2024, Vol. 9, No. 4
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2024,
9(4):
379-409.
doi: 10.1016/j.jobab.2024.05.003
Abstract:
Bacterial cellulose is a versatile material with applications in many industries. However, the widespread uptake of bacterial cellulose faces challenges including high production costs and lack of scalability. One approach to address these obstacles is the use of alternative substrates and media, compared to the Hestrin-Schramm (HS) media. By evaluating and selecting appropriate media and substrates, the production of bacterial cellulose can be more efficient: enabling sustainable systems and supply chains where less energy and materials are lost, and the output production is increased. The purpose of this paper is to analyze the current landscape of bacterial cellulose alternative media and substrates (ingredients). Through a systematic review of 198 papers, this review identifies 299 alternative substrates from 12 industries and 101 bacterial cellulose-producing strains, which were systematically compared. This review also finds that there are methodological gaps in this field such as data variability, papers mislabelling the HS media or not using a comparison media, and a lack of strain names. This alternative substrate analysis for bacterial cellulose production demonstrates that overall, for some applications alternative substrates can be taken into consideration that are not only cheaper, but also produce higher yields than HS media.
Bacterial cellulose is a versatile material with applications in many industries. However, the widespread uptake of bacterial cellulose faces challenges including high production costs and lack of scalability. One approach to address these obstacles is the use of alternative substrates and media, compared to the Hestrin-Schramm (HS) media. By evaluating and selecting appropriate media and substrates, the production of bacterial cellulose can be more efficient: enabling sustainable systems and supply chains where less energy and materials are lost, and the output production is increased. The purpose of this paper is to analyze the current landscape of bacterial cellulose alternative media and substrates (ingredients). Through a systematic review of 198 papers, this review identifies 299 alternative substrates from 12 industries and 101 bacterial cellulose-producing strains, which were systematically compared. This review also finds that there are methodological gaps in this field such as data variability, papers mislabelling the HS media or not using a comparison media, and a lack of strain names. This alternative substrate analysis for bacterial cellulose production demonstrates that overall, for some applications alternative substrates can be taken into consideration that are not only cheaper, but also produce higher yields than HS media.
2024,
9(4):
410-432.
doi: 10.1016/j.jobab.2024.07.002
Abstract:
As the global population continues growing, the demand for textiles also increases, putting pressure on cotton manufacturers to produce more natural fiber from this already undersupplied resource. Synthetic fibers such as polyester (PET) can be manufactured quickly and cheaply, but these petroleum-based products are detrimental to the environment. With increased efforts to encourage transparency and create a more circular textile economy, other natural alternatives must be considered. This article discusses the existing condition and future possibilities for man-made cellulosic fibers (MMCFs), with an emphasis on using non-woody alternative feedstocks as a starting material. This work focuses on conversion technology suitable for producing textile-grade fibers from non-wood-based dissolving pulp, which may be different in nature from its woody counterpart and therefore behave differently in spinning processes. Derivatization and dissolution methods are detailed, along with spinning techniques and parameters for these processes. Existing research related to the spinning of non-woody-based dissolving pulp is covered, along with suggestions for the most promising feedstock and technology combinations. In addition, an emerging method of conversion, in which textile fibers are spun from a hydrogel made of an undissolved nano/micro-fibrillated fiber suspension, is briefly discussed due to its unique potential. Methods and concepts compiled in this review relate to utilizing alternative feedstocks for future fibers while providing a better understanding of conventional and emerging fiber spinning processes for these fibers.
As the global population continues growing, the demand for textiles also increases, putting pressure on cotton manufacturers to produce more natural fiber from this already undersupplied resource. Synthetic fibers such as polyester (PET) can be manufactured quickly and cheaply, but these petroleum-based products are detrimental to the environment. With increased efforts to encourage transparency and create a more circular textile economy, other natural alternatives must be considered. This article discusses the existing condition and future possibilities for man-made cellulosic fibers (MMCFs), with an emphasis on using non-woody alternative feedstocks as a starting material. This work focuses on conversion technology suitable for producing textile-grade fibers from non-wood-based dissolving pulp, which may be different in nature from its woody counterpart and therefore behave differently in spinning processes. Derivatization and dissolution methods are detailed, along with spinning techniques and parameters for these processes. Existing research related to the spinning of non-woody-based dissolving pulp is covered, along with suggestions for the most promising feedstock and technology combinations. In addition, an emerging method of conversion, in which textile fibers are spun from a hydrogel made of an undissolved nano/micro-fibrillated fiber suspension, is briefly discussed due to its unique potential. Methods and concepts compiled in this review relate to utilizing alternative feedstocks for future fibers while providing a better understanding of conventional and emerging fiber spinning processes for these fibers.
2024,
9(4):
433-464.
doi: 10.1016/j.jobab.2024.02.001
Abstract:
Lignin is a rich renewable aromatic resource that can produce high-value-added chemicals. Lignin is regarded as one of the three major components of lignocellulosic biomass, which is composed of phenylpropane units connected by C-O bond and C-C bond. The cleavage of two chemical bonds is the main catalytic pathway in the production of chemicals and fuels from lignin. Although the cleavage of C-O converts lignin into valuable aromatic compounds and renewable carbon sources, selective depolymerization for C-C bonds is an important method to increase the yield of aromatic monomers. Therefore, in this review, we summarized the latest research trends on C-C bond selective cleavage in lignin and lignin model compounds, focusing on various catalytic systems, including hydrogenolysis, oxidate, photocatalysis, and electrocatalysis. By analyzing the current status of C-C bond breakage, the core issues and challenges related to this process and the expectations for future research were emphasized.
Lignin is a rich renewable aromatic resource that can produce high-value-added chemicals. Lignin is regarded as one of the three major components of lignocellulosic biomass, which is composed of phenylpropane units connected by C-O bond and C-C bond. The cleavage of two chemical bonds is the main catalytic pathway in the production of chemicals and fuels from lignin. Although the cleavage of C-O converts lignin into valuable aromatic compounds and renewable carbon sources, selective depolymerization for C-C bonds is an important method to increase the yield of aromatic monomers. Therefore, in this review, we summarized the latest research trends on C-C bond selective cleavage in lignin and lignin model compounds, focusing on various catalytic systems, including hydrogenolysis, oxidate, photocatalysis, and electrocatalysis. By analyzing the current status of C-C bond breakage, the core issues and challenges related to this process and the expectations for future research were emphasized.
2024,
9(4):
465-485.
doi: 10.1016/j.jobab.2024.07.003
Abstract:
Cellulose nanocrystals (CNCs) have garnered increased attention due to their renewable nature, abundant feedstock availbility, and good mechanical properties. However, one of the bottlenecks for its commercial production is the drying process. Because of the low CNC concentrations in suspension after isolation, CNC drying requires the removal of a large amount of water to obtain dry products for the following utilization and saving shipping costs. A novel multi-frequency, multimode, modulated ultrasonic drying technology was developed for CNC drying to improve product quality, reduce energy consumption, and increase production rate. CNCs dried with different drying technologies were characterized by Fourier transform infrared (FT-IR) spectra analysis, X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and redispersibility to measure the quality and property changes. Under the same temperature and airflow rate, ultrasonic drying enhanced drying rates, resulting in at least a 50% reduction in drying time compared to hot air drying. The mean particle sizes of CNC from ultrasonic drying changed little with settling time, indicating good redispersibility. In addition, ultrasonic dried CNCs exhibited good stability in aqueous solutions, with the zeta potentials ranging from -35 to -65 mV. Specific energy consumption and CO2emissions of various CNC drying technologies were evaluated. Energy consumption of ultrasonic drying is significantly reduced compared to other drying technologies. Moreover, the potential CO2 emissions of the fully electrified ultrasonic drying could be net zero if renewable electricity is used.
Cellulose nanocrystals (CNCs) have garnered increased attention due to their renewable nature, abundant feedstock availbility, and good mechanical properties. However, one of the bottlenecks for its commercial production is the drying process. Because of the low CNC concentrations in suspension after isolation, CNC drying requires the removal of a large amount of water to obtain dry products for the following utilization and saving shipping costs. A novel multi-frequency, multimode, modulated ultrasonic drying technology was developed for CNC drying to improve product quality, reduce energy consumption, and increase production rate. CNCs dried with different drying technologies were characterized by Fourier transform infrared (FT-IR) spectra analysis, X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and redispersibility to measure the quality and property changes. Under the same temperature and airflow rate, ultrasonic drying enhanced drying rates, resulting in at least a 50% reduction in drying time compared to hot air drying. The mean particle sizes of CNC from ultrasonic drying changed little with settling time, indicating good redispersibility. In addition, ultrasonic dried CNCs exhibited good stability in aqueous solutions, with the zeta potentials ranging from -35 to -65 mV. Specific energy consumption and CO2emissions of various CNC drying technologies were evaluated. Energy consumption of ultrasonic drying is significantly reduced compared to other drying technologies. Moreover, the potential CO2 emissions of the fully electrified ultrasonic drying could be net zero if renewable electricity is used.
2024,
9(4):
486-494.
doi: 10.1016/j.jobab.2024.09.002
Abstract:
Cavitation in water only, no matter whether hydrodynamic or acoustic, is a zero-waste circular economy process to convert industrial citrus processing waste into high-performance polysaccharides in high demand in a single-step at room temperature and ambient pressure using a modest amount of electricity as the only energy input. Following previous reports in which we used hydrodynamic cavitation, we now use an industrial acoustic sonicator to demonstrate the general viability of cavitation to convert biowaste residue of the industrial squeezing of pigmented sweet orange (Citrus sinensis) into highly bioactive “IntegroPectin” pectin and micronized cellulose “CytroCell”. From biomedicine through advanced composite membranes, said biomaterials hold great applicative potential. We conclude discussing the economic and technical feasibility of industrial implementation of the “CytroCav” process.
Cavitation in water only, no matter whether hydrodynamic or acoustic, is a zero-waste circular economy process to convert industrial citrus processing waste into high-performance polysaccharides in high demand in a single-step at room temperature and ambient pressure using a modest amount of electricity as the only energy input. Following previous reports in which we used hydrodynamic cavitation, we now use an industrial acoustic sonicator to demonstrate the general viability of cavitation to convert biowaste residue of the industrial squeezing of pigmented sweet orange (Citrus sinensis) into highly bioactive “IntegroPectin” pectin and micronized cellulose “CytroCell”. From biomedicine through advanced composite membranes, said biomaterials hold great applicative potential. We conclude discussing the economic and technical feasibility of industrial implementation of the “CytroCav” process.
2024,
9(4):
495-507.
doi: 10.1016/j.jobab.2024.07.001
Abstract:
A multiscale methodology approach was employed integrating microscopic analysis of the biomasses present in the biocomposite (lignocellulosic and fungal) to understand their macroscopic response in terms of physical and mechanical properties. Colombian native strain Ganoderma gibbosum, used for the first time in the production of biocomposites was cultivated on peach palm fruit peel flour and sugar cane bagasse wet dust, individually and as a mixture. During the solid-state fermentation were monitoring the change that occurred in substrate composition such as glucan, arabinoxylan, and lignin through biomass compositional analysis using structural carbohydrates and lignin. Moreover, fungal biomass formation was monitored via scanning electron microscopy. The resulting biocomposites underwent characterization through flexural and water absorption tests. Our findings indicated that G. gibbosum primarily degraded the polysaccharides in each of the evaluated media. However, lignin degradation to 15.06 g/g was only observed in the mixture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1:1, accompanied by a reduction in glucan and arabinoxylan weights to 26.1 and 7.72 g/g, respectively. This polymer degradation, combined with a protein-rich source in the mixture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1:1, facilitated the production of a fungal skin (biological matrix) with a high hyphal density of 65%, contributing to Young's modulus of 3.83 MPa, elongation without failure, and low water absorption rate in this biocomposite (55%). The lignocellulosic biomass in the culture media acted as a filler for mechanical interlocking with the matrix and provided attachment points for water absorption. Thus, our study establishes a connection between the microscopic scale and the macroscopic behavior of this biocomposite, assessing structural carbohydrates and lignin analysis during solid-state fermentation (SSF), laying the groundwork for a more customized design of mycelium-based biocomposites. Finally, this study demonstrates the possibility of tailoring nutrient composition by designing their culture media to obtain physical-mechanical properties according to the application requirement.
A multiscale methodology approach was employed integrating microscopic analysis of the biomasses present in the biocomposite (lignocellulosic and fungal) to understand their macroscopic response in terms of physical and mechanical properties. Colombian native strain Ganoderma gibbosum, used for the first time in the production of biocomposites was cultivated on peach palm fruit peel flour and sugar cane bagasse wet dust, individually and as a mixture. During the solid-state fermentation were monitoring the change that occurred in substrate composition such as glucan, arabinoxylan, and lignin through biomass compositional analysis using structural carbohydrates and lignin. Moreover, fungal biomass formation was monitored via scanning electron microscopy. The resulting biocomposites underwent characterization through flexural and water absorption tests. Our findings indicated that G. gibbosum primarily degraded the polysaccharides in each of the evaluated media. However, lignin degradation to 15.06 g/g was only observed in the mixture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1:1, accompanied by a reduction in glucan and arabinoxylan weights to 26.1 and 7.72 g/g, respectively. This polymer degradation, combined with a protein-rich source in the mixture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1:1, facilitated the production of a fungal skin (biological matrix) with a high hyphal density of 65%, contributing to Young's modulus of 3.83 MPa, elongation without failure, and low water absorption rate in this biocomposite (55%). The lignocellulosic biomass in the culture media acted as a filler for mechanical interlocking with the matrix and provided attachment points for water absorption. Thus, our study establishes a connection between the microscopic scale and the macroscopic behavior of this biocomposite, assessing structural carbohydrates and lignin analysis during solid-state fermentation (SSF), laying the groundwork for a more customized design of mycelium-based biocomposites. Finally, this study demonstrates the possibility of tailoring nutrient composition by designing their culture media to obtain physical-mechanical properties according to the application requirement.
2024,
9(4):
508-517.
doi: 10.1016/j.jobab.2024.09.001
Abstract:
Selective conversion of biomass into targeted molecules like polyols, especially, from cellulosic compounds, is being widely investigated as a sustainable process to produce biodiesel and bio-additives. The known process involves two steps, namely hydrolysis and hydrogenation. Thus, it requires two different catalytic materials or bifunctional catalysts. In this context, the present work reports a new catalytic approach based on the use of tandem catalysts, consisting of the combination of an acid solid catalyst (active for hydrolysis) and a supported metal catalyst (active for hydrogenation). Two different functionalized activated carbons and the resin Amberlyst 15 have been tested as solid acid catalysts, and Ru nanoparticles supported on the original activated carbon (SA) are the metal catalyst part of the tandem. All the tested tandem catalysts exhibited higher activity than the supported Ru catalyst did. The highest cellulose conversion and selectivity to sorbitol (70% and 86%, respectively) have been obtained over a novel tandem catalyst, which resulted from a physical mixture between a sulfuric acid modified SA carbon (SASu) and Ru loaded SA (Ru/SA), leading to a tandem catalyst (Ru/SA+SASu). This novel-designed tandem catalyst is reusable. Based on tandem catalysts with a solid-solid system combination, the adopted novel-designed catalytic approach is cost-efficient and sustainable, and can be considered promising for the green production of high-added-value chemicals.
Selective conversion of biomass into targeted molecules like polyols, especially, from cellulosic compounds, is being widely investigated as a sustainable process to produce biodiesel and bio-additives. The known process involves two steps, namely hydrolysis and hydrogenation. Thus, it requires two different catalytic materials or bifunctional catalysts. In this context, the present work reports a new catalytic approach based on the use of tandem catalysts, consisting of the combination of an acid solid catalyst (active for hydrolysis) and a supported metal catalyst (active for hydrogenation). Two different functionalized activated carbons and the resin Amberlyst 15 have been tested as solid acid catalysts, and Ru nanoparticles supported on the original activated carbon (SA) are the metal catalyst part of the tandem. All the tested tandem catalysts exhibited higher activity than the supported Ru catalyst did. The highest cellulose conversion and selectivity to sorbitol (70% and 86%, respectively) have been obtained over a novel tandem catalyst, which resulted from a physical mixture between a sulfuric acid modified SA carbon (SASu) and Ru loaded SA (Ru/SA), leading to a tandem catalyst (Ru/SA+SASu). This novel-designed tandem catalyst is reusable. Based on tandem catalysts with a solid-solid system combination, the adopted novel-designed catalytic approach is cost-efficient and sustainable, and can be considered promising for the green production of high-added-value chemicals.
2024,
9(4):
518-533.
doi: 10.1016/j.jobab.2024.07.004
Abstract:
Caragana korshinskii kom. (CKK) waste, a common forestry byproduct in northwest of China, presents challenges in its transformation into alternative ruminant feed due to its initial nutritional limitations and unappealing palatability. Conventional strategies, such as ensiling and fungal-based solid-state fermentation (SSF) cannot effectively address this issue in practice. Herein, a two-stage bioaugmentation (TBA) process was devised, leveraging the benefits of ensiling and SSF. During the anaerobic ensiling phase, CKK waste was inoculated with Lactiplantibacillus plantarum LP1, effectively suppressing potential animal pathogens such as Aspergillus and Nocardiopsis while enriching the material with potential probiotics like Pediococcus and Lactiplantibacillus, reaching an abundance of 95.7%. In the subsequent aerobic SSF stage, the ensiled CKK underwent inoculation with the white-rot fungus Irpex lacteus F17, which became enriched to 87.9%. Comprehensive multi-omics analysis identified Irpex as the key taxon, possessing an extensive redox enzyme system that led to the improvement in nutrient composition, reduction of astringent phenolic substances, and mitigation of mycotoxins. As a result, the crude protein content of the CKK increased by 39.2%, while lignin, total phenolic substances, and tannic acid content decreased by 24.4%, 52.2%, and 51.4%, respectively. The mycotoxin levels, including aflatoxin B1, zearalenone, and vomitoxin, were rendered negligible, confirming the safety. Overall, this study demonstrates the TBA strategy can successfully transform challenging and unpalatable CKK waste into a nutrient-enriched and safe mycelium-based bioproduct, thereby enabling the valorization of a previously underutilized forestry resource as a promising alternative feed.
Caragana korshinskii kom. (CKK) waste, a common forestry byproduct in northwest of China, presents challenges in its transformation into alternative ruminant feed due to its initial nutritional limitations and unappealing palatability. Conventional strategies, such as ensiling and fungal-based solid-state fermentation (SSF) cannot effectively address this issue in practice. Herein, a two-stage bioaugmentation (TBA) process was devised, leveraging the benefits of ensiling and SSF. During the anaerobic ensiling phase, CKK waste was inoculated with Lactiplantibacillus plantarum LP1, effectively suppressing potential animal pathogens such as Aspergillus and Nocardiopsis while enriching the material with potential probiotics like Pediococcus and Lactiplantibacillus, reaching an abundance of 95.7%. In the subsequent aerobic SSF stage, the ensiled CKK underwent inoculation with the white-rot fungus Irpex lacteus F17, which became enriched to 87.9%. Comprehensive multi-omics analysis identified Irpex as the key taxon, possessing an extensive redox enzyme system that led to the improvement in nutrient composition, reduction of astringent phenolic substances, and mitigation of mycotoxins. As a result, the crude protein content of the CKK increased by 39.2%, while lignin, total phenolic substances, and tannic acid content decreased by 24.4%, 52.2%, and 51.4%, respectively. The mycotoxin levels, including aflatoxin B1, zearalenone, and vomitoxin, were rendered negligible, confirming the safety. Overall, this study demonstrates the TBA strategy can successfully transform challenging and unpalatable CKK waste into a nutrient-enriched and safe mycelium-based bioproduct, thereby enabling the valorization of a previously underutilized forestry resource as a promising alternative feed.
2024,
9(4):
534-547.
doi: 10.1016/j.jobab.2024.09.003
Abstract:
Lignin serves as a promising Ultraviolet (UV) absorber within sunscreen industry. However, the commercial development of lignin-containing sunscreens faces challenges due to their low sun protection factor (SPF) and dark color in cosmetics industry. In this study, dual modifications on the chemical and physical structures of lignin were conducted to address these challenges. Initially, methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) was grafted onto alkali lignin (AL) through an atom transfer radical polymerization reaction, resulting in a polymer of AL-graft-MBBT3 (AL-g-MBBT3). The sunscreen prepared with 10% AL-g-MBBT3 displays outstanding sun protection performance with a SPF of 42.93 and a light color with a color difference value (ΔE) of 45.6, in contrast to 10% AL with a SPF of 4.74 and a ΔE value of 49.5. Subsequently, AL-g-MBBT3 was transformed into normal submicron spheres (AL-g-MBBT3N) and TiO2-loading submicron spheres (AL-g-MBBT3/TiO2). The sun protection performances of 10% AL-g-MBBT3N@C and AL-g-MBBT3/TiO2@C sunscreens obviously surpass that of AL-g-MBBT3@C sunscreen, achieving SPFs of 60.38 and 66.20, respectively. Additionally, there is a considerable improvement in the color of these sunscreens, with ΔE values of 41.8 and 36.3, respectively. These results provide valuable insights into exploring lignin's high-value applications in sunscreen.
Lignin serves as a promising Ultraviolet (UV) absorber within sunscreen industry. However, the commercial development of lignin-containing sunscreens faces challenges due to their low sun protection factor (SPF) and dark color in cosmetics industry. In this study, dual modifications on the chemical and physical structures of lignin were conducted to address these challenges. Initially, methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) was grafted onto alkali lignin (AL) through an atom transfer radical polymerization reaction, resulting in a polymer of AL-graft-MBBT3 (AL-g-MBBT3). The sunscreen prepared with 10% AL-g-MBBT3 displays outstanding sun protection performance with a SPF of 42.93 and a light color with a color difference value (ΔE) of 45.6, in contrast to 10% AL with a SPF of 4.74 and a ΔE value of 49.5. Subsequently, AL-g-MBBT3 was transformed into normal submicron spheres (AL-g-MBBT3N) and TiO2-loading submicron spheres (AL-g-MBBT3/TiO2). The sun protection performances of 10% AL-g-MBBT3N@C and AL-g-MBBT3/TiO2@C sunscreens obviously surpass that of AL-g-MBBT3@C sunscreen, achieving SPFs of 60.38 and 66.20, respectively. Additionally, there is a considerable improvement in the color of these sunscreens, with ΔE values of 41.8 and 36.3, respectively. These results provide valuable insights into exploring lignin's high-value applications in sunscreen.
2024,
9(4):
548-564.
doi: 10.1016/j.jobab.2024.09.004
Abstract:
Many effective pretreatment methods (such as dilute acid, dilute alkali, ionic liquids, etc.) have been developed for lignocellulose upgrading, but several defaults of low working mass, high sugar loss and extra cost of solid-liquid separation and water washing hinder their large-scale application in industry. Besides, the valorization of lignin-rich residue from pretreated biomass after hydrolysis or fermentation greatly contributes to the economy and sustainability of lignocellulosic biorefinery, which is usually underestimated. This study developed a densification pretreatment with binary chemicals (densifying lignocellulosic biomass with sulfuric acid (SA) and metal salt (MS) followed by autoclave treatment ((DLCA(SA-MS)), which was conducted under mild condition (121 ℃) with a biomass working mass as high as 400 kg/m3. The DLCA(SA-MS) biomass achieved over 95% sugar retention, 90% enzymatic sugar conversion and a high concentration of fermentable sugar (212.3 g/L) with superior fermentability. Furthermore, bio-adsorbent derived from DLCA(SA-MS) biomass residue was highly adsorptive and suitable for dyeing wastewater treatment, providing a feasible and eco-friendly method for lignin-rich residue valorization. These findings indicated that DLCA(SA-MS) pretreatment enables the full-component utilization of biomass and boosts the economic viability of lignocellulosic biorefinery.
Many effective pretreatment methods (such as dilute acid, dilute alkali, ionic liquids, etc.) have been developed for lignocellulose upgrading, but several defaults of low working mass, high sugar loss and extra cost of solid-liquid separation and water washing hinder their large-scale application in industry. Besides, the valorization of lignin-rich residue from pretreated biomass after hydrolysis or fermentation greatly contributes to the economy and sustainability of lignocellulosic biorefinery, which is usually underestimated. This study developed a densification pretreatment with binary chemicals (densifying lignocellulosic biomass with sulfuric acid (SA) and metal salt (MS) followed by autoclave treatment ((DLCA(SA-MS)), which was conducted under mild condition (121 ℃) with a biomass working mass as high as 400 kg/m3. The DLCA(SA-MS) biomass achieved over 95% sugar retention, 90% enzymatic sugar conversion and a high concentration of fermentable sugar (212.3 g/L) with superior fermentability. Furthermore, bio-adsorbent derived from DLCA(SA-MS) biomass residue was highly adsorptive and suitable for dyeing wastewater treatment, providing a feasible and eco-friendly method for lignin-rich residue valorization. These findings indicated that DLCA(SA-MS) pretreatment enables the full-component utilization of biomass and boosts the economic viability of lignocellulosic biorefinery.
2024,
9(4):
565-576.
doi: 10.1016/j.jobab.2024.06.001
Abstract:
Organotin mercaptide-based thermal stabilizer is recognized for its effectiveness in enhancing thermal stability of polyvinyl chloride (PVC). In this study, we synthesized an organotin mercaptide-based thermal stabilizer from palm fatty acid distillate, which is a by-product of palm oil refining process, and then evaluated its thermal stabilizing effects on PVC and compared its efficacy and economics to those of mixed metal stearate. The synthesized thermal stabilizer manifests as methyltin mercaptoethyl carboxylate sulfides. Both dehydrochlorination and two-roll mill discoloration tests have demonstrated the high efficacy of the resulting thermal stabilizer in stabilizing PVC, surpassing the performance of mixed metal stearate, as evidenced by the lower dosage required. The synthesized PVC thermal stabilizer not only provides effective stabilization but also presents a competitive viable alternative.
Organotin mercaptide-based thermal stabilizer is recognized for its effectiveness in enhancing thermal stability of polyvinyl chloride (PVC). In this study, we synthesized an organotin mercaptide-based thermal stabilizer from palm fatty acid distillate, which is a by-product of palm oil refining process, and then evaluated its thermal stabilizing effects on PVC and compared its efficacy and economics to those of mixed metal stearate. The synthesized thermal stabilizer manifests as methyltin mercaptoethyl carboxylate sulfides. Both dehydrochlorination and two-roll mill discoloration tests have demonstrated the high efficacy of the resulting thermal stabilizer in stabilizing PVC, surpassing the performance of mixed metal stearate, as evidenced by the lower dosage required. The synthesized PVC thermal stabilizer not only provides effective stabilization but also presents a competitive viable alternative.
2024,
9(4):
577-591.
doi: 10.1016/j.jobab.2024.06.002
Abstract:
This study aimed to systematically find an alternative solvent to replace hexane for the extraction of bio-oil with high γ-oryzanol content from rice bran (RB). The selection involved predicting solubility through Hansen solubility theory, experimental validation, determination of suitable extraction conditions, and comparison of oil quality with that of conventional hexane. A wide variety of solvents: subcritical water (SCW), supercritical carbon dioxide (SCCO2), bio-based solvents (alcohols and terpenes), and liquefied dimethyl ether (LDME), were initially assessed for rice bran oil (RBO) and γ-oryzanol solubility using Hansen solubility spheres. Solvents demonstrating high solubility for both RBO and γ-oryzanol, including LDME, ethyl acetate, acetone, and others (alcohols and SCCO2) known for effective vegetable oil extraction, were selected/identified for experimental extraction comparison. Among these, LDME performed better overall, affording greater solubility and requiring less solvent, shorter duration, lower pressure, and no additional co-solvents for equivalent extractions. Optimal conditions for LDME extraction were identified as 30 ℃ with a solvent-to-sample ratio of 10 mL/g and an extraction time of 10 min. Oils extracted with LDME and hexane displayed similar fatty acid compositions and no adverse effects on RB protein and carbohydrate structures after LDME extraction were observed. This study demonstrates LDME as a promising alternative to replace hexane for RBO extraction to further valorize this abundant low-cost RB residue into bio-oil and its γ-oryzanol and de-oil RB co-products.
This study aimed to systematically find an alternative solvent to replace hexane for the extraction of bio-oil with high γ-oryzanol content from rice bran (RB). The selection involved predicting solubility through Hansen solubility theory, experimental validation, determination of suitable extraction conditions, and comparison of oil quality with that of conventional hexane. A wide variety of solvents: subcritical water (SCW), supercritical carbon dioxide (SCCO2), bio-based solvents (alcohols and terpenes), and liquefied dimethyl ether (LDME), were initially assessed for rice bran oil (RBO) and γ-oryzanol solubility using Hansen solubility spheres. Solvents demonstrating high solubility for both RBO and γ-oryzanol, including LDME, ethyl acetate, acetone, and others (alcohols and SCCO2) known for effective vegetable oil extraction, were selected/identified for experimental extraction comparison. Among these, LDME performed better overall, affording greater solubility and requiring less solvent, shorter duration, lower pressure, and no additional co-solvents for equivalent extractions. Optimal conditions for LDME extraction were identified as 30 ℃ with a solvent-to-sample ratio of 10 mL/g and an extraction time of 10 min. Oils extracted with LDME and hexane displayed similar fatty acid compositions and no adverse effects on RB protein and carbohydrate structures after LDME extraction were observed. This study demonstrates LDME as a promising alternative to replace hexane for RBO extraction to further valorize this abundant low-cost RB residue into bio-oil and its γ-oryzanol and de-oil RB co-products.
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