Biomass Conversion and Biorefinery最新文献

Abstract

The combustion of second-generation (non-edible) biomass may be leveraged to jointly improve energy, environmental quality, and value-added products. This study used thermoanalytical methods to characterize and jointly optimize the energetic, environmental (gas-to-ash responses), and operational performances of the combustion of Lycium barbarum L. (LBL) in the N₂/O₂ and CO₂/O₂ atmospheres. The increased heating rate rendered the reactions more intense and delayed them in the thermogravimetric curve. CO₂ delayed the reactions. Activation energy was in the range of 166.95-177.45 kJ/mol. The main gaseous products detected were H₂O, CH₄, CO₂, CO, C=O, C-O(H), C=C and NH₃. The optimal combination of the N₂/O₂ atmosphere and the range of ≥ 671 °C simultaneously minimized the emissions of the gaseous products. LBL ash was of the K type and had a serious slagging tendency and high deposition risk. The CO₂/O₂ atmosphere aggravated the slagging.

Graphical Abstract

This study undertakes a comparative examination of the efficacy of biomass-derived tamarind shell powder and roasted chickpeas fillers within Kenaf fiber reinforced vinyl ester composite. The main objective of this research was to study the impact of adding biomass fillers into the natural fibre-reinforced vinyl ester resin composite. Since these two fillers are available in huge volume, converting the same as useful reinforcement provide valuable insights. The fabrication method employed adhered to the hand layup technique, and testing procedures followed ASTM standards. Overall, the composites containing tamarind shell powder demonstrated superior performance across various tests. For instance, in mechanical testing, the AT2 designation exhibited remarkable results with a tensile strength of 150MPa, flexural strength of 181MPa, ILSS of 32.7MPa, impact energy of 5.34J, and a hardness of 78. In terms of wear properties, the AT3 composite displayed the lowest wear rate of 0.017mm3/Nm and a coefficient of friction (COF) of 0.25, indicating enhanced wear resistance. Additionally, the AT3 composite showcased superior thermal conductivity properties, recording 0.46W/mK. Despite these advantages, the A composite designation showed the lowest water absorption, primarily attributed to the increased hydrophilic nature resulting from the inclusion of tamarind and roasted chickpeas fillers. Notably, tamarind exhibited a slightly reduced hydrophilic nature compared to roasted chickpeas. These findings underscore the potential of tamarind shell powder as a promising filler material for improving the performance of Kenaf fiber reinforced vinyl ester composites, particularly in mechanical, wear, thermal conductivity, and water absorption aspects.

In the present investigation, banana fibers extracted from Ethiopia are utilized to fabricate the composites with different fiber architectures in the epoxy matrix. Six different types of composites—untreated/treated chopped banana epoxy composite (UCBEC/TCBEC), untreated/treated woven banana epoxy composite (UWBEC/TWBEC), and untreated/treated chopped banana woven banana epoxy composite (UCBWBEC/TCBWBEC)—are prepared with the hand layup technique. The prepared composites are subjected to three-point flexural tests to confirm the structural integrity. Flexural strength and modulus of all the composites were evaluated experimentally while numerical simulation was performed using finite element analysis (FEA) to validate the results. Experimental results showed that TWBEC (treated woven banana epoxy composite) composites attained an 11 to 25% higher flexural strength than other compositions due to fiber treatment and weaving patterns. Additionally, the interaction between fiber and matrix was explored through appropriate theoretical modeling. Results inferred that full-oriented, continuous woven matting reinforcements increase shear strength while chopped fiber reinforcement has decreased shear strength due to discontinuity and higher aspect ratio. A scanning electron microscope was used to examine post-fracture surfaces to look into the failure process. The results of the numerical simulation are utilized in order to validate the findings of the study. The numerical results are in good agreement with experimental findings with a 5% accuracy loss. Finally, the outcomes of the present study are compared with those of previous research, presented in the format of a property map.

Since environmental pollution causes cancer, mutagenesis, and teratogenic consequences in living things, it has emerged as one of the most devastating threats to human life in the industrialized world. To cope with this issue, bioremediation seems to be the most cost-effective and eco-friendly method that works by utilizing bio-based materials as precursor substances for the production of useful plants’ secondary metabolites. This review will specifically focus on nature identical vanillin, one of the widely used flavoring ingredients, by providing its brief introduction, demographic origin, and its types. The aim of this review centralizes around the importance of the eco-friendly, cost-effective, and sustainable production of vanillin through different precursors that can be obtained from fruit wastes. It will also highlight the suitable approaches that can be employed to produce vanillin by microbial conversion of fruit waste. Additionally, it will elaborate the mechanisms underlined by different microbial species to synthesize bio-vanillin. Moreover, this article will also underline the pharmacotherapeutic potential of vanillin that will contribute to the greater goal of developing safe treatments to prevent infectious disorders.

Recent developments in reinforced plastics for a range of engineering applications have utilized natural fiber mat as a reinforcing material. The goal of the current work is to create a biocomposite material by adding a natural fiber mat with polymer. Areca fiber mats were combined with epoxy to fabricate five areca fiber mat-based biocomposites via the hand lay-up technique. These areca fiber mats were reinforced with epoxy in the number of mat layers or weight of fiber mat varying (0, 1, 2, 3, and 4). Tensile, flexural, and impact strengths of the manufactured areca fiber mat composite were investigated. We used SEM to conduct a morphological examination on specimens that had undergone tensile and flexural fracture. The thermogravimetric analysis (TGA) method was used to study the thermal strength of the novel areca fiber mat composites. We also conducted experiments on water absorption and biodegradability. The results indicated that the morphologies of the composites enhanced the mechanical characteristics by increasing the bonding between the epoxy and areca fiber mat. The three-layer areca fiber mat composite has better mechanical strength (tensile 41.8 MPa, flexural 192 MPa, and impact 2.9 J) and thermal qualities (highest thermal stability 17.9 %) than the other four composites. SEM scans also support the areca fiber mat composite.

Feather is a high recalcitrance keratin-based biomass, and keratin-degrading microorganisms have been seen as beneficial tools for its biodegradation and production of valuable products with biomedical and industrial applications. In the current study, the isolated keratinolytic bacteria was identified on the base of its 16 S rDNA sequencing data as Bacillus halotolerans, and its efficiency in the hydrolysis of feather with the preservation of most of its amino acid constituent was estimated by high-performance liquid chromatography Pico-Tag (HPLC PICO-TAG) method. The produced hydrolysate possessed antioxidant activity of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of 52.3 ± 5.6 mmole TE/g without possessing any cytotoxicity to human normal skin fibroplast cell line BJ-1 estimated by MTT assay. Moreover, the isolated strain was capable for producing keratinase under submerged fermentation of feather that was optimized by combining single-variable-at-a-time optimization with the application of statistical designs (Plackett-Burman and Box-Behnken). The optimum keratinase activity was 140.83 U/mL that was enhanced by 3.2-fold of the estimated initial activity, and the purified enzyme possessed optimum activity at pH 9.5 and 70 °C with a half-life of 69.3 min. Finally, the applicability of the purified enzyme in the dehairing of bovine hide was examined in comparison to sodium sulfide (Na₂S) and lime (Ca(OH)₂) conventional method. The results estimated the efficiency of the examined bio-treatment process, it achieved complete dehairing after 2 h with a good skin quality as manifested by scanning electron microscope (SEM). In addition, a significant reduction of the pollution load parameters was estimated.

The complex structure of lignocellulosic biomass is a key factor impeding its bioconversion. This study identified three fungi with high lignin-degrading efficiency from decayed wood and established a fungal consortium named MR. Utilizing response surface methodology, the study optimized enzyme production by MR. This resulted in achieving a maximum laccase activity of 668.83 U/L under specific conditions: 68.91 mL working volume, 12.16% inoculum, 22.57 carbon-to-nitrogen ratio, and 6.2 days of incubation. The effectiveness of MR’s hydrolysis was demonstrated by utilizing 10 g/L soybean straw as the sole carbon source, with an 8% inoculum and a 4-day inoculation period. The relative degradation rate of lignin remained at 68.4%. The acetic acid concentration in the hydrolysate reached 209.85 mmol/L, representing over 80% of all volatile fatty acids. These findings suggest that the fungal consortium MR holds significant promise for efficiently converting lignocellulosic biomass into bioenergy and biofuels, offering a potentially sustainable solution to address energy and environmental challenges.

Graphical abstract

The modification of clay material using a natural polymer starch. The authors evaluate the thermal modifications of starch and their impact on the clay composite. They detail the process of preparing starch and examine how varying concentrations of starch (20%, 40%) affect the mechanical properties and structure of the clay composite. A good dispersion of the components in the mix was observed via an electron scanning microscope. Using the nano indentation method, it was observed that the materials with the highest elasticity had the lowest amount of clay and the highest concentration of glycerol. The experimental findings indicate that increasing the concentration of starch and its heat treatment time enhances clay strength by up to 74%. The addition of starch is observed to result in a denser structure for the clay composite, evidenced by an increase in bulk density (up to 2.5%) and reduction in shrinkage by over 1%. This modification approach shows great promise, offering both environmental friendliness and elevated mechanical properties for the resulting clay material.

A new energy system that utilizes solid oxide fuel cell (SOFC) and biomass gasification for integrated cooling, heating, and power with carbon capture is being evaluated. The suggested energy system is comprehensively evaluated utilizing the 4E analysis (energy, exergy, economics, and environment) under constant SOFC AC output power of 120 kW. The cooling model’s total energy and exergy efficiency are 67.2% and 48.3%, respectively, while the heating model achieved 71.6% and 49%, respectively. The gasifier, SOFC, WGSMR-burner, HX-1, and HX-3 have the highest exergy destruction, with respective values of 37.78 kW, 6.24 kW, 11.318 kW, 18.42 kW, and 17.536 kW. According to the economic study, if payback is desired within 5 years, the power tariff should be 0.13$/KW, which is roughly comparable to the market price. By varying the effect parameters ER, S/B ratio, and FU, the energy system produced low carbon dioxide emissions of approximately 0.11 to 0.15 t/GJ, which shows that it has limited environmental impact.

In order to improve the milling efficiency and wear resistance of hammer mills, diamond grains were brazed onto a T-shaped SUS 304 stainless steel hammer with an orderly patterned arrangement. The impact of grain arrangement patterns, size, and density on the milling efficiency and wear resistance of the hammer was investigated through the milling of maize kernels under an actual hammer milling condition. The milled maize powder and wear characteristics of the brazed diamond hammer were observed using a scanning electron microscope (SEM), and the particle size distribution of milled maize powder was analyzed using a laser particle size analyzer, and the wear of the hammers was measured by an electronic balance. The hammer with brazed diamond grains exhibited a significant increase in milling efficiency and wear resistance, surpassing that of the SUS 304 stainless steel hammer by more than 1.76 and 8 times, respectively. Optimal milling efficiency was attained through the use of brazed diamond grains incorporating an inclined arrangement pattern, small grain size, and low arrangement density. On the other hand, hammers with normal arrangement patterns, large grain size, and high arrangement density of diamond grains demonstrated superior wear resistance. The brazed diamond hammer takes into account both milling efficiency and wear resistance, because the orderly brazed diamond grains result in a substantial increase in the contact area with the material, thereby enhancing impact and friction. By appropriately selecting the arrangement patterns, density, and grain size of diamond grains, hammers with varying levels of milling efficiency and wear resistance can be obtained.