ChemEcon - 2023

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item: Conference-Abstract
Biodiesel production using rendered oil from waste chicken skin
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Wickramathilaka, A; Gunarathne, S; Rathnayake, M; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Biodiesel is a prominent biofuel that can be locally produced from various feedstock options to replace/blend with diesel. This study explores the feasibility of biodiesel production from waste chicken skin in the laboratory-scale. The average yield of rendered oil obtained from waste chicken skin is 280 mL/kg. The rendered chicken skin oil displayed minimal impurities and exhibited a yellow color, demonstrating the presence of natural pigments. To determine the suitability of the rendered oil for biodiesel production, experimental tests were conducted to measure the Free Fatty Acid (FFA) content and Acid Value (AV). The FFA content was found to be less than 3%, indicating the possibility of direct conversion of rendered chicken skin oil into biodiesel via transesterification. The biodiesel yield obtained from the rendered chicken skin oil samples ranged with an average yield of 43%. The results demonstrate the potential of waste chicken skin as a viable feedstock for local biodiesel production. While density and net calorific value are nearly the same, biodiesel samples display significantly lower kinematic viscosity, suggesting improved flow characteristics while reporting a higher flash point than that of diesel, indicating the requirement of a higher ignition temperature. Further, an economic analysis was also performed to evaluate the overall production cost of a scaled-up biodiesel production plant from waste chicken skin. This study demonstrates the potential of waste chicken skin as a viable feedstock for biodiesel production and supports important findings for future developments of commercial scale biodiesel production from locally available bio-waste/food-waste sources.
item: Conference-Abstract
ChemECon 2023 Solutions worth spreading (Pre Text)
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Proceedings of ChemECon 2023 Solutions worth spreading
item: Conference-Abstract
Dye sensitized solar cells using natural dyes derived from chaetomorpha, microcladia borealis, elisolandia elongate and sea lettuce
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Illlankoon, HMUB; Sumudushantha, WANT; De Alwis, A; Perera, U; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Natural dye-sensitized solar cells (DSSCs) are a promising area in renewable energy. These innovative devices employ natural dyes extracted from plants to absorb sunlight and convert it into electricity. The dyes (anthocyanins in berries or chlorophyll in green plants), act as sensitizers, absorbing sunlight and generating excited electrons. One of the significant advantages of natural DSSCs is their eco-friendly nature, as they utilize renewable resources and have a low environmental impact compared to traditional solar cells. Moreover, their production is cost-effective and can be easily scaled up for industrial applications. With ongoing R&D efforts, natural DSSCs have the potential to contribute significantly to a cleaner and sustainable energy future. Reinforcing above, this study investigated the efficiencies of DSSCs produced using dyes of novel seaweed varieties (Microcladia borealis, Ellisolendia elongata, sea lettuce and Chaetomorpha) from shallow seas in Sri Lanka. Dye extracts from sea weeds have been studied sparsely with DSSCs. This research dives into the extensive color resources contained in the Sri Lankan seaweeds. The absorption of the dye and the electron emitting efficiency of the dye showed a clear relationship which can be further used in research for better dyes without following the full procedure of producing the cell. Additionally, the research opens a path for further research whether nano TiO is a mandatory factor in producing a DSSC. The highest efficiency was shown by dye extracted from Microcladia borealis which was 1.7x10 %.
item: Conference-Abstract
Effect of the filler materials in urea formaldehyde adhesives used in wood composite manufacturing industry
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Chandrarathna, AHMHG; Weerakoon, SJ; Sethunga, DSMDP; Walpalage, S; Gunawardena, S; Narayana, S; Gunasekera, M
This research examines the effect of filler materials on urea formaldehyde (UF) adhesives used in the wood composite manufacturing industry. The study compares the performance of wheat flour, a commonlyused but expensivefiller, with coal fly ash and wood fly ash, waste productswith adverse environmental impacts. The objectives include evaluating the impact of coal fly ash and wood fly ash fillers on adhesive viscosity and the mechanical properties (bending strength and modulus of elasticity) of wood composites and comparing the results with wheat flour. Viscosity measurements conducted with a Brookfield viscosity meter indicate a significant increase in UF adhesive viscosity over time with the addition of wheat flour. Wood fly ash shows minimal impact on viscosity, while coal fly ash contributes moderately compared to wheat flour and wood fly ash. Bending tests (ASTM D790) and empirical equations, following EN-325 sampling standards, are employed to assess the effect of filler materials and concentration on bending strength and modulusof elasticity in the final wood composites. Plywood bonded with coal fly ash demonstrates the highest bending strength and modulus of elasticity, with wheat flour as the reference filler. Both wheat flour and coal fly ash exhibit improved bending strength with increasing filler concentration, whilewood fly ash exhibits the opposite effect. In conclusion, coal fly ash proves to be a suitable substitute for wheat flour as a filler in urea formaldehyde adhesives, providing satisfactory adhesive properties and enhancing the performance of wood composites.
item: Conference-Abstract
Enhancing the sustainability of microalgae biomass generation for production of alpha-linolenic acid via integration of reverse osmosis (ro) reject streams
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Wickramasinghe, S; Ovitigala, M; Ariyadasa, TU; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Industrial reverse osmosis (RO) reject streams are a significant source of pollution in surface water bodies and requires effective treatment. Microalgae-based treatment of RO reject streams is an interesting approach as it generates valuable biomass concurrent to bioremediation. This approach also enhances the sustainability of microalgae biomass production by eliminating the requirement of external nutrient supply and reducing the freshwater footprint. However, there is a significant gap in research on utilization of RO reject streams generated by food/pharmaceutical industries for synthesis of microalgaebased high-value bioproducts. The current study was performed to ascertain the potential of using RO reject streams from the local food (RO1) and pharmaceutical (RO2) industries to cultivate Desmodesmus sp. for synthesis of alpha-linolenic acid. Accordingly, a screening experiment was conducted by growth of Desmodesmus sp. in RO1 and RO2 under dilutions of 25%, 50%, 75% and 100% (undiluted sample). Results showed that the highest biomass yields were obtained in 100% RO1 and 100% RO2. Thereafter, Desmodesmus sp. was cultured in 100% RO1 and 100% RO2 using photobioreactors with Modified Bold’s Basal media (3N-BBM) used as the control. Results showed that the use of RO reject streams resulted in a positive effect on the growth and biochemical composition of Desmodesmus sp. The high lipid content in biomass showcased that the use of RO reject streams could enhance the sustainability of microalgae-based alpha-linolenic acid production. However, further research is needed to study the toxicology effects and assess the techno-economic feasibility of using RO reject as the growth media.
item: Conference-Abstract
Experimental design and analysis of synergistic effects of ultrasonication and process parameters for optimization of Lycra and Tricot fabrics dyeing process
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Madhuhansi, UPR; Manujitha, ULL; Rathnayake, M; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Ultrasonication emerges as a promising technique to utilize in the dyeing processes in textile industries to minimize energy consumption. The efficacy of ultrasonication in the dyeing process has been demonstrated in this research, particularly in Lycra and Tricot fabrics, where achieving optimal temperature and contact time conditions can result in reduced energy consumption, cost-effectiveness, and improved product dyeing quality. The factorial experimental design and analysis technique was utilized to experimentally evaluate the synergistic effects of the major process parameters. The product dyeing quality was chosen as the dependent variable and was quantitatively determined by a specific spectrophotometer. Through a comprehensive ANOVA study on the experimental results, it has been scientifically demonstrated that ultrasonication, combined with contact time and temperature of the dyeing bath, significantly impacts the ultimate product dyeing quality. Based on the findings, it is imperative to establish that optimal dyeing results for the intertwined Lycra and Tricot fabrics can be achieved by employing ultrasonication at temperatures ranging from 60°C to 70°C, with contact times exceeding 45 minutes in comparison to the conventional dyeing process carried out at 98°C and 1 hour respectively. These findings highlight the efficacy of ultrasonication in enhancing the dyeing process for both Lycra and Tricot. Ultrasonication demonstrated a substantial improvement over previous results obtained without ultrasonication, resulting in a noteworthy reduction of 39% in operating temperature and 25% in contact time. This underlines the synergistic effects of ultrasonication and process parameters, wherein ultrasonication acts as a catalyst, enhancing dye penetration and fixation within the fabric structure. The integration of ultrasonication in the dyeing process offers significant advantages, including reduced energy consumption, improved process efficiency, and enhanced fabric quality, making it a promising technique for achieving sustainable dyeing goals.
item: Conference-Abstract
Integration of food industry wastewater for cultivation of desmodesmus sp. to synthesize alpha-linolenic acid
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Gamage, GDNC; Hannadige, SKHN; Ariyadasa, TU; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Microalgae biomass production for food and fuel applications necessitates the use of resources such as water and nutrients, raising sustainability concerns. This study aimed to integrate food industry wastewaters as a source of nutrients and water for microalgae cultivation while simultaneously performing bioremediation. Nonetheless, wastewaterbased microalgae cultivation requires the identification of suitable wastewater streams, nutrient loads, and appropriate media sterilization methods to prevent culture failure due to contamination. In the current study, the microalga Desmodesmus sp. was cultivated in wastewater-based media for synthesis of the nutritionally-valuable alpha-linolenic acid. This study is the first in literature wherein a comparative assessment was performed between autoclaving and filtration as methods for wastewater sterilization. A screening experiment for Desmodesmus sp. growth was performed using brewery wastewater (BrW), coconut processing industry wastewater (CW) and biscuit wastewater (BiW) obtained from the food industry, under 25%, 50%, 75%, and 100% (undiluted) concentrations. Undiluted BiW was the most suitable media, as it resulted in the highest final biomass yields. Thereafter, undiluted BiW sterilized by autoclaving and filtration was used to culture Desmodesmus sp. in photobioreactors with Modified Bold’s Basal Media used as the control. BiW showed higher biomass yields and specific growth rate compared to the control. A higher lipid productivity of 16.78 mg L d was exhibited in autoclaved medium as compared to 9.92 mg L d in the filtered medium. Thus, BiW sterilized via autoclaving was identified as a promising growth medium for alpha linolenic acid production from a circular economic perspective.
item: Conference-Full-text
Meta-analysis of microbial communities from wastewateractivated sludge
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Kaluthanthri, KPHPP; Lahiru, LP; Vidanage, PW; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Traditional mathematical models utilized in wastewater treatment plants (WWTPs) design encounter limitations in accurately characterizing the intricate metabolic functions transpiring within bacterial cells. Nevertheless, the progress in sequencing technologies and computational power has made it easier to study and identify the taxonomic and functional aspects of microorganisms present in wastewater treatment plants (WWTPs). Furthermore, adopting a systems biology approach enables a holistic comprehension of the ecological interactions between microbial communities and their subsequent effects on the efficiency of the treatment process. This study conducted a meta-analysis to identify the core microbial community members of municipal wastewater treatment plants, community diversities across the different regions, and correlations among key microbial families. A mathematical model was developed to represent the relationship between relative abundance and occurrence frequency of microbial families. Principal component analysis and network analysis were used to identify community diversities and microbial correlations. While important microbial species and their relationships were identified, no significant variations were observed among different geographical regions. Through the application of meta-analysis, it is possible to leverage the obtained results to provide a comprehensive understanding of the factors that influence the dynamics of the process.
item: Conference-Abstract
Natural dye-sensitized solar cells (ndsscs) based on extracted natural dyes and develop ndsscs based power bank
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Abeyrathna, BASM; Dayarathna, WAKT; Perera, U; De Alwis, A; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Natural Dye-Sensitized Solar Cells (nDSSCs) have gained attention for their use of natural dyes and electrode materials, with a focus on efficiency and absorption spectra. Promising results have been obtained with various natural dyes, such as Blue butterfly pea flower dye achieving 0.142% efficiency, Spinach Seeds dye achieving 0.067%, and Yellow Allamanda flower dye achieving 0.038%. These findings demonstrate the potential of natural dyes as efficient sensitizers in nDSSCs. The process of pigment extraction involved a rotary evaporator, which was applied to conductive glass coated with titanium dioxide (TiO2). The resulting solar cell immersed in the dye as the electrolyte, and its light absorption and efficiency were evaluated. The absorption spectra revealed that each natural dye had specific absorption characteristics, allowing effective light harvesting in nDSSCs. FTO glasses with nano TiO2 exhibited higher current density and open-circuit voltage compared to FTO glasses with normal TiO2 powder and ITO glasses with TiO2 fine powder. This study supports the potential of natural dyes as efficient sensitizers and highlights the possibility of using recycled electrode materials, such as FTO glasses from used nDSSCs and ITO glasses from recycled LCD panels, to enhance nDSSC performance. In conclusion, this research demonstrates the promising performance of natural dyes in nDSSCs and provides valuable insights into efficiency and absorption spectra. The use of recycled electrode materials promotes sustainability and circular economy principles. Future studies should focus on stability enhancement, process optimization, and scalability of nDSSC technology for commercialization and integration with other energy conversion systems.
item: Conference-Abstract
Nutrient recovery from food industry solid waste for cultivation of the microalga Desmodesmus sp. for production of alpha-linolenic acid
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Dayanath, WMS; Edirisinghe, D; Ariyadasa, TU; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
The generation of food waste by the food processing industry poses significant environmental and economic challenges globally. This study investigated the potential of utilizing industrial food waste as a source of nutrients for cultivation of the microalga Desmodesmus sp. to produce value-added biomass rich in alpha-linolenic acid. The objectives of the study were to identify the type of food waste and dilution factor of food waste hydrolysate to maximize biomass and alpha-linolenic acid yields, and assess the efficacy of nutrient recovery. The current study is the first in reported literature to utilize industrial food waste for synthesis of microalgae-based alpha-linolenic acid. First, a screening experiment was performed for growth of Desmodesmus sp. in hydrolysates of brewery waste (BrW), biscuit waste (BiW), and Thriposha waste (TW) with four dilution factors; 25%, 50%, 75% and 100% (undiluted hydrolysate). Higher biomass yields were achieved in all waste types compared to the control medium (modified Bold’s Basal media; 3N-BBM), with the maximum yield obtained using 100% TW. Thereafter, Desmodesmus sp. was cultured in photobioreactors using 100% TW, with a 3N-BBM control. The biomass growth rate and specific growth rate achieved in 100% TW hydrolysate were 0.503 g L d and 0.214 d respectively, which were significantly higher than the control. Biomass analysis showed that a significantly higher lipid content was present in the 100% TW-cultivated biomass, suggesting a higher alpha-linolenic acid extraction potential. Nevertheless, further research on techno-economic feasibility assessment and toxicology analysis is required prior to large-scale adoption of this process.
item: Conference-Abstract
Parametric optimization and retrofitting of the tea withering process to maximize energy savings; a mathematical modelling approach case study: talawakelle tea estates plc
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Pathirage, GT; Rathnayake, MRMKT; Gunarathne, DS; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Tea industry in Sri Lanka holds significant economic importance, contributing substantially to the country's overall revenue and foreign exchange earnings. However, the industry faces a critical challenge in the form of high production costs, primarily driven by the considerable energy consumption involved, including the usage of electricity and fuelwood. Among the various stages of tea production, the withering process emerges as the most energy-intensive unit operation. Traditionally, the control of the withering process has relied on the subjective judgement and experience of supervisors based on factors such as temperature, leaf characteristics, and environmental conditions. Consequently, ensuring optimal control and energy efficiency in the withering process has become a considerable challenge. To address this challenge and improve energy efficiency, a model was developed to predict moisture content during the withering process. The model also aims to optimize the control of air flow rate and temperature based on these predictions. Simulations were conducted using the model to identify the optimal withering time for a given set of inputs, with the objective of minimizing both electrical and thermal energy consumption. Simulation results revealed that the lowest electrical energy consumption was achieved with a withering time of 14 hours, while the lowest thermal energy consumption occurred at 10 hours. These findings highlight the potential for optimizing flow rate and temperature variations at different stages of the withering process to achieve energy efficiency. Development of this predictive model and its subsequent simulations provide a foundation for the future automation of the tea withering process.
item: Conference-Abstract
Performance analysis of batch fractional distillation of essential oils, a simulation study for cinnamon leaf oil
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Ahamed, MNI; Dissanayake, WULR; Kumarage, NDI; Amarasinghe, ADUS; Narayana, M; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Batch distillation is a popular method used in the fractionation of essential oils. The feasibility of separation to achieve a target purity in the product from a given feed composition depends mainly on the Reflux ratio (R) and the Number of plates (N). Batch distillation process is simulated in this study for enriching Eugenol in Cinnamon leaf oil as a case study. Four Performance Parameters, namely the Average Production Rate (APR), Product Yield (Y), Average Heating Requirement (AHR), and Average Cooling requirement (ACR) are considered for the analysis. The contour plots generated from the simulation study are useful for Eugenol manufacturers to identify the range of R and N for feasible separation and to select the suitable combination of R and N to maximize APR or Y and minimize the AHR and ACR. According to the simulation results for a feed containing 88.8 weight percent Eugenol, the enrichment of 95 weight percent could be achieved by operating at N values from 1 to 25 and R values from 0.25 to 5.00. However, the range of N and R for feasible separation is found to depend on the feed composition and the target purity of Eugenol in the product.
item: Conference-Abstract
Predicting vapor pressures of components of essential oils using machine learning models
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Ambawalage, PM; Gunaratne, KS; Chathuranga, RMNA; Amarasinghe, ADUS; Narayana, M; Kumarage, NDI; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Essential oils contain a complex mixture of organic compounds with unique scent profiles and therapeutic effects. The increasing market demand for essential oils and their components has led to a growing interest in optimizing batch distillation processes for their fractionation. Since experimental approaches are time-consuming and resourceintensive, researchers are resorting to modeling and simulation methods to improve these separations. To achieve accurate simulations, thermodynamic property data are crucial but challenging to obtain experimentally. Therefore, predictive methods have been proposed to estimate these properties at different temperatures. This study proposes a pathway to develop machine learning models for vapor pressure prediction in essential oil fractionation simulations using data calculated through such predictive methods. The models are trained using the data so calculated and then validated using experimental data. Thirteen machine learning algorithms are employed, and their performance is evaluated using various criteria. The performance of these machine learning models are then compared with that of traditional interpolation techniques. The results demonstrate that machine learning models provide a greater overall accuracy of vapor pressure predictions than interpolation methods. Ensembled machine learning models are found to be effective for some compounds but not superior to using its best performing singular algorithm-based machine learning model counterpart. Though the proposed pathway focuses on vapor pressure prediction for constituents in cinnamon leaf oil, it can also be used to predict properties like enthalpy of vaporization and specific heat capacity relevant to essential oil fractionation, for other types of essential oils as well.
item: Conference-Abstract
Production of biochar and wood vinegar via slow pyrolysis of biomass
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Perera, RKNM; Deshan, NAS; Gunarathne, DS; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
The production of biochar, a carbon-rich material derived from biomass pyrolysis, has gained significant attention due to its potential applications in soil improvement, carbon sequestration, and renewable energy. This research presents a preliminary study on the co-production of biochar and wood vinegar from various biomass sources, namely rice husk, bamboo, and corn cob. Biochar was produced by slow pyrolysis at around a temperature of 310-330°C in an inert atmosphere with a residence time of 45 minutes in a lab-scale reactor. Thermal decomposition behavior obtained from Thermogravimetric Analysis (TGA) was the basis for selecting suitable pyrolysis temperatures. Yields of biochar, wood vinegar, and non-condensible gases were determined and the resulting biochar samples were subjected to characterization using Scanning Electron Microscopy (SEM) and TGA. The SEM analysis provided insights into the surface morphology and microstructure of the biochar samples, while elemental composition analysis helped to identify the presence of Carbon, Oxygen, and other elements. TGA evaluated the resistance of produced biochar to degradation under high temperatures. Further, calculated Acetic acid concentration gives the quality of the wood vinegar produced. The findings of this study revealed that the choice of biomass source significantly affects the properties of produced biochar. Overall, this research contributes to the understanding of the slow pyrolysis process for biochar and wood vinegar co-production and provides valuable insights into the properties and potential applications of biochar and wood vinegar.
item: Conference-Abstract
Prospects and challenges for a green hydrogen economy in Sri Lanka
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Karunasena, DI; Himal, SNL; Subasinghe, SADT; Egodage, SM; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
The global energy landscape is experiencing a significant shift towards Green Hydrogen as a sustainable and clean energy paradigm. This research highlights Sri Lanka's potential to invest in this new venture due to its abundant renewable energy capacity. This study evaluated the most suitable hydrogen producing electrolyzer for Sri Lanka and Green Hydrogen production capacity in Sri Lanka against available renewable energy. Further, studies about favourable hydrogen utilization pathways in Sri Lanka. A literature survey was conducted to obtain data related to the AWE, AEM, PEM, and SOE electrolyzer technologies and they were evaluated against capital expenditure, operating expenditure, performance, and technological maturity in selecting an electrolyzer for Sri Lanka. Projected renewable energy capacity for 2030 with peak demand and average demand was considered in the calculation of producible Green Hydrogen amount. For utilization pathways in Sri Lanka, the intensiveness of infrastructure requirement, costeffectiveness, policy and regulations, environmental impact, and safety were analyzed for selected utilization opportunities which included grid balancing, fertilizer production, and fuel blend. Implementing an Alkaline Water Electrolyzer (AWE) was identified as the optimal choice for Green Hydrogen production technology in Sri Lanka and has the capacity to produce 13,500 MWh of Green Hydrogen. It was concluded that produced Green Hydrogen can be utilized as energy storage to mitigate grid imbalance or as a feedstock for fertilizer production. Although use of this technology holds tremendous potential for supporting Sri Lanka's energy needs, an in-depth study should be done towards utilization pathways.
item: Conference-Abstract
A techno-economic analysis of the monash ammonia process
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Gamage, AGKV; Sharanga, KMHG; Subasinghe, SADT; Egodage, SM; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Due to the significant carbon footprint associated with conventional ammonia production methods, there has been a growing interest in electrochemical approaches for ammonia production. Although initial yield rates were relatively low in conventional electrochemical methods, a team at Monash University in Australia successfully developed a method capable of producing ammonia with a higher yield at room temperature with 100% faradic efficiency. To assess the potential for scaling up this technology, a techno-economic analysis has been conducted. Assuming a scale of 1 MW for the pilot plant, the NH3 production rate was obtained as 934.64 kg/day. The total capital cost was estimated at $736,913, the daily operating cost at $1192.80, and the daily income at $977.61. Consequently, the plant incurred a daily loss of $215.19. Based on these findings, it can be concluded that the scale-up plant is currently not economically viable. This is primarily attributed to the present high cost of the electrolyzer stack and renewable energy. However, there is a promising trend of decreasing costs for electrolyzers and renewable energy. If this trend continues, there is potential for the scale-up plant to become a viable option in the future.
item: Conference-Abstract
Technoeconomic analysis of bioethanol production from rice straw
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Perera, M; Palliyaguruge, S; Gunawardena, S; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Bio-diesel production from waste cooking oil offers a sustainable solution to waste management and energy challenges. This research focuses on the esterification process, a crucial step in bio-diesel production, to reduce the free fatty acid (FFA) content in waste cooking oil before transesterification. The study presents a kinetic model for esterification, accommodating different FFAs, including oleic acid, linoleic acid, and palmitic acid. The model was developed using Aspen Plus software, considering key factors like alcohol type, alcohol-to-oil ratio, reaction temperature, catalyst type, and the amount of catalyst. Sensitivity analysis was conducted to optimize process parameters, aiming for high bio-diesel yield and low unreacted FFA content. The investigation primarily centered on determining the optimum reaction time while ensuring efficient reduction of unreacted free fatty acid level to facilitate the separation process. To achieve this, the unreacted free fatty acid content was targeted to be reduced to 2.5 wt%, a level chosen to streamline the subsequent separation steps. The research demonstrates that a reaction time of 90 minutes leads to a FAME yield of approximately 97% while the unreacted free fatty acid level is maintained below 2.5% (from an initial level of 10%), thereby presenting a promising pathway to improve the overall efficiency of FAME production. This research contributes to enhancing bio-diesel production efficiency and fostering a greener energy system by utilizing waste cooking oil as a renewable resource for sustainable bio-fuel production.
item: Conference-Abstract
Ultrasonic modification of adsorbents for enhancement of the performance in dye removal from aqueous solution
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Kuruwita, KHM; Perera, LKKN; Amarasinghe, BMWPK; Walpalage, S; Gunawardena, S; Narayana, M
The effect of the ultrasonic modification of the adsorbent towards adsorbent capacity for dye removal from aqueous solutions was tested. A cationic dye, Crystal Violet was chosen as the textile dye. The adsorbents for the experiment included commercially available activated carbon, Albizia sawdust, and dried-areca nut husk (puwak). For each adsorbent, two sets of batch adsorption experiments were carried out, one with and one without ultrasonic treatment, while keeping all the other parameters constant. The experimental results showed an increase in adsorption capacity due to sonication. Sonicated activated carbon, saw dust and areca nut husk showed 93%, 92% and 90% dye removal respectively. Activated carbon showed 33% increase in adsorption capacity compared to non-sonicated material, which was the highest enhancement due to sonication, whereas saw dust and areca nut husk showed only 1% and 5.8% increase. Kinetic analysis showed that 86% of the dye removal from the sonicated activated carbon had taken place within the first 16 minutes of the experiment. Kinetic data was fit to the pseudo-second order model. The intra-particle diffusion model proved that film diffusion was significant in controlling the adsorption of dyes onto the adsorbent in addition to intra-particle diffusion. FTIR analysis showed that the existence of hydrogen bonds, C=C bonds, aromatic rings, aliphatic-iodo compounds, and other molecules contributed to the dye adsorption. SEM analysis showed that adsorption had happened into the resultant enlarged pores due to ultrasonic vibrations. The overall summary of the experiment through the results and analysis revealed that the vibration occurred during the ultrasonic treatment was the biggest contributor to enhancement of adsorption capacity of activated carbon.

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