Biofuels Bioproducts & Biorefining-Biofpr最新文献

A fast, reliable, low-cost, and efficient method for the recovery of xylan from agro-residue materials is needed to improve the use of xylan in industrial processes. Xylan was extracted from two agrowastes (corncobs and wheat bran) using a cost-effective alkali extraction method. The characteristic band patterns and bending vibrations associated with hemicellulose and beta glycoside linkage could be seen in the corncob-extracted xylan (CCEx) and wheatbran-extracted xylan (WBEx). Scanning electron microscopy (SEM) analysis showed that the extracted xylans consisted of aggregated and nonaggregated particles with irregular morphology and rough surfaces. Particle-size analysis displayed average sizes of 205.6, 210.8, and 794.2 nm for commercial beechwood xylan (Bx), CCEx, and WBEx, respectively. Alkali extraction was performed with different concentrations of NaOH, from 5% to 20%, with a solid–liquid ratio of 1:20. It was found that 82.90 and 76.77% of xylan were extracted from corncob and wheat bran, respectively, which represents a higher yield obtained in a shorter duration in comparison with studies in the literature. The enzymatic hydrolysis of wheat bran and corncob that used 250 IU/mL of Enterobacter hormaechie KS1 xylanase yielded 334.38 and 162.35 mg/g of xylooligosaccharides. Their properties were studied and were found to be very similar to those of commercial xylan. They could reduce costs if applied in industry.

Endophytic bacteria have not been reported widely for their lipolytic abilities, so they are not used for large-scale lipase production. The purpose of this study was to explore an endophytic bacterium for the production of lipase implementing cost-effective techniques, including the use of Cassia fistula seeds, as a substrate in the production medium and stem pieces of Phragmites karka as the immobilization matrix. The endophytic strain Bacillus sp. E4 was originally isolated from the halophytic plant Arthrocnemum macrostachyum. Bacillus sp. E4 produced 6.05 IU mL⁻¹ lipase in the presence of powdered seeds of Cassia fistula (golden shower tree). Initial trial experiments using a one-factor-at-a-time approach led to an improvement in lipase titers to 10.05 IU mL⁻¹. Consequently, investigations using the Plackett–Burman design suggested the influence of three significant factors – incubation period, inoculum size, and substrate concentration – on lipase production. They were optimized using the Box–Behnken design (BBD). In the response optimization experiment, strain E4 yielded 52.35 IU mL⁻¹ lipase, which was in accordance with the predicted yield and indicated an overall 8.65 fold improvement in lipase production. To investigate the use of free cells, strain E4 was immobilized on the stem pieces of a halophytic plant, Phragmites karka, which was used for the first time as an immobilization matrix. The immobilized cells retained lipase production ability for up to six cycles with the highest yield of 110 IU mL⁻¹, which corresponded to an improvement of more than eighteenfold. Scanning electron micrographs confirmed the colonization of E4 cells in the matrix and demonstrated the utilization of C. fistula seeds. Fourier transform infrared spectroscopy affirmed the utilization of components including fatty acids by the immobilized E4 cells. The study suggests that endophytic bacterial strains could be applied for the production of lipase with the utilization of nontraditional oil sources.

This work studies red mud, a residue from the processing of bauxite, as a support catalyst in the thermocatalytic reforming (TCR) process, using wood, digestate, and straw as case studies. Thermocatalytic reforming is a thermochemical process for the conversion of biomass into biofuels, combining intermediate pyrolysis and catalytic reforming and resulting in high-quality biofuels. The quantity and quality of the catalyst in the postreformer is vital as it influences the reactions taking place in it. Normally, nonreactive components of the char produced in the process act as the catalyst in the postreformer but adding a support catalyst may improve the products. In this work, red mud is introduced in the process by mixing it with the feedstock in a ratio of 1:3. The results, in comparison with normal TCR experiments on the same feedstock materials, show that the introduction of red mud into the process generally reduces the biochar yield and generally increases the biogas and product water yields, and the bio-oil yield remains constant. Its introduction also increases the hydrogen fraction of the gas and tends to reduce the nitrogen and sulfur content of the products, thus improving their quality. These observations are consistent across feedstock materials and postreformer temperatures. The results therefore suggest that red mud is a good support catalyst for increasing the gas yield, increasing the hydrogen fraction of the gas, and improving the quality of the products from the TCR process.

Succinic acid is recognized as a key component in the production of various commercially important chemical commodities. Technical-economic analysis can provide valuable insights into the feasibility of large-scale biochemical production of succinic acid. In this study, the effects of scale on the design of a biorefinery using sugarcane bagasse were evaluated using a detailed process modeling methodology. Four processes were simulated and compared, three based on patents from biosuccinic acid (bio-SA) manufacturing companies and one based on a process economic program report (PEP). This methodology allowed for the analysis of scale benefits for each technological route. A comprehensive economic evaluation was conducted by comparing the biochemical processes in terms of investment and production costs, as well as the minimum selling price (MSP) of bio-SA. Results show that the MSP of more promising process designs ranged from 3105 to 2095 $ t⁻¹, which is compatible with the cost of petrochemical-based succinic acid. Moreover, for capacities above 90 kt year⁻¹, the MSP remains virtually constant, and every process evaluated revealed a breakdown in the project economy of scale. A sensitivity and risk analysis was carried out to evaluate the impacts of several process parameters on the project's technoeconomic analysis, resulting in bio-SA selling price and investment costs as parameters with the highest impact on economic viability.

Agave plants, found primarily in arid and semi-arid regions, have been utilized by indigenous communities for various purposes for thousands of years. They currently serve as crops to produce alcoholic beverages and fibers. Despite their importance, there is limited understanding of the relationship between agave and soil. This article addresses some of the knowledge gaps regarding the interactions and benefits of the agave-soil approach. Among all the documents reviewed, 153 discussed individual soil parameters (45 physical, 68 chemical, and 40 biological), 59 explored interactions between them, and 130 did not address soil aspects (i.e., soil was merely presented as a substrate for the growth and development of plants and was not examined in the study's findings). Moreover, the historical evolution of the research highlights two distinct periods (from 1985 to 2000 and between 2010 to 2023) of notable publication activity, with recent years witnessing a surge in studies involving soil management techniques, genetic improvement of agave species, bioremediation, and the use of residues for bioenergy, biofuel, and soil amendments. There is a notable increasing trend in diverse research areas interested in these interactions, reflecting a broader recognition of the importance of understanding soil functioning in agave cultivation. Indeed, from 2010 to 2023, the use of the keyword ‘soil’ increased by 96% in studies of agave cultivation. This shift in research trends suggests that scientific advances in agave cultivation and soil science can be expected, contributing to sustainable agriculture and the long-term viability of agave-based industries. This article underscores an opportunity for further research to optimize agave cultivation and processing (e.g., soil management and productivity), for different purposes while conserving soil health and promoting sustainable land-use practices.

To reach the goals set by the US Department of Energy's Sustainable Aviation Fuel (SAF) Grand Challenge, currently available feedstocks may be insufficient. Giving priority to developing, prototyping and reducing the cost of algal feedstock before investing and lining up locations is important. As the production of algal feedstocks advances, a simplified conversion approach using more mature technologies can help reduce the investment risk for algae-based fuels. Reducing process complexity to the steps described here [namely, conversion of lipids to HEFA (hydroprocessed esters and fatty acids) fuels and relegating the remainder of the biomass to anaerobic digestion or food/feed production] enables the near-term production of algal SAF but presents challenging economics depending on achievable cultivation costs and compositional quality. However, these economics can be improved by present-day policy incentives. With these incentives, the modeled algae-to-HEFA pathway could reach a minimum fuel selling price as low as $4.7 per gasoline gallon equivalent depending on the carbon intensity reduction that can be achieved compared with petroleum. Uncertainty about algal feedstock production maturity in the current state of technology and the future will play a large role in determining the economic feasibility of building algae-to-HEFA facilities. For example, if immaturity increases the feedstock price by even 10%, SAF production in 2050 is about 58% of the production which could have been achieved with mature feedstock. Additionally, growth in this conversion pathway can be notably boosted through the inclusion of subsidies, and also through higher-value coproducts or higher lipid yields beyond the scope of the process considered here.

This article aims to review the various techniques used to produce diesel from lignocellulosic biomass. Data were collected using the Web of Science database to identify trends, barriers, and prospects associated with the alternative methods used. The analysis reviewed 359 papers published between 2006 and 2021, focusing on three key areas: biomass pretreatment, biomass conversion, and biorefining. Pretreatment technologies require extensive research to reduce excessive energy and reagent consumption, thereby reducing overall costs. Fast pyrolysis and lipid-producing microorganisms have been shown to be the most promising conversion routes due to their versatility in utilizing different lignocellulosic residues and producing a wide range of marketable co-products. The most widely used method used for refining is hydroprocessing coupled with catalysts, with the objective of improving bio-oil quality. Two of the main challenges are the excessive cost of the overall process and the limitations imposed by the technology. These limitations require processing optimization to achieve sustainable production and valuable co-products. The growth of lignocellulosic diesel production will depend on the integration with other biodiesel and biofuel production processes by the optimization of new processes and the generation of new bioproducts to increase efficiency and reduce costs for commercial viability.

In the evolving field of bioproducts, materials that synergize sustainability with functionality are of paramount importance. Mycelium composites, derived from intricate networks of fungal filaments, are gaining traction as innovative bioproducts that offer a compelling blend of eco-friendliness, renewability, and adaptability. As the quest intensifies for alternatives that can mitigate the environmental toll of conventional products, mycelium-based solutions are emerging as beacons on the sustainable bioproducts horizon. Their transition from niche innovations to mainstream applications depends on their ability to overcome a series of fabrication challenges. This review paper investigates the critical challenges faced in the fabrication of mycelium composite. It examines rigorously some essential factors leading to fabrication failure, such as contamination, inconsistent growth, insufficient moisture, inappropriate pH, and improper substrate preparation. The review offers a comprehensive analysis of each factor influencing mycelium growth and the resulting composite properties, with an emphasis on preventative and mitigating strategies. Through an in-depth exploration of case studies detailing unsuccessful mycelium composite fabrication, the significance of understanding these failure factors is emphasized. The paper culminates in a forward-thinking discourse on potential strategies for refining fabrication processes, and identifies promising research areas poised to enhance both the success rate and overall efficiency of mycelium composite production.

In this study, biochars with different structures were prepared through HNO₃ oxidation and secondary pyrolysis to study the relationship between the structure of biochar and its selectivity for the adsorption of light and heavy aromatics in bio-oil. The results showed that the adsorption rates of biochar with different structures ranged from 2.90 to 4.00 g bio-oil per g biochar. The influence of pore structure was dominant, followed by the influence of O-containing functional groups and the degree of graphitization. The higher the adsorption capacity of biochar for bio-oil, the smaller the concentrations of the light aromatic model compounds in the absorbed bio-oil (ABO). Among the five light aromatics, biochar has the best adsorption selectivity for dihydroxybiphenyl and the worst for eugenol and propyl phenol. This is attributed to the diphenyl ring structure of dihydroxybiphenyl, which makes it more susceptible to adsorption, and other light model compounds only have one benzene ring. In summary, biochar demonstrates better adsorption selectivity for heavy aromatics than light aromatics. The more developed the pore structure is, the more enriched O-containing functional groups are, and the higher the graphitization degree of biochar is, the better the selective adsorption of aromatic compounds in bio-oil.