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The increasing global demand for a renewable transportation fuels has motivated the search for alternatives such as biodiesel. The focus of this work was to completely characterize waste vegetable oil and evaluate its potentials as a feedstock for biodiesel production. The waste vegetable oil was extensively characterized to determine its key properties and chemical composition such as acid value, viscosity, iodine value, saponification value, fatty acid composition etc. The results showed that the waste vegetable oil exhibited desirable properties, such as a low free fatty acid value of 5.28%, a kinematic viscosity of 38.03 mPas, and iodine value of 82.90 mg I2/100g oil and a saponification of 207.10 mg KOH/g oil, indicating its suitability for biodiesel production. Furthermore, its fatty acid profile showed a blend of saturated and unsaturated fatty acids which play important role in the quality of biodiesel. This work has shown that waste vegetable oil is a potential feedstock for biodiesel production.

The ongoing use of traditional fossil-based fuels has a variety of negative environmental effects, motivating the need to seek out sustainable and environmentally favorable alternatives such as biodiesel. One of the major challenges associated with the biodiesel process is the cost associated with the feedstocks. Thus, there is motivation to seek out alternative and low-cost feedstocks for biodiesel production. Thus, the focus of this work was to assess the potentials of waste vegetable oil (WVO) and Sesamum indicum oil as inexpensive and sustainable feedstocks for biodiesel production. This was done by completely characterizing both oils to determine their key characteristic which indicate their suitability for producing biodiesel. The results showed that free fatty acid content, viscosity, peroxide value, density and saponification value of WVO and Sesamum indicum oil were 2.9 and 1.89 %, 21.4 and 6.40 mm2/s, 2.8 and 3.1 meq O2/g, 971 and 896 kg/m3, and 190 and 174.6 mg KOH/g respectively. These values were comparable with those reported in literature and indicated the suitability of both oil feedstocks for biodiesel production.

Indexación: Scopus. The use of waste materials as feedstock for biosynthesis of valuable compounds has been an intensive area of research aiming at diminishing the consumption of non-renewable materials. In this study, P. putida KT2440 was employed as a cell factory for the bioconversion of waste vegetable oil into medium-chain-length Polyhydroxyalkanoates. In the presence of the waste oil this environmental strain is capable of secreting enzymes with lipase activities that enhance the bioavailability of this hydrophobic carbon substrate. It was also found that the oxygen transfer coefficient is directly correlated with high PHA levels in KT2440 cells when metabolizing the waste frying oil. By knocking out the tctA gene, encoding for an enzyme of the tripartite carboxylate transport system, an enhanced intracellular level of mcl-PHA was found in the engineered strain when grown on fatty acids. Batch bioreactors showed that the KT2440 strain produced 1.01 (g⋅L −1 ) of PHA whereas the engineered ΔtctA P. putida strain synthesized 1.91 (g⋅L −1 ) after 72 h cultivation on 20 (g⋅L −1 ) of waste oil, resulting in a nearly 2-fold increment in the PHA volumetric productivity. Taken together, this work contributes to accelerate the pace of development for efficient bioconversion of waste vegetable oils into sustainable biopolymers. © 2018 Elsevier Ltd. https://www.sciencedirect.com/science/article/pii/S135951131831451X?via%3Dihub

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.

Petroleum-based fuels are now widely known as environmentally unfriendly because of non-renewable supplies and its contribution to environmental pollution. The challenge, therefore is to ensure appropriate energy supplies at minimum cost. There is an increasing energy demand in the world and nowadays it can be fulfilled only on the basis of fossil fuels. Therefore, it is necessary to evolve a renewable energy source with lower environmental impact. One alternative solution can be oils of plant origin, like vegetable oils and non-edible oils. With waste vegetable oil methyl ester, biofuel dependency can be decreased. Therefore, the aim of this research paper is to analyze the economic and environmental effect of waste vegetable oil methyl ester compared to fossil fuels. In some cases only the age of vehicles could raise burdens to biofuel utilization in road vehicles. Transport and energy policy ? on a large scale ? can play an important role in fuel consumption. Author is aware that waste vegetable oil methyl ester can play only a limited role in biofuel substitution.

Syngas production from biomass gasification and its use in combined heat and power (CHP) generation systems is a feasible alternative to traditional fuels in Internal Combustion Engines (ICEs), although its quality is poorer in terms of calorific value and energy density. Therefore, a viable option for its exploitation can be assured if ICEs operate in dual-fuel (DF) mode, where employing non-edible oils (as Waste Vegetable Oils, WVO) as a further residual material may solve issues related both to the utilization of diesel fuels and to the high costs for biodiesel production. The practice promotes a virtuous circle to enhance material recovery without disposal. A combined experimental-numerical activity for the analysis of the performances of a Compression Ignition (CI) engine in the DF mode with syngas and WVO is here presented. An appropriate pre-heating system is mounted on the engine injection line to reduce the WVO viscosity. Experimental data collected in terms of in-cylinder pressure cycle, heat release rates and main pollutants at different loads are used to validate a properly developed three-dimensional (3D) Computational Fluid Dynamics (CFD) model, that helps investigating the detail of the syngas fuelling on power output and emissions.

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.

Biodiesel is a renewable diesel fuel produced from fats and oils. Waste Vegetable Oil (WVO) is an important feedstock for biofuel production. WVOs availability as wastes from restaurants, workplace canteens and residential users and their utilization will reduce environmental pollution. In the present work, WVO has been transesterified in a pilot plant under different conditions. The assessment of the parameters affecting the biodiesel conversion factor has been investigated, namely catalyst type and concentration and alcohol concentration. In order to maximize the yield of the process and to obtain biodiesel with lower specific gravity, an optimization process has been carried out.

Se han investigado las ventajas de un sistema de digestión anaerobia en dos fases para el tratamiento de una mezcla de los residuos oleosos (RO) generados en el procesado de aceites vegetales usados y purín porcino (PP), 1/5 v/v, utilizando dos digestores semi-continuos operados a 37±1 ºC. Los experimentos fueron llevados a cabo a tiempos hidráulicos de residencia (THR) de 0.5, 1, 2 y 4 días en la primera etapa (reactor acidogénico) y de 11.5, 15, 18 y 20 días en la segunda etapa (reactor metanogénico). Los resultados revelaron que el THR tiene una gran influencia en la eliminación de demanda química de oxígeno soluble (DQOs) y sólidos disueltos totales (SDT). La máxima eficiencia de eliminación de DQOs, SDT y producción máxima de biogás fueron de 86.4% y 81.9% y 0.65 m³ biogás por kilogramo de sólido disuelto volátil (SDV) eliminado (65% CH4) respectivamente, conseguidas todas a un THR total de 20 días. This study investigates the advantages of two-phase anaerobic digestion for treating a mixture (1/5 v/v) of used vegetable oils processing wastes and pig manure using two semi-continuous digesters operated at mesophilic temperature (37±1 ºC). The experiments were conducted at hydraulic retention times (HRT) of 0.5, 1, 2 and 4 days in the first stage (acidifier) and at HRT of 11.5, 15, 18 and 20 days in the second stage (methanizer). The results revealed that the HRT had a high influence on the soluble chemical oxygen demand (CODs) and total dissolved solids (TDS) removal. The maximum total CODs removal efficiency of 86.4% and TDS removal efficiency of 81.9% was achieved at 20 days of global HRT. The maximum biogas production of 0.65 m³ per kilogramme of volatile dissolved solids (VDS) removed (65% CH4) was also achieved at 20 days of HRT.