Waste Cooking Oil Research Articles

Characterization of light components in rubber-oil mixtures reclaimed asphalt and their effect on the self-healing performance of asphalt

The aging process of asphalt pavement results in the loss of light components (saturates and aromatics) in asphalt, necessitating the use of regenerators for restoration. The study examined the variation pattern of light components in reclaimed asphalt and their effect on the self-healing performance of asphalt after regeneration. Two types of aged asphalt were analyzed using low-temperature co-pyrolysis products of waste tire crumb rubber (WTCR) and waste cooking oil (WCO). The reclaimed asphalt was fractionated into light components using the SARA (saturates, aromatics, resins, and asphaltenes) method. The regenerator containing the highest concentration of light components was identified through the Soxhlet extraction test. The compound compositions and functional groups of the light components in reclaimed asphalt were characterized using gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR). Moreover, the self-healing performance of the reclaimed asphalt was evaluated using a dynamic shear rheometer (DSR). The results indicate that the 260-1-WROM regenerator produced an optimal content of light components under pyrolysis conditions at 260 °C for 1 h. Incorporating the 260-1-WROM regenerator in RTFO resulted in an increase in hopanoids, oxygenates, heterocyclics, and aromas. Similarly, the PAV regeneration process exhibited elevated levels of paraffins, hopanoids, oxygenates, alkanes, heterocyclics, and aromatic compounds. However, the presence of 260-1-WROM failed to increase the contents of steroids. Both types of reclaimed asphalts exhibited superior self-healing capabilities compared to 70#A, RTFO, and PAV. This suggests that 260-1-WROM effectively restored the light components in the aged asphalt, thereby optimizing the flowability of the reclaimed asphalt and enhancing its self-healing properties. Given the above findings, the recommended dosage for 260-1-WROM is 8 % for RTFO and 10 % for PAV.

In-depth multi-component analysis of bio-aviation fuel derived from waste cooking oil using comprehensive two-dimensional gas chromatography mass spectrometry

In-depth multi-component analysis of bio-aviation fuel derived from waste cooking oil using comprehensive two-dimensional gas chromatography mass spectrometry

Pemberdayaan Masyarakat Pondok Pesantren (Santriwati) dalam Pembuatan Sabun Cuci Pakaian Berbahan Dasar Minyak Jelantah

Waste cooking oil/used cooking oil which is blackish brown is residue from the frying process that still contains fatty acids which have the potential to be used to make soap. At the Al Ihsan Puteri Islamic boarding school, Banjarmasin used cooking oil waste has not been managed well. This activity aims to educate the Islamic boarding school community (santriwati) and boarding school administrators about making washing soap from used cooking oil as a solution so that used cooking oil can be reused in other forms. Participants in the activity were 15 female students at the Al Ihsan Puteri Banjarmasin Islamic Boarding School. This activity consists of discussion (counseling) and direct practice. The chemistry knowledge education material explains the impact of used cooking oil on the body, while the soap-making training material explains the cold saponification method through demonstrations. The service results show that almost 100% of the students who initially did not know how to reuse used cooking oil in soap, now know how to reuse used cooking oil. Students also increase their knowledge and skills in reacting with materials in the saponification process.

Box-Behnken assisted RSM and ANN modelling for biodiesel production over titanium supported zinc-oxide catalyst

Global utilization of Green fuels mitigates the harmful effects of climate change caused by greenhouse gas emissions from fossil fuels. Biodiesel was identified as an alternative fuel to satisfy the growing need for energy. Waste cooking oil is applied as a feedstock due to legitimate worries about using food crops to produce fuel. In this study, optimization of biodiesel synthesized from waste cooking soybean oil in the presence of a novel enhanced titanium-supported zinc oxide (ZnO/TiO2) catalyst had been reported. The aim was to use DOE to correlate relationships between optimal biodiesel productivity and the operating parameters. The influence of catalyst loading, methanol-to-oil ratio, and reaction temperature were investigated using a time-efficient Box-Behnken design of response surface methodology and artificial neural network. The predicted and experimental yield was comparable with 94.04 % (BBD-RSM), 93.99 % (ANN), and 94.42 % respectively. A significant biodiesel yield of 94.93 % was obtained at optimal operating conditions of catalyst loading (21.9 wt%), reaction temperature of 55 OC, and methanol oil ratios of 8:1. Comparative analysis indicates higher prediction capabilities for RSM than the ANN model in terms of lowest error functionality and highest correlation coefficient. However, the obtained FAME has properties within the standard limits set for biodiesel.

Graphene Incorporated Sugar Derived Carbon Aerogel for Pyridine Adsorption and Oil-Water Separation.

Herein, we have synthesized a three-dimensional and hydrophobic graphene incorporated carbon aerogel (G-SCA) derived from sugar. G-SCA is being used as a multifunctional sorbent material for removing various advanced water-soluble and insoluble pollutants. Initially, G-SCA is being explored for the adsorption of nitroarenes (nitrophenols, 3-nitroaniline), an insecticide (Phoskill), an antibiotic (ciprofloxacin), and a pharmaceutical drug precursor (pyridine). Later, the same G-SCA is also explored in the absorption of various protic and aprotic organic solvents, and oils (including crude oil, waste cooking oil, and waste engine oil), with excellent recyclability checked up to 10 cycles. Moreover, oil-water separation experiments are also being done in various industrial wastewater and seawater samples to support the real-life accessibility of the present approach. Large-scale applicability of G-SCA is also checked by performing crude oil-seawater separation experiments using a laboratory-scale prototype demonstrating the successful continuous recovery of crude oil.

Effect of CaO/Fe2O3 Ratio and Oil/Methanol Molar Ratio on Biodiesel Production from Waste Cooking Oil

Biodiesel is a renewable liquid fuel that can be produced through the transesterification reaction of biomass. The objective of this research was to examine the effect of comparative composition of CaO and Fe2O3 on CaO/Fe2O3 catalysts from eggshells and Fe2O3 in the production of biodiesel from waste cooking oil. In addition, it was also studied the effect of the ratio of oil and methanol on the yield and characteristics of the biodiesel produced. Catalysts were prepared through impregnation. The esterification-transesterification process was carried out with the conditions WCO:methanol molar ratio of 1:3, 1:6, 1:9, 1:12 and 1:15, catalyst (3%wt oil), heated at 65°C for 3 hours with a stirring scale of 1200 rpm. The results showed biodiesel production using CaO: Fe2O3 catalyst with the ratio of CaO: Fe2O3 70:30 and WCO:methanol molar ratio of 1:9 obtained higher yield (84.5%) compared to others. The best biodiesel yield produced is the CaO:Fe2O3 catalyst ratio of 70:30 and the WCO:methanol molar ratio of 1:9 with a biodiesel yield of 84.50% with a methyl ester content of 99.63% and a FAME yield of 84.14%. The biodiesel produced has met the requirements of the Indonesian National Standard (SNI) in terms of density and viscosity.

Evaluation of the properties of bio-asphalt derived from waste cooking oil and low-density polyethylene through the pyrolysis process

The aim of this study is to prepare a bio-asphalt for flexible pavement construction using a fixed-bed pyrolysis reactor. This method involves incorporating waste cooking oil (WCO) and low-density polyethylene (LDPE) as feedstock materials. Through this study, an attempt has been made to make use of waste materials and promote the use of environmentally friendly binders in sustainable road construction. The pyrolysis experiment was conducted at different temperatures, varying from 250 °C to 500 °C for different blends of waste cooking oil (WCO) and low-density polyethylene (LDPE), i.e., 1:0, 3:1, 1:1, 1:3, and 0:1, respectively. At a temperature of 350 °C, the pyrolysis process is more effective for converting various blends of waste cooking oil (WCO) and low-density polyethylene (LDPE) into bio-asphalt. The maximum bio-asphalt yield of 82 wt% was reported for the 1:3 blend at a temperature of 350 °C. The elemental analysis of an equal mass of waste cooking oil (WCO) and low-density polyethylene (LDPE) reported a carbon content of 83.93 wt%, a hydrogen content of 13.29 wt%, and a lower oxygen content of 2.55 wt%. The Gas Chromatography Mass Spectrography (GC-MS) analysis indicated the presence of chemical compounds such as pentadecane, heptadecane, dodecane, cyclopentylpropyl, and hexacosene in the 1:1 blend. The thermogravimetric and derivative thermogravimetric analyses indicate that the 1:1 blend and 1:3 blend can withstand temperatures around 473 °C and 475 °C, respectively. The Fourier transform infrared spectroscopy (FT-IR) analysis showed the presence of alkane, alkene, ester, and other aromatic compounds. Based on this present study, it has been noted that the chemical composition of a 1:1 blend of waste cooking oil (WCO) and low-density polyethylene (LDPE)-based bio-asphalt contains similar chemical compositions as asphalt binder, and it can be used as a modifier for conventional asphalt binder.

On the Influence of Engine Compression Ratio on Diesel Engine Performance and Emission Fueled with Biodiesel Extracted from Waste Cooking Oil

Despite the extensive research on biodiesels, further investigation is warranted on the impact of compression ratios on emissions and engine performance. This study addresses this gap by evaluating the effects of increasing the engine’s compression ratio on engine performance metrics—brake-specific fuel consumption (BSFC), power, torque, and exhaust gas temperature—and emissions—unburnt hydrocarbons (HCs), carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and oxygen (O2)—when fueled with a 20% blend of waste cooking oil biodiesel (WCB20) and petroleum diesel (PD) under various operating conditions. The viscosity of the prepared fuels was measured at 25 °C and 40 °C. Experiments were conducted on a single-cylinder diesel engine under wide-open throttle conditions at three different speeds (1400 rpm, 2000 rpm, and 2600 rpm) and two compression ratios (16:1 and 18:1). The results revealed that at a lower compression ratio, both WCB20 and petroleum diesel exhibited reduced BSFC compared to higher compression ratios. However, increasing the compression ratio from 16:1 to 18:1 significantly decreased HC emissions but increased CO2 and NOx emissions. Engine power increased with engine speed for both fuels and compression ratios, with WCB20 initially producing less power than diesel but surpassing it at higher compression ratios. WCB20 demonstrated improved combustion quality with lower unburnt hydrocarbons and carbon monoxide emissions due to its higher oxygen content, promoting complete combustion. This study provides critical insights into optimizing engine performance and emission characteristics by manipulating compression ratios and utilizing biodiesel blends, paving the way for more efficient and environmentally friendly diesel engine operations.

Low temperature pyrolysis of waste cooking oil using marble waste for bio-jet fuel production

Limestone powder, a by-product of top-down marble processing, exhibited high thermal stability and functionality as catalysts for the low-temperature pyrolysis of waste cooking oil (WCO) into biofuel. The marble waste (MW) contains calcite, dolomite, and quartz composites (CaCO3/MgCO3/SiO2) as non-uniform microcrystallites. Pyrolysis at 380 °C in 1 h increased the hydrocarbon composition of biofuel and reduced carboxylic acid. The biofuel composition contains 80 % hydrocarbon within the jet fuel C8-16 ranges. MW reduced the carboxylic acid concentration from 49 % in catalyst-free pyrolysis to less than 4 %. The optimum condition was obtained at 3 % MW, yielding 43.55 % linear hydrocarbon, 11.1 % cyclic hydrocarbon, and 1.02 % aromatic compounds that satisfied the bio-jet fuel classification. The incorporation of varying percentages of marble waste demonstrates a significant enhancement in the cyclic compounds, elevating the yield from ∼3 % in catalyst-free pyrolysis to an impressive ∼35 %. The hydrocarbon yield is higher when using 3%MW > 1%MW > 6%MW > 9%MW. Dolomite and calcite mixture in MW catalyzed triglyceride conversion to hydrocarbon by adsorbing carbonate in triglycerides to drive C–O bond dissociation. These studies provide a roadmap for the utilization of abundant resources locally available in Indonesia to sustain local energy demand.

Education of Waste Cooking Oil Processing into Aromatherapy Candles for 2 Junior High School Karanganyar Students

Waste is a complex problem and an important challenge for the sustainable development of a circular economy and can have social, environmental and economic impacts. This service aims to provide education to students so that students can have high knowledge and awareness of waste processing and can utilize used cooking oil waste to make aromatherapy candles. This service was carried out at 2 Junior High School Karanganyar on Thursday, June 20 2024. The service method was socialization and direct practice in making aromatherapy candles. Students have the skills and are successful in making aromatherapy candles according to the material presented by the speaker. This activity succeeded in increasing students' awareness and knowledge regarding household waste management. Students showed high enthusiasm in following the process of processing used cooking oil waste into useful products such as aromatherapy candles, while also expressing their creativity in this process. Positive support from teachers also contributed to the successful implementation of this waste treatment.

The investigation of rheological properties of rejuvenated asphalt binder with waste cooking oil as rejuvenator

Asphalt binder plays a significant role in the performance of asphalt pavement. However, due to the limited availability of crude oil and the increasing cost of asphalt, alternatives are being investigated. Reclaimed asphalt pavements (RAP) provide a sustainable solution for the increasing demand of asphalt. However, the amount of RAP which can be utilized in asphalt mixtures is limited due to production and performance issues. Incorporation of high RAP content calls for rejuvenators, which rejuvenate the aged binder and increases the degree of blending. Among various rejuvenators, waste cooking oil (WCO) is gaining increased attention due to its availability and concern towards environmental pollution. When combined in proper proportions with RAP, WCO is a potential rejuvenator, which restores the properties of aged binder to that of unaged asphalt binder. This addresses two problems simultaneously and can greatly benefit the economy and environment. This study focuses on the viscoelastic and rheological properties of the rejuvenated binder with WCO and RAP. The rheological properties are evaluated using frequency sweep test by assessing the complex shear modulus and rutting parameter of different binders. The viscoelastic properties are studied using multiple stress creep recovery (MSCR) test. The data of the MSCR test is analysed with the Burger model to understand the viscoelastic properties of the rejuvenated RAP binder. For each of 75, 60 and 45% RAP, three different oil proportions are selected, and the optimum WCO content is identified. The study concludes that higher RAP content results in lower viscous strain and higher elastic strain, whereas after mixing of higher WCO, the viscous strain increases, and elastic strain decreases. Hence, it is crucial to mix WCO and RAP in the optimum ratio to obtain the desired rheological and viscoelastic properties.

An artificial intelligence approach to model and optimize biodiesel production from waste cooking oil using life cycle assessment and market dynamics analysis

Biodiesel has emerged as a viable alternative to fuel, offering a more sustainable and environmentally friendly energy option. The current study explores the modeling and optimization of biodiesel production from waste cooking oil using artificial intelligence and genetic algorithms. The study focuses on enhancing five process parameters: methanol-to-oil molar ratio, catalyst concentration, reaction temperature, reaction time, and stirring speed. The optimization of these parameters is complemented by a life cycle assessment to reduce environmental impact. The approach considers biodiesel yield, high heating value, and energy consumption as output variables, thereby advancing sustainable biodiesel production. The findings indicated that, under optimal conditions (methanol-to-oil ratio of 1:6.9, stirring rate of 500 rpm, reaction duration of 20 s, reaction temperature of 30 °C and catalyst concentration of 1), the transesterification process achieved the maximum biodiesel yield of 97.76 %. The optimization reached a low environmental impact in the production of biodiesel in an efficient way. Additionally, SWOT analysis helps to develop strategic methods that can enhance efficiency and increase competitiveness. The research suggests that, by optimizing the chemical process in biodiesel production, it is possible to achieve a high yield and high heating value of the biofuel, along with feasible environmental mitigation strategies.

Bio‐Based Thermosetting Resins from Waste Cooking Oil

AbstractIn order to face the environmental concern about the use of traditional fossil‐based monomers for the production of thermosetting resins, herein this study reports the synthesis of bio‐based materials from waste cooking oil (WCO). In this context, this study explores the epoxidation‐acrylation strategy for the synthesis of the starting functionalized oil for the production of thermosetting resins composed of only WCO‐derived monomers or in combination with terpenic comonomers such as limonene and myrcene. Furthermore, employing myrcene as comonomer produces thermosetting resins that reveal the best properties in terms of mechanical strength if compared to the homopolymer ones.

Blending biomass-based liquid biofuels for a circular economy: Measuring and predicting density for biodiesel and hydrocarbon mixtures at high pressures and temperatures by machine learning approach

Circular economy is an efficient approach to deal with the rapidly increasing demand for energy and its environmental impact. It involves switching to renewable and sustainable energy sources. By providing an alternative to traditional energy resources, biodiesel promotes a circular economy paradigm that embraces renewable energies rather than fossil fuels. As an alternative to fossil fuels, liquid biodiesel helps to improve energy efficiency and reduce pollution. Furthermore, blending biodiesel has proven to be economically and environmentally viable. Knowledge of the thermodynamic properties of biodiesel, such as densities and coefficients of expansivity and compressibility, plays an important role in understanding and determining the behavior of the fuel under different operating conditions. The blend densities of Soybean Oil Biodiesel (SOB) with hexane and Waste Cooking Oil Biodiesel (WCOB) with heptane in four volume ratios were experimentally studied. An Anton Paar vibrating tube densimeter HPM DMA has been used for accurate measurements of densities of the biofuels and their blends. Density measurements were performed at temperatures ranging from 298.15 K to 393.15 K, and pressures between 0.1 MPa and 140 MPa. This work also aims to develop accurate prediction models of the properties of biodiesel blends under various conditions, such as changes in temperature and pressure, which are essential for optimizing energy production processes and engine performance. In this context, the dataset was first investigated with Tait Equation of State (Eos) to determine thermodynamic parameters which including isothermal compressibility and isobaric expansivity. It showed generally low standard deviations. Furthermore, these new experimental densities were also modeled with Artificial Neural Network (ANN) as a machine learning method. This paper models proved that the machine learning method is a suitable tool to model the thermo-physical characteristics of liquid fuels. The findings of this study have the potential to provide valuable guidance to engine engineering applications developers regarding operating conditions and the selection of suitable biodiesel for their system.

Enhancing the Mechanical Strength and Thermal Stability of Polylactic Acid (PLA) with the Addition of Epoxidized Waste Cooking Oil (EWCO)

Polylactic Acid (PLA) comes from renewable resources, has a reasonable biodegradability rate, and is used in biomedical, food packaging, textiles, and agricultural applications. PLA offers high mechanical strength and the ability to compost, similar to polyethylene terephthalate (PET) and nylon. However, the brittleness of PLA has always limited its usage. Therefore, bio-based plasticizers in the biopolymer matrices can increase flexibility (elasticity), durability, and workability. This study aims to determine the optimal blending ratio for the PLA blended with epoxidized waste cooking oil (EWCO) to enhance the mechanical and thermal properties of PLA/EWCO. The mechanical strength test consists of the hardness test (N/mm<sup>2</sup>), flexural strength (MPa), and impact energy (kJ/m<sup></sup>) adopted to evaluate the plasticizing characteristics. The thermal stability analysis involves glass transition temperature (T<sub>g</sub>) (°C), cold-crystallization temperature (T<sub>cc</sub>) (°C) and melting temperature (T<sub>m</sub>) (°C). The blending ratio is 97.5PLA/2.5EWCO, 95PLA/5EWCO, 92.5PLA/7.5EWCO and 90PLA/10EWCO. As a result, 97.5:2.5 of PLA/EWCO reduces intermolecular interactions by stimulating more free volume in biopolymer chains’ mobility and enhancing the flexibility and elasticity of the PLA blends. Ultimately, the brittleness of PLA decreased with increasing EWCO bio-based plasticizer.

Using Mental Modeling to Study the Management of Used Cooking Oil in Kuala Nerus

Recycling of used cooking oil is an effort by collecting, processing and reusing solid waste or materials that have been used for the purpose of environmental conservation. This study was conducted to identify the level of knowledge and awareness of used cooking oil management among the community in the Kuala Nerus district, Terengganu. The study involved 30 respondents in the community, namely traders, used cooking oil wholesalers, households, students and the government. The study used a mixed method, i.e. qualitative and quantitative research using fuzzy cognitive modelling including individual mental model modeling. The results of the study showed that the knowledge of cooking oil waste recycling among the respondents was still at a moderate level. The results of the study found that for the aspect of qualitative analysis, there were four themes that emerged, namely knowledge, awareness, attitude and culture. While descriptive analysis identifies the most dominant relationship strength is the theme of awareness. The recommendations in this study are necessary to improve the management of used cooking oil in Kuala Nerus through a comprehensive and integrated approach. This study proposes a legal approach, encourages the expansion of this study to a higher level and improves the provision of used cooking oil management infrastructure.

Microbial Biosynthesis of Medium-Chain-Length Polyhydroxyalkanoate (mcl-PHA) from Waste Cooking Oil.

Waste cooking oil is a common byproduct in the culinary industry, often posing disposal challenges. This study explores its conversion into the valuable bioplastic material, medium-chain-length polyhydroxyalkanoate (mcl-PHA), through microbial biosynthesis in controlled bioreactor conditions. Twenty-four bacterial isolates were obtained from oil-contaminated soil and waste materials in Mahd Ad-Dahab, Saudi Arabia. The best PHA-producing isolates were identified via 16S rDNA analysis as Neobacillus niacini and Metabacillus niabensis, with the sequences deposited in GenBank (accession numbers: PP346270 and PP346271). This study evaluated the effects of various carbon and nitrogen sources, as well as environmental factors, such as pH, temperature, and shaking speed, on the PHA production titer. Neobacillus niacini favored waste cooking oil and yeast extract, achieving a PHA production titer of 1.13 g/L, while Metabacillus niabensis preferred waste olive oil and urea, with a PHA production titer of 0.85 g/L. Both strains exhibited optimal growth at a neutral pH of 7, under optimal shaking -flask conditions. The bioreactor performance showed improved PHA production under controlled pH conditions, with a final titer of 9.75 g/L for Neobacillus niacini and 4.78 g/L for Metabacillus niabensis. Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) confirmed the biosynthesized polymer as mcl-PHA. This research not only offers a sustainable method for transforming waste into valuable materials, but also provides insights into the optimal conditions for microbial PHA production, advancing environmental science and materials engineering.

A bifunctional catalyst from waste eggshells and its application in biodiesel synthesis from waste cooking oil

Improvement in biofuel synthesis technology could facilitate widespread utilization of biodiesel, and an efficient operation in terms of cost. Catalyst enhancement through mineralization of waste biogenic material is vital for biodiesel production. In this study, biodiesel production was from waste cooking oil (WCO) using a bifunctional catalyst synthesized from waste eggshells and ferric sulfate. The CaO precursor developed from calcined eggshell at 800 °C for 3 h was impregnated with ferric sulfate at a ratio of 1:1. The Bifunctional catalyst synthesized was characterized using an X-ray diffractometer, scanning electron microscopy, Fourier transform infrared spectroscopy and energy-dispersive X-ray analysis. The bifunctional catalyst was applied in a one-pot reaction of WCO and methanol to produce biodiesel. The reaction was modeled using the Taguchi orthogonal array design to maximize biodiesel production. The heterogeneous catalyst contained Ca (20.7 %), Fe (18.5 %), S (4.5 %), and O (54.8 %). The identified crystalline phases are CaSO4/Fe2O3 and CaSO4.0.5H2O/Fe2O3. A maximum biodiesel yield of 89.94 wt% was observed under the operating conditions of methanol/oil molar of 5:1, time of 45 min, temperature of 70 °C, and catalyst amount of 4 wt%. The reusability of the catalyst was established for (four) 4 cycles without further treatment. The synthesized biodiesel met the standard specifications. Hence, the synthesized catalyst proved effective in the transesterification of oil with a moderately high free fatty acid, thereby the bifunctional catalyst could expedite biodiesel production from waste cooking oil, and this biofuel could serve as fuel in powering diesel engines.

Optimization of biodiesel yield from waste cooking oil and sesame oil using RSM and ANN techniques

In the era of global energy crises and the pressing concern of fossil fuel depletion, the quest for sustainable alternatives has become paramount. The current study aims to optimize biodiesel extraction from a combination of waste cooking oil (WCO) and sesame seed oil (SSO) through response surface methodology (RSM) and artificial neural network (ANN). The cold flow properties of biodiesel produced from WCO are a major obstacle to the commercial use of biodiesel. On the other hand, SSO possesses better oxidation stability and cold flow properties. A mixture of waste cooking oil (i.e. 70 % by volume) and sesame seed oil (i.e. 30 % by volume) has been prepared for biodiesel production via a microwave-assisted transesterification process. For biodiesel yield optimization, the interaction among the operating parameters is developed by RSM, whereas biodiesel yield is predicted by ANN. The operating parameters include reaction speed, RPM (100–600 rpm), reaction time (1–5 min), methanol to oil ratio (8:1–12:1 v/v), and catalyst concentration (0.1–2 % w/w). The highest biodiesel yield of 94 % is found at a reaction speed of 350 rpm, reaction time of 3 min, catalyst concentration of 1.05 w/w, and methanol to oil ratio of 10:1. Furthermore, it is discovered that when estimating biodiesel production rate depending on reaction constraints, ANN shows lower comparative error compared to RSM. The results show that ANN outperforms RSM in terms of percentage improvement when it comes to biodiesel production prediction.

Biodiesel Production from Waste Cooking Oil Using Recombinant Escherichia coli Cells Immobilized into Fe3O4-Chitosan Magnetic Microspheres.

Developing reusable and easy-to-operate biocatalysts is of significant interest in biodiesel production. Here, magnetic whole-cell catalysts constructed through immobilizing recombinant Escherichia coli cells (containing MAS1 lipase) into Fe3O4-chitosan magnetic microspheres (termed MWCC@MAS1) were used for fatty acid methyl ester (FAME) production from waste cooking oil (WCO). During the preparation process of immobilized cells, the effects of chitosan concentration and cell concentration on their activity and activity recovery were investigated. Optimal immobilization was achieved with 3% (w/v) chitosan solution and 10 mg wet cell/mL cell suspension. Magnetic immobilization endowed the whole-cell catalysts with superparamagnetism and improved their methanol tolerance, enhancing the recyclability of the biocatalysts. Additionally, we studied the effects of catalyst loading, water content, methanol content, and reaction temperature on FAME yield, optimizing these parameters using response surface methodology and Box-Behnken design. An experimental FAME yield of 89.19% was gained under the optimized conditions (3.9 wt% catalyst loading, 22.3% (v/w) water content, 23.0% (v/w) methanol content, and 32 °C) for 48 h. MWCC@MAS1 demonstrated superior recyclability compared to its whole-cell form, maintaining about 86% of its initial productivity after 10 cycles, whereas the whole-cell form lost nearly half after just five cycles. These results suggest that MWCC@MAS1 has great potential for the industrial production of biodiesel.