Search Results (87)

The selective separation of aromatics from slurry oil (SLO)—a low-value byproduct of fluid catalytic cracking—remains a major industrial challenge. This study investigates the use of subcritical water (Sub-CW) as a green and tunable solvent to extract aromatics from SLO in a semi-batch system operating at 250–325 °C. At 325 °C and a water-to-oil mass ratio of 6:1, the extract yield reaches 16 wt%, with aromatic hydrocarbons accounting for over 90 wt% of the extract, predominantly composed of 3- to 4-ring polycyclic aromatic hydrocarbons. Comprehensive characterization via simulated distillation, SARA analysis, FT-IR, and ¹H-NMR confirms the selective enrichment of aromatics and effective separation from saturates and asphaltenes. To elucidate the molecular basis of this selectivity, principal component analysis of Hansen solubility parameters was performed. The results revealed a temperature-dependent solubility trend in Sub-CW, whereby the affinity for hydrocarbons follows the order aromatics > cycloalkanes > alkanes. This solubility preference, supported by both experimental data and theoretical analysis, offers new insight into subcritical solvent design and provides a basis for process intensification in SLO valorization. Full article

In this study, an extract of white grape marc (GME), a by-product obtained during the winemaking process, was applied to the surface of gilthead seabream (Sparus aurata) fillets, which were then stored under refrigeration (4 °C) for a period of 14 days. The effects of GME were compared with those of ascorbic acid (one of the few additives authorized for fresh fish in the EU) and distilled water (as a control batch). Samples were taken at 1, 2, 4, 7, 9, 11, and 14 days postmortem (dpm) cold storage, and several objective quality parameters were measured (instrumental color, pH, water holding capacity, texture profile analysis—TPA, lipid oxidation, and microbial spoilage). The results showed that the grape extract significantly improved several of the parameters studied, not only compared to the control batch, but even compared to the ascorbic acid batch. Thus, GME slowed down the proliferation of psychrophilic bacteria, prevented the oxidation of muscle lipids, and even improved the firmness of the fillets compared to the other two experimental groups. On the other hand, minor effects on color, pH, or water retention capacity were observed. In the context of the scarcity of approved food additives for fresh fish in the EU and the strong consumer rejection of synthetic substances for this purpose, this grape extract could well represent a viable alternative. In addition to its natural origin, the use of GME as a food additive could also contribute to the valorization of winery by-products as part of a circular bioeconomy strategy. Full article

Using convolutional neural networks (CNNs) to recognize forest fires in complex outdoor environments is a hot research direction in the field of intelligent forest fire recognition. Due to the storage-intensive and computing-intensive characteristics of CNN algorithms, it is difficult to implement them at edge terminals with limited memory and computing resources. This paper uses a FPGA (Field-Programmable Gate Array) to accelerate CNNs to realize forest fire recognition in the field environment and solves the problem of the difficulty in giving consideration to the accuracy and speed of a forest fire recognition network in the implementation of edge terminal equipment. First, a simple seven-layer lightweight network, LightFireNet, is designed. The network is compressed using a knowledge distillation method and the classical network ResNet50 is used as the teacher network to supervise the learning of LightFireNet so that its accuracy rate reaches 97.60%. Compared with ResNet50, the scale of LightFireNet is significantly reduced. Its model parameter amount is 24 K and its calculation amount is 9.11 M, which are 0.1% and 1.2% of ResNet50, respectively. Secondly, the hardware acceleration circuit of LightFireNet is designed and implemented based on the FPGA development board ZYNQ Z7-Lite 7020. In order to further compress the network and speed up the forest fire recognition circuit, the following three methods are used to optimize the circuit: (1) the network convolution layer adopts a depthwise separable convolution structure; (2) the BN (batch normalization) layer is fused with the upper layer (or full connection layer); (3) half float or ap_fixed<16,6>-type data is used to express feature data and model parameters. After the circuit function is realized, the LightFireNet terminal circuit is obtained through the circuit parallel optimization method of loop tiling, ping-pong operation, and multi-channel data transmission. Finally, it is verified on the test dataset that the accuracy of the forest fire recognition of the FPGA edge terminal of the LightFireNet model is 96.70%, the recognition speed is 64 ms per frame, and the power consumption is 2.23 W. The results show that this paper has realized a low-power-consumption, high-accuracy, and fast forest fire recognition terminal, which can thus be better applied to forest fire monitoring. Full article

Fruit brandy equipment commonly uses partial condensation (dephlegmation) to generate reflux in the distillation column. Here, we examined the effect of dephlegmation on the composition of fruit brandies in both lab-scale and large-scale settings. In lab-scale experiments, the dephlegmator led to a pronounced enrichment of ethanol in the distillate due to preferred condensation of water, while the concentration of flavor compounds was differentially affected. Some compounds were enriched in the distillate, some were depleted, and some were unaffected by dephlegmation compared with the control without a dephlegmator. Large-scale fruit brandy equipment relying exclusively on dephlegmation was compared as standard with an enrichment section containing three trays. In the equipment relying on dephlegmation, tail components such as fusel alcohols were less well separated from the middle run, which led to a reduced yield of clean spirit in the middle run. In triangle tests, the spirits from the two devices could be clearly differentiated, but there was no clear preference for one spirit or the other. This study provides for the first time detailed data on the influence of dephlegmators on the behavior of flavor compounds during fruit brandy distillation. Full article

The production of fruit brandies is based on distilling fermented fruit juices. Distillation equipment is usually made of copper. In traditional manufacturing, it consists of a boiler (batch) distiller, a boiler (pot), a steam pipe, and a condenser, all of which are made of pure copper. This study determined the corrosion parameters for copper (Cu) and Cu72Zn28 (in wt%) alloy in fermented apricot juice at room temperature. The fermentation process examined in this research utilized natural strains of yeast and bacteria, supplemented by active dry yeast Saccharomyces cerevisiae strains. This research used the following methods: open circuit potential (OCP), linear polarization resistance (LPR), and Tafel extrapolation to identify corrosion parameters. Cu had a 3.8-times-lower value of corrosion current density than brass, and both were within the range of 1–10 μA·cm⁻², with an excellent agreement between LRP and Tafel. This study proved that Cu is an adequate material for the distillation of fruit brandies from a corrosion perspective. Despite this, there are occasional reports of corrosion damage from the field. Significant corrosion impacts can arise, as evidenced by laboratory tests discussed in this paper. In the absence of a highly corrosive environment, this study indicates that, to some extent, microbiologically influenced corrosion (MIC) can influence the degradation of the equipment material. Full article

Ethanol production by fermentation results in obtaining, in addition to the main product, ethyl alcohol, by-products and secondary products, which include carbon dioxide, fusel oil, and ester–aldehyde cut. Fusel oil, despite its low yield and the large volume of ethanol production, accumulates at distilleries, which ultimately raises the question of its disposal or the rational use of this by-product. Fusel oil, being a complex mixture, can serve as a source of technical alcohols used in various sectors of the economy, including the food industry, pharmaceuticals, organic synthesis, perfume, and cosmetics industries, as well as the production of paints and varnishes. However, the complexity of using fusel oil lies in its difficult separation. The reason for this is the presence of water, which forms low-boiling azeotropes with aliphatic alcohols. Our study aimed to develop a process flow diagram (PFD) that allows individual components from fusel oil to be obtained without extraneous separating agents (not inherent in fusel oil). This condition is necessary to obtain products labeled as natural for further use in the food, perfume, cosmetic, and pharmaceutical industries. The distinctive feature of this work is that the target product is not only isoamyl alcohol but also all other alcohols present in the composition of fusel oil. To achieve this goal and create a mathematical model, the Aspen Plus V14 application, the Non-Random Two Liquid (NRTL) thermodynamic model, and the Vap-Liq/Liq-Liq phase equilibrium were used. Fusel oil separation was modeled using a continuous separation PFD to obtain ethanol, water, isoamyl alcohol, and raw propanol and butanol cuts. The Sorel and Barbet distillation technique was used to isolate ethanol. The isolation of isopropanol and 1-propanol, as well as isobutanol and 1-butanol, was modeled using the batch distillation method. The isolation of fusel oil components was based on their thermodynamic properties and the selection of appropriate techniques for their separation, such as extraction, distillation, pressure swing distillation, and decantation. The simulation of fusel oil separation PFD showed the possibility of obtaining the components of a complex mixture without separating agents, as discussed earlier. Ethanol corresponds to the quality of rectified ethyl alcohol, and 1-butanol and isoamyl alcohols to anhydrous alcohols, whereas isopropanol (which contains an admixture of ethanol), 1-propanol, and isobutanol are obtained as aqueous solutions of different concentrations of alcohols. However, due to a distillation boundary in the raw propanol and butanol cuts, these mixtures cannot be separated completely, which leads to the production of intermediate fractions. To eliminate intermediate fractions and obtain anhydrous isopropanol, 1-propanol, and isobutanol in the future, it is necessary to solve the dehydration problem of either fusel oil or the propanol–butanol mixture. Full article

Sorghum distillers grains (SDGs) produced from a sorghum liquor company were used for generating biohydrogen via dark fermentation at pH 4.5–6.5 and 55 °C with a batch test, and the biohydrogen electricity generation potential was evaluated. The experimental results show that pH markedly affects hydrogen concentration, hydrogen production rate (HPR) and hydrogen yield (HY), in that high acidic pH values result in high values. The HPR and HY ranged from 0.76 to 3.2 L/L-d and 21.4 to 62.3 mL/g chemical oxygen demand, respectively. These hydrogen production values were used to evaluate bioelectricity generation using a newly developed gas/liquid-fuel engine. The results show a new and prospective biomass source for biohydrogen production, bioelectricity generation and simultaneously solving the problem of treating SDGs when producing kaoliang liquor. Applications of the experimental results are also discussed. Full article

The excessive mineralization of organic molecules during anaerobic fermentation increases the availability of nitrogen and carbon. For this reason, the development of downstream processing technologies is required to better manage ammonia and carbon dioxide emissions during the storage and land application of the resulting soil organic amendment. The present work investigated classical distillation as a technology for valorizing ammoniacal nitrogen (NH₄⁺-N) in anaerobic digestate. The results implied that the direct isolation of ammonium bicarbonate (NH₄HCO₃) was possible when applying the reactive distillation to the food waste digestate (FWD) with a high content of NH₄⁺-N, while the addition of antifoam to the agrowaste digestate (AWD) was necessary to be able to produce an aqueous solution of NH₄HCO₃ as the distillate. The reason was that the extraction of NH₄HCO₃ from the AWD required a higher temperature (>95 °C) and duration (i.e., steady state in batch operation) than the recovery of the inorganic fertilizer from the FWD. The titration method, when applied to the depleted digestate, offered the quickest way of monitoring the reactive distillation because the buffer capacity of the distillate was much higher. The isolation of NH₄HCO₃ from the FWD was attained in a transient mode at a temperature below 90 °C (i.e., while heating up to reach the desired distillation temperature or cooling down once the batch distillation was finished). For the operating conditions to be regarded as techno-economically feasible, they should be attained in the anaerobic digestion plant by integrating the heat harvested from the engines, which convert the biogas into electricity. Full article

Continuous distillation (CD) by steam is a patented emerging technology that allows us to obtain essential-oil fractions from citrus juices. It presents benefits such as reducing steam consumption by 50%, lowering environmental impact, and, by its design, obtaining fractions enriched in terpenic and oxygenated compounds that can be further processed. The CD of essential oils from Mexican lime juice (Citrus aurantifolia) was studied and the results were compared with conventional steam distillation (batch) in terms of steam consumption, extraction yield, chemical composition, and quality of the essential oils. Different steam flows were used: distillation without a packed column (sc); with packed column (cc); and steam flows of 10, 15, and 20 mL/min with a reflux ratio of 0.5, 1, and 2, respectively. CD was superior in terms of composition, extraction energy savings (0.63 kg steam/kg juice with 1.39 kg steam/kg juice in the conventional), and the extraction yield recovery efficiency was >90%. Gas chromatography-mass spectrometry analysis of the extracted essential oils indicated that the use of CD with a column increases the fractionation of volatile compounds. The result of this study demonstrates that CD can be used as an alternative method to extract the essential oil from lime or any citrus fruit, obtaining differentiated fractions in aroma and composition. Full article

Plastics, once regarded as a revolutionary material shaping modern society, now pose an unprecedented threat to our environment. Household solid waste sorting stations produce several fractions, one of which contains a high concentration of Low-Density Polyethylene (LDPE) film waste (packaging, sunscreen film, etc.). This fraction is difficult to recycle because it contains quite a lot of impurities. Usually, it is sent to cement factories that burn it together with other fuels. However, with some processing techniques such as catalytic pyrolysis, this fraction could be valorized. In this paper, experiments were carried out in batches at a laboratory-scale installation, with a processing capacity of 1–3 kg of waste. A pyrolysis reactor was connected to a distillation column, enabling separation of the fractions. The gaseous and liquid fractions were characterized by GC-FID-TCD (gases) and GC-MS (liquids) analysis. Natural catalysts such as bentonite or clinoptilolite were studied and used in the melting of plastic mass to simplify the process as much as possible. To test the activity of the catalysts, the pyrolysis of LDPE granules was initially studied. It was found that natural zeolites are much more active than bentonite and that a minimum concentration of 5–10% is needed to have a positive effect on the composition of the fractions (increasing the weight of the light fractions (C1–C6, C6–C10, and C11–C13) in relation to the heavy fractions (C13–C20 and C20+). Catalytic pyrolysis gives a completely different distribution of light hydrocarbons. The best catalyst selected from LDPE lab experiments was then tested upon the pyrolysis of plastic film waste obtained by a waste treatment plant. The research objective reported in this paper was to obtain a fraction of combustible gases in the largest possible proportion, which can be much more easily exploited by burning in an engine that drives an electric generator. Full article

Turmeric rhizomes (Curcuma longa) and black cumin seeds (Nigella sativa) are polyherbal ingredients used for the management of cancer and other chronic inflammatory diseases in Nigerian ethnomedicine. Previous studies have shown the antioxidant, anti-inflammatory, and anticancer activities of the individual plant extracts. However, the two spices have not been biologically potentiated in their combined form. Therefore, this study obtained essential oils (EOs) from the combined spices and evaluated their inhibitory effects on free radicals, protein denaturation, and cancer proliferation. The EOs were extracted by hydro-distillation (HD) and characterized by gas chromatography-mass spectrometry (GC-MS). In vitro antioxidant assessment was conducted based on DPPH, hydrogen peroxide (H₂O₂), nitric oxide (NO), and ferric ion (Fe³⁺) radical scavenging assays. The cytotoxicity of the oil against non-tumorigenic (HEK293) and cancerous (HepG2 and HeLa) cell lines was determined following the MTT cell viability assay. An in silico molecular docking analysis of the oil constituents was also performed. Six batches of EOs I–VI were afforded, comprising twenty-two major constituents, with aromatic Ar-turmerone being the most prominent compound. There was a marked improvement in the bioactivity of the oils upon repeated HD and as a combination. The batch VI oil exhibited the best activity, with a cytotoxicity (CC₅₀) of 10.16 ± 1.69 µg/100 µL against the HepG2 cell line, which was comparable to 5-fluorouracil (standard, CC₅₀ = 8.59 ± 1.33 µg/100 µL). In silico molecular docking suggested δ-curcumene, Ar-curcumene, Ar-turmerol, and Ar-turmerone among the promising compounds based on their high binding energy scores with NOX2, NF-κB, and mdm2 proteins. In conclusion, the oils from the turmeric–black cumin combined possess a considerable inhibition ability against free radicals, protein denaturation, and cancer proliferation. This study’s findings further underscore the effectiveness of turmeric–black cumin as a polyherbal medicinal ingredient. Full article

This study examined the effect of experimental factors and conditions on the removal of nitrogen-containing heterocyclic compounds (NCHCs) by performing equilibrium extraction using formamide or formamide aqueous solution as a solvent to remove NCHCs contained in crude methylnaphthalene oil (CMNO). The CMNO used as a raw material in this study contained three types of NCHCs (quinoline, isoquinoline, and indole) classified as group A, and six kinds of non-NCHCs (naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, biphenyl, dibenzofuran, and fluorene) classified as group B. Increasing the volume fraction of water to the solvent before the extraction run increased the raffinate residual rate but conversely decreased the removal rate of group A. The increase in the volume fraction of solvent to feed before the extraction run and operating temperature decreased the residual rate of raffinate but conversely increased the removal rate of group A. Over the entire range of extraction conditions performed in this study, the removal rate of group A ranged from 10.8% to 70.7%. Considering that these experimental results were obtained using only a single stage of batch equilibrium extraction, the formamide extraction method applied in this study showed excellent performance in terms of the residual rate of raffinate and the removal rate of group A. Therefore, it was expected to be an alternative to the reaction extraction method using acids and bases applied so far to separate NCHCs in the distillation residue of coal tar. Full article

Yacon, known for its fructooligosaccharides, fructans, and inulin content, has shown potential for novel beverage production. This study explores the feasibility of creating a distilled yacon-based beverage. Hydrolysis was utilized to release simple sugars from agave and yacon roots; these were then processed into three distinct batches of distilled beverage. The different methods led to tests varying the sugar content, yeast strains for fermentation, distillation efficiency, aging processes, and sensory evaluations. The distilled beverages demonstrated varying fermentation yields and distillation efficiencies, with one batch aged in Colombian white oak and the others in glass, highlighting differences in flavor profiles. The study concluded that yacon could serve as a versatile base for alcoholic beverage production. The second batch of the distilled beverage, optimized for fermentation and distillation efficiencies, represented promising advancements in yacon-based alcohol production. Future research should focus on process optimization and commercial viability to expand yacon’s presence in the alcoholic beverage industry. Full article

Yeast is one of the co-products of ethanol plants, which can be used as a nutritional supplement in animal feed due to its high protein content. Given the importance of yeast contribution to the nutritional properties of DDG (dried distillers’ grains), the aim of this study was to assess how different levels of aeration affect the biomass production and the quality of yeast providing new insights into yeast production, offering an alternative source of income for the corn ethanol industry. For this purpose, yeasts were grown in a fed-batch process, and different concentrations of aeration in the medium were tested, namely 0.5, 1.0, and 1.5 volume of air per volume of wort per minute (v v⁻¹ min⁻¹). At the end of the cellular biomass production process, yeasts grown with 0.5 (v v⁻¹ min⁻¹) aeration in the reactor showed higher biomass formation (19.86 g L⁻¹), cellular yield (g g⁻¹), and a lower formation of succinic acid (0.70 g L⁻¹) and acetic acid (0.11 g L⁻¹). Aeration influenced an increase of 1.0% in the protein content in yeast. In conclusion, lower levels of aeration in the yeast production process enables more efficient sugar utilization for biomass formation and is a potential strategy to increase the protein content and the commercial value of DDG. Full article

The rapid increase in soil and water pollution is primarily attributed to anthropogenic factors, notably the mismanagement of post-consumer plastics on a global scale. This exploratory research design evaluated the effectiveness of natural hydrophobic cattail (Typha Latifolia) fibres (CFs) as bio-adsorbents of microplastic particles (MPPs) from wastewater. The study investigates how the composition of the adsorption environment affects the adsorption rate. Straightforward batch adsorption tests were conducted to evaluate the “spontaneous” sorption of MPPs onto CFs. Five MPP materials (PVC, PP, LDPE, HDPE, and Nylon 6) were evaluated. Industrial wastewater (PW) and Type II Distilled Water (DW) were employed as adsorption environments. The batch test results show that CFs are effective in removing five MPP materials from DW and PW. However, a higher removal percentage of MPPs was observed in PW, ranging from 89% to 100% for PVC, PP, LDPE, and HDPE, while the adsorption of Nylon 6 increased to 29.9%, a removal increase of 50%. These findings indicate that hydrophobic interactions drive the “spontaneous and instantaneous” adsorption process and that adjusting the adsorption environment can effectively enhance the MPP removal rate. This research highlights the significant role that bio-substrates can play in mitigating environmental pollution, serving as efficient, sustainable, non-toxic, biodegradable, low-cost, and reliable adsorbents for the removal of MPPs from wastewaters. Full article