Search Results (40)

Lemon catnip (Nepeta cataria var. citriodora) is an underutilized aromatic and medicinal plant known for its high essential oil yield and distinctive lemon-like scent, and is widely used in the pharmaceutical, cosmetic, food, and biopesticide industries. Unlike typical catnip, it lacks nepetalactones and is rich in terpene alcohols, such as nerol and geraniol, making it a promising substitute for lemon balm. Despite its diverse applications, little attention has been paid to the valorization of byproducts from essential oil distillation, such as hydrolates and their secondary recovery oils. This study aimed to thoroughly analyze the volatile compound profiles of the essential oil from Lemon catnip and the recovery oil derived from its hydrolate over three consecutive growing seasons, with particular emphasis on how temperature and precipitation influence the major volatile constituents. The essential oil was obtained via semi-industrial steam distillation, producing hydrolate as a byproduct, which was then further processed using a Likens–Nickerson apparatus to extract the recovery oil, also known as secondary oil. Both essential and recovery oils were predominantly composed of terpene alcohols, with nerol (47.5–52.3% in essential oils; 43.5–54.3% in recovery oils) and geraniol (25.2–27.9% in essential oils; 29.4–32.6% in recovery oils) as the primary components. While sesquiterpene hydrocarbons were mostly confined to the essential oil, the recovery oil was distinguished by a higher presence of monooxygenated and more hydrophilic terpenes. Over the three-year period, elevated temperatures led to increased levels of geraniol, geranial, neral, and citronellal in both oils, whereas cooler conditions favored the accumulation of nerol and linalool, especially in the recovery oils. Higher precipitation was associated with elevated concentrations of nerol and linalool but decreased levels of geraniol, geranial, and neral, possibly due to dilution or degradation processes. Full article

Cellulosic raw materials are the most common source of carbon on Earth and are in great demand for the production of high-value-added products. Cellulosic feedstocks represent a strong matrix consisting of cellulose, lignin, and hemicelluloses. The efficient transformation of cellulosic raw materials into fermentable sugars requires the use of effective pretreatment strategies. The methods employed for pretreatment should be efficient, have low operating costs, and exhibit lower environmental impact. The present review describes pretreatment methods like liquid hot water (LHW) and steam explosion (SE) and highlights peculiar features, benefits and disadvantages of these processes. The effectiveness of these pretreatment methods and their effect on cellulosic raw materials strongly depends on the type of feedstock (component composition), pretreatment method, and pretreatment conditions (pressure, temperature, time, etc.). The LHW pretreatment requires neither addition of chemicals and catalysts nor grinding stage, but requires high energy inputs. The SE pretreatment is regarded as environmentally friendly and requires lower energy inputs, but contributes to the formation of toxic compounds. The life cycle assessment approach demonstrated that the SE pretreatment outperforms dilute acid pretreatment methods and allows the reduction of energy inputs, thereby improving the environmental performance of the process, while the LHW method improves long-term energy security and creates a greener future. Full article

Background: Cancer and fibrotic diseases represent major global health challenges, underscoring the need for safe, multifunctional natural therapies. Although natural products possess notable anticancer properties, their clinical translation is often hindered by non-selective cytotoxicity toward normal cells. Moreover, their therapeutic potential against chronic conditions such as idiopathic pulmonary fibrosis (IPF) remains insufficiently explored. This study aimed to evaluate the efficacy and safety of a natural hydrosol blend, The Greatest Love of Nature (TGLON), in inhibiting cancer cell proliferation and mitigating IPF. Methods: TGLON, composed of 12 steam-distilled plant hydrosols, was chemically characterized by gas chromatography–mass spectrometry (GC-MS). Its cytotoxicity was assessed using the MTT assay against five human cancer cell lines (A-549, HepG2, MCF-7, MKN-45, and MOLT-4) and normal human lung fibroblasts (MRC-5). In vivo safety and therapeutic efficacy were evaluated in Sprague Dawley rats and a bleomycin-induced IPF mouse model, following protocols approved by the Institutional Animal Care and Use Committee (IACUC). Results: TGLON maintained >90% viability in MRC-5 cells at an 80-fold dilution and significantly inhibited the proliferation of A-549 (41%), HepG2 (84%), MCF-7 (50%), MKN-45 (38%), and MOLT-4 (52%) cells. No signs of toxicity were observed in rats administered TGLON orally at 50% (v/v), 10 mL/kg. In mice, TGLON alleviated bleomycin-induced pulmonary inflammation and fibrosis. Conclusions: TGLON exhibited selective anticancer and anti-fibrotic activities under non-toxic conditions, supporting its potential as a bioactive agent for early-stage disease prevention and non-clinical health maintenance. Full article

Biomass fluidized bed gasification technology has attracted significant attention due to its high efficiency and clean energy conversion capabilities. However, its industrial application has been limited by insufficient technological maturity. This paper systematically reviews the research progress on biomass fluidized bed gasification characteristics; compares the applicability of bubbling fluidized beds (BFBs), circulating fluidized beds (CFBs), and dual fluidized beds (DFBs); and highlights the comprehensive advantages of CFBs in large-scale production and tar control. The gas–solid flow characteristics within CFB reactors are highly complex, with factors such as fluidization velocity, gas–solid mixing homogeneity, gas residence time, and particle size distribution directly affecting syngas composition. However, experimental studies have predominantly focused on small-scale setups, failing to characterize the impact of flow dynamics on gasification reactions. Therefore, numerical simulation has become essential for in-depth exploration. Additionally, this study analyzes the influence of different gasification agents (air, oxygen-enriched, oxygen–steam, etc.) on syngas quality. The results demonstrate that oxygen–steam gasification eliminates nitrogen dilution, optimizes reaction kinetics, and significantly enhances syngas quality and hydrogen yield, providing favorable conditions for downstream processes such as green methanol synthesis. Based on the current research landscape, this paper employs numerical simulation to investigate oxygen–steam CFB gasification at a pilot scale (500 kg/h biomass throughput). The results reveal that under conditions of O₂/H₂O = 0.25 and 800 °C, the syngas H₂ volume fraction reaches 43.7%, with a carbon conversion rate exceeding 90%. These findings provide theoretical support for the industrial application of oxygen–steam CFB gasification technology. Full article

NaZSM-5 powder and membranes were hydrothermally prepared. Their (1) steam (H₂O) adsorption properties and (2) the permeation and separation of gas and H₂O were evaluated before and after the cation exchange of Na⁺ to K⁺ or Cs⁺. The quantity of adsorbed H₂O decreased as the size of the cation increased, indicating that the micropore volume and effective pore size of ZSM-5 decreased after cation exchange. The H₂ and N₂ permeances after cation exchange were less than 5% of the values before cation exchange, indicating a significant reduction in gas permeability. In contrast, the reduction of the H₂O permeance values of the ZSM-5 membranes before and after K⁺ or Cs⁺ exchange was lower than that of H₂, resulting in improved H₂O/H₂ separation performance. Compared with the NaZSM-5 membrane, the K⁺- or Cs⁺-exchanged ZSM-5 membranes exhibited superior H₂O permselectivity, particularly at dilute H₂O concentrations (<1 vol%). Full article

Spheres comprising 10 wt.% Mo₂C/γ-Al₂O₃, synthesized through the sucrose route, exhibited unprecedented catalytic activity for olefin hydrogenation within an industrial naphtha feedstock that contained 23 wt.% olefins, as determined by supercritical fluid chromatography (SFC). The catalyst demonstrated resilience to sulfur, exhibiting no discernible deactivation signs over a tested 96 h operational period. The resultant hydrogenated naphtha from the catalytic process contained only 2.5 wt.% olefins when the reaction was conducted at 280 °C and 3.44 × 10⁶ Pa H₂, subsequently blended with Athabasca bitumen to meet pipeline specifications for oil transportation. Additionally, the carbide catalyst spheres effectively hydrogenated olefins under steam conditions without experiencing any notable hydrogenation in the aromatics. We propose the supported carbide catalyst as a viable alternative to noble metals, serving as a selective agent for olefin elimination from light petroleum distillates in the presence of steam and sulfur, mitigating the formation of gums and deposits during the transportation of diluted bitumen (dilbit) through pipelines. Full article

Pentachlorophenol (PCP) is a ubiquitous emerging persistent organic pollutant detected in the environment and foodstuffs. Despite the dietary intake of PCP being performed using surveillance data, the assessment does not consider the bioaccessibility and bioavailability of PCP. Pork, beef, pork liver, chicken and freshwater fish Ctenopharyngodon Idella-fortified by three levels of PCP were processed by RIVM and the Caco-2 cell model after steaming, boiling and pan-frying, and PCP in foods and digestive juices were detected using isotope dilution–UPLC-MS/MS. The culinary treatment and food matrix were significantly influenced (p < 0.05) in terms of the bioaccessibility and bioavailability of PCP. Pan-frying was a significant factor (p < 0.05) influencing the digestion and absorption of PCP in foods, with the following bioaccessibility: pork (81.37–90.36%), beef (72.09–83.63%), pork liver (69.11–78.07%), chicken (63.43–75.52%) and freshwater fish (60.27–72.14%). The bioavailability was as follows: pork (49.39–63.41%), beef (40.32–53.43%), pork liver (33.63–47.11%), chicken (30.63–40.83%) and freshwater fish (17.14–27.09%). Pork and beef with higher fat content were a key factor in facilitating the notable PCP bioaccessibility and bioavailability (p < 0.05). Further, the exposure of PCP to the population was significantly reduced by 42.70–98.46% after the consideration of bioaccessibility and bioavailability, with no potential health risk. It can improve the accuracy of risk assessment for PCP. Full article

The most significant ectoparasitic mite of honeybees, Varroa destructor, has a detrimental effect on bee health and honey output. The principal strategy used by the control programs is the application of synthetic acaricides. All of this has resulted in drug resistance, which is now a major worry for beekeeping. As a result, research on alternate products and techniques for mite management is now required. The aim of this study was to determine whether essential oils (EOs) extracted from botanical species of Lamiacae, typical of the Calabria region of Southern Italy, could reduce the population of the mite V. destructor. Among the best-known genera of the Lamiaceae family are oregano, rosemary and thyme, whose EOs were employed in this study. By steam distillation, the EOs were extracted from Origanum vulgare subsp. viridulum (Martrin-Donos) Nyman, Thymus capitatus Hoffmanns. and Link, Thymus longicaulis C.Presl and Salvia rosmarinus Schleid. plant species harvested directly on the Calabrian territory in their balsamic time. Each EO went to the test in vitro (contact toxicity) against V. destructor. Fifty adult female mites, five for each EO and the positive and negative control, were used in each experimental replicate. The positive controls comprised five individuals treated to Amitraz dilute in acetone, and the negative controls included five individuals exposed to acetone alone. To create the working solution to be tested (50 μL/tube), the EOs were diluted (0.5 mg/mL, 1 mg/mL, 2 mg/mL and 4 mg/mL) in HPLC-grade acetone. After 1 h of exposure, mite mortality was manually assessed. Origanum vulgare subsp. viridulum, Thymus capitatus and Thymus longicaulis were the EOs with the highest levels of efficiency at 2 mg/mL, neutralizing (dead + inactivated), 94%, 92% and 94% of parasites, respectively. Salvia rosmarinus EO gave a lower efficacy, resulting in a percentage of 38%. Interestingly, no adverse effects were highlighted in toxicity tests on honeybees. These results show that these OEs of the Lamiaceae family have antiparasitic action on V. destructor. Therefore, they could be used, individually or combined, to exploit the synergistic effect for a more sustainable control of this parasite mite in honeybee farms. Full article

As they continuously evolve, plants will remain a renewable source for antimicrobial compounds. Omani frankincense is produced by B. sacra trees and is graded into Hojari, Nejdi, Shazri or Sha’bi. Air can be a source for pathogenic or food spoilage microbes; thus, inactivating airborne microbes is necessary in environments such as food and animal production areas. This study investigated the antimicrobial activity and the chemistry of steam-distilled oils of Hojari and Sha’bi grades. It also analyzed the antimicrobial activity of frankincense smoke and the size of its solid particles. Chemical analysis was performed using gas chromatography mass spectrometry (GC-MS). The antimicrobial activity of the oils against Staphylococcus aureus (NCTC 6571), Bacillus spp., Escherichia coli (NCTC 10418), Pseudomonas aeruginosa (NCTC 10662), Saccharomyces cerevisiae, Candida albicans, Aspergillus flavus, Aspergillus ochraceus, Aspergillus niger, Penicillium citrinum, Alternaria alternata and Fusarium solani was determined using well diffusion and micro-well dilution methods. A microscopic technique was used to determine the size of frankincense smoke solid particles. Microbes were exposed to frankincense smoke to test their susceptibility to the smoke. Hojari and Sha’bi oils were similar in composition and contained monoterpenes and sesquiterpenes. The Hojari and the Sha’bi oils possessed broad spectrum antimicrobial activity. The largest growth inhibition zones were obtained with S. cerevisiae and F. solani. An MIC of 1.56% (v/v) was found with E. coli, S. cerevisiae and F. solani. Frankincense smoke contained fine irregular solid particles with a diameter range of 0.8–2287.4 µm, and thus may pose a health risk to susceptible individuals. The smoke had potent antimicrobial activity against S. aureus, E. coli, and airborne bacteria, yeast and mold, with a maximum inhibition of 100%. It was concluded that Hojari and Sha’bi frankincense oils and smoke had significant antimicrobial activity that can be exploited in controlling human, animal and plant pathogenic microbes. Full article

Pretreatment technologies are proposed to break the crosslinked biomass matrix and facilitate bioconversion processes or chemical agent attacks in reaction schemes. However, most of the pretreatments are studied in single-step schemes, limiting the integral valorization of the feedstock composition. Therefore, sequential pretreatments could maximize this valorization by isolating more biomass fractions or removing unwanted compounds. This work focuses on proposing and assessing different sequential pretreatments for the isolation of lignocellulosic fractions. After a pretreatment screening, ten technical and economic indicators were assessed through a heuristic analysis. Data from the literature were used to evaluate five operational indicators and as the specification of processing units in simulation schemes to also evaluate five techno-energetic and economic indicators. As a main result, it was concluded that the sequential pretreatments of dilute acid (DA) with wet air oxidation (WAO) could be the most optimal for cellulose isolation, steam explosion (SE) with DA for hemicellulose fractionation, and DA with kraft process for lignin solubilization. Additionally, the DA and WAO sequence may be the most efficient in biorefinery designs since it maximizes biomass fractionation, producing two hydrolyzed liquors, one rich in sugars and the other in soluble lignin, as well as a cellulose-rich solid. Full article

In this work, a reliable kinetic reaction mechanism was revised to accurately reproduce the detailed reaction paths of steam reforming of methane over a Ni/Al${}_2$O${}_3$ catalyst. A steady-state fixed-bed reactor experiment and a 1D reactor catalyst model were utilized for this task. The distinctive feature of this experiment is the possibility to measure the axially resolved temperature profile of the catalyst bed, which makes the reaction kinetics inside the reactor visible. This allows for understanding the actual influence of the reaction kinetics on the system; while pure gas concentration measurements at the catalytic reactor outlet show near-equilibrium conditions, the inhere presented temperature profile shows that it is insufficient to base a reaction mechanism development on close equilibrium data. The new experimental data allow for achieving much higher quality in the modeling efforts. Additionally, by carefully controlling the available active surface via dilution in the experiment, it was possible to slow down the catalyst conversion rate, which helped during the adjustment of the reaction kinetics. To assess the accuracy of the revised mechanism, a monolith experiment from the literature was simulated. The results show that the fitted reaction mechanism was able to accurately predict the experimental outcomes for various inlet mass flows, temperatures, and steam-to-carbon ratios. Full article

The SCR performance of V₂O₅-WO₃/TiO₂ SCR-catalysts characterized by different surface W density (2.1W/nm² and 9.5W/nm²) and different surface V density varying in the range 1–8V/nm² has been investigated in order to clarify existing controversies on the preferential involvement of electronic and geometric effects in the catalytic properties. It was found that tungsten has a weak effect on the VO_x cluster size distribution through contraction of dilution effect. In contrast, the optimal interaction between W and V, when both reach their highest composition, appears to be a relevant parameter that can enhance their acidic properties and improve the catalytic efficiency in dry conditions. On the other hand, an absence of significant interaction leads to discontinuity due to deactivation. In the presence of steam, acidic properties are averaged, lowering the impact of the V to W ratio. Finally, the critical importance of acidic properties which outperform redox properties in the definition of active site is pointed out in the light of this study. Full article

Pre-treatments at relatively high temperatures (range 160 °C–220 °C) are currently used to transform lignocellulosics into biofuels and chemicals. In this step, several molecules with an inhibitory effect in the subsequent fermentation processes are generated. These inhibitors include low-molecular-weight molecules and lignin fragments that can be removed by water washing. However, this procedure also removes valuable soluble carbohydrates which are then difficult to recover from the diluted stream. In this work, a new method to detoxify steam-exploded substrates is reported. The procedure is based on the evaporation of low-weight acids and aldehydes, which leaves all the sugars in the solid matrix, while the cellulose hornification (an irreversible modification of the cellulose fibres that depresses the saccharification yield) is prevented by adding steam to the hot fluidizing flow stream. Two systems were tested: a 0.1 kg/batch oscillating fluidized bed and a continuous fluidized bed dryer operating downstream of a steam explosion plant with a treatment capacity of 150 kg/h. The detoxified substrates were subjected to enzymatic hydrolysis and fermentation to obtain bioethanol, with a yield that was 14% higher than that obtained from substrates detoxified with conventional methods of drying or washing. Full article

The North-Colombian region has enormous potential for producing bioproducts and bioenergy from agricultural residues. Yet, scaling bioproducts and bioenergy to industrial practice requires further investigation, especially for environmental impact minimization and improved process safety. This work assesses two alternatives for valorizing cassava residues via acetone, butanol, and ethanol (ABE) fermentation. Two ABE fermentation routes are assessed. In Route 1, pretreatment and purification involve dilute-acid pretreatment and multi-effect distillation and decantation operations, while Route 2 includes steam explosion and reactive distillation. Hazard Identification and Risk Assessment (HIRA) and Waste Reduction Algorithm (WAR) were applied to assess ABE fermentation. Simulation results indicate butanol yields of 0.10–0.12 kg/kg feedstock and net energy ratio (NER) <1. Route 2 shows the highest total output of Potential Environmental Impacts (PEI) with 5.56 PEI/kg butanol. Both ABE fermentation routes obtained Fire and Explosion Damage Index (FEDI) values above 300 for acetone and ethanol recovery/purification stages. Both routes are classified as “hazardous” considering the flammability of handled substances, and their relative safety performance is remarkably similar. These results pave the way toward deploying both routes for adding value to the cassava residues in North Colombia by applying safe, efficient, and environmentally friendly transformation technologies. Full article

First-generation (1G) bioethanol is one of the most used liquid biofuels in the transport industry. It is generated by using sugar- or starch-based feedstocks, while second-generation (2G) bioethanol is generated by using lignocellulosic feedstocks. Distillers’ dried grains with solubles (DDGS) is a byproduct of first-generation bioethanol production with a current annual production of 22.6 million tons in the USA. DDGS is rich in fiber and valuable nutrients contents, which can be used to produce lignocellulolytic enzymes such as cellulases and hemicellulases for 2G bioethanol production. However, DDGS needs a pretreatment method such as dilute acid, ammonia soaking, or steam hydrolysis to release monosaccharides and short-length oligosaccharides as fermentable sugars for use in microbial media. These fermentable sugars can then induce microbial growth and enzyme production compared to only glucose or xylose in the media. In addition, selection of one or more suitable microbial strains, which work best with the DDGS for enzyme production, is also needed. Media optimization and fermentation process optimization strategies can then be applied to find the optimum conditions for the production of cellulases and hemicellulases needed for 2G bioethanol production. Therefore, in this review, a summary of all such techniques is compiled with a special focus on recent findings obtained in previous pieces of research conducted by the authors and by others in the literature. Furthermore, a comparison of such techniques applied to other feedstocks and process improvement strategies is also provided. Overall, dilute acid pretreatment is proven to be better than other pretreatment methods, and fermentation optimization strategies can enhance enzyme production by considerable folds with a suitable feedstock such as DDGS. Future studies can be further enhanced by the technoeconomic viability of DDGS as the on-site enzyme feedstock for the manufacture of second-generation bioethanol (2G) in first-generation (1G) ethanol plants, thus bridging the two processes for the efficient production of bioethanol using corn or other starch-based lignocellulosic plants. Full article