Optimization of biodiesel synthesis using ultrasound and mechanical stirring methods: a comparative study

Energy security and air pollution is the challenging issues now days. Biodiesel is an effective alternative fuel. In present study, biodiesel is prepared using waste cooking oil. Mechanical stirring and ultrasonic cavitation method is used to draw biodiesel. Present study showed that mechanical stirring method provides higher yield % as compared to ultrasonic cavitation method. The reaction time in case of ultrasonic cavitation is significantly lesser as compared to mechanical stirring method.

In an AC1W IDI Lister Petter diesel engine, ignition delay reduced exponentially with an increase in engine speed for hempseed oil (HSO), camelina seed oil (CSO) and rapeseed oil (RSO). The polyunsaturated fuels HSO produced ignition delays which were 0.6 to 12.4%, 18.7 to 32.1% and 10.8 to 26.8% longer than RSO, rapeseed methyl ester (RME) and mineral diesel (MD) fuel respectively whilst CSO produced ignition delays which were 0 to 9.8%, 18.4 to 29.1% and 11.8 to 24.8% longer than RSO, RME and MD fuel respectively. Ignition delays increased with a 5o Crank Angle (CA) advance in fuel injection timing by 2.7 to 19.2%, 0.9 to 11.1% and 0.12 to 17.0% for RSO, CSO and HSO respectively. A reduction in ignition delay was noted for RSO, CSO and HSO by 5 to 7.1%, 1.4 to 9.5% and 7.9 to 13.5% except above 3100rpm at 5oCA retarded fuel injection timing. Maximum power outputs of HSO (4.12kW), and CSO(4.38kW) were lower when compared with MD fuel (4.43kW) however maximum power outputs for RSO (4.47kW) and RME (4.63kW) were both higher when compared with MD fuel (4.43kW) at standard fuel injection timing. After 28 days HSO, CSO, RME and WCOME increased in acid value from 8.1 to 178.4% and peroxide value varied from -63.64% to 321.85%. Ignition delay, combustion chamber peak pressure signal and rate of pressure rise were unaffected by storage of the oils. Advancing fuel injection timing by 5oCA in a 1.5L Tempest (BMC) engine had no significant effect on the power, torque and BMEP for RME, NOx and smoke emissions increased by 10.7 to 41.5% and by 24.5 to 74.3% respectively and CO reduced by 14.4 to 21.6% at BMEP BMEP>250kPa. HSO and CSO gave 4.9% and 5.6% higher maximum power than RSO, 12.6% and 13.3% more than RME and WCOME and 17.4% and 18.1% more than MD fuel respectively in a 1.8L NA IDI Ford Courier. HSO used 2.6 to 15.9% and 1.8 to 11.2% more fuel than RME and WCOME respectively whilst CSO used 2.1 to 16.3% and 2.1 to 12% more fuel than RME and WCOME respectively except above 3700rpm. HSO and CSO used 9.1 to 42.6% and 0 to 43.1% more fuel than MD fuel for all engine speeds. Mean NOx increased by 11.4 to 40.2% for HSO and 15.7 to 35.1% for CSO above 1800rpm compared with RME. NOx was higher by 11.9 to 34.6% for HSO and by 16.2 to 29.7% higher for CSO for all engine speeds than WCOME. Both HSO and CSO increased NOx by 6.9 to 55.1% and 5.1 to 56.9% compared with MD fuel above 1800rpm. RME and WCOME gave 2.2 to 26.7% and 1.8 to 25% greater NOx respectively than MD fuel above 3750rpm. After 492kWh use, RME gave carbon deposits on cylinder head, valves, piston crown and fuel injector in a 2kW DI diesel generator and the top piston ring was seized. Carbon build up on the inlet valve and port was between 1.2 x 10-3 and 3.8 x 10-3mm/kWh. An exponential rise in lubricating oil consumption and fuel consumption after 288kWh indicated the start of engine wear out. Neoprene and reinforced polyurethane are not suitable materials for RME fuel lines. The use of 100% RME in a 1.3L TDI ESB fleet vehicle resulted in a reduction in the maximum power output (40.4kW) of 6.9% after 11023km (nine months) to 37.6kW whilst maximum power output (53.5kW) reduced by 4.4% to 48.75kW with the use of 30%RME/70% MD fuel in a 2.0L TDI ESB fleet vehicle after 22459km (nine months).

The present study investigated the production of biodiesel from Jatropha curcas,Azadirachta indica, Hevea brasiliensis oil seed via transesterification methods: base catalysed and supercritical methanol, a catalyst-free process, as a cleaner alternative to conventional chemically catalyzed process. In biodiesel production using base catalyzed transesterification, temperature, methanol: oil molar ratio, catalyst type, catalyst concentration and agitation were found to have significant role on ester conversion. For supercritical transesterification method, reaction was performed in a tubular reactor, at 250°C, with 200 rpm, varying the pressure in the range from 1 to 100 bars. The results obtained showed that non-catalytic supercritical methanol technology required 3, 4, 5 min reaction time to produce 98, 97.17 and 87.1% biodiesel from J. curcas, A. indica and H. brasiliensis seed oil, respectively. Compared to conventional catalytic methods, which required at least 1 h reaction time to obtain similar yield, supercritical methanol technology has been shown to be superior in terms of time and energy consumption. Apart from the shorter time, it was found that separation and purification of the products were simpler since no catalyst is involved in the process. Hence, formation of side products such as soap in catalytic reactions does not occur in the supercritical methanol method. Key words: Biodiesel, Jatropha curcas, Azadirachta indica, Hevea brasiliensis,supercritical

The kinetics granules of boric acid (GBA) dissolution were investigated based on the solution temperature and stirring frequency. Experimental mass transfer coefficients were determined and compared with theoretical values. The results indicate that increasing the stirring frequency and the solvent temperature increases the mass transfer coefficient. A computational relationship was derived, enabling the prediction of GBA dissolution based on solution temperature and stirring frequency. These findings highlight the significant impact of reactor parameters and mixing conditions on the mass transfer process in solid-liquid systems. The study’s results facilitate the simulation and optimization of mass transfer processes in solid-liquid systems, contributing to the optimization of chemical industry technological processes and reducing the energy consumption of the dissolution process.

The ex situ decontamination of uranium polluted soils was performed by alkaline washing using mechanical agitation and ultrasound field. Two types of polluted soils were considered in terms of texture and organic content. The tests were performed using experimental design: a 23 factorial plan for mechanical washing and Taguchi L18 orthogonal matrix for ultrasound (US)-assisted decontamination. The factors considered in mechanical washing were temperature, duration, and pH. For ultrasound decontamination, the US frequency was added. The optimum was estimated based on statistical analysis and validated by confirmation experiments. The study revealed that in ultrasound field, the decontamination degree is increased with over 25% compared with mechanical stirring, while the duration of the process is drastically reduced (from 120 to 25min). The most important factor leading to the increase of decontamination is the ultrasound frequency. To refine the result, artificial neural network modeling and subsequent optimization by genetic algorithms were also carried out for the decontamination in ultrasound field, and new optimum operating conditions were identified and validated. The best operating conditions identified were temperature around 50°C, pH = 8, and ultrasound frequency of 24kHz. In these conditions, the decontamination degree reached 85% for Soil 1 (characterized by low clay and organic content) and 69% for Soil 2 (with high clay and organic content).

Biodiesel is the biofuel most commonly used in Europe, covering approximately 80% of the biofuel market. However, the relationship between biofuel industry and food prices push towards the adoption of new generation biodiesels which could minimize the impact of biofuels production on human food chain. Biodiesel sourced from non-edible seed oils like Jatropha Curcas could therefore be a viable solution for biodiesel production, since allows green cover to wasteland. More recently, also Hydrotreated Vegetable Oil (HVO), obtained by means of a refinery-based process that converts vegetable oils into paraffinic hydrocarbons, has been gaining an increasing attention. The effects of using high percentage blends of ultra low sulphur diesel and biofuels (FAME and HVO) in a Euro 5 small displacement passenger car diesel engine on combustion process, full load performance and part load emissions have been evaluated in this work. Moreover, a characterization of Particulate Matter (PM) in terms of mass, chemical composition and particles number and size distribution was assessed as well. The impacts that fuels with different physical and chemical properties may have on injection, combustion and on ECU calibration process were evaluated by means of specific tests campaign involving different injection timings under part load operation. Results highlighted that the implementation of models for blending detection, on engines ECUs, could be of crucial importance for a wider usage of biofuels in transportation sector. In addition, the effects on engine torque were analyzed, for both a standard ECU calibration (i.e. without any special tuning for the different fuel characteristics) and for a specifically adjusted ECU calibration obtained by properly increasing the injected fuel quantities to compensate for the lower Lower Heating Value (LHV) of the biofuels: with the latter, the same torque levels measured under diesel operation could be observed with the biodiesel too, with lower smoke levels, thus highlighting the potential for maintaining the same level of performance while achieving substantial emissions benefits. Moreover, the effects of biodiesel blends on brake specific fuel consumption and on engine-out exhaust emissions (CO2, CO, HC, NOx and smoke) were also evaluated at several part load operating conditions, representative of the New European Driving Cycle (NEDC). Both standard and specific calibrations were evaluated, highlighting an average rise of fuel consumption in good agreement with LHV decrease, at same fuel conversion efficiency and CO2 emissions. A decrease of NOx emissions when using a specifically adjusted engine calibration, along with a considerable smoke emission reduction were observed as well. Due to increasing concerns about the hazardous effects that particulate matter could have on human health, PM emissions were evaluated under normal engine operating mode at part load operation. PM gravimetric analysis at medium and high load operating points showed a good correlation with soot measurements carried out by means of standard laboratory equipment (i.e. smokemeters). On the contrary, at low loads, the same instrument underestimated the Soluble Organic Fraction (SOF) fraction of PM especially when biofuel was used. Thermo-gravimetric analysis confirmed the outcomes from gravimetric analysis: the significance of standard measurements which are commonly carried out during the engine calibration activity should be carefully considered when biofuels are adopted. Finally, the assessment of the toxicological potential of PM when HVO and Rapeseed Methyl Ester (RME) were used was carried out. Results highlighted that PM from HVO had a higher mutagenic effect respect to PM emissions obtained with other fuels

ABSTRACTBiodiesel as an alternative to fossil fuels has been developed consistently in last few years due to its several advantages such as renewable and biodegradable fuel, reduction of global warming, less air pollution, low sulfur content, low toxic emission, high cetane number, less water and soil pollution, and fewer health risks. In this paper, the effects of methanol-to-oil molar ratio, catalyst amount and reaction time on the transesterification of Karabi oil to biodiesel were investigated. Methanol with calcium oxide as a heterogeneous catalyst was used for the transesterification process at a temperature of 60 °C using different methods of biodiesel production such as mechanical stirring (MS) and ultrasonic cavitation (US). US techniques have shown a faster reaction rate than the MS method. The maximum biodiesel yield of 94.1% was obtained in 2 hours using a methanol-to-oil molar ratio of 12:1, a catalyst amount of 5 w/w% and a reaction temperature of 60 °C by the ultrasonic cavitation method, along with improved physiochemical characteristics and very reduced energy consumption.

Mathematical model to assess the impacts of aflatoxin contamination in crops, livestock and humans

Sensitivity analysis of the penicillin fermentation process model based on LHS-EPRCC

In this research, we developed a coinfection model of tuberculosis and COVID-19 with the effect of isolation and treatment. We obtained two equilibria, namely, disease-free equilibrium and endemic equilibrium. Disease-free equilibrium is a state in which no infection of tuberculosis and COVID-19 occurs. Endemic equilibrium is a state in which there occurs not only the infection of tuberculosis and COVID-19 but also the coinfection of tuberculosis and COVID-19. We assumed that the parameters follow the uniform distribution, and then, we took 1,000 samples of each parameter using Latin hypercube sampling (LHS). Next, the samples were sorted by ranking. Finally, we used the partial rank correlation coefficient (PRCC) to find the correlation between the parameters with compartments. We analyzed the PRCC for three compartments, namely, individuals infected with COVID-19, individuals infected with tuberculosis, and individuals coinfected with COVID-19 and tuberculosis. The most sensitive parameters are the recovery rate and the infection rate of each COVID-19 and tuberculosis. We performed the optimal control in the form of prevention for COVID-19 and tuberculosis. The numerical simulation shows that these controls effectively reduce the infected population. We also concluded that the effect of isolation has an immediate impact on reducing the number of COVID-19 infections, while the effect of treatment has an impact that tends to take a longer time.

Periodic oscillations in HIV transmission model with intracellular time delay and infection-age structure

Community-acquired pneumonia (CAP) is a common respiratory infection that happens outside of hospitals, and it is caused by bacteria, viruses, or fungus. It remains a serious threat to the world, particularly affecting children, the elderly, and immunocompromised individuals. The fractional-order pneumonia model has been developed in this study to determine the disease dynamics in the system. The model stability is proved for the existing equilibrium points. Global sensitivity analysis was carried out utilizing Latin hypercube sampling (LHS) and partial rank correlation coefficient (PRCC) to find the key parameters influencing disease transmission. Control analysis is considered as an effective strategy for preventing the spread of the disease pneumonia. It is often necessary to combine timely treatment, immunization, and boosting immunity. However, eliminating this disease in the population will be challenging if control strategies aren’t given at the appropriate time and in sufficient quantity. We conduct a cost-effectiveness analysis of four optimal control strategies utilizing numerical methods. Our findings indicate that vaccination is the most cost-effective and efficient control intervention among the strategies compared.

Biodiesel production from low cost, inedible oil represents an increasingly important target for reasons of both sustainability and cost. In this work, we comprehensively verify the batch reproducibility of a sulfonic acid functionalized carbonaceous material (SAFACAM) as catalyst for biodiesel production from inedible feedstock Jatropha curcas oil (JCO). The current catalyst benefits the environment through its atom-efficient, one-pot preparation from an abundant natural biomass derivative (glucose) and has the potential to reduce the overall biodiesel production cost by converting inexpensive raw materials. In this context, JCO has emerged as a crop of interest to the energy sector, potentially providing a reliable and renewable energy source for many countries. Through a central composite design (CCD) approach using response surface methodology (RSM), a 98.7 ± 0.6% conversion of biodiesel is achieved (methanol-to-oil molar ratio 20:1, reaction time 50 min, reaction temperature 120 °C and catalyst loading 9 wt % (with respect to oil)). The chemically satisfactory composition of the biodiesel product has been verified, the reusability of catalyst has been tested, and a significant enhancement in performance when using microwave heating demonstrated. An 83.0 ± 0.8% conversion of JCO is reported in the fifth cycle of reuse.

Transesterification reaction in biodiesel manufacturing process is slow because it takes place in a two-phase system. This problem can be overcome by adding a co-solvent that is not reactive. The addition of co-solvent aims to form a single phase system. Therefore, this study is conducted with the aim of understanding the effect of adding co-solvent of methyl ester Tetra Hydro Furan (THF) produced in the transesterification reaction of biodiesel from Jatropha curcas oil (Jatropha oil). The variables studied were the number of THF and reaction time. In addition, transesterification reactions are also carried out without the addition of co-solvent (conventional method) for comparison. The reaction temperature is maintained at 300C and atmospheric pressure. The results showed that transesterification reaction with the addition of co-solvent is 2-10 minutes faster than the conventional reaction. Transesterification reaction with the addition of co-solvent produces higher methyl ester amount than conventional methods. 94.79% methyl ester amount is achieved when the mass ratio of THF:Methanol = 2:1, molar ratio of Jatropha oil: Methanol = 1:6 and 1.3% NaOH catalyst-weight.

The objective of the present work is to find out the viable substitute fuel for diesel and control of pollutants from compression ignition engines. Therefore, in this present investigation an attempt has been made to study the effect of 20% proportion of five different biodiesel diesel blend in diesel engine. The 20% proportion of biodiesel such as Jatropha, Pongamia, Mahua, Annona and Nerium and 80% of diesel and it is denoted as J20, P20, M20, A20 and N20 are used in the present investigation. The experimental results showed that the brake thermal efficiency of the different biodiesel blend is slightly lower when compared to neat diesel fuel. However, N20 blend, have shown improvement in performance and reduction in exhaust emissions than that of other biodiesel diesel blends. From, the experimental work, it is found that biodiesel can be used up to 20% and 80% of diesel engine without any major modification. The conducted experiments were conducted on a four cylinder four stroke DI and turbo charged diesel engine using biodiesel blends of waste oil, rapeseed oil, and corn oil with normal diesel. The peak cylinder pressure of the engine running with bio diesel was slightly higher than that of diesel. The experiments were conducted on a four cylinder four stroke diesel engine using bio diesel made from corn oil.