Catalytic Processes in Biofuel Production and Biomass Valorization

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Biomass Catalysis".

Deadline for manuscript submissions: closed (30 March 2022) | Viewed by 26310

Special Issue Editor

Institute of Nanotechnology, CNR NANOTEC, 73100 Lecce, Italy
Interests: sustainable chemistry; organic chemistry; flow chemistry; material chemistry; nanotechnology
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Public attention to energy consumption and the related emissions of pollutants is increasing. The constant increase in the costs of raw materials derived from petroleum and the growing concerns surrounding the environmental impact have given considerable impetus to research into new products from renewable raw materials and to the proposal of technological solutions that reduce energy consumption, the use of hazardous substances and waste production, while promoting a model of sustainable development. The valorization of waste materials is a viable alternative to traditional disposal systems, including in the field of renewable energy and biofuels.

This Special Issue aims to focus on sustainable chemistry, biomass valorization, biofuels, biodiesel production, waste production, raw materials and glycerol. The topics of this Special Issue include both experimental and theoretical contributions. Original research papers, communications and review articles will be considered for submission.

Dr. Claudia Carlucci
Guest Editor

Manuscript Submission Information

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Keywords

  • sustainable chemistry
  • biomass valorization
  • biofuel
  • biodiesel production
  • waste production
  • raw materials
  • glycerol

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Published Papers (9 papers)

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Editorial

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2 pages, 147 KiB  
Editorial
Editorial: Special Issue on “Catalytic Processes in Biofuel Production and Biomass Valorization”
Catalysts 2022, 12(12), 1643; https://doi.org/10.3390/catal12121643 - 14 Dec 2022
Viewed by 653
Abstract
The valorization of waste materials is a viable alternative to traditional disposal systems, including in the field of renewable energy, biofuels and biomass [...] Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)

Research

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16 pages, 3269 KiB  
Article
Activated Bentonite Nanocomposite for the Synthesis of Solketal from Glycerol in the Liquid Phase
Catalysts 2022, 12(6), 673; https://doi.org/10.3390/catal12060673 - 20 Jun 2022
Cited by 5 | Viewed by 2016
Abstract
Activated bentonites are low-cost acid catalysts used in several reactions. However, their application at an industrial scale is affected by the formation of colloidal suspensions when these bentonites are in aqueous solutions. In order to overcome these limitations, this work proposes obtaining a [...] Read more.
Activated bentonites are low-cost acid catalysts used in several reactions. However, their application at an industrial scale is affected by the formation of colloidal suspensions when these bentonites are in aqueous solutions. In order to overcome these limitations, this work proposes obtaining a catalyst based on a composite containing natural bentonite within a silica–resin structure, which allows separating and re-utilizing the catalyst more easily and without centrifugal filtration requirements. By means of characterization techniques, the present study determined that the activated bentonite composite presented a total specific surface area of ~360 m2 g−1, ~4 mmol of acid sites per gram of bentonite, and sites with strong acid strength, all of which bestowed activity and selectivity in the solketal synthesis reaction from glycerol and acetone, reaching equilibrium conversion within a short reaction time. Furthermore, the present work developed a Langmuir–Hinshelwood–Hougen–Watson kinetic model, achieving an activation energy of 50.3 ± 3.6 kJ mol−1 and a pre-exponential factor of 6.4 × 106 mol g−1 L−1 s−1, which are necessary for reactor design. Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
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21 pages, 2031 KiB  
Article
Thermal Conversion of Sugarcane Bagasse Coupled with Vapor Phase Hydrotreatment over Nickel-Based Catalysts: A Comprehensive Characterization of Upgraded Products
Catalysts 2022, 12(4), 355; https://doi.org/10.3390/catal12040355 - 22 Mar 2022
Cited by 5 | Viewed by 2505
Abstract
In the present work, we compared the chemical profile of the organic compounds produced in non-catalytic pyrolysis of sugarcane bagasse at 500 °C with those obtained by the in-line catalytic upgrading of the vapor phase at 350 °C. The influence over the chemical [...] Read more.
In the present work, we compared the chemical profile of the organic compounds produced in non-catalytic pyrolysis of sugarcane bagasse at 500 °C with those obtained by the in-line catalytic upgrading of the vapor phase at 350 °C. The influence over the chemical profile was evaluated by testing two Ni-based catalysts employing an inert atmosphere (N2) and a reactive atmosphere (H2) under atmospheric pressure with yields of the liquid phase varying from 55 to 62%. Major changes in the chemical profile were evidenced in the process under the H2 atmosphere, wherein a higher degree of deoxygenation was identified due to the effect of synergistic action between the catalyst and H2. The organic fraction of the liquid phase, called bio-oil, showed an increase in the relative content of alcohols and phenolic compounds in the GC/MS fingerprint after the upgrading process, corroborating with the action of the catalytic process upon the compounds derived from sugar and carboxylic acids. Thus, the thermal conversion of sugarcane bagasse, in a process under an H2 atmosphere and the presence of Ni-based catalysts, promoted higher deoxygenation performance of the pyrolytic vapors, acting mainly through sugar dehydration reactions. Therefore, the adoption of this process can potentialize the use of this waste biomass to produce a bio-oil with higher content of phenolic species, which have a wide range of applications in the energy and industrial sectors. Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
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16 pages, 16748 KiB  
Article
Development of a Mesoporous Silica-Supported Layered Double Hydroxide Catalyst for the Reduction of Oxygenated Compounds in E. grandis Fast Pyrolysis Oils
Catalysts 2021, 11(12), 1527; https://doi.org/10.3390/catal11121527 - 15 Dec 2021
Cited by 4 | Viewed by 1707
Abstract
Biomass fast pyrolysis oil is a potential renewable alternative to fossil fuels, but its viability is constrained by its corrosiveness, low higher heating value and instability, caused by high oxygenate concentrations. A few studies have outlined layered double hydroxides (LDHs) as possible catalysts [...] Read more.
Biomass fast pyrolysis oil is a potential renewable alternative to fossil fuels, but its viability is constrained by its corrosiveness, low higher heating value and instability, caused by high oxygenate concentrations. A few studies have outlined layered double hydroxides (LDHs) as possible catalysts for the improvement of biomass pyrolysis oil characteristics. In this study, the goal was to reduce the concentration of oxygen-rich compounds in E. grandis fast pyrolysis oils using CaAl- and MgAl- LDHs. The LDHs were supported by mesoporous silica, synthesised at different pHs to obtain different pore sizes (3.3 to 4.8 nm) and surface areas (up to 600 m2/g). The effects of the support pore sizes and use of LDHs were investigated. GC/MS results revealed that MgAl-LDH significantly reduced the concentrations of ketones and oxygenated aromatics in the electrostatic precipitator oils and increased the concentration of aliphatics. CaAl-LDH had the opposite effect. There was little effect on the oxygenate concentrations of the heat exchanger oils, suggesting that there was a greater extent of conversion of the lighter oil compounds. Bomb calorimetry also showed a marked increase in higher heating values (16.2 to 22.5 MJ/kg) in the electrostatic precipitator oils when using MgAl-LDH. It was also found that the mesoporous silica support synthesised at a pH of 7 was the most effective, likely due to the intermediate average pore width (4 nm). Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
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17 pages, 2367 KiB  
Article
One-Pot Tandem Catalytic Epoxidation—CO2 Insertion of Monounsaturated Methyl Oleate to the Corresponding Cyclic Organic Carbonate
Catalysts 2021, 11(12), 1477; https://doi.org/10.3390/catal11121477 - 02 Dec 2021
Cited by 7 | Viewed by 2392
Abstract
Conversion of unsaturated fatty acids, FAMEs or triglycerides into the corresponding cyclic organic carbonates involves two reaction steps—double-bond epoxidation and CO2 insertion into the epoxide—that are generally conducted separately. We describe an assisted-tandem catalytic protocol able to carry out carbonation of unsaturated [...] Read more.
Conversion of unsaturated fatty acids, FAMEs or triglycerides into the corresponding cyclic organic carbonates involves two reaction steps—double-bond epoxidation and CO2 insertion into the epoxide—that are generally conducted separately. We describe an assisted-tandem catalytic protocol able to carry out carbonation of unsaturated methyl oleate in one-pot without isolating the epoxide intermediate. Methyl oleate carbonate was obtained in 99% yield and high retention of cis-configuration starting from methyl oleate using hydrogen peroxide and CO2 as green reagents, in a biphasic system and in the presence of an ammonium tungstate ionic liquid catalyst with KBr as co-catalyst. Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
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10 pages, 4389 KiB  
Article
Enhancement of Biological Pretreatment on Rice Straw by an Ionic Liquid or Surfactant
Catalysts 2021, 11(11), 1274; https://doi.org/10.3390/catal11111274 - 22 Oct 2021
Cited by 10 | Viewed by 1865
Abstract
Fungal delignification can be a feasible process to pretreat biomass for bioethanol production if its performance is improved in terms of efficiency through a few modifications. The aim of this study was to enhance the biodelignification pretreatment of rice straw using laccase in [...] Read more.
Fungal delignification can be a feasible process to pretreat biomass for bioethanol production if its performance is improved in terms of efficiency through a few modifications. The aim of this study was to enhance the biodelignification pretreatment of rice straw using laccase in the presence of ionic liquid (1-Allyl-3-methylimidazolium chloride, [AMIM]Cl) or surfactant (TritonX-100). Addition of 750 mg/L [AMIM]Cl and 500 mg/L TritonX-100 increases the lignin removal to 18.49% and 31.79%, which is higher than that of laccase only (11.97%). The enzymatic saccharification process was carried out based on different strategies. The highest cellulose conversion, 40.96%, 38.24%, and 37.91%, was obtained after 72 h of enzymatic saccharification when the substrate was washed with distilled water after pretreatment of rice straw with laccase + TritonX-100, laccase + [AMIM]Cl, and laccase only, respectively. In addition, the morphology and structure changes of pretreated and untreated rice straw were studied. Both surface area and cellulose crystallinity are substantially altered after laccase + [AMIM]Cl and laccase + TritonX-100 pretreatment. Enhanced saccharification efficiency of rice straw was achieved by laccase pretreatment with ionic liquid or surfactant in a single system. Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
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Review

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31 pages, 9375 KiB  
Review
An Overview on the Production of Biodiesel Enabled by Continuous Flow Methodologies
Catalysts 2022, 12(7), 717; https://doi.org/10.3390/catal12070717 - 29 Jun 2022
Cited by 15 | Viewed by 3394
Abstract
Biodiesel was produced via transesterification reaction catalyzed by acids, bases, enzymes or supercritical fluids. The catalysis was homogeneous or heterogeneous and the process could be carried out in batch or using a continuous flow process. Microreactors allowed us to obtain better control of [...] Read more.
Biodiesel was produced via transesterification reaction catalyzed by acids, bases, enzymes or supercritical fluids. The catalysis was homogeneous or heterogeneous and the process could be carried out in batch or using a continuous flow process. Microreactors allowed us to obtain better control of the experimental variables, such as temperature, pressure and flow rate, carrying out the reactions in safe conditions, avoiding exothermic and dangerous processes. The synthetic methodologies in continuous flow, combined with other technologies as microwave irradiation or ultrasounds, led to complete automation of the process with an increase in efficiency, also applicable on an industrial scale. Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
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37 pages, 548 KiB  
Review
Current State and Perspectives on Transesterification of Triglycerides for Biodiesel Production
Catalysts 2021, 11(9), 1121; https://doi.org/10.3390/catal11091121 - 18 Sep 2021
Cited by 48 | Viewed by 8149
Abstract
Triglycerides are the main constituents of lipids, which are the fatty acids of glycerol. Natural organic triglycerides (viz. virgin vegetable oils, recycled cooking oils, and animal fats) are the main sources for biodiesel production. Biodiesel (mono alkyl esters) is the most attractive alternative [...] Read more.
Triglycerides are the main constituents of lipids, which are the fatty acids of glycerol. Natural organic triglycerides (viz. virgin vegetable oils, recycled cooking oils, and animal fats) are the main sources for biodiesel production. Biodiesel (mono alkyl esters) is the most attractive alternative fuel to diesel, with numerous environmental advantages over petroleum-based fuel. The most practicable method for converting triglycerides to biodiesel with viscosities comparable to diesel fuel is transesterification. Previous research has proven that biodiesel–diesel blends can operate the compression ignition engine without the need for significant modifications. However, the commercialization of biodiesel is still limited due to the high cost of production. In this sense, the transesterification route is a crucial factor in determining the total cost of biodiesel production. Homogenous base-catalyzed transesterification, industrially, is the conventional method to produce biodiesel. However, this method suffers from limitations both environmentally and economically. Although there are review articles on transesterification, most of them focus on a specific type of transesterification process and hence do not provide a comprehensive picture. This paper reviews the latest progress in research on all facets of transesterification technology from reports published by highly-rated scientific journals in the last two decades. The review focuses on the suggested modifications to the conventional method and the most promising innovative technologies. The potentiality of each technology to produce biodiesel from low-quality feedstock is also discussed. Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
22 pages, 7839 KiB  
Review
A Focus on the Transformation Processes for the Valorization of Glycerol Derived from the Production Cycle of Biofuels
Catalysts 2021, 11(2), 280; https://doi.org/10.3390/catal11020280 - 20 Feb 2021
Cited by 13 | Viewed by 2409
Abstract
Glycerol is a valuable by-product in the biodiesel industries. However, the increase in biodiesel production resulted in an excess production of glycerol, with a limited market compared to its availability. Precisely because glycerol became a waste to be disposed of, the costs of [...] Read more.
Glycerol is a valuable by-product in the biodiesel industries. However, the increase in biodiesel production resulted in an excess production of glycerol, with a limited market compared to its availability. Precisely because glycerol became a waste to be disposed of, the costs of biodiesel production have reduced. From an environmental point of view, identifying reactions that can convert glycerol into new products that can be reused in different applications has become a real necessity. According to the unique structural characteristics of glycerol, transformation processes can lead to different chemical functionalities through redox reactions, dehydration, esterification, and etherification, with the formation of products that can be applied both at the finest chemical level and to bulk chemistry. Full article
(This article belongs to the Special Issue Catalytic Processes in Biofuel Production and Biomass Valorization)
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