Processing Demands Research Articles

Exergetic analyses of air-fuel preheated cogeneration plants in food production

Lower emissions and better performances in food production also affect the cost, the environmental effects, and the quality of the products of the agriculture and food industry. The aim of this study is to investigate and to analyze the exergetic performance of the production of heat exergy and power, to reuse waste heat and to give optimum reaction and to adapt to changing demands of the food production process and agriculture. Because of those reasons, an air fuel preheated (recuperative) cogeneration plant is taken to analyze the exergetic performance and working conditions by using exergy analysis and 1st and 2nd laws of thermodynamics. Energy and exergy efficiencies, combustion chamber and gas-turbine outlet temperatures, electric-heat exergy rates, specific works, and total electric and heat energies and exergies are calculated by taking various environmental temperatures and various excess air coefficient. Effects of the environmental temperatures and the excess air coefficient on the exergetic performance of the recuperative cogeneration plants were calculated, obtained, and discussed. For the best exergetic performance and working conditions, some recommendations were done for agriculture and for the food production process. In that study, it is found that, the recuperative cogeneration plants can obtain and give the best solutions and can adapt to changing demands of heat and electric rates. Also, it was found that, lower ambient temperatures give better electric efficiency, but lower heat exergy and electric rates. However, higher excess air coefficient increases the performance of the recuperative (air fuel preheated) cogeneration plants.

Does emotional valence affect cognitive performance and neurophysiological response during decision making? A preliminary study.

This study investigated the impact of the emotional valence of external situations (EVES) on cognitive performance and electrophysiological (EEG) responses during decision-making. 26 healthy adults underwent a modified version of the Trier social stress test, performing five interview-style discourses. Each discourse entailed preparing a speech under increasingly stressful conditions. Participants were also exposed to gradually increasing EVES (i.e., an examining committee displaying progressively more negative-connoted emotional facial expressions). In addition, after each speech, participants completed an arithmetic task to test how emotional manipulation affected cognitive performance. Behavioral data (preparation times) and EEG data (frequency bands) were collected to assess stress regulation, stress resilience, and cognitive performance. The results indicate that EVES significantly influenced stress regulation and resilience, as reflected in the behavioral data. Neurophysiological findings showed increased parietal lobe activity (P4) in the theta and delta bands with rising emotional valence, plateauing from the preparation of the second discourse onward. This suggests enhanced emotional processing and attentional demands. However, gamma band activity decreased in P4 during the preparations for the two discourses following the first, indicating a shift of cognitive resources from higher cognitive functions to emotional processing. This highlights the cognitive cost of maintaining performance and stress regulation under emotionally charged conditions. Such findings suggest that emotional valence modulates cognitive performance and that specific neural mechanisms are involved in managing stress responses. The findings underscore the complex relationship between emotion, cognition, and neural mechanisms, offering valuable insights for stress regulation and resilience, and enhancing performance under pressure.

ОБГРУНТУВАННЯ КРИТЕРІЇВ ФОРМУВАННЯ ПОПИТУ ТА ПРОПОЗИЦІЇ РИНКУ ПРАЦІ РЕГІОНУ

The article examines the parameters and modern views on the formation of the regional labor market. Scientific views on the definition and substantiation of the parameters of the formation of regional labor markets were studied, and the criterion characteristics of the region were analyzed. The criteria for the formation of the labor market of the region are substantiated, among which the main parameters that are the basis for the development of the latter are determined. The author proposed an extended description of the specified criteria, including territorial, economic, demographic, and educational and qualification criteria. The territorial criterion determines the boundaries of the territory of the functioning of the labor market and is closely related to the economic criterion, which is formed within the boundaries of the territorial entity. The economic criterion is determined by the specificity of the region, available natural resources, production, market and personnel potential, which allows performing certain types of economic activities that ensure the optimal branch structure of the region's economy. The demographic criterion characterizes the accumulation, formation and distribution of the population within the region and the labor force within the regional labor market. The educational qualification criterion is closely related to the demographic factor and demonstrates the degree of compliance of the offer on the market with the needs of the leading industries of the region. The author analyzed the influence of each of the proposed criteria on the formation of the labor market of the region as a whole. Proposed stages of formation of demand and supply in the labor market of the region, which contain logical sequential steps of formation of demand in key and auxiliary sectors of the economy and the sequence of formation of supply to balance the processes in the labor market of the region. A model of the formation of the labor market of the region has been developed, which takes into account the criteria for the formation of the latter, includes the processes of interaction of all market participants, contains the stages of formation of key processes (demand and supply) and takes into account the influence of state regulation.

O Seguro de W&I como instrumento facilitador do processo negocial de aquisição de participação social de controlo

Corporate acquisitions, known in national and international legal jargon as M&A transactions, are based on a demanding, challenging and complex negotiation process, dynamic and phased over time, characterised by its uncertainty. The pre-contractual phase is characterised by an information asymmetry between Buyer and Seller. This informational inequality leads the negotiating parties to take ab initio particular precautions in order to protect their respective interests, setting up mechanisms and designing solutions to safeguard against future pathological scenarios, allowing for the allocation of negotiating risks and providing the negotiating process with legal certainty and security, thereby promoting its predictability and transparency. We propose in this study to analyse the specific features of the W&I Insurance as a tool for mitigating transactional risk and to identify its impact on the negotiation process of company’s acquisitions.

Holographic fabrication of reconfigurable diffractive elements

The fabrication of Diffractive Optical Elements (DOEs) involves the analog patterning of material surfaces on the scale of light wavelength. This typically requires multi-step lithographic processes. Differently from the photoresists of standard lithography, thin films of amorphous azobenzene-containing polymers (azopolymers) can directly produce a structured surface using a single irradiation step with structured light. The resulting surface reliefs can be used directly as planar phase-modulating DOEs without the need for any post-exposure process. Additionally, the surface geometry and its optical functionality can be reconfigured at will. Here, we demonstrate reprogrammable and ready-to-use azopolymer diffractive gratings, lenses, and holographic projectors, produced by grayscale digital holographic patterns. By exploiting the all-optical scheme based of computer-generated holography, the diffraction behavior of the DOEs is optimized during the developing of structured surfaces. Full all-optical reconfigurability of the fabricated devices is also achieved. Our approach provides a versatile, efficient, and all-optical reversible fabrication framework for DOEs, making it a promising option to overcome the demanding, cumbersome, and irreversible fabrication processes typically involved in the realization of planar diffractive optical devices.

Note on the Dual-Task Paradigm and its Use to Measure Listening Effort.

People regularly communicate in complex environments, requiring them to flexibly shift their attention across multiple sources of sensory information. Increasing recruitment of the executive functions that support successful speech comprehension in these multitasking settings is thought to contribute to the sense of effort that listeners often experience. One common research method employed to quantify listening effort is the dual-task paradigm in which individuals recognize speech and concurrently perform a secondary (often visual) task. Effort is operationalized as performance decrements on the secondary task as speech processing demands increase. However, recent reviews have noted critical inconsistencies in the results of dual-task experiments, likely in part due to how and when the two tasks place demands on a common set of mental resources and how flexibly individuals can allocate their attention to them. We propose that in order to move forward to address this gap, we need to first look backward: better integrating theoretical models of resource capacity and allocation as well as of task-switching that have been historically developed in domains outside of hearing research (viz., cognitive psychology and neuroscience). With this context in mind, we describe how dual-task experiments could be designed and interpreted such that they provide better and more robust insights into the mechanisms that contribute to effortful listening.

Identification of continuous-time Hammerstein model using improved Archimedes optimization algorithm

Although various optimization algorithms have been widely employed in multiple applications, the traditional Archimedes optimization algorithm (AOA) has presented imbalanced exploration with exploitation phases and the propensity for local optima entrapment. Therefore, this article identified various continuous-time Hammerstein models based on an improved Archimedes optimization algorithm (IAOA) to address these concerns. The proposed algorithm employed two principal modifications to mitigate these issues and enhance identification accuracy: (i) exploration and exploitation phase recalibrations using a revised density decreasing factor and (ii) local optima entrapment alleviation utilizing safe experimentation dynamics. Various advantages were observed with this proposed algorithm, including a lower number of coefficient criteria, improved accuracy in Hammerstein model identification, and diminished processing demands by reducing gain redundancy between nonlinear and linear subsystems. This proposed algorithm also discerned linear and nonlinear subsystem variables within a continuous-time Hammerstein model utilizing input and output data. The process was evaluated using a numerical example and two practical experiments [twin-rotor system (TRS) and electro-mechanical positioning system (EMPS)]. Several parameters were then analyzed, such as the convergence curve of the fitness function, frequency and time domain-related responses, variable deviation index, and Wilcoxon's rank-sum test. Consequently, the proposed algorithm reliably determined the most optimal design variables during numerical trials, demonstrating 54.74 % mean fitness function and 75.34 % variable deviation indices enchantments compared to the traditional AOA. Improved mean fitness function values were also revealed in the TRS (11.63 %) and EMPS (69.63 %) assessments, surpassing the conventional algorithm. This proposed algorithm produced solutions with superior accuracy and consistency compared to various established metaheuristic strategies, including particle swarm optimizer, grey wolf optimizer, multi-verse optimizer, AOA, and a hybrid optimizer (average multi-verse optimizer-sine-cosine algorithm).

Oxygenated bio-fuel synthesis in reactive distillation: A technological reform under process intensification

Chemical Engineering processes demands separation of reaction products to obtain them in purest form. Reactive Distillation facilitates this feature by incorporating a reactive zone for reaction between conventional rectifying and stripping zone for distillation. It also aid for solid catalyst incorporation of amphoteric nature to avoid repetitive addition of catalyst for different experimental run and will also improve the product yield. The other beneficial features of Reactive Distillation include reduced synthesis cost, reduced utility space required and higher selectivity. This technique is introduced in this paper for synthesis of oxygenated bio-fuel. For this, fuel additive of ether family namely Tert Amyl Ethyl Ether (TAEE) is synthesized using ethanol. Similarly, Biodiesel synthesis is done using transesterification of waste cooking oil with methanol. Both fuel-oxygenate (TAEE) and biodiesel are then blended in varying proportion to improve ignition quality of biodiesel fuel. The study is done experimentally and analyzed under object oriented modeling mode in simulation. Optimization of synthesis process is done using revamping in experimental mode corresponding to sensitivity analysis in simulation. The congruence results show that purity of 95 % and 65 % for biodiesel and TAEE respectively is obtained in reactive distillation corresponding to reboiler duty of 2 kW and reflux ratio 4.

Enactment and impact analysis of active learning strategies utilized for the basic science courses in the evaluation of engineering students

The new era of teaching learning process demands more clearance of theoretical aspects utilizing visual strategies. Accordingly, this research focuses on usefulness of student team achievement division (STAD) and project based learning (PjBL) as active learning strategies for comprehensive understanding of basic science courses. The study revealed increased effectiveness of learning, encouraging equal participation, active engagement and supportive learning environment for better understanding of concepts in basic science courses. The usefulness of active learning strategies has been studied by conduction of STAD & PjBL activities for the Engineering Mathematics and Engineering Chemistry courses respectively. The appropriate evaluation and comparative analysis done before and after activity allows to elaborate the efficacy of visual strategies utilized for understanding theoretical concepts. Keywords—Active learning tools, Basic Science Courses, Evaluation Rubrics, Project Based Learning, Student Team Achievement Division

«ЕҢБЕККЕ БАУЛУ» ПӘНІН ОҚЫТУДА БАСТАУЫШ СЫНЫП ОҚУШЫЛАРЫНЫҢ ШЫҒАРМАШЫЛЫҚ ІС-ӘРЕКЕТІН ҚАЛЫПТАСТЫРУДЫҢ ЖОЛДАРЫ

The problem of shaping personality of a student possessing the skills of creative knowledge application in the educational process demands attention and investigation. A person equipped with such skills can enact changes in societal development and become an active participant in the process. To assess the relevance of the article, an analysis of regulatory documents and research by both domestic and foreign scientists working in this field was conducted. Consequently, definitions of the concept of "creative activity" were proposed. Additionally, the article described components essential for developing creative activities in young students, including motivational, creative-cognitive, and intellectual aspects, and outlined their criteria and indicators. The goal of the study is to identify methods for fostering creative actions in the educational process. These actions should be purposeful and principled, encourage unconventional thinking skills, and support universal learning activities that lead to various forms of self-expression. The experimental cohort comprised 63 students of 2nd grade (groups "A" and "B") of the General Secondary School № 49. The experimental work was divided into three stages: ascertaining, forming, and controlling. At the ascertainment stage, a new level was determined using the methodology of creative thinking by P. Torrens, while at the formation stage, three approaches were considered: project-based learning (PBL), utilization of media resources, and STEM learning. The results of the comparative analysis demonstrated the effectiveness of the work during the formation stage.

Automated and advanced document processing system in the woodworking industry

This article presents a detailed framework for the seamless integration of a new document processing system within the operational workflow of a company. The proposed plan prioritizes both continuity and parallel deployment to ensure minimal disruption during implementation. It includes a thorough decomposition of system use cases, illustrated with block diagrams, along with sample mock-ups of the user interface to facilitate understanding among developers, designers, and technical writers throughout the development process. The primary objectives of this initiative are to boost employee productivity, reduce costs associated with production downtime, and guarantee the system’s scalability to meet evolving document processing demands.

Isolation, Identification and Screening of Humic Acid Producing Fungi from Soil Environment of Oil palm (Elaeisguineensis) Associated with Empty Fruit Bunches

The demand for sustainable and sustainable biotechnological processes has developed as a result of a growing interest in converting agricultural waste into valuable products. In this study, fungal strainswere isolated from soil environment ofoil palm empty fruit bunchesandscreened for humic acid production. In Osun state, Nigeria, soil sample was taken from a local palm oil mill. Different colonies of fungi were obtained for further research using the serial dilution plating procedure. Plate screening was used to evaluate the fungal biomass as well as colony diameter of the fungal isolates, and a submerged fermentation test was used to measure the amount of humic acid concentration the isolates produced. Fungal isolates were identified by using molecular methods and morphological analysis. The fungi species Aspergillusniger, Rhizopusstolonifer, and Penicilliumchrysogenum were isolated from the soil environment. When compared to Rhizopusstolonifer, Aspergillusniger grew more superiorly in terms of zone diameter (26.5 1.50 mm) and biomass (2.23 0.16 g), while Penicilliumchrysogenum showed no growth. Throughout the fermentation process, Aspergillusnigeralso produced a greater quantity of humic acid, with concentrations varying from 0.70 mg/l to 2.20 mg/l. Aspergillusniger strain HR18's existence was confirmed by molecular analysis. This experiment proved that Aspergillusniger can efficiently produce humic acid from OPEFB, providing a useful method for waste utilization and sustainable practices.

OPTIMALISASI PRODUKSI ASESORIS SEPEDA MOTOR DI CV BOUDY MOTOR MENGGUNAKAN METODE SIMPLEKS PROGRAM LINEAR DENGAN SOFTWARE POM-QM

CV Boudy Motor is one of the automotive businesses engaged in manufacturing, production of variations of motorcycle accessories. Demand, inventory and production processes constitute a package system in the productivity of industrial profits. This study aims to determine optimal production and profit using the simplex linear program method with POM-QM software. The calculation results, the optimal production for footstep products is 1,000 pcs and a variation ruler is 2,600 pcs. The total overall profit obtained by CV Boudy Motor from footstep products and variation rulers for per day is Rp. 6,900,000 and for per month with 26 days of active period is Rp. 179,000,000 assuming the profit is in accordance with the goal function and fixed constraint function.

Coupled bio-chemo-hydro-mechanical modeling of microbially induced calcite precipitation process considering biomass encapsulation using a micro-scale relationship

Geomaterials with inferior hydraulic and strength characteristics often need improvement to enhance their engineering behaviors. Traditional ground improvement techniques require enormous mechanical effort or synthetic chemicals. Sustainable stabilization technique such as microbially induced calcite precipitation (MICP) utilizes bacterial metabolic processes to precipitate cementitious calcium carbonate. The reactive transport of biochemical species in the soil mass initiates the precipitation of biocement during the MICP process. The precipitated biocement alters the hydro-mechanical performance of the soil mass. Usually, the flow, deformation, and transport phenomena regulate the biocementation technique via coupled bio-chemo-hydro-mechanical (BCHM) processes. Among all, one crucial phenomenon controlling the precipitation mechanism is the encapsulation of biomass by calcium carbonate. Biomass encapsulation can potentially reduce the biochemical reaction rate and decelerate biocementation. Laboratory examination of the encapsulation process demands a thorough analysis of associated coupled effects. Despite this, a numerical model can assist in capturing the coupled processes influencing encapsulation during the MICP treatment. However, most numerical models did not consider biochemical reaction rate kinetics accounting for the influence of bacterial encapsulation. Given this, the current study developed a coupled BCHM model to evaluate the effect of encapsulation on the precipitated calcite content using a micro-scale semiempirical relationship. Firstly, the developed BCHM model was verified and validated using numerical and experimental observations of soil column tests. Later, the encapsulation phenomenon was investigated in the soil columns of variable maximum calcite crystal sizes. The results depict altered reaction rates due to the encapsulation phenomenon and an observable change in the precipitated calcite content for each maximum crystal size. Furthermore, the permeability and deformation of the soil mass were affected by the simultaneous precipitation of calcium carbonate. Overall, the present study comprehended the influence of the encapsulation of bacteria on cement morphology-induced permeability, biocement-induced stresses and displacements.

Development of a multi-stage model for freezing of a suspended binary solution droplet

The importance of developing spray freeze-drying technology for extending the shelf life of biological and pharmaceutical materials has never been greater, given the increasing food shortage and the strong demand for pharma processes. In particular, the optimal thermal design and application of spray freeze-drying technologies now depend on the estimation of nucleation behavior for droplet solidification (especially the droplets of binary mixtures). Although earlier nucleation models could estimate the nucleation rate and temperature of solidifying droplets, few considered extreme environmental factors, such as extremely low ambient temperatures below −60C∘. To ensure the preservation and storage of biological and pharmaceutical products, such as vaccines and protein drugs, these conditions are essential. Hence, developing an accurate and trustworthy mathematical framework for simulating nucleation is paramount. In this study, a multi-stage, hybrid analytical-numerical model for droplet solidification is developed while coupled with a gradient-based optimization algorithm. Specifically, the five-stage solidification of binary mixtures is simulated (including supercooling of liquid, nucleation, recalescence, equilibrium freezing, and subcooling of solid), which captures the dynamic behaviors of temperature and composition or solute concentration during phase change. The heterogeneous nucleation of a binary-mixture droplet in a frigid environment is predicted and validated against a series of experiments on single suspended droplets at a wide range of ambient temperatures between −20 and −160C∘. The freezing curves of different solute concentrations are also validated against experimental data. It is found that significant variations in interfacial tension lead to abrupt changes in nucleation temperature for extremely cold environments. Further, the effects of the concentration, contact angle, droplet size, and heat transfer coefficient are investigated.

Suggestions for Introducing Some New Terms in Pelvic and Acetabular Surgery

Background. The rapid advancement of modern surgical methods for treating pelvic bone fractures has underscored the necessity for developing a new terminological framework. This is because the classical anatomical terminology of the pelvis no longer aligns with the demands of the therapeutic process and scientific research in this field. The traditional set of anatomical names and landmarks falls short in providing detailed descriptions of all intricacies of injuries when employing contemporary surgical techniques. The existing terminology system needs to catch up with the level of contemporary pelvic surgery, enabling a comprehensive and understandable characterization of existing pathology and the treatment being administered for all medical professionals.
 Purpose of the study was to create names for certain parts of the pelvic bones and their areas that currently lack specific designations and to propose the developed terms for professional discussion.
 Methods. A retrospective analysis was conducted on X-rays and computer tomography scans of patients with pelvic bone injuries, performed from 2020 to 2022. A list of potential new anatomical terms was compiled through a literature review.
 Results. In several cases, we encountered a deficiency of terms in diagnosing pelvic injuries and describing surgical procedures. New terms were developed to denote areas of the pelvis and their injuries, including the pubic bone base, vertical fractures of the pubic bone base, longitudinal fractures of the pubic bone base, incomplete rupture of the pubic symphysis, the base of the ilium, longitudinal fracture of the iliac base, fracture-subluxation and fracture-dislocation of the iliac base, calcar of the iliac bone, calcar spike, and the bone corridor.
 Conclusions. The incorporation of new anatomical terms into clinical practice will help enhance the precision of diagnosis and surgical planning in pelvic fractures. Standardizing the terminology will promote uniformity in approaches and knowledge sharing among specialists, ultimately improving the quality of surgical care for patients with pelvic injuries.

Optimizing PEEK impact strength through multi-objective FDM 3D printing

Thermoplastic materials such as Polylactic acid, Acrylonitrile Butadiene Styrene, Polyethylene terephthalate glycol, Nylon, and Thermoplastic polyurethane are favoured in Fused deposition modeling 3D printing due to their cost-effectiveness and versatile properties. However, with the introduction of high grade thermoplastic material poses compatibility challenges with existing machines and processes, impeding widespread adoption in FDM 3D printing. Incorporating new materials into 3D printing requires adjustments to hardware, software, and settings, leading to potential expenses and time investments. Maintaining quality control and consistency becomes complex as each material demands specific parameters and processing conditions. This variability hinders achieving consistent part quality in 3D printing. Moreover, achieving optimal FDM parameters for high-grade polymers (HGPs) like Polyether ether ketone (PEEK) is a challenge due to the distinctive nature of the property, requiring specialized careful considerations during its optimization process. The considerable thermal gradient and heat distribution during printing can lead to residual stresses and deformations, significantly affecting the quality and, in particular, its impact strength. This article optimizes an industry grade 3D printing PEEK based on the limited number of process parameters, namely, build orientation, in-fill density and chamber temperature. Further, the research tries to derive a predictive model for Impact Strength (IS), which is an important consideration for the 3D printed object. In this article, along with the Impact Strength, Printing Time and Material Usage are also studied to find empirical evidence of association between these output variables or response variables. The result indicates that there is a positive significant correlation or association between them. When utilizing a specific parameter setup, the resulting IS of 86.5 kJ/m², a print time of 89 minutes, and a material usage of 3.26 grams are achieved. Notably, there is a measurable reduction of 9.18% in printing time and a 11.66% decrease in material usage when the print density is set to 100% to optimize impact strength. This optimization approach proves the use of composite desirability is a better approach where multiple objectives need to be achieved. The proposed regression model predicts the impact strength with coefficient of determination value more than 50%.

Evaluation of the hardness and wear behavior of date seed powder/epoxy composites as potential biomaterials

The date palm, or Phoenix dactylifera, is a crop that is grown for food and is used by many people on a regular basis. The cultivation of date palms, their processing, and consumer demand all produce tons of waste. Date palm seeds can account for up to 10 % of the total weight of the fruits. A topic of interest for research is the application of date seed waste in the fields of engineering, nutrition, and cosmetics. This work aims to show that epoxy/palm seed date composites are suitable for use as biomaterials by examining their wear behavior. Give a brief introduction to a few ideas before going over the fundamental idea of wear resistance. Future wear resistance improvements in biomedical applications and other industries that might benefit from this addition will continue to be achieved through the use of date palm seed microparticles in epoxy. In this study, epoxy composites containing palm seed particles are made by the mixing procedure. The studied composites made from date palm seed powder particles has micron particle size of 150 which is mixed with epoxy as a matrix. The percentages of date palm seeds are varying from 5 % to 20 %. The 20 percent sample had the best results, losing 7.03 percent of their starting weight. The 10 percent group, which lost 9.4 percent, the 15 percent group, which lost 12.2 percent, and the 5 percent sample, which lost 19.95 percent, were the next in line. Each of the four samples had 1 kg to 5 kg of weight applied to them at five different rotation speeds. Upon analysis of all the samples under investigation, it was discovered that the date palm seeds enhanced and increased wear resistance, leading to better outcomes.

(Electrodeposition Division Research Award) New Frontiers of Electrodeposition for Metallic Finishes

The interest in scientific research within the metal finishing sector is growing. The demand for durable metals and adaptable manufacturing processes is increasing across a wide range of applications, from aerospace and automotive to machinery and jewelry. In that respect, alloy plating offers better answers in terms of economic growth and environmental sustainability due to fine-tuning composition, morphology, and crystallinity [1]. Here, current trends in alloy electrodeposition research are reviewed highlighting open challenges and process innovations from an industrial perspective. Combining basic electrochemical techniques with spectroscopic, microscopic, and structural techniques is crucial for characterizing the structure-activity relationship for many different technological devices. Particular attention is devoted to advances in industrial quality control and viable solutions for the reduction of precious metal content in electroplated accessories as well as the replacement of cyanide and nickel baths with non-toxic compounds. Project funded under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.3 - Call for tender No. 341 of 15 March 2023 of Italian Ministry of University and Research (MUR) funded by the European Union - NextGenerationEU - Project code PE_00000004, CUP B83C22004890007, Project title "3A-ITALY - Made-in-Italy circolare e sostenibile".

Waste animal fat with hydrothermal liquefaction as a potential route to marine biofuels.

Unused animal waste rendered fat is a potential feedstock for marine biofuels. In this work, bio-oil was generated using hydrothermal liquefaction (HTL) of nitrogen-free and low sulfur rendered bovine fat. Maximum bio-oil yield of 28 ± 1.5% and high heating value of 38.5 ± 0.16 MJ·kg‒1 was obtained at 330 °C at 50% animal fat solid load and 20 min retention time. The nitrogen and sulfur content were negligible, making the produced bio-oil useful marine biofuel, taking into account current stringent regulations on NOx and SOx emissions. The economic analysis of the process, where part of the bovine fat waste is converted to the bio-oil and the semi-solid residues can be used to supply the heat demand of the HTL process and alternately generate electricity, showed that our process is likely to generate a positive profit margin on a large scale. We also showed the growing economic importance of electricity in the revenues as commercial production becomes more energy efficient.