Recycling of Waste Oils: Technology and Application

Reducing the impact of human activity on the environment and, in general, on Earth, represents the most challenging target of the next years [...]

Study on Influence of Use of Waste Cooking and Engine Oil on the Properties of Bituminous Concrete

Bitumen is defined as a gelatinous viscid mixture of hydrocarbons attained naturally or as a residue from petroleum refinement which is used for pavement materialization and roofing. Bitumen is employed as a binder for flexible pavements throughout the globe. Though bitumen is non-hazardous under normal conditions but when heated it becomes toxic and has consequences of environmental degradation. Also, bitumen being a product of non-renewable source of energy i.e. petroleum will led to depletion of petroleum reserves. It is a key challenge in highway industry to scale back the dependence on fossil fuels & to recycle the highway waste. The asphalt industry is undoubtedly a sector that contains a sustainable environmental impact, one amongst the main component being binder, bitumen, which is produced from petroleum. Bitumen generation results in enormous amounts of carbon dioxide emission which causes hazardous environmental impact. This research work is about the employment of waste oils as the alternative binders. The waste oils employed are waste cooking and waste engine oil. These are studied and analyzed as a step towards sustainable environment. This project work will provide an alternative or modified binder as well as will serve with the better way for safe disposal of waste oils generated. Thus, this project is beneficial concerning both the environmental aspects of alternative binder and safe disposal of waste oils. Keywords: Pavements, Bitumen, Engine Oil, Cooking Oil, Addition Percentage, Highway Industry.

Validation of an improved European standard method for the determination of PCBs in oil samples

Two European standard methods (EN 12766 and EN 61619) are currently used for the determination of PCBs in specific oil matrix. However, apolar matrix compounds (e.g. hydrocarbons) elute from the adsorbent together with the PCBs and are injected into the analytical system where their presence contaminates the inlet, detectors and columns; and decreases system performances. Insufficient cleanup causes delay of elution of PCBs from GC columns. By using new sulfoxide-bonded silica, PCBs are better separated from aliphatic hydrocarbons because the specificity of the stationary phase for these compounds is much higher that that used in both standard methods. A gas chromatograph AT6890 with two capillary columns of different polarities (HP-5MS and DB-1701) coupled to two μECDs is used. Oven temperature program is as followed: 90°C (1 min), 70°C/min to 180°C, 5°C/min to 230°C (0.1 min), 1.5°C/min to 280°C. Run time is 46 min. The procedure was validated through regular analysis of blanks, fortified samples (transformer oil, motor used and unused oil) and certified materials (BCR-449 and BCR-420, waste mineral oils, high and low PCB levels). Two internal standards were used (PCB 30 and PCB 209). An average recovery ± RSD of 82.8 ± 5.4 % was achieved for all six PCBs in different matrices. The LOQ per single PCB congener is 0.2 mg kg-1. The average recovery ± RSD for the BCR-420 is 92.0 ± 4.6 % and for the BCR-449 is 105 ± 2.5 % for all certified PCBs in waste oils.

Biodiesel Production From Lignocellulosic Biomass Using Oleaginous Microbes: Prospects for Integrated Biofuel Production

Biodiesel is an eco-friendly, renewable, and potential liquid biofuel mitigating greenhouse gas emissions. Biodiesel has been produced initially from vegetable oils, non-edible oils, and waste oils. However, these feedstocks have several disadvantages such as requirement of land and labor and remain expensive. Similarly, in reference to waste oils, the feedstock content is succinct in supply and unable to meet the demand. Recent studies demonstrated utilization of lignocellulosic substrates for biodiesel production using oleaginous microorganisms. These microbes accumulate higher lipid content under stress conditions, whose lipid composition is similar to vegetable oils. In this paper, feedstocks used for biodiesel production such as vegetable oils, non-edible oils, oleaginous microalgae, fungi, yeast, and bacteria have been illustrated. Thereafter, steps enumerated in biodiesel production from lignocellulosic substrates through pretreatment, saccharification and oleaginous microbe-mediated fermentation, lipid extraction, transesterification, and purification of biodiesel are discussed. Besides, the importance of metabolic engineering in ensuring biofuels and biorefinery and a brief note on integration of liquid biofuels have been included that have significant importance in terms of circular economy aspects.