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In the present global scenario, manufacturing industries are trying to make the process more sustainable by improving economic feasibility, machining efficiency, environment, and operator's safety as prescribed by ISO-14000 standards. The present study investigates the machining efficiency and sustainability analysis of the single wall carbon nano tube (SWCNT) mixed rotary electric discharge machining (EDM) process by utilizing waste vegetable oil (WVO) as a dielectric medium. Peak current, pulse on time, pulse off time, powder concentration, and tool rotation are taken as an input variable. The result reveals that SWCNT mixed rotary EDM utilizing WVO as a dielectric fluid exhibit 119.91% higher material removal rate (MRR) and 61.23% lower surface roughness (SR) as compared to the EDM process using EDM oil as a dielectric medium. Further, due to the superior thermo-physical properties of WVO, the proposed dielectric shows better surface morphology, lower recast layer thickness, better wear resistance, and low micro-hardness of machined surface as compared to EDM oil. Finally, the sustainability index analysis result concludes that WVO could be a better replacement of hydrocarbon-based oils in the EDM industry to make the process more sustainable in terms of cost, performance, ecological balance, and operator's safety. [ABSTRACT FROM AUTHOR]

In order to study the effects of different amounts of waste vegetable oil, diffusion temperature and time on the mutual diffusion behavior between waste vegetable oil and aged asphalt, a three-layer molecular diffusion model considering the change of asphalt aging degree with the depth of asphalt film was proposed. Combined with Fourier transform infrared spectroscopy (FTIR) test and macroscopic softening point test, the mutual diffusion behavior between waste vegetable oil regenerant and aged asphalt was analyzed. The results show that the waste vegetable oil regenerant realizes the regeneration of aged asphalt by supplementing the light components in the aged asphalt and reducing the agglomeration of asphaltene. The increase of temperature, waste vegetable oil content and diffusion time will enhance the mutual diffusion efficiency of waste vegetable oil and aged asphalt, and the influence of temperature is the most significant. However, as the temperature increases, the increase in diffusion efficiency decreases. The results of Pearson correlation analysis show that the diffusion coefficient between simulation and macro is significantly correlated, and the three-layer molecular diffusion model can effectively characterize the mutual diffusion behavior of rejuvenator and aged asphalt. [ABSTRACT FROM AUTHOR]

The aging of asphalt-binder during long-term use is an important reason for the decline in road performance of asphalt mixtures. In this study, waste vegetable oil (fried for 1-2h) was investigated as a rejuvenator of asphalt-binder. The optimisation effect of waste vegetable oil on the performance of asphalt-binder with different aging degrees (RTFOT, PAV15/20/48h) was evaluated by testing their conventional physical properties, high-temperature properties, and low-temperature properties. The molecular dynamics method was used to construct models, and the diffusion properties, solubility properties, adsorption energy, and asphaltene aggregation were calculated. The influences of linoelaidic acid and oleic acid molecules on aged asphalt-binder molecules were evaluated. The changes in the functional groups of the aged asphalt-binder after the addition of waste vegetable oil were analyzed by infrared spectrometry, and the changes in the microstructure of the aged asphalt-binder surface were observed by scanning electron microscopy. The results revealed that waste vegetable oil could regenerate aged asphalt-binder and significantly improve their physical and high-/low-temperature properties. Waste vegetable oil molecules are compatible with aged asphalt-binder molecules, improve their diffusion behaviour, enhance their adsorption capacity, and slightly reduce the aggregation of asphaltenes. Overall, waste vegetable oil shows great potential for the regeneration of aged asphalt-binder. [ABSTRACT FROM AUTHOR]

With the rapid evolution of the pavement industry and growing traffic on roadways, construction materials have also evolved, with non-traditional materials increasingly being employed. The key motivation for using non-conventional components was the scarcity of natural resources and their high costs, which drove the trend toward using waste materials in asphalt pavement construction to achieve environmental sustainability. This paper aims to provide an overview of the effect of adding waste vegetable oil (WVO) to asphalt binders and asphalt concrete mixtures. The information was obtained from several Scopus database studies conducted over the period of 2005 to 2022 and was used to evaluate the performance of asphalt under different dosages of WVO. It was concluded that almost all the researchers reached an agreement that adding WVO to the asphalt reduces the softening point, viscosity, complex modulus, creep stiffness, the resistance to deformation, and elastic recovery quality of asphalt. On the other hand, it increases its penetration, ductility, phase angle, m value, stress relaxation characteristic, and thermal cracking resistance. For asphalt mixtures, it was found that adding WVO increases the flow value and Voids in Mineral Aggregate (VMA). In contrast, it reduces stability and the air voids in the mixture. [ABSTRACT FROM AUTHOR]

The recovery of waste vegetable oil is a complex problem due to the variety of sources that generate it. The current collection systems do not manage to collect all the waste vegetable oil. The collection system must solve two main problems: identify the location of both the collection points and the collection centers and design routes that guarantee the optimization of resources. Therefore, the objective of this article was to develop a waste vegetable oil logistics collection system. The system integrates all sources of waste vegetable oil generation classified into three sectors: industrial, services, and residential, and it optimizes the collection routes. The developed system was compared with the current collection system that operates in Mexicali city. The developed system increases the collected waste vegetable oil by 1078%, reduces the fuel consumption per route by 37%, and improves the transportation capacity utilization by 93%. In addition, it decreases transportation costs by 73%. Water pollution is reduced by 78% and CO2e emissions per route by 14%. The waste vegetable oil collection logistics system can be implemented in any city since it adapts to its needs and characteristics. [ABSTRACT FROM AUTHOR]

The pavement recycling method is one of the practical ways to integrate sustainable development into transportation infrastructure, and it has been adopted worldwide. The use of reclaimed asphalt pavement (RAP) in new asphalt highways is limited due to the ageing effects caused by UV damage and weathering on the asphalt binder. To address this issue, waste vegetable oil (WVO) and waste engine oil (WEO) have been proposed as potential rejuvenating agents to enhance the recyclability of pavements containing RAP. This study evaluated the effectiveness of WEO and WVO as chemical rejuvenating agents through various tests on both aged and virgin asphalt binders. The tests included measurements of ductility, fire, and flash points, softening points, and penetration. The results indicate that the addition of WEO and WVO can improve the low-temperature properties of asphalt binders when mixed with RAP, resulting in reduced stiffness. The mixture containing WEO and WVO exhibited improved stability compared to the control, suggesting enhanced flow with increasing waste oil content in comparison to aged binder, albeit with slightly reduced flow compared to the virgin binder. This study demonstrates the potential of WEO and WVO as recycling agents to enhance the performance of bituminous mixes incorporating RAP. [ABSTRACT FROM AUTHOR]

This article presents an efficient iron(III) molecular catalyst for the production of biodiesel from waste vegetable oils. The approach involved an initial screening of eight salophen complexes with various substituents on the arene rings, leading to the selection of the simplest unsubstituted species as the most active catalyst. Under optimized conditions, this catalyst demonstrated the capability to achieve complete conversion of the oil at a low catalyst loading (0.10% mol/mol) and convenient conditions (160 °C, 20/1 MeOH/oil ratio). [ABSTRACT FROM AUTHOR]

As part of the efforts in overcoming global energy crisis, this research work focuses on the transesterification of waste vegetable oil, using calcined periwinkle shells and wet impregnated zinc oxide as catalysts. Periwinkle shells were calcined at 850 °C for 3 h, using carbolite furnace to obtain CaO catalyst and part of the catalyst was wet impregnated with ZnO. The quality of the calcined CaO obtained (81.6%) was established through XRF analysis. The three parameters considered during the transesterification of the treated waste oil were methanol/oil ratio (0.2–0.8 v/v), catalyst concentration (4–8 wt/wt%) and reaction time (1–2 h). At methanol/oil ratio of 0.34 v/v, catalyst concentration of 4.12 wt/wt% and reaction time of 2 h, the optimum biodiesel yield of 84.96% was obtained using calcined CaO catalyst and a yield of 81.33% using impregnated ZnO/CaO catalyst. Brake power of 4.47 kW was obtained for both the biodiesel produced and pure diesel standard. Other mechanical properties, physical properties, as well as the chemical composition of the biodiesel produced revealed high level of conformity of the biodiesel produced to ASTM standards. [ABSTRACT FROM AUTHOR]

The rapid growth of the world population and the rapid diversification of consumption habits due to technological advancements have increased waste production. An investigation of the effects of biomass products, such as waste vegetable oil and waste agricultural ash, on bitumen's physical and chemical properties was conducted in this study. By recycling biomass products, this study aimed to improve the performance and stability of bituminous hot mixtures, optimize the number of additives, and create more economical designs. Using the Taguchi method, 0%, 2%, 4% by weight of waste vegetable oil and 0%, 3%, and 6% by weight of waste agricultural ash were added to 70/100 penetration pure bitumen with an orthogonal array of L9. For 10, 20, and 30 min, modified bitumen samples were prepared at 170 °C, 180 °C, and 190 °C with a constant mixing speed of 3000 RPM. The samples were tested for penetration, softening point, flash point, rolling thin film oven (RTFOT), FTIR, and Marshall Design stability and flow. Based on the obtained performance statistics, 95% confidence levels were assigned to the predictions. The stability and softening point values decreased as the oil content increased, while flash and penetration values increased. With increasing ash content, stability, flash, and softening point values increased, and penetration values decreased. Compared to oil and ash additives, mixing temperature and time had relatively little effect on the modification process. Overall, the optimum parameter levels were 4% for oil, 0% for ash, 170 °C for temperature, and 10 min for time. [ABSTRACT FROM AUTHOR]

The pavement recycling method is one of the practical ways to integrate sustainable development into transportation infrastructure, and it has been adopted worldwide. The use of reclaimed asphalt pavement (RAP) in new asphalt highways is limited due to the ageing effects caused by UV damage and weathering on the asphalt binder. To address this issue, waste vegetable oil (WVO) and waste engine oil (WEO) have been proposed as potential rejuvenating agents to enhance the recyclability of pavements containing RAP. This study evaluated the effectiveness of WEO and WVO as chemical rejuvenating agents through various tests on both aged and virgin asphalt binders. The tests included measurements of ductility, fire, and flash points, softening points, and penetration. The results indicate that the addition of WEO and WVO can improve the low-temperature properties of asphalt binders when mixed with RAP, resulting in reduced stiffness. The mixture containing WEO and WVO exhibited improved stability compared to the control, suggesting enhanced flow with increasing waste oil content in comparison to aged binder, albeit with slightly reduced flow compared to the virgin binder. This study demonstrates the potential of WEO and WVO as recycling agents to enhance the performance of bituminous mixes incorporating RAP.

When properly compatibilized, the blending of polyethylene (PE) and polyamide (PA) leads to materials that combine low prices, suitable processability, impact resistance, and attractive mechanical properties. Moreover, the possibility of using these polymers without prior separation may be a suitable opportunity for their recycling. In this work, the use of an epoxidized waste vegetable oil (EWVO) was investigated as a green compatibilizer precursor (CP) for the reactive blending of a high-density PE (HDPE) with a polyamide-6 (PA6). EWVO was synthesized from waste vegetable cooking oil (WVO) using ion-exchange resin (Amberlite) as a heterogeneous catalyst. HDPE/PA6 blends were produced with different weight ratios (25/75, 75/25, 85/15) and amounts of EWVO (1, 2, 5 phr). Samples with WVO or a commercial fossil-based CP were also prepared for comparison. All the blends were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, and mechanical tests. In the case of HDPE/PA6 75/25 and 85/15 blends, the addition of EWVO at 2 phr showed a satisfactory compatibilizing effect, thus yielding a material with improved mechanical properties with respect to the blend without compatibilizer. On the contrary, the HDPE/PA6 25/75 ratio yielded a material with a high degree of crosslinking that could not be further processed or characterized. In conclusion, the results showed that EWVO had a suitable compatibilizing effect in HDPE/PA6 blends with high HDPE content, while it resulted in unsuitable for blends with high content of PA6. [ABSTRACT FROM AUTHOR]

Waste vegetable oils are highly valued for industrial uses. Thermal processing of these oils alters their physicochemical properties, necessitating an examination of how temperature affects their qualities. The idea of abrasive flow machining (AFM) media to finish any complex shapes and surfaces can also be accomplished using waste vegetable oils and waste coal ash. In this paper, to finish FDM parts, waste coal ash was used to develop an environmentally friendly and sustainable AFM finishing media that contains SiC powder as abrasive particles, waste vegetable oil as a liquid synthesizer, and glycerin as an additive. Taguchi's orthogonal array L9-based experimental design was used to optimize the viscosity of AFM media for better surface improvement. One of the fundamental limitations of fused filament fabrication or fused deposition modeling (FFF/FDM) is the inherent surface quality of the process, which is particularly tied to the layer thickness utilized during manufacture. The FDM technique was used in the current study to fabricate the ABS (acrylonitrile–butadiene–styrene) material's hemispherical ball-shaped workpiece, which was subsequently finished with a one-way AFM process. The present study focuses on the analysis of newly developed AFM media using rheological tests, Fourier Transform Infrared (FTIR) spectroscopic method, thermogravimetric analysis (TGA), and finishing experiments on FDM printed hemispherical ball-shaped workpieces to assess the effectiveness of newly developed media in comparison to traditional media. For FDM printed hemispherical ball-shaped workpieces, the largest percentage improvement in average surface roughness (Ra) achievable by coal-ash-based medium (50% coal-ash) is 83%. The initial surface roughness was improved by 83.67%, from 9.80 to 01.60 µm. [ABSTRACT FROM AUTHOR]

Bu çalışmada lignoselülozik dolgu maddesi olarak atık gazete kâğıdı lifi, bitkisel atık yağ kullanılmış, polimer olarak da geri dönüştürülmüş polipropilen kullanılmıştır. Atık gazete kâğıdı öğütülüp ve yaklaşık 24 saat boyunca 60˚C˚'de kurutma fırınında bekletildikten sonra %10, %20 ve %30 oranlarında geri dönüştürülmüş polipropilen ile karıştırılmıştır. Atık bitkisel yağ ise %2.5 oranında ilave edilmiştir. Karışımlar 170°C,175°C,180°C,185°C ısı kademelerinde ayarlanmış olan ekstrüzyon makinasına konulmuştur. Ekstrüzyon yöntemiyle üretilen kompozitlerin mekanik ve termal özellikleri belirlenmiştir. Atık gazete kağıdı lifi oranının ilkin eğilme mukavemetini azalttığı, daha sonra ise arttırdığı gözlenmiştir. Termal özelliklerde atık bitkisel yağ kullanımının olumlu etkisi olup ısıl direnci arttırmıştır. DSC analiz sonuçları incelendiğinde, atık gazete kağıdı lifinin kristalenliği arttırdığı sonucuna varılmıştır. Bu çalışma ile tümüyle atık olan bileşenlerin kompozit üretiminde kullanılabilir olduğu ve vaks gibi atık bitkisel yağların kullanılabileceği sonucuna ulaşılmıştır.

Because of its application potential and biodegradability, poly(3-hydroxybutyrate-co-3-hydroxyvalerate;PHBV), a member of the polyhydroxyalkanoates (PHA) biopolymer family, is one of the most extensively studied PHA. High PHBV productivity with a significant amount of hydroxyvalerate (HV) content is very appealing for commercial scale production. The goal of this study was to investigate the efficiency of various defined limitation strategies, namely nitrogen, phosphorus, and oxygen-limitation, for high yield PHBV production by Cupriavidus necator H16 with increased HV unit using waste frying vegetable oil (WFO) and propionic acid (PA) in a high cell density culture (5 L bioreactor). With optimized WFO and PA feeding, highest PHBV harvest (121.7 ± 2.59 g/L; HV 13.9 ± 0.44% (w/w)) and volumetric productivity (2.03 ± 0.04 gPHBV/L·h) were obtained in oxygen-limited operation, while highest HV content (19.8 ± 0.28 wt%) and yield coefficient (0.43 ± 0.017 gHV/gPA) were observed during phosphorus-limited cultivation. Although nitrogen limitation is widely applied in the production of PHA, nitrogen-limited cultivation had the lowest cell dry matter, PHBV production, volumetric productivity, oil-to-HB and PA-to-HV yield coefficients for the given conditions. The results of the present study demonstrate the highest PHBV yield together with the highest HV content using WFO as main carbon source and PA as the HV precursor ever reported in the literature. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate;PHBV), a member of the polyhydroxyalkanoates (PHA) biopolymer family, is one of the most extensively studied PHA due to its high application potential and biodegradability properties. High PHBV productivity with substantial amount of hydroxyvalerate (HV) content is of great interest for commercial scale PHA production to compete with conventional plastic costs. In this study, we investigated the effectiveness of different nutrient limitation strategies in optimizing the production of PHBV from waste frying vegetable oil and propionic acid. Although there are individual studies investigating the performance of operational PHBV production strategies such as nitrogen, phosphorus, or oxygen limitation, none of them have comprehensively compared the effect of different limitation strategies on PHA production parameters using waste frying vegetable oil as the main carbon source and propionic acid as the cheapest HV precursor. To our knowledge, this is the first study that evaluates the impact of these three limitation strategies on the efficient production of PHBV from waste frying oil and propionic acid in high cell density fermentations of Cupriavidus necator H16. The results demonstrate the highest PHBV yield together with the highest HV content using waste frying oil as main carbon source and propionic acid as the cheapest HV precursor ever reported in the literature. In addition, it is shown that the PHBV yield and its HV content could be intercorrelated by switching between oxygen and phosphorus-limited strategies for desired material specifications. [ABSTRACT FROM AUTHOR]

The staircase/stair-stepping effect causes wrapping, shrinkage, and surface roughness in additively manufactured (AM) parts. Consequently, abrasive flow finishing (AFF) or abrasive flow machining (AFM) may be employed to improve the AM part surface finish. This study developed an environmentally friendly AFM media using rice husk ash as base material, waste vegetable oil as a liquid synthesizer, and natural additives, i.e. glycerin. The new newly developed rice husk ash-based AFM media (HSAFM) characterization was done using Fourier Transform Infrared (FTIR) spectroscopic method and thermogravimetric analysis (TGA). AFM medium viscosity was optimized using a Taguchi design ( L 9 ). These FDM-printed extrusions die inserts were finished using optimized AFM media in a one-way AFM system. A new AFM fixture with a mandrel guide was developed to direct media flow inside the die cavity to ensure uniform finishing. Experimental research has been done on finishing the FDM-printed extrusion die insert pattern using the Box–Behnken Design (BBD)-based experimental design of the response surface methodology (RSM) technique. The surface roughness Ra Δ 28.16 μ m was improved by 96% with the following process parameters: media viscosity of 60 Pa/s, the layer thickness of 0.3, and 90 min of finishing time. [ABSTRACT FROM AUTHOR]

A valorization strategy of waste vegetable oil (WVO) as an alternative fraction in blend fuels is proposed in this study. The effect of blending WVO with diesel and kerosene is investigated by formulating three blends comprising of 0.20, 0.35, and 0.50 fraction as WVO. Upon characterization, the blend fuels are found to be within the standards for diesel, except for the viscosity of fraction containing diesel-WVO (D-WVO) blend. The kerosene-WVO (K-WVO) blends demonstrated fuel properties close to diesel. K-WVO blends showed better engine performance, with lower fuel consumption and elevated thermal efficiency relative to diesel. Lower density and viscosity, higher calorific value and superior volatility of kerosene is the probable reason. K-WVO blends resulted in lower CO, but higher HC emissions than diesel and D-WVO. However, a slight rise in NOx, particulate matter and soot emissions were observed with the addition of WVO in diesel and kerosene. Blending WVO with fossil fuels has reduced the overall price of the fuel. The engine running cost of K-WVO blends recorded a 52–61% reduction as compared to similar D-WVO blends. Also, the potential environmental impacts associated with WVO blends are much lower compared to pure diesel. Moreover, the K-WVO_0.50 blend showed maximized reduction in PEIs as compared to its diesel counterpart. Thus, the direct blending of WVO as an alternative fraction in fossil fuels can be considered as an economic and superior route for valorizing a common liquid waste. [ABSTRACT FROM AUTHOR]

This article presents an efficient iron(III) molecular catalyst for the production of biodiesel from waste vegetable oils. The approach involved an initial screening of eight salophen complexes with various substituents on the arene rings, leading to the selection of the simplest unsubstituted species as the most active catalyst. Under optimized conditions, this catalyst demonstrated the capability to achieve complete conversion of the oil at a low catalyst loading (0.10% mol/mol) and convenient conditions (160 °C, 20/1 MeOH/oil ratio).

This study aims to investigate the potential of zeolitic based catalysts for biodiesel production from waste sunflower vegetable oil. The zeolite-based catalyst was prepared by two impregnation steps. The obtained catalyst was examined for the transesterification reaction. The effect of operating variables and the synergetic effects between those variables were investigated. Other parameters such as catalyst impregnation time, stirring speed and catalyst particle size were also studied. Furthermore, the physical and chemical properties of the oil and the produced biodiesel were measured. Nearly complete 100% conversion and 96.7% yield were achieved using 11.5 MeOH/oil molar ratio, 6.4% catalyst dosage, at 50°C reaction temperature and reaction time of 2 hours. The properties of the obtained biodiesel are in agreement with the values specified by US and EU standards. [ABSTRACT FROM AUTHOR]

In this study, waste vegetable oil (WVO) subjected to different heating durations was blended with diesel fuel at different blend ratios. The blends were evaluated for carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NO) emissions and for the engine performance parameters. The properties of WVO-diesel blends were similar to that of diesel. The brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) of WVO-diesel blends was comparable to that of diesel. However, blending WVO in proportions of 0.50 with diesel results in 38% reduction in the overall cost and results in reduced CO, HC and NO emission. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effects of waste vegetable oil and waste engine oil modifications on chemical compositions, physical and rheological properties of pure bitumen. The modified binders in the study were prepared by including waste vegetable oil and waste engine oil at 7 different ratios in pure binders. To reveal the main chemical compositions of waste vegetable oil and waste engine oil, gas chromatography–mass spectrometry was used. To evaluate the physical and mechanical properties of pure binders and binders with waste oils, penetration, softening point, flash point, and force ductility tests were conducted. To determine the rheological properties of binders with waste vegetable oil and waste engine oil modifications, rotational viscometer and dynamic shear rheometer tests were conducted. Furthermore, Fourier-transform infrared spectroscopy was used to investigate the differences between the functional groups of pure binder and modified binders. In conclusion, the inclusion of waste vegetable oil and waste engine oil in pure bitumen resulted in decreases in the viscosity and softening point of asphalt mixtures while leading to increases in penetration value. Moreover, as the additive content increased, the complex modulus values were decreased in both types of mixtures. The increases in phase angle indicated that the binders had a more viscous structure. As the additive content increased in both the waste vegetable oil binder and the waste engine oil binder, the elasticity values decreased. Finally, it was determined that the deformation energy of the binders decreased with the increase of the additive content. [ABSTRACT FROM AUTHOR]

The primary motivation for researching biofuels is to meet the world’s energy requirements. Demand for fossil fuels is rising significantly due to population expansion. Biodiesel is a promising renewable energy source that, if implemented effectively, has the potential to reduce the dependency on fossil fuels. Because biodiesel is a cleaner fuel that requires no engine modification, its implementation is not complicated. It can directly be used in diesel engines or as a blended diesel with fossil diesel. Seven different vegetable oils were utilized to replicate restaurant waste cooking oil in the laboratory to make biodiesel. The qualities of biodiesel produced were investigated and compared to determine how they vary depending on the chemical composition of the oil source. The physical appearance of biodiesel varies slightly depending on the oil source. Density, kinematic viscosity, flash point, and acid levels, on the other hand, are all within acceptable biodiesel criteria for all types of oil sources used. [ABSTRACT FROM AUTHOR]

In this study, pure and self-healing asphalt mixture samples were obtained by adding capsules containing waste vegetable oil to mixtures at 0.25, 0.50, 0.75 and 1.00% ratios. Afterwards, creep test with a constant stress was carried out on the samples, and the resistance of asphalt mixtures against permanent deformation was investigated. Relaxation modulus values were obtained by using the creep compliance values that measured at the end of the experiment with mathematical transformations. Then, the relaxation modulus results were fitted to the Generalized Maxwell Model, which is a common model used to represent the viscoelastic properties of asphalt mixtures, and Prony series parameters were obtained. The results showed that the addition of capsule reduced the permanent deformation strength of the asphalt mixture. In addition, the curve fitting processes were successfully performed and the desired parameters were obtained with high accuracy.

Microbial fuel cells (MFCs) have been recently proven to synthesise biosurfactants from waste products. In classic bioreactors, the efficiency of biosynthesis process can be controlled by the concentration of nitrogen content in the electrolyte. However, it was not known whether a similar control mechanism could be applied in current-generating conditions. In this work, the effect of nitrogen concentration on biosurfactant production from waste cooking oil was investigated. The concentration of NH 4 Cl in the electrolyte ranged from 0 to 1 g L−1. The maximum power density equal to 17.5 W m−3 was achieved at a concentration of 0.5 g L−1 (C/N = 2.32) and was accompanied by the highest surface tension decrease (to 54.6 mN m−1) and an emulsification activity index of 95.4%. Characterisation of the biosurfactants produced by the LC-MS/MS method showed the presence of eleven compounds belonging to the mono- and di-rhamnolipids group, most likely produced by P. aeruginosa , which was the most abundant (19.6%) in the community. Importantly, we have found a strong correlation (R = −0.96) of power and biosurfactant activity in response to C/N ratio. This study shows that nitrogen plays an important role in the current-generating metabolism of waste cooking oil. To the best of our knowledge, this is the first study where the nitrogen optimisation was investigated to improve the synthesis of biosurfactants and power generation in a bioelectrochemical system. [Display omitted] • 11 types of rhamnolipids produced in bioelectrochemical system. • Optimised NH 4 Cl concentration for power and biosurfactants production. • The highest reported performance for MFCs degrading waste oil. • Direct correlation between power, surface tension and nitrogen. • Identification of the microorganisms involved in the process. [ABSTRACT FROM AUTHOR]

When properly compatibilized, the blending of polyethylene (PE) and polyamide (PA) leads to materials that combine low prices, suitable processability, impact resistance, and attractive mechanical properties. Moreover, the possibility of using these polymers without prior separation may be a suitable opportunity for their recycling. In this work, the use of an epoxidized waste vegetable oil (EWVO) was investigated as a green compatibilizer precursor (CP) for the reactive blending of a high-density PE (HDPE) with a polyamide-6 (PA6). EWVO was synthesized from waste vegetable cooking oil (WVO) using ion-exchange resin (Amberlite) as a heterogeneous catalyst. HDPE/PA6 blends were produced with different weight ratios (25/75, 75/25, 85/15) and amounts of EWVO (1, 2, 5 phr). Samples with WVO or a commercial fossil-based CP were also prepared for comparison. All the blends were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, and mechanical tests. In the case of HDPE/PA6 75/25 and 85/15 blends, the addition of EWVO at 2 phr showed a satisfactory compatibilizing effect, thus yielding a material with improved mechanical properties with respect to the blend without compatibilizer. On the contrary, the HDPE/PA6 25/75 ratio yielded a material with a high degree of crosslinking that could not be further processed or characterized. In conclusion, the results showed that EWVO had a suitable compatibilizing effect in HDPE/PA6 blends with high HDPE content, while it resulted in unsuitable for blends with high content of PA6.

Increasing air pollution is one of the significant problems globally, especially in developing countries that are caused mainly by exhaust emissions from motor vehicles. This study aims to analyse the performance of a diesel engine using biodiesel as fuel and compare it with pure diesel oil. In the present study, biodiesel was produced from waste vegetable oil. The transesterification was performed with methyl alcohol in the presence of catalyst potassium hydroxide. Blends B10 and B20 were made by mixing pure diesel and biodiesel fuel. Various parameters such as brake specific fuel consumption, brake thermal efficiency, mass flow rate, and brake power were calculated. At 5 kg load, the brake thermal efficiency for B10 was higher compared to pure diesel and B20 by 13.72% and 10.02 %, respectively, while the fuel consumption time was 2.35 % and 3.56 % more than pure diesel for B10 and B20, respectively. At no-load conditions, the fuel consumption rate for B10 was maximum, 5.17 % and 12.38 % more than that of B20 and pure diesel, respectively. Thus, without compensating for the power and brake thermal efficiency, vegetable oil-based biodiesel and its blends can be used in CI diesel engines as an alternative fuel.

The present paper describes the use of an easily accessible polymer-grafted sulfonated carbon composite catalyst for the synthesis of α-hydroxy ethers as bio-lubricants from waste vegetable oil via chemical modification involving esterification, epoxidation, and ring-opening reaction. A variety of α-hydroxy ethers were synthesized using different fatty alcohols for the evaluation of physicochemical properties. The bio-lubricants synthesized from 2-ethyl hexanol and dodecanol were found to be most promising as they exhibited lower pour point (< − 27 °C) and higher viscosity index (VI) 97 and 143, respectively. High VI and a lower pour point indicate ROP-3 and ROP-5 to be the most promising candidates as bio-lubricant for various applications. [ABSTRACT FROM AUTHOR]

The disposal of used waste vegetable oil is a significant concern from the pollution point of view. Several studies have already been made to produce biodiesel/blending with diesel in CI engines. However, the cost benefit analysis makes this process non-viable. Also, several works of literature are available in the admitting of non-edible oil blends in CI engines. This paper analyses the admitting the gasified waste vegetable oil (WVO) with non-edible oil (NEO) in CI engine. The mixture of WVO and NEO has been auto-gasified before admitting them in CI engine. Auto gasification is converting the solid combustible waste into the gaseous product with bio-oxygen and catalytic ash. This way, the temperature of the gasification process is reduced and makes direct admission is feasible. From the various trails, it has been found that the optimised performance ratio for the WVO and NEO mixture is 50:50. The cost-benefit analysis of bio diesel production and usage in CI engine has been analysed and reported in this paper. The EIA of WVO disposal has also been carefully analysed and reported. [ABSTRACT FROM AUTHOR]

Reclaimed asphalt pavement (RAP) is the deteriorated pavement material, containing aged binder and aggregates. A rejuvenator is normally added to the mixture to reduce its stiffness, by blending with the aged binder and changing the properties of the mixture. Therefore, it is necessary to have an insight into the microstructure of the RAP and rejuvenated RAP. In this study, waste engine oil (WEO), waste vegetable oil (WVO) and waste grease (WG) are used as rejuvenators, at different dosages. The interaction between the rejuvenator and RAP is evaluated through microscopic analysis, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. The microscopic analysis has provided the orientation and distribution of the aggregate, depicting the significant increase in coating of aged binder on the RAP with the increase in the rejuvenator dosage. The FTIR and XRD results have shown that rejuvenator has restored the asphaltenes and maltenes ratio and fluidity of the RAP. WG has comprehensively enhanced the asphaltenes and maltenes ratio, compared to the WEO and WVO. However, microscopic analysis suggests that the WG has high agglomeration. Overall, it is concluded that 6% WVO is a perfect dosage to enhance fluidity of the RAP. [ABSTRACT FROM AUTHOR]

In this work, Camellia oleifera Abel shell was used as a feedstock to prepare biochar by HNO3 impregnation and pyrolysis. The biochar was used for the catalytic pyrolysis of waste vegetable oil to prepare bio-oil. Experimental results showed that HNO3 solution treatment had an important effect on the groups and structure of the biochar catalyst. When the solid/liquid ratio of pretreatment was 1:3, the Brunauer–Emmett–Teller specific surface area of the 1:3–600°C biochar is 392.65 m2/g, which is approximately 677 times higher than that of untreated biochar. Moreover, the biochar catalyst had a remarkable catalytic performance. The selectivity of the monocyclic aromatic hydrocarbon in the bio-oil was up to 78.82%, and the oxy-compound could be completely removed at the catalytic temperature of 600°C. However, the increase of the catalyst-to-waste vegetable oil ratio and catalytic temperature decreased the bio-oil yield.

The rise in global energy demand has encouraged exploring into other innovative methods of generating renewable fuels from different forms of waste. Due to its accessibility, culinary used vegetable oil is regarded as a potential source for profitable production of biodiesel. In the present study, the viability of producing biodiesel from used vegetable oil (UVO) by utilizing CaO catalyst (derived from the calcination of chicken eggshell and impregnated with KNO3 and NaNO3) was studied. Higher yield of biodiesel was obtained at methanol/oil mole ratio of (9–10) and CaO catalyst concentration of (2.0–3.0) wt/wt% Oil, for the three forms of catalyst used. Also, higher yield of biodiesel was obtained when CaO with impregnated KNO3 was used, followed by the operation involving CaO with impregnated NaNO3. At optimum conditions of methanol/oil mole ratio of 9 and catalyst concentration of 2.4 wt/wt% Oil, the yields of biodiesel obtained were 90% (for unimpregnated catalyst), 92% (using CaO impregnated with NaNO3) and 95% (using CaO impregnated with KNO3). The higher biodiesel yield obtained for CaO impregnated with KNO3 (compared to the yield from CaO impregnated with NaNO3) could be traced to a more reactive nature of potassium and arrangement of electrons of both potassium and sodium. The results of the tests and analysis on biodiesel properties reveal that quality biodiesel were produced from the three forms of catalyst used. This is because, each of the values of the properties considered falls within the ASTM standard.

There has increased in environmental pollution due to rapid population growth in the world. Environmental conscience of society can reduce environmental pollution. Conducting surveys can determine the existence of this conscience and public awareness on environmental issues. In addition, survey results guide the activities of municipalities, public institutions and non-governmental organizations that work to prevent environmental pollution. This study was conducted to determine with individuals living in Battalgazi and Yeşilyurt, which are the central districts of Malatya province, to determine their awareness on "environmental effects and recycling of waste vegetable oils". The results were evaluated by applying a questionnaire consisting of 19 questions. 150 individuals from each district and in total 300 individuals participated in the questionnaire which consisted of information about demography, environmental effects and recycling of waste vegetable oils. The study determined the public awareness on the effects of domestic waste oils on water, air and soil pollution and recycling (especially raw materials in biodiesel production). Following the survey, information has been provided about the effects of waste vegetable oils on the environment by creating awareness to eliminate these effects or minimalize them. Based on the survey results, it has been determined that: (i) frying consumption is inversely proportional to the age of the participants; (ii) even though specific questions were asked, the majority of the population have comprehensive knowledge on these specific issues; (iii) they follow internet, TV, radio, newspapers and magazines related to the subject, especially about the environmental awareness; (iv) informative activities of non-governmental organizations and municipalities are effective.

Asphalt pavements are amongst the most recycled materials in the contemporary world depending on the environmental and financial advantages. The introduction of Recycled Asphalt Pavement (RAP) on newly produced asphalt pavement is possible by the utilization of rejuvenating agents, which should contain oily fractions. For this purpose, within the scope of this study, three types of agents with optimum amounts (by weight of bitumen) were utilized 5.4% Waste Engine Oil (WEO), 5.1% Waste Vegetable Oil (WVO), and 6.8% Commercial Rejuvenating Agent (CRA). The highest applicable RAP content in mixtures depends on the rejuvenator type determined by Marshall Mix Design tests (air voids, flow, and stability). Rejuvenation facilitated the use of 50 to 60% of additional RAP material in the mixtures depending on the rejuvenator type. Indirect Tensile Strength (ITS) test results declared that RAP mixtures, when subjected to the rejuvenation process, resulted in relatively less brittleness and enhanced durability properties compared to the unmodified ones. Additionally, cost comparison analyses demonstrated encouraging results as the cost-benefit ratio exceeded up to 55% for mixtures involving high percentages of rejuvenated RAP. As a final analysis, Return on Investment (ROI) values were calculated for each rejuvenator type by the cost of upgrading the facility to handle RAP and the profit of RAP usage. Consequently, ROI was calculated as a return time in months, which unveils an extremely profitable opportunity in the industry.

Increasing environmental awareness and threats to the environment have made the recycling of biomass products necessary. The goal of this paper is to study the tribological properties of fatty acid methyl esters derived from waste frying oils under different lubrication conditions. For this purpose, the performance of candidate fatty acid methyl esters was compared with a mineral base oil. For the determination of tribological properties, a pin-on-disc wear tester was used. The experiments were carried out in three replications at different loads (5, 10, and 15 N) and different sliding speeds (100, 300, and 600 r/min) and a 1000 m sliding distance under dry, boundary-mixed, and fluid lubrication conditions. After the wear amount of the test specimens was determined by the mass loss method, their Archard wear indexes were calculated. Scanning electron microscopy surface images were used for visual analysis and energy-dispersive X-ray spectroscopy images for chemical analysis. The surface contact angles and surface tensions of the lubricant test specimens were also measured experimentally. In all experimental results, it has been found that the tribological properties of used frying oil fatty acid methyl esters such as friction, wear, and surface adhesion are generally better than the base oil under all lubrication conditions. Fatty acid methyl esters is a biodegradable, recycling, and environmentally friendly product and can be confirmed as a lubricant and/or an oil additive candidate. [ABSTRACT FROM AUTHOR]

In this study, the rheological properties of pure binders and modified bitumen that were prepared with these binders were investigated under various temperatures and frequencies. In the study, the B 50/70 class pure bitumen, which was obtained from the TUPRAS refinery in Batman, was used as the main binder. Waste oils were used as additives at 2%, 4%, 6%, 8%, 10%, 12% and 14% ratios. Pure and modified bitumen were subjected to dynamic shear rheometer (DSR) tests at 4 different temperatures (40 °C, 50 °C, 60 °C, and 70 °C) and 10 different frequencies (between 0.01 Hz and 10 Hz). As a result of the DSR tests, it was determined that the modified bitumen that was prepared with waste engine oil had higher complex shear modulus and lower phase angle values compared to the modified bitumen prepared with waste vegetable oil, which pointed to elastic behaviors at higher levels in favor of engine oil modification. It was also determined that waste vegetable oil proved more effective at 2% and 3% additive ratios in terms of the complex shear modulus values while waste engine oil modification was more effective at 2% and 4% additive ratios. In conclusion, it was discovered that waste engine oil was more effective in preparing modified bitumen compared to waste vegetable oil. [ABSTRACT FROM AUTHOR]

The study presented the blends of waste vegetable oil with kerosene (K-WVO) as diesel substitutes. Three K-WVO blends containing 0.20, 0.35, and 0.50 fraction of WVO in kerosene are comprehensively analyzed for combustion, performance, emissions, economics, and environmental impacts. The engine performance and combustion profiles of the blends were comparable to that of diesel. The blend containing 0.20 fraction as WVO demonstrated better fuel consumption and combustion efficiency than diesel. K-WVO blends showed lower specific carbon monoxide emissions but higher unburnt hydrocarbon emissions relative to diesel. The emission of nitrogen oxide was similar for the blend fuels and diesel. The blends were found to be much economic than diesel. A 52–61% reduction in running cost can be achieved by substituting diesel with a K-WVO blend. The blends with higher WVO fraction are found to be more economic. The use of K-WVO blends can be expected to lower the global warming potential by 19.6–21% compared to diesel fuel. Largely, the blend fuels were found to have lower environmental impacts compared to diesel. The study showed that the benefits associated with a blend depend on blend composition. The blend with a lower WVO content can have better engine performance and emission characteristics, but blend with a higher WVO has more economic and environmental benefits. Thus, the comprehensive assessment presented in the study can be used as a guide toward defining the proper WVO-kerosene blend composition based on the proposed objective. [ABSTRACT FROM AUTHOR]

A combined experimental and numerical characterization of a Compression Ignition (CI) engine is here presented under Diesel and Waste Vegetable Oil (WVO) fueling at different loads. Main objective is to prove the feasibility of preheated WVO as substitute of Diesel fuel in CI engine for cogeneration purposes without modifying the engine geometry. After a characterization of the WVO physical properties, an appropriate pre-heating system is mounted on the engine injection line in order to reduce viscosity. The in-cylinder pressure analysis reveals no significant differences under both fuelling modes, despite an increased fuel consumption measured for WVO. This last provides higher NOx, CO and CO 2 emissions, with a strong reduction (50–80%) of the soot amount. The potential impact of employing WVO is then assessed through a Life Cycle Assessment (LCA) methodology with focus on the fuel production and use stages. A reduction in all the major impact categories is noticed with respect to Diesel fueling. At the same time, a 3D CFD model of the engine is developed and validated. The WVO injection process shows slower spray break-up and evaporation rates due to higher viscosity and density. Despite the higher penetration lengths and increased amount of fuel burnt closer to the cylinder walls, the soot at the exhausts remains low as a consequence of the absence of aromatic compounds and an enhanced oxidation process due to the presence of oxygen atoms in the WVO molecules. This aspect is also responsible of the increased NOx release. • A preheating circuit is needed to make WVO viscosity compliant with engine specifications. • A 20%–25% increase in fuel consumption is needed to reach the set loads under WVO. • WVO injection is characterized by slower spray break-up and evaporation phenomena than Diesel. • WVO determines higher NOx, CO and CO 2 emissions and lower soot than Diesel. • LCA analysis reveals major impact reduction under WVO fueling. [ABSTRACT FROM AUTHOR]

Carbon sequestration and utilization are currently gaining attention as they help to reduce the emission of greenhouse gases in the atmosphere. This study explores the possibility of using carbon dioxide as a feedstock for the production of ammonium carbamate, a precursor molecule for urea production. Waste cooking oil was used as the indispensable nonaqueous medium for the formation of pure ammonium carbamate. This makes the process completely ecofriendly and cost‐effective. A continuous process of ammonium carbamate production at 20°C results in 88.86% consumption of carbon dioxide. The highest yield of ammonium carbamate was achieved at an NH3/CO2 ratio of 2.5. A three‐stage setup was also found to increase the yield of ammonium carbamate. The reusability of oil after each cycle was checked and it was found that the formation of the product is comparatively less compared to the previous cycle. Lower yield was observed when the same experiment was carried out with fresh oil (sunflower oil). The exit gas from the process was found to be rich in ammonia that can be further used for the production of struvite, a phosphate fertilizer. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The present paper aimed at studying the effectiveness of waste vegetable oil (WVO) as rejuvenator in restoring the desired properties of recycled asphalt mixes. The effectiveness of rejuvenators was first evaluated based on aging resistance, rutting, and fatigue performance of rejuvenated bitumen blends of recovered reclaimed asphalt pavement (RAP) bitumen and virgin bitumen. Bitumen was also characterized chemically by conduction thin layer chromatography–flame ionization detector (TLC–FID) analysis and Fourier transform infrared spectroscopy (FTIR) analysis. The rutting and fatigue resistance of asphalt mixes with high RAP content (60% and 90%), and rejuvenator was also evaluated. Comparison of the results of TLC–FID analysis on RAP bitumen and rejuvenated bitumen suggested that the WVO was able to reinstate the lighter fractions of bitumen. Two new peaks were observed in rejuvenated bitumen FTIR absorbance spectrum at 1,744 and 1,160 cm-1. These peaks respectively correspond to C═O and C─ O─ C stretches of saturated fatty acid ester, which is a major component of WVO. Multiple stress creep and recovery test on bitumen and a wheel-tracker test on asphalt mixes suggest that the rutting performance might not be an issue if the rejuvenator dosage selection is based on the target viscosity (at 60°C) or the softening point of the virgin bitumen type that is commonly adopted by the applicable road agency. Rejuvenated bitumen, when evaluated based on a linear amplitude sweep test, has shown inferior fatigue resistance compared to virgin bitumen. Such behavior of rejuvenated bitumen could be attributed to the presence of a high concentration of more reactive unsaturated fatty acids inherited from WVO. However, from indirect tensile fatigue tests on the asphalt mixes, it was found that the fatigue performance of rejuvenated recycled asphalt mixes is satisfactory. [ABSTRACT FROM AUTHOR]

Alkylated waste vegetable oil is a versatile intermediate product in the synthesis of bio-based materials. Heterogeneous catalytic condition with high conversion rate in the direct alkylation of waste vegetable oil was reported and the deactivation mechanism of catalyst was revealed. The total exchange capacity, elemental composition and pyrolysis product of catalyst before and after the alkylation reaction were analysed by back titration, elemental analysis, electrospray ionization mass spectrometry, gas chromatography mass spectrometry and pyrolysis-gas chromatography/mass spectrometry, respectively. The results indicated that the metallic and non-metallic (C, H) elements contents of the catalyst have very much increased with great changes in pyrolysis product and a slight decrease in the total exchange capacity. The formation of insoluble polymers through Diels–Alder cycloaddition between triglycerides was proved to be the major factor causing the dysfunction of the catalytic centre. The metal ions from corrosion of the reactor were the minor factor causing about 2.56% loss of the catalytic centre. Moreover, the catalyst was able to maintain high catalytic efficiency when replacing the raw materials with other waste vegetable oil having low concentration of polyunsaturated fatty acids, which is significant for producing not only the aryl fatty acids derivatives but also the bio-based surfactants.

Objective This experiment was conducted to investigate the effects of crude glycerin from waste vegetable oil (CGWVO) on performance, carcass traits, meat quality, and muscle chemical composition. Methods Twenty-four crossbred (Thai Native×Anglo Nubian) uncastrated male goats (16.8± 0.46 kg body weight [BW]) were assigned to a completely randomized design and subjected to four experimental diets containing 0%, 2%, 4%, and 6% of CGWVO (63.42% of glycerol and 47.78% of crude fat) on a dry matter (DM) basis. The diets were offered ad libitum as total mixed rations twice daily. The feed intake, feeding behavior, growth performance, carcass and meat traits, and muscle chemical composition were evaluated. Results Based on this experiment, there were significant differences (p>0.05) among groups regarding DM intake, growth performance, and carcass traits where goats receiving 6% of CGWVO had lower daily DM intake, growth performance, and carcass traits than those fed on 0%, 2%, and 4% of CGWVO. There were no effects of CGWVO on carcass length, carcass width, Longissimus muscle (LM) area, Warner-Bratzler shear force, pH and color of LM at 45 min after slaughter, as well as on other carcass cut and muscle chemical composition. Conclusion In conclusion, the addition of up to 4% of DM in the diets for crossbred finishing goats seems to be the most interesting strategy, since it promotes greatest animal performance. Moreover, this study was a suitable approach to exploit the use of biodiesel production from waste vegetable oil for goat production.

The present study valorizes waste vegetable oil (WVO) as a renewable alternative blend fraction of diesel to fuel a compression ignition engine. Response surface (RS) approach is employed to predict engine performance—fuel consumption (FC) and thermal efficiency (TE)—using three factors–three levels of experimental design array. The factors selected for the study are thermal treatment time of WVO (h), WVO fraction in the blend, and engine torque due to load (Nm). The model predictions are well correlated with the experimental data. Based on the D-optimality criterion, the blend containing 0.50 fraction as 47 h thermally treated WVO at an engine torque of 14.72 Nm is the RS model-optimized blend. The experimental outcomes of the optimized blend are FC = 0.5094 kg/h and TE = 23.70%. The suitability of the optimized factor settings established in the study was verified using waste frying oil (WFO) as a diesel blend. The FC and TE of the optimized WVO–diesel and WFO–diesel blends are compared with the literature values. The model-optimized WVO–diesel blend recorded 14.3% and 17.6% lesser CO and NOx emissions, respectively, and is 45% more economical than neat diesel. The direct blending of WVO with diesel and optimization of the blend fraction and the thermal treatment duration of WVO for better engine performance are a novel approach. The work accounted in this report presents a holistic study toward sustainable utilization of WVO in diesel-driven vehicles and can be helpful to various stakeholders. [ABSTRACT FROM AUTHOR]

The study presents a comparative evaluation of waste vegetable oil (WVO) versus transesterified waste vegetable oil (WVBD) in diesel blends for engine performance, emission characteristics, economics, and sustainability as an alternative fuel for a compression ignition engine. The impact of blend fraction and blend type on the fuel properties were determined. Increased WVO or WVBD fraction in the blend resulted in increased density, viscosity, flash points, and reduced calorific value. WVBD blends showed lower fuel consumption and better thermal efficiency performance, whereas other engine performance parameters were comparable to WVO blends. Emission characteristics of all the blends were comparable under all load conditions. Economic analysis showed that WVO blends are more cost-effective than WVBD blends. The sustainability analysis using the life cycle assessment methodology revealed lower environmental impacts were associated with WVO blends as compared to WVBD blends. The study pegs WVO blend as a more sustainable and economical diesel fuel alternative against the predominant and more explored WVBD blend. [ABSTRACT FROM AUTHOR]

The rise in global energy demand has encouraged exploring into other innovative methods of generating renewable fuels from different forms of waste. Due to its accessibility, culinary used vegetable oil is regarded as a potential source for profitable production of biodiesel. In the present study, the viability of producing biodiesel from used vegetable oil (UVO) by utilizing CaO catalyst (derived from the calcination of chicken eggshell and impregnated with KNO3 and NaNO3) was studied. Higher yield of biodiesel was obtained at methanol/oil mole ratio of (9–10) and CaO catalyst concentration of (2.0–3.0) wt/wt% Oil, for the three forms of catalyst used. Also, higher yield of biodiesel was obtained when CaO with impregnated KNO3 was used, followed by the operation involving CaO with impregnated NaNO3. At optimum conditions of methanol/oil mole ratio of 9 and catalyst concentration of 2.4 wt/wt% Oil, the yields of biodiesel obtained were 90% (for unimpregnated catalyst), 92% (using CaO impregnated with NaNO3) and 95% (using CaO impregnated with KNO3). The higher biodiesel yield obtained for CaO impregnated with KNO3 (compared to the yield from CaO impregnated with NaNO3) could be traced to a more reactive nature of potassium and arrangement of electrons of both potassium and sodium. The results of the tests and analysis on biodiesel properties reveal that quality biodiesel were produced from the three forms of catalyst used. This is because, each of the values of the properties considered falls within the ASTM standard. [ABSTRACT FROM AUTHOR]

Dependency of Turkey on foreign energy adversely affects the economy of the country and may cause energy shortage in the near future. As a primary domestic energy source, coal is used for energy production in addition to imported oil and gas. However, significant amount of fine coal is lost together with tailings in coal washeries. Recovering of fine coals from these tailings will make an economic contribution to country. In the present study, fine coals were recovered from tailings of a coal washery in Turkey by using oil agglomeration method. Flotation was used in agglomerate separation stage of oil agglomeration. Results were compared with that of previous study in which agglomerates were recovered by screening. The performance of the process increased sharply when flotation was used instead of screening in agglomerate separation stage. A clean coal with 28% ash was recovered from the washery tailings containing 55% ash by 85% combustible recovery. [ABSTRACT FROM AUTHOR]