Biofuels Bioproducts & Biorefining-Biofpr最新文献

Conventional jet fuels derived from fossil sources contribute to greenhouse gas emissions and air pollution, leading to climate change. Recent studies have shown that biobased jet fuels from different feedstocks offer a more sustainable alternative to conventional fuels as they are derived from renewable biomass, reducing greenhouse gas emissions. The major feedstocks reviewed are jatropha curcas, camelina, karanja oil, waste cooking oil, and municipal solid waste. They offer diverse benefits for sustainable aviation fuel development. As a comparative analysis, this review examined jet fuel characteristics based on their physicochemical properties, namely energy content, viscosity, calorific value, cetane number, and freezing and flash points. The objective was to understand the influence of the properties on performance evaluation, environmental impact, and combustion characteristics. The properties of biojet fuels are compared with their fossil counterparts to validate their suitability as renewable alternatives and their benefits in terms of emissions reduction and engine performance. Biojet fuels perform better in terms of lower sulfur content, lower soot content, and a lower freezing point, their aromatic content, and their high cetane number. This study enhances the understanding of biojet fuels and their quality, and supports the development of sustainable fuel options. Overall, adherence to the American Society for Testing and Materials (ASTM) D7566-18 standard is crucial for the acceptance and integration of biojet fuels into the aviation sector. Future research should explore feedstocks such as wood biomass, wastepaper, and agricultural residues for biojet fuels. It should also investigate the combustion and emission characteristics of biosourced aviation fuel at higher blending ratios (>50% by volume) with fossil Jet A-1.

This study aimed to improve the production of biodiesel from white palm larvae (WPL) and to evaluate its potential as a feedstock. The larvae were grown using kitchen and palm waste for 21 days, and the crude oil was then extracted. The extracted oil was analyzed for its physicochemical properties and fatty acid composition. The analysis found that the feedstock oil contained a high quantity of monounsaturated fatty acids, indicating its suitability for biodiesel production. To optimize the production process, response surface methodology (RSM) was employed. A central composite design was used to study four operating conditions: temperature, methanol-to-oil mole ratio, esterification time, and catalyst loading for esterification, as well as transesterification time and catalyst concentration. The best conditions for esterification were a methanol-to-oil ratio of 18:1, a temperature of 70 °C, 120 min of reaction time, and a 4% H₂SO₄ catalyst. For transesterification, the optimal conditions were a methanol-to-oil ratio of 10:1, a temperature of 65 °C, 90 min of reaction time, and a 2% KOH catalyst concentration. The experimental data fit well with models, with significant P-values and high R² values. The biodiesel produced under the optimized conditions met the fuel quality standards set by Brazilian, European, and American standards. In conclusion, this study successfully optimized the biodiesel production process from white palm larvae and confirmed its suitability as a feedstock. The feedstock oil had properties that were suitable for biodiesel production, and the optimized conditions resulted in biodiesel that met fuel-quality standards.

This study aimed to assess the feasibility of utilizing sweet potato waste for distilled beverage production in two process scenarios: (i) acid hydrolysis and (ii) enzymatic hydrolysis. Laboratory experiments were conducted using in natura sweet potato waste and the data obtained were used to design a production system capable of producing 1000 L of distillate per day. Net present value (NPV), internal rate of return (IRR), and discounted payback indicators were used for economic analysis, with a minimum attractiveness rate (MARR) of 15%. The initial investment for the projects was BRL 1 139 610.86 (USD 223 146.80) for enzymatic hydrolysis and BRL 1 314 824.54 (USD 257 455.36) for acid hydrolysis. Packaging costs were identified as the greatest expenses in the process. Assuming a selling price of BRL 14.50 (USD 2.84), the enzymatic hydrolysis process demonstrated an NPV of BRL 4 792 520.77 (USD 938 421.92) and IRR of 83.39%, and the acid hydrolysis process showed an NPV of BRL 2 191 636.78 (USD 429 143.68) and IRR of 42.49%. Consequently, establishing a production plant for distilled beverages proved to be more economically attractive when employing the enzymatic hydrolysis process and fermentation simultaneously, resulting in a return on investment within 1.46 years of operation. Upon scrutinizing the gain matrix, it became apparent that critical factors with the potential to affect the project's feasibility detrimentally, if increased, included the cost of acquiring packaging, the final volumetric fraction of the distilled beverage, and the tax rate. Nevertheless, an upturn in the selling price of the beverage and a process improvement yield both have the potential to underpin the project effectively.

There has been a growing interest in ecofriendly enzymatic processes. However, enzyme solubility limits the application of many biocatalysts in continuous systems, requiring the development of cost-effective strategies for enzyme immobilization. Based on this premise, this study investigated the application of lipase immobilized in starch–alginate beads for oil transesterification in a tubular reactor. An economical derivative was produced by immobilizing Eversa Transform 2.0 in 50:50 (w/w) starch–alginate beads using the jet-cutting technique. The biocatalyst had a particle size of about 500 μm and activity of 138.67 ± 18.53 U g⁻¹. X-ray photoelectron spectroscopy showed nitrogen content ranging from 6.38% to 7.29%, with uniform distribution of lipase throughout the beads. Nitrogen isotherms were characteristic of mesoporous materials, with an average pore diameter of 48.09 Å and low surface area (0.69 m² g⁻¹). A face-centered central composite design was used to study soybean oil transesterification. In the best four runs, the process achieved a mean triglyceride conversion of 45%. High ester productivity levels (2.05 × 10⁻²% ester g⁻¹ biocatalyst min⁻¹ or 1.5 × 10⁻⁴% ester U⁻¹ min⁻¹) were obtained. Biocatalyst reuse led to a twofold increase in ester concentration (14.57% vs 7.7%). These findings confirm the successful development of a low-cost biocatalyst suitable for use in continuous reactions.

The development of aviation biofuels is a key strategy for reducing carbon emissions in the aviation industry. This study aimed to establish a surrogate model for aviation biofuels using a hybrid approach that combined explicit equations with an artificial neural network (ANN). The low heating value was calculated using an explicit equation, whereas the ANN predicted changes in density, viscosity, surface tension with temperature, and the distillation curve of the surrogate model. An optimization algorithm was then employed to identify suitable substitutes, which consisted of 11.44% n-decane, 43.43% n-dodecane, 43.11% n-tetradecane, and 2.02% methylcyclohexane. The maximum error between the physical properties of the surrogate components and the measured biofuels did not exceed 7%. The ignition delay time of the substitute components matched that of real aviation biofuels at an equivalence ratio of 1.0 and a pressure of 10 bar.

Mesoporous niobium-based solid acid catalysts were successfully synthesized using the soft template method with sodium lignosulfonate (SLS) as the template. In most studies the template is calcined to form mesopores after hydrothermal synthesis; however, in this study SLS was retained to produce niobium-carbon composite catalysts. The catalysts obtained were characterized by X-ray diffraction, nitrogen adsorption–desorption, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and static contact angle measurements. The catalytic activity of the solids was also investigated in the conversion of glucose to 5-hydroxymethylfurfural (HMF) using pure water as the solvent. Under optimal conditions, niobium-carbon composite catalyst achieved a glucose conversion yield of 65.1% and an HMF yield of 42.1%. The enhanced catalytic activity was attributed to the timely extraction of the HMF by the carbonized SLS.

Supercritical fluid impregnation (SFI) is an emerging technique for the incorporation of target compounds into solid matrices. It has attracted attention in the food industry, where it can be applied. As it does not use organic solvents and supercritical CO₂ is the most commonly used fluid, SFI is considered to be an ecofriendly and ‘green’ strategy. A review of the literature is essential in order to understand the complex interactions that occur in SFI. This is a scoping review of SFI applied to the food industry from 2018 to 2023. The search used the Web of Science, Scopus, and Science Direct databases. Guiding questions were identified, publications related to the topic were selected, and the information was extracted, organized, and grouped. An overview of the SFI, its operational characteristics, challenges, prospects, and strategies is presented. Initially, 329 records were found; 38 publications were eventually selected for inclusion in this scoping review. The results indicate that the packaging sector has been the focus of publications. However, trends include applications of SFI in micronization, developing of food waste biorefineries, and food protection from direct impregnation. This scoping analysis is therefore a powerful tool for creating new research into the application of SFI to food.

1,3-Propanediol (1,3-PDO) has multiple practical applications, for example as an antifreeze and protective agent and as a monomer of partially renewable polyester and polyurethane. The main method for 1,3-PDO production is currently microbial fermentation. Bio-based 1,3-PDO can use renewable materials as substrates, and the process is mild and environmentally friendly.

Genetic engineering of microorganisms is crucial to achieve substrate diversity, reduce byproducts to decrease production costs, and facilitate the downstream processing of 1,3-PDO. This paper reviews the metabolic engineering of 1,3-PDO in natural and non-natural producers. In particular, it discusses current progress using non-natural synthetic pathways to obtain 1,3-propanediol.

Finally, strategies such as integrated production with other high-value-added products are proposed for successful commercialization.

The utilization of lignocellulosic biomass for the generation of diverse value-added biochemicals and biofuels is crucial in modern biorefineries and bioenergy initiatives, contributing significantly to the pursuit of a climate-neutral future. Agricultural, forest and industrial sources of lignocellulosic biomass serve as exceptionally renewable precursors in biorefinery processes. In spite of its abundance, the effective breakdown of biomass poses a significant challenge. Thus, it is essential to integrate various unit processes, including biochemical, thermochemical, physical, enzymatic and catalytic conversion, to generate a wide array of bio-based products. Intensive integration of these processes not only enhances yield and reduces reaction time but also proves to be economically efficient. Furthermore, these process integration approaches may contribute to the establishment of a circular bioeconomy through biorefineries, effectively reducing both bioresource waste and greenhouse gas emissions. This review offers fundamental insights into biomass and its chemistry, with a detailed discussion on lignocellulosic conversion systems. It explores how integrating conversion processes can facilitate the transition toward a circular economy. Additionally, it summarizes the challenges and prospects associated with advancing integrated biorefineries and circular economy principles to achieve complete biomass valorization.

Clostridium autoethanogenum is a model microbe capable of converting carbon monoxide (CO) into bioethanol and useful biochemicals. Successful process optimization when using CO as the primary carbon source requires an understanding of the influence of process parameters and growth medium components on cell growth and end-product formation. We conducted a full factorial analysis of the effects of CO total pressure, pH, yeast extract (YE), and cysteine concentrations on acetic acid, ethanol, and biomass production utilizing C. autoethanogenum with CO as the primary substrate. Maximum ethanol production of 0.71 g L^–1 was obtained at a pH of 4.5, yeast extract concentration of 0.5 g L^–1 , CO pressure of 1.8 atm, and cysteine concentration of 1.5 g L^–1. There was a tenfold enhancement when the pH was lowered from 6 to 4.5 and the YE concentration was reduced to 0.5 g L^–1. Response optimization using the reduced gradient algorithm confirmed these results. The information presented in this study could prove valuable for process engineering design by assisting with the selection of parameters that yield syngas blends specifically intended for increased ethanol production.