evaluate the effect of pretreatment and different technological conditions on the course of ABE fermentation of rye straw (RS) and the composition of volatile compounds in the distillates obtained. The highest concentration of ABE and butanol was obtained from the fermentation of pretreated rye straw by alkaline hydrolysis followed by detoxification and enzymatic hydrolysis. After 72 h of fermentation, the maximum butanol concentration, productivity, and yield from RS were 16.11 g/L, 0.224 g/L/h, and 0.402 g/g, respectively. Three different methods to produce butanol were tested: the two-step process (SHF), the simultaneous process (SSF), and simultaneous saccharification with ABE fermentation (consolidation SHF/SSF). The SHF/SSF process observed that ABE concentration (21.28 g/L) was higher than in the SSF (20.03 g/L) and lower compared with the SHF (22.21 g/L). The effect of the detoxification process and various ABE fermentation technologies on the composition of volatile compounds formed during fermentation and distillation were analyzed. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Production of ABE solvents (butanol, ethanol, and acetone) in four different variants: (I) fermentation of pretreated RS by alkaline hydrolysis; (II) fermentation of pretreated RS by enzymatic hydrolysis; (III) fermentation of pretreated RS by alkaline hydrolysis followed by enzymatic hydrolysis; (IV) fermentation of pretreated RS by alkaline hydrolysis followed by detoxification and enzymatic hydrolysis.</p>
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<p>Production of acetone, butanol, and ethanol in the three fermentation methods (SHF, SSF, SHF/SSF) using <span class="html-italic">C. acetobutylicum</span> DSM 1731.</p>
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<p>Butanol production, ABE production, and ABE productivity from rye straw under the SHF method.</p>
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<p>Butanol production, ABE production, and ABE productivity from rye straw under the SSF method.</p>
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<p>Butanol production, ABE production, and ABE productivity from rye straw under the SHF/SSF method.</p>
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19 pages, 5124 KiB  
Article
Preparation and Properties of Composite Double-Network Gel for Inhibiting Coal Spontaneous Combustion
by Jianguo Wang, Zhenzhen Zhang, Wen Fu and Yifan Zhao
Molecules 2024, 29(14), 3365; https://doi.org/10.3390/molecules29143365 - 17 Jul 2024
Viewed by 650
Abstract
In order to improve the inhibition effect of gel on coal spontaneous combustion, a chitosan (CS)/polyacrylamide (PAM)/metal ion (Al3+) composite double-network gel was developed in this study. The optimum formula of the composite double-network gel was determined using orthogonal experimentation. [...] Read more.
In order to improve the inhibition effect of gel on coal spontaneous combustion, a chitosan (CS)/polyacrylamide (PAM)/metal ion (Al3+) composite double-network gel was developed in this study. The optimum formula of the composite double-network gel was determined using orthogonal experimentation. The microstructure, water retention, compressibility, and anti-destruction properties of the composite double-network gel were analyzed. The inhibition effect of the composite double-network gel on coal spontaneous combustion was studied via infrared spectroscopy and a synchronous thermal analyzer from the micro and macro perspectives. The results show that the composite double-network gel has a denser interpenetrating double-network structure and a larger void ratio than the ordinary gel. The water retention rate was 55% after standing at 150 °C for 12 h. The deformation memory ratio of the composite double-network gel was 78%, which was 26.8% higher than that of the ordinary gel, and the compressive strength also increased by 59.96%. In addition, the critical temperature point and the maximum thermal weight-loss rate temperature point decreased by 7.01 °C and 39.62 °C, respectively, and the composite double-network gel effectively reduced active functional groups in the treated coal sample, such as hydroxyl and aliphatic hydrocarbons. In this study, a CS/PAM/Al3+ composite double-network gel was produced, which exhibited good gel performance and inhibition effects, with physical effects such as the covering, wetting, and cementation of coal. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Effects of various factor levels on gelation time.</p>
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<p>Effects of various factor levels on gel viscosity.</p>
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<p>Effects of various factor levels on gel strength.</p>
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<p>(<b>a</b>)<b>.</b> Scanning electron microscope images of plain gel. (<b>b</b>) Scanning electron microscope images of composite double-network gel.</p>
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<p>Water loss rate change curves of two gels under constant temperature conditions.</p>
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<p>Fitting curves of water loss rates of two gels at 120 °C.</p>
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<p>Weight-loss rate change curves under heating environment from 30 to ~170 °C.</p>
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<p>Digital images of gel under different mechanical actions.</p>
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<p>Force–displacement curves of two gels.</p>
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<p>(<b>a</b>) Before gel compression performance test; (<b>b</b>) gel compression performance.</p>
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<p>Stress–strain curves of two gels.</p>
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<p>Infrared absorption spectra of different coal samples.</p>
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<p>Absorbance change and its decline.</p>
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<p>Peak area changes and decline.</p>
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<p>TG–DTG curves of raw coal and composite double-network gel-treated coal samples.</p>
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<p>Preparation process.</p>
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<p>Diagram of gel formation mechanism.</p>
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44 pages, 3718 KiB  
Review
Integration of Digestate-Derived Biochar into the Anaerobic Digestion Process through Circular Economic and Environmental Approaches—A Review
by Mohamed Zbair, Lionel Limousy, Méghane Drané, Charlotte Richard, Marine Juge, Quentin Aemig, Eric Trably, Renaud Escudié, Christine Peyrelasse and Simona Bennici
Materials 2024, 17(14), 3527; https://doi.org/10.3390/ma17143527 - 16 Jul 2024
Viewed by 818
Abstract
The growing energy consumption and the need for a circular economy have driven considerable interest in the anaerobic digestion (AD) of organic waste, offering potential solutions through biogas and digestate production. AD processes not only have the capability to reduce greenhouse gas emissions [...] Read more.
The growing energy consumption and the need for a circular economy have driven considerable interest in the anaerobic digestion (AD) of organic waste, offering potential solutions through biogas and digestate production. AD processes not only have the capability to reduce greenhouse gas emissions but also contribute to the production of renewable methane. This comprehensive review aims to consolidate prior research on AD involving different feedstocks. The principles of AD are explored and discussed, including both chemical and biological pathways and the microorganisms involved at each stage. Additionally, key variables influencing system performance, such as temperature, pH, and C/N ratio are also discussed. Various pretreatment strategies applied to enhance biogas generation from organic waste in AD are also reviewed. Furthermore, this review examines the conversion of generated digestate into biochar through pyrolysis and its utilization to improve AD performance. The addition of biochar has demonstrated its efficacy in enhancing metabolic processes, microorganisms (activity and community), and buffering capacity, facilitating Direct Interspecies Electron Transfer (DIET), and boosting CH4 production. Biochar also exhibits the ability to capture undesirable components, including CO2, H2S, NH3, and siloxanes. The integration of digestate-derived biochar into the circular economy framework emerges as a vital role in closing the material flow loop. Additionally, the review discusses the environmental benefits derived from coupling AD with pyrolysis processes, drawing on life cycle assessment investigations. Techno-economic assessment (TEA) studies of the integrated processes are also discussed, with an acknowledgment of the need for further TEA to validate the viability of integrating the biochar industry. Furthermore, this survey examines the techno-economic and environmental impacts of biochar production itself and its potential application in AD for biogas generation, aiming to establish a more cost-effective and sustainable integrated system. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>A general description of anaerobic digestion plants.</p>
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<p>General description of the anaerobic digestion process and pathways.</p>
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<p>Electron transfer mechanism during AD process. (<b>a</b>) Mediated transfer through hydrogen/formate. (<b>b</b>) DIET via membrane-bound electron transport proteins (pink). (<b>c</b>) DIET via conductive materials.</p>
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<p>Schematic representation of biomass conversion to biochar and its characterization.</p>
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<p>Combined production of biochar and renewable energy from waste and via anaerobic digestion and pyrolysis. (Reprinted from [<a href="#B18-materials-17-03527" class="html-bibr">18</a>], with permission from Elsevier).</p>
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17 pages, 953 KiB  
Review
The Impact of Various Factors on Long-Term Storage of Biodiesel and Its Prevention: A Review
by Wenbo Ai, Haeng Muk Cho and Md. Iqbal Mahmud
Energies 2024, 17(14), 3449; https://doi.org/10.3390/en17143449 - 13 Jul 2024
Viewed by 570
Abstract
With the continuous growth of global energy demand and increasingly prominent environmental issues, the research and utilization of renewable energy as a substitute for traditional fossil fuels have gained significant importance. Biofuels, recognized as a key renewable energy source, are widely considered a [...] Read more.
With the continuous growth of global energy demand and increasingly prominent environmental issues, the research and utilization of renewable energy as a substitute for traditional fossil fuels have gained significant importance. Biofuels, recognized as a key renewable energy source, are widely considered a viable alternative to fossil fuels. The primary component of biodiesel is fatty acid methyl esters (FAMEs), which are prone to oxidative degradation due to their unsaturated nature during storage and transportation. Various studies have identified several factors influencing the stability of biodiesel, including oxygen, temperature, light, water content, microbial growth, and the corrosion of metal storage tanks. This article provides a comprehensive summary of the effects of different environmental factors on the storage stability of biodiesel and explores the interrelationships between these factors. To enhance the storage stability of biodiesel, several strategies have been proposed, such as optimizing production processes, adding antioxidants, controlling storage environments, and conducting regular inspections. This review aims to provide a theoretical basis for the long-term storage of biodiesel and promote its widespread application in practical scenarios. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Transesterification reaction principle [<a href="#B15-energies-17-03449" class="html-bibr">15</a>].</p>
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<p>Micrographs of corroded surfaces for (<b>a</b>) 304 type stainless steel, (<b>b</b>) 1018 carbon exposed to chicken fat-based biodiesel [<a href="#B105-energies-17-03449" class="html-bibr">105</a>].</p>
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13 pages, 2585 KiB  
Article
Thermal Decomposition of Bio-Based Plastic Materials
by Inés Oliver, Juan A. Conesa and Andres Fullana
Molecules 2024, 29(13), 3195; https://doi.org/10.3390/molecules29133195 - 5 Jul 2024
Viewed by 611
Abstract
This research delves into a detailed exploration of the thermal decomposition behavior of bio-based polymers, specifically thermoplastic starch (TPS) and polylactic acid (PLA), under varying heating rates in a nitrogen atmosphere. This study employs thermogravimetry (TG) to investigate, providing comprehensive insights into the [...] Read more.
This research delves into a detailed exploration of the thermal decomposition behavior of bio-based polymers, specifically thermoplastic starch (TPS) and polylactic acid (PLA), under varying heating rates in a nitrogen atmosphere. This study employs thermogravimetry (TG) to investigate, providing comprehensive insights into the thermal stability of these eco-friendly polymers. In particular, the TPS kinetic model is examined, encompassing the decomposition of three distinct fractions. In contrast, PLA exhibits a simplified kinetic behavior requiring only a fraction described by a zero-order model. The kinetic study involves a systematic investigation into the individual contributions of key components within TPS, including starch, glycerin, and polyvinyl alcohol (PVA). This detailed analysis contributes to a comprehensive understanding of the thermal degradation process of TPS and PLA, enabling the optimization of processing conditions and the prediction of material behavior across varying thermal environments. Furthermore, the incorporation of different starch sources and calcium carbonate additives in TPS enhances our understanding of the polymer’s thermal stability, offering insights into potential applications in diverse industries. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Comparison between the decomposition of different TPS samples using a variety of starch from different vegetables. All samples contain PVA, zinc stearate as a lubricant, and glycerin as a plasticizer in the same proportion. Curves were obtained at 5 K/min.</p>
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<p>Fitting obtained for the decomposition of TPS based on a potato for the three different heating rates tested.</p>
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<p>Details of the decomposition of the different fractions modeled for the thermal decomposition of TPS potato-based starch.</p>
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<p>Thermal decomposition of pure starch from potato, glycerin, PVA, and TPS made using potato and cassava starch. Curves were obtained at 5 K/min.</p>
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<p>Thermal decomposition of TPS using starch from potato in the presence of different amounts of calcium carbonate. Curves were obtained at 5 K/min.</p>
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<p>Thermal decomposition of PLA at three different heating rates under pyrolytic conditions. Experimental and calculated curves are shown.</p>
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16 pages, 2855 KiB  
Article
Effects of Process Variables on Physico-Mechanical Properties of Abura (Mitrogyna ciliata) Sawdust Briquettes
by Joseph Ifeolu Orisaleye, Simeon Olatayo Jekayinfa, Adebayo Adeyemi Ogundare, Mojirade Rashidat Shittu, Oluwatomiwa Olalekan Akinola and Kazeem Olabisi Odesanya
Biomass 2024, 4(3), 671-686; https://doi.org/10.3390/biomass4030037 - 1 Jul 2024
Viewed by 515
Abstract
Efficient utilization of biomass requires conversion into forms that can be optimally applied in energy generation. Briquetting involves the compaction of biomass into solid blocks that are more efficient than raw biomass, and provides ease of transport and handling. These are improved when [...] Read more.
Efficient utilization of biomass requires conversion into forms that can be optimally applied in energy generation. Briquetting involves the compaction of biomass into solid blocks that are more efficient than raw biomass, and provides ease of transport and handling. These are improved when the briquettes possess a high density, shatter index, and compressive strength. Due to differences in nature and composition, it is imperative to define optimum conditions for the production of quality and durable briquettes for individual biomasses that are compacted into briquettes. This study investigated the effects of process variables on the strength, durability, and density of biomass briquettes produced using Abura sawdust. The lateral compressive strength and drop shatter index were investigated whilst varying the temperature (100–150 °C), pressure (9–15 MPa), and hold time (15–30 min). The compressive strength ranged between 2.06 and 5.15 MPa, whilst the shatter index was between 50 and 600. Briquette density was between 518.8 and 822.9 kg/m3. The pressure was significant to the determination of the compressive strength (p < 0.1) and the shatter index (p < 0.05). The pressure, temperature, and hold time are significant to the briquette density. Physical and mechanical characteristics of the binderless Abura sawdust briquettes can be improved by optimizing the densification variables during the briquetting process when moderate pressures are used for compaction. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Particle size distribution of sawdust.</p>
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<p>Plots to check assumptions of ANOVA for compressive strength: (<b>a</b>) normal probability plots; (<b>b</b>) residual versus fits; (<b>c</b>) residual versus observation order.</p>
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<p>Comparison of experimental values with predicted values of compressive strength.</p>
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<p>Contour plot of compressive strength with pressure and temperature.</p>
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<p>Plots to check assumptions of ANOVA for shatter index: (<b>a</b>) normal probability plots; (<b>b</b>) residual versus fits; (<b>c</b>) residual versus observation order.</p>
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<p>Comparison of experimental values of shatter index with predicted values.</p>
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<p>Contour plot of shatter index with pressure and hold time.</p>
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<p>Plots to check assumptions of ANOVA for density: (<b>a</b>) normal probability plots; (<b>b</b>) residual versus fits; (<b>c</b>) residual versus observation order.</p>
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<p>Comparison of experimental values of density with predicted values.</p>
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<p>Contour plot of density with (<b>a</b>) pressure and temperature; (<b>b</b>) pressure and hold time; and (<b>c</b>) temperature and hold time.</p>
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11 pages, 610 KiB  
Article
Cropping Flax for Grain and Fiber: A Case-Study from Italy
by Piernicola Masella, Giulia Angeloni and Incoronata Galasso
Biomass 2024, 4(2), 599-609; https://doi.org/10.3390/biomass4020032 - 6 Jun 2024
Viewed by 531
Abstract
Flax (Linum usitatissimum L.) can be grown both as an oil crop and as a fiber crop, and this offers new opportunities when included in the framework of a whole-crop biorefinery, a system in which a range of products are made from [...] Read more.
Flax (Linum usitatissimum L.) can be grown both as an oil crop and as a fiber crop, and this offers new opportunities when included in the framework of a whole-crop biorefinery, a system in which a range of products are made from portions of grain and straw and in which both of these should be satisfactorily produced. In the present experiment, the effect of flax genotypes (7 varieties), cultivation sites (two locations) and seasons (two years) were tested with a standard randomized complete block design, in search of a compromise for the production performance for both grain and straw, with the aim of reintroducing flax back into the northern Italian environment. Overall, grain yield reaches an average value of about 1.4 t ha−1 (dw), while straw yield reaches 2.77 t ha−1 (dw). The former is strictly dependent on the environmental effects of the growing site and season, while the effect of genotype was not significant. The straw yield also depends on the second-order interaction of the factors analyzed, although the performance of three varieties, Festival, Solal and Linoal, was noteworthy and seemed to respond well in both environments. Overall, it was found that flax can be conveniently grown for both grain and straw production. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Box-plot of grain yield as affected by the main effects of locality of cultivation and season (Graph A); straw yield as affected by the interaction of locality of cultivation and season (Graph B); box-plot of straw yield as affected by the interaction of locality of cultivation and variety (Graph C); * indicate outlier values.</p>
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14 pages, 2091 KiB  
Article
Evaluation of Biogas Production from Swine Manure Using a UASB Reactor (Upflow Anaerobic Sludge Blanket) with Long-Term Operation
by Ana Marcela Mosquera, Juan Martín Delgado, Aura Alexandra Ramón, Juan Esteban Vásquez and Mariana Peñuela
Energies 2024, 17(11), 2723; https://doi.org/10.3390/en17112723 - 3 Jun 2024
Viewed by 576
Abstract
To meet Colombia’s energy needs by 2050, a total installed capacity of 42 MW across its power generation infrastructure is required. To achieve this, transitioning to cleaner energy sources, such as biomass—a non-conventional renewable energy—is necessary. Biomass is a promising renewable source for [...] Read more.
To meet Colombia’s energy needs by 2050, a total installed capacity of 42 MW across its power generation infrastructure is required. To achieve this, transitioning to cleaner energy sources, such as biomass—a non-conventional renewable energy—is necessary. Biomass is a promising renewable source for thermal and electrical energy production. This study researched the production of biogas from swine manure using a UASB reactor to valorize this waste. Swine manure was collected every 20 days from a pig farm with a capacity of 200 sows, located in Santa Rosa de Osos, Antioquia. The flow rate was increased three times (1.30 L d−1, 1.62 L d−1, and 2.08 L d−1) to reduce the hydraulic retention time (HRT) and enhance biogas production. The volatile and total solids, chemical oxygen demand (COD), alkalinity, and biogas composition were measured over one year. The proposed system achieved 87.40% COD remotion from the feed stream and generated a yield of 507 mLCH4 gVS−1, with an HRT of 19 days and an OLR of 4.27 gCOD L−1 d−1. The reactor produced biogas with a CH4 content of 67.7%, CO2 content of 18.1%, and H2S content of 1413 ppm. This study highlights the effectiveness of the UASB reactor for biogas production using swine manure as a substrate. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Diagram of the UASB reactor used in this study.</p>
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<p>Process diagram for biogas production using anaerobic digestion on UASB reactor fed with swine manure solution.</p>
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<p>Biogas production and methane composition over time. “Avg. Q1” represents the average for feed flow rate 1 (1.3 L d<sup>-1</sup>), “Avg. Q2” represents the average for feed flow rate 2 (1.6 L d<sup>-1</sup>), and “Avg. Q3” represents the average for feed flow rate 3 (2.1 L d<sup>-1</sup>).</p>
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<p>COD in influent and effluent streams and its remotion in the system. The dashed lines represent the points where the system’s feed flow was increased.</p>
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<p>Monitoring of the VFA/ALK ratio and pH during the study period. The dashed red line represents the maximum value of the VFA/ALK ratio necessary for good performance without the need for corrective action, according to the literature.</p>
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18 pages, 4206 KiB  
Article
One-Step Hydrothermal/Solvothermal Preparation of Pt/TiO2: An Efficient Catalyst for Biobutanol Oxidation at Room Temperature
by Lijun Lei, Qianyue Cao, Jiachen Ma and Fengxiao Hou
Molecules 2024, 29(7), 1450; https://doi.org/10.3390/molecules29071450 - 24 Mar 2024
Viewed by 981
Abstract
The selective oxidation of biobutanol to prepare butyric acid is an important conversion process, but the preparation of low-temperature and efficient catalysts for butanol oxidation is currently a bottleneck problem. In this work, we prepared Pt-TiO2 catalysts with different Pt particle sizes [...] Read more.
The selective oxidation of biobutanol to prepare butyric acid is an important conversion process, but the preparation of low-temperature and efficient catalysts for butanol oxidation is currently a bottleneck problem. In this work, we prepared Pt-TiO2 catalysts with different Pt particle sizes using a simple one-step hydrothermal/solvothermal method. Transmission electron microscopy and X-ray diffraction results showed that the average size of the Pt particles ranged from 1.1 nm to 8.7 nm. Among them, Pt-TiO2 with an average particle size of 3.6 nm exhibited the best catalytic performance for biobutanol. It was capable of almost completely converting butanol, even at room temperature (30 °C), with a 98.9% biobutanol conversion, 98.4% butyric acid selectivity, and a turnover frequency (TOF) of 36 h−1. Increasing the reaction temperature to 80 and 90 °C, the corresponding TOFs increased rapidly to 355 and 619 h−1. The relationship between the electronic structure of Pt and its oxidative performance suggests that the synergistic effect of the dual sites, Pt0 and Pt2+, could be the primary factor contributing to its elevated reactivity. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>TEM images of Pt-TiO<sub>2</sub> with different Pt particle sizes; the insets are the high-resolution TEM images. (<b>A</b>) Pt(1.1)-TiO<sub>2</sub>; (<b>B</b>) Pt(2.6)-TiO<sub>2</sub>; (<b>C</b>) Pt(3.6)-TiO<sub>2</sub>; (<b>D</b>) Pt(5.3)-TiO<sub>2</sub>; (<b>E</b>) Pt(8.7)-TiO<sub>2</sub>.</p>
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<p>XRD patterns of Pt-TiO<sub>2</sub> with different Pt particle sizes.</p>
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<p>Pt 4<span class="html-italic">f</span> XPS spectra of Pt-TiO<sub>2</sub> catalysts. Dark gray is the raw XPS spectra, red is the fitted XPS spectra, and light blue is the baseline selected for the XPS fit. Dark blue, dark red, orange, and green are the fitted peaks of Pt<sup>0</sup> 4f<sub>7/2</sub>, Pt<sup>0</sup> 4f<sub>5/2</sub>, Pt<sup>2+</sup> 4f<sub>7/2</sub>, and Pt<sup>2+</sup> 4f<sub>5/2</sub>, respectively.</p>
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<p>Normalized Pt-L<sub>3</sub> edge XANES spectra (<b>A</b>), and Fourier transform magnitudes of the EXAFS spectra (<b>B</b>) of three Pd-TiO<sub>2</sub> catalysts.</p>
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<p>Oxidation performance of butanol catalyzed by Pt(3.6)-TiO<sub>2</sub> with reaction time.</p>
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<p>Plots of conversion of butanol and ethanol with Pt particle size in Pt-TiO<sub>2</sub> catalysts.</p>
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<p>Performance of leaching of Pt(3.6)-TiO<sub>2</sub> after removal from reactor at reaction time of 4 h. The dotted circle represents removing the catalyst from the reaction system.</p>
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<p>Stability of Pt(3.6)-TiO<sub>2</sub> for aerobic oxidation of butanol (<b>A</b>). Reaction conditions: 50 mg of Pt-TiO<sub>2</sub> catalysts, certain amount of aliphatic alcohol, 8 mL of H<sub>2</sub>O, and 0.5 MPa of O<sub>2</sub>. After reaction, the catalyst was centrifuged, washed several times with deionized water and ethanol, then dried in an oven at 100 °C. For the second reaction, catalyst, substrate, and internal standard were reintroduced into the reactor, which was repeated six times in this order. TEM image of Pt(3.6)-TiO<sub>2</sub> after six cycle reactions (<b>B</b>); the inset is the high-resolution TEM image. Pt particle size of used Pt(3.6)-TiO<sub>2</sub> is shown in (<b>C</b>).</p>
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<p>IR spectra of ethanol adsorption over Pt(3.6)-TiO<sub>2</sub> at different temperatures within or without air. Reaction conditions: The Pt(3.6)/TiO<sub>2</sub> catalyst was first purged with Ar gas (30 mL min<sup>−1</sup>) at 300 °C to remove adsorbents on the surface. Ethanol vapor (25 °C) was introduced into the in situ reaction cell by means of Ar gas bubbling, and air was introduced into the sample surface through a gas injector.</p>
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<p>Schematic diagrams of catalytic mechanism over dual Pt<sup>0</sup> and Pt<sup>2+</sup> sites of Pt(3.6)-TiO<sub>2</sub>. Vö represents the oxygen vacancies on PdO.</p>
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<p>Schematic diagram of hydrothermal/solvothermal synthesis of Pt-TiO<sub>2</sub> catalysts with different sizes.</p>
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11 pages, 4907 KiB  
Article
Molecular Dynamics Simulations of Thermal Transport of Carbon Nanotube Interfaces
by Shijun Zhou, Shan Qing, Xiaohui Zhang, Haoming Huang and Menglin Hou
Energies 2024, 17(6), 1506; https://doi.org/10.3390/en17061506 - 21 Mar 2024
Viewed by 908
Abstract
In this paper, non-equilibrium molecular dynamics simulations are used to study the interfacial heat exchange capacity of one-dimensional carbon nanotube nested structures. When the radius of the CNT substrate is increased from 1.356 to 2.712 nm, the ITC has a great enhancement from [...] Read more.
In this paper, non-equilibrium molecular dynamics simulations are used to study the interfacial heat exchange capacity of one-dimensional carbon nanotube nested structures. When the radius of the CNT substrate is increased from 1.356 to 2.712 nm, the ITC has a great enhancement from 1.340 to 2.949 nw/k. After this, we investigate the effects of overlap length, CNT length, and van der Waals interaction strength on the thermal resistance of the interface between carbon nanotubes. Firstly, we found that the nesting depth can significantly increase the ITC, and the increase in ITC is more obvious at an overlap length of 40 Å than at 30 Å. After this, the effect of length on the interfacial thermal conductivity is investigated, and the interfacial thermal conductivity is enhanced by 33.8% when the length is increased to 30 nm. Finally, the effect of van der Waals interaction strength was investigated, and the ITC increased from 1.60 nW/K to 2.71 nW/K when the scale factor was increased from 1 to 2. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>(<b>a</b>) (40,40) CNT axial temperature distribution. (<b>b</b>) (45,45) CNT@(40,40) CNT axial temperature distribution, and (<b>c</b>) the corresponding cumulative energy change in the cold and hot zones used in the calculation of the axial thermal conductivity. (<b>c</b>) Temperature distribution along the axial direction of CNT@BNNT and (<b>d</b>) the corresponding cumulative energy change in the cold and hot zones used in the calculation of the interfacial thermal conductivity. The insets in (<b>a</b>,<b>b</b>) illustrate the corresponding simulation setup.</p>
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<p>(<b>a</b>). Temperature distribution of (50,50) CNT@(45,45) CNT. (<b>b</b>). Variation of energy of different CNT-based cold and heat sources. (<b>c</b>). VDOS at different radii.</p>
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<p>(<b>a</b>). Interfacial thermal conductivity. (<b>b</b>). Interfacial heat flow.</p>
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<p>(<b>a</b>). Variation of energy of CNT hot and cold sources with different lengths. (<b>b</b>). Interfacial thermal conductivity of different lengths. (<b>c</b>). VDOS at different lengths.</p>
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<p>(<b>a</b>). Variation of energy of CNT hot and cold sources with different χ. (<b>b</b>). Interfacial thermal conductivity of different χ. (<b>c</b>). VDOS of CNT inner and outer tubes at χ = 1.25. (<b>d</b>). VDOS of CNT inner and outer tubes at χ = 2.0.</p>
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32 pages, 5432 KiB  
Review
An Updated Review of Recent Applications and Perspectives of Hydrogen Production from Biomass by Fermentation: A Comprehensive Analysis
by Dayana Nascimento Dari, Isabelly Silveira Freitas, Francisco Izaias da Silva Aires, Rafael Leandro Fernandes Melo, Kaiany Moreira dos Santos, Patrick da Silva Sousa, Paulo Gonçalves de Sousa Junior, Antônio Luthierre Gama Cavalcante, Francisco Simão Neto, Jessica Lopes da Silva, Érico Carlos de Castro, Valdilane Santos Alexandre, Ana M. da S. Lima, Juliana de França Serpa, Maria C. M. de Souza and José C. S. dos Santos
Biomass 2024, 4(1), 132-163; https://doi.org/10.3390/biomass4010007 - 1 Mar 2024
Cited by 3 | Viewed by 2143
Abstract
Fermentation is an oxygen-free biological process that produces hydrogen, a clean, renewable energy source with the potential to power a low-carbon economy. Bibliometric analysis is crucial in academic research to evaluate scientific production, identify trends and contributors, and map the development of a [...] Read more.
Fermentation is an oxygen-free biological process that produces hydrogen, a clean, renewable energy source with the potential to power a low-carbon economy. Bibliometric analysis is crucial in academic research to evaluate scientific production, identify trends and contributors, and map the development of a field, providing valuable information to guide researchers and promote scientific innovation. This review provides an advanced bibliometric analysis and a future perspective on fermentation for hydrogen production. By searching WoS, we evaluated and refined 62,087 articles to 4493 articles. This allowed us to identify the most important journals, countries, institutions, and authors in the field. In addition, the ten most cited articles and the dominant research areas were identified. A keyword analysis revealed five research clusters that illustrate where research is progressing. The outlook indicates that a deeper understanding of microbiology and support from energy policy will drive the development of hydrogen from fermentation. Full article
(This article belongs to the Topic Biomass for Energy, Chemicals and Materials)
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<p>Search and analysis criteria used in the research methodology.</p>
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<p>Annual distribution of scientific publications on hydrogen from fermentation (data exported on 27 December 2023).</p>
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<p>Main journals that published the most in the area of hydrogen generation through biological and fermentative methods in the last five years. (<b>A</b>) The 20 journals with at least five documents that published the most and were cited within this theme. (<b>B</b>) Temporal map of the number of journals that published the most in the area.</p>
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<p>Bibliometric Analysis. (<b>A</b>) Cartographic representation of publications by country. (<b>B</b>) Network visualization map of the most significant collaborations between countries. (<b>C</b>) Co-authorship cluster map between top institutions.</p>
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<p>Bibliometric Analysis. (<b>A</b>) Grouping map of authors with the highest number of co-authorships. (<b>B</b>) Authors’ production over time.</p>
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<p>Distribution of research areas related to fermentative hydrogen production.</p>
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<p>Occurrence-based keywords: (<b>A</b>) Network visualization map of the 100 keywords with at least five occurrences. (<b>B</b>) Density map of the most relevant keywords.</p>
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