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The advent of computer vision and pattern detection capabilities has given rise to the use of imaging technology in feedback and control processes. One such example is the use of imaging in agricultural post-harvesting equipment to enable machine automation through the use of imaging at the discharge. To explore this, the thesis will consist of developing a simulation in Python of the cracking process of pecans using experimental data, computer vision, and artificial intelligence (AI). In the cracking process, there are some variables as data that are the input for the machine and the output as videos recorded on the exit of cracking. Some classifications for the type of crack are determined, and the goal is to know and be able to modify the inputs to obtain the desired class of crack. An AI model will be tested and trained in Python with experimental data.
The thesis titled: “Evaluating pyrolysis results: The impact of biomass particle size and operating temperatures across biomass types” focuses on studying the impacts of two biomasses ‘pelletized wood and straw’ pyrolysis, and the effect of changes in the particle size. Pelletized form samples used in this study were of size of 10-15 mm while the crushed forms were of sizes that were 2.5mm or smaller in diameter and operating temperatures of 300°C, 550°C, and 800°C. Higher temperatures were seen to increase the yield of gas and decrease the yield of char, especially at 800°C when Biomass 2 recorded a significantly higher yield of gas, especially in the pellet form. The research showed that reduced particle sizes and temperatures between 550°C and 800°C enhanced the volumes of gases produced and fewer solid by-products remaining. It was found that the yield of bio-oil from both biomass types was higher at 550°C, a fact that suggests that this temperature is a critical tipping point for the maximum yield of the liquid product. Even though using higher temperatures may lead to an increase in gas production. A balance conversion was observed at this temperature with an optimum thermochemical conversion efficiency in mass balance, high char formation, and higher oil yields. Furthermore, the highest production mass balance efficiency was found to be over 90% for 550°C in less than 2mm size and 800°C pelletized form in both of the biomasses.
The most noticeable improvements to the device were made to better determine the safety and efficacy of the pyrolysis process. After it was determined that the nitrogen purge to prevent oxidation was unnecessary in this experiment, it was suggested only to be used for cooling the device after pyrolysis is finished. A permanently wired thermocouple was installed to provide a constant, precise temperature reading.
This thesis focuses on the development and optimization of a stable pyrolysis process for biomass, aimed at enabling accurate mass balancing of the resulting products: pyrolysis oil, char, and gas. Pyrolysis plays a key role in converting organic materials, such as biomass and waste, into valuable resources, contributing to renewable energy production and waste reduction. The first part of the project was dedicated to setting up a reliable and reproducible pyrolysis process that would ensure consistent product yields and enable precise mass balancing across multiple biomass types. This process was optimized to minimize mass losses and ensure efficient conversion of biomass.
Once the process was stabilized, various biomass sources (rootstocks, green waste, sewage sludge) were pyrolyzed, and the resulting products were analyzed for their water, ash, and carbon content. High-Performance Thin-Layer Chromatography (HPTLC) was used to investigate the chemical composition of pyrolysis oils and assess the impact of mixing different biomasses. The results showed that the target compounds (bends, which is not seen in other oil chromatogram) were retained after mixing, leading to increased oil yield (≈40%) and an optimized product (increasing or decreasing the concentration of target compounds) composition suitable for industrial applications. This research demonstrates the potential for selective biomass mixing and mass-balanced pyrolysis to enhance pyrolysis oil production and quality for sustainable energy solutions
The design and performance of tandem blade impellers in centrifugal
compressors is investigated holistically numerically and experimentally in this thesis.
The major goals are to maximize flow characteristics by creative impeller designs and increase energy economy. ANSYS Workbench software, BladeGen, TurboGrid and CFX modules allowed a thorough investigation of flow dynamics and performance criteria.Its capacity to raise the circumferential timing factor, lower flow losses, and enhance flow stability made tandem blade design the preferred choice. During the design phase, high quality meshes were produced; convergence and mesh independence tests were carried out to guarantee the dependability of simulation findings. Several impeller designs' performance was assessed under varying running conditions including pressure ratios and isentropic efficiency.According to the findings, tandem blade design reduces flow separation and boosts stability at low and high flow rates, so greatly improving the efficiency of centrifugal compressors generally. The study also emphasizes how crucial ideal flow control and posture of the impeller are for extending the compressor's running range. This study helps industrial and automotive sectors' more energy efficient and high-performance centrifugal compressors to be developed.
The “Enhanced Renewable-Energy Production from Co-Digestion of Waste Biomass and Sewage Sludge Based on Bio-Economic Prospects” could be the key to stopping reliance on fossil fuels that harm the ozone layer, change the climate over time, and increase global warming. Previous technologies were not mature enough to compete economically with fossil fuels, the microbial electrolysis cell in particular had weak points, and many configurations so the most optimal must be specific, optimizing it via combining with other technologies like anaerobic digestion helps overcome its limitations. The data used regarding different factors affecting the MEC’s performance (reactor design, cathode material, and surface area, anode material and surface area, micro-organism type, substrate, and membrane type) was taken mainly from previous studies and combined, then carefully examining the results, the findings give real hope in the future of renewable energy, especially with the MEC combined with the anaerobic digestion technology, and indicate that it is very possible to replace the fossil fuel energy, designing the most optimal MEC paired with economically profitable AD. However, research is still needed to further give the MEC paired with AD an edge.
This thesis delves into the optimization of chitin-rich mealworm residue sourced from the University of Warmia and Mazury in Olsztyn for the purpose of biogas production. The study focused on two types of mealworm residue, namely shell and frass, which represent the collected exoskeletons of the worms and the entirety of the residue from mealworm farming, respectively.
Cellulase enzyme initially enhanced biogas production significantly, showing promising results with a notable increase of up to 23% from shell waste and 30% from frass substrates. These findings underscore the potential of enzymatic interventions to augment biogas production from such substrates.
Subsequently, the study sought to optimize the activity of chitinase enzyme to facilitate the degradation of chitin content present in the mealworm residue. However, the Chit36-TA chitinase enzyme, exhibited no activity on the shell waste. As a result, various pretreatment methods, encompassing enzymatic, mechanical, and thermal approaches, were explored to promote chitin degradation. Despite these efforts, none of the pretreatment methods yielded significant improvements in chitin degradation.
This study underscores the complexities involved in enzymatic pretreatment strategies for chitin-rich waste materials. While cellulase showed promise in enhancing biogas production, the limited efficacy of chitinase highlights the need for further research to explore alternative methods for efficient chitin degradation. Such endeavors are crucial for unlocking the full potential of mealworm residue as a valuable substrate for biogas production, thereby contributing to the sustainable management of organic waste and renewable energy generation.
Finally, the application of chitinase in the biogas reactor was evaluated, revealing no positive influence on biogas production from shell substrates.
Reinstallation of the plant for formation of aerosols by homogeneous nucleation during evaporation
(2024)
Aerosol formation during homogeneous nucleation through evaporation is a complex process that plays a crucial role in atmospheric aerosol formation, influencing cloud formation, precipitation, and air quality. In process engineering, an aerosol can be generated undesirably, for example during flue gas scrubbing or condensation. As a result, the pollutant is discharged from the process as fine particles in the gas and must be subsequently separated in a very complex and cost-intensive manner. On the other hand, some processes also aim to produce aerosols of a certain size and concentration which will be used, for example, in cosmetics and pharmaceuticals.
This thesis investigates the factors that influence aerosol formation during homogeneous nucleation through evaporation, focusing on the effects of temperature, different heights of a direct contact column, and gas-phase composition. The rate of homogeneous nucleation is strongly influenced by temperature and pressure. As temperature decreases, the energy barrier required for the formation of a critical nucleus decreases as well, leading to an escalation in nucleation rates. Similarly, elevated pressure conditions result in a higher concentration of gas-phase molecules, fostering collisions and subsequently augmenting nucleation rates. The role of pressure in homogeneous nucleation is closely tied to the concept of vapor pressure and the phase transition from liquid to gas. Certain gas-phase species, such as water vapor, exhibit a higher propensity for nucleation compared to others due to their favorable intermolecular interactions. The presence of these species can bolster aerosol formation during homogeneous nucleation. These findings offer valuable insights into the processes governing the formation and enlargement of aerosol particles in a technical process such as wettening , thereby contributing to a more comprehensive understanding of aerosol dynamics.
The research employed HPTLC Pro System and other HPTLC instruments from CAMAG® to conduct various laboratory tests, aiming to compile a database for subsequent analyses. Utilizing MATLAB, distinct codes were developed to reveal patterns within analyzed biomasses and pyrolysis oils (sewage sludge, fermentation residue, paper sludge, and wood). Through meticulous visual and numerical analysis, shared characteristics among different biomasses and their respective pyrolysis oils were revealed, showcasing close similarities within each category. Notably, minimal disparity was observed in fermentation residue and wood biomasses with a similarity coefficient of 0.22. Similarly, for pyrolysis oils, the minimal disparity was found in fermentation residues 1 and 3, with a disparity coefficient of 1.41. Despite higher disparity coefficients in certain results, specific biomasses and pyrolysis oils, such as fermentation residue and sewage sludge, exhibited close similarities, with disparity coefficients of 0.18 and 0.55, respectively. The database, derived from triplicate experimentation, now serves as a valuable resource for rapid analysis of newly acquired raw materials. Additionally, the utility of HPTLC PRO as an investigation tool, enabling simultaneous analysis of up to five samples, was emphasized, although areas for improvement in derivatization methods were identified.
Steroid hormones (SHs) are a rising concern due to their high bioactivity, ubiquitous nature, and prolonged existence as a micropollutants in water, they pose a potential risk to both human health and the environment, even at low concentrations. Estrogens, progesterone, and testosterone are the three important types of steroids essential for human development and maintaining multiorgan balance, are focus to this concern. These steroid hormones originate
from various sources, including human and livestock excretions, veterinary medications, agricultural runoff, and pharmaceuticals, contributing to their presence in the environment. According to the recommendation of WHO, the guidance value for estradiol (E2) is 1 ng/L. There are several methods been attempted to remove the SH micropollutant by conventional water and wastewater technologies which are still under research. Among the various methods, electrochemical membrane reactor (EMR) is one of the emerging technologies that can address the challenge of insufficient SHs removal from the aquatic environment by conventional treatment. The degradation of SHs can be significantly influenced by various factors when treated with EMR.
In this project, the removal of SH and the important mechanism for the removal using carbon nanotube CNT-EMR is studied and the efficiency of CNT-EMR in treating the SH micropollutant is identified. By varying different parameters this experiment is carried out with the (PES-CNTs) ultrafiltration membrane. The study is carried out depending upon the SH removal based on the limiting factor such as cell voltage, flux, temperature, concentration, and type of the SH.
As the population grows, so does the amount of biowaste. As demand for energy grows, biogas is a promising solution to the problem. Lignocellulosic materials are challenged of slow degradability due to the presence of polymers such as cellulose, lignin and hemicellulose. There are several pretreatment methods available to enhance the degradability of such materials, including enzymatic pretreatment. In this pretreatment, there are few parameters that can influence the results, the most important being the enzyme to solid ratio and the solid to liquid ratio. During this project, experiments were conducted to determine the optimal conditions for those two factors. It was discovered that a solid to liquid ratio of 31 g of buffer per 1 gram of organic dry matter produced the highest reducing sugar release in flasks when combined with 34 mg of protein per 1 gram of organic dry mass. Additionally, another experiment was carried out to investigate the impact of enzymatic pretreatment on biogas production using artificial biowaste as a substrate. Artificial biowaste produced 577,9 NL/kg oDM, while enzymatically pretreated biowaste produced 639,3 NL/kg oDM. This resulted in a 10,6% rise in cumulative biogas production compared to its use without enzymatic pretreatment. By the conclusion of the investigation, specific cumulative dry methane yields of 364,7 NL/kg oDM and 426,3 NL/kg oDM were obtained from artificial biowaste without and with enzymatic pretreatment, respectively. This resulted in a methane production boost of 16,9%. Additionally in case of the reactors with enzymatically pretreated substrate kinetic constant was lower more than double, where maximum volume of biogas increased, comparing to the reactors without enzymatic pretreatment.