Antonia Flávia Justino Uchoa

Bio: Antonia Flávia Justino Uchoa is an academic researcher from Federal University of Ceará. The author has contributed to research in topics: Asphalt & Dynamic shear rheometer. The author has an hindex of 3, co-authored 7 publications receiving 34 citations.

Potential Bio-Based Lubricants Synthesized from Highly Unsaturated Soybean Fatty Acids: Physicochemical Properties and Thermal Degradation

Abstract: The use of mineral lubricants and petroleum derivatives has become, along the years, harmful to the environment, so renewable raw materials have gained expressive notoriety. The innovation of this ...

Biolubricant Production from Several Oleaginous Feedstocks Using Lipases as Catalysts: Current Scenario and Future Perspectives

Abstract: In recent years, biolubricants have been gaining further prominence than conventional petroleum-based lubricants. This trend is observed in almost all sectors relying on these products, regardless of their applications. Environmental problems caused by coventional lubricants and the depletion of oil reserves that have led to the need for renewable and biodegradable lubricants are among the factors that contribute to such growing trend. Biolubricants have several advantages over mineral oil lubricants such as high biodegradability, low toxicity, excellent lubricating performance, and minimal impact on the environment and human health. In addition, they can be produced using several types of oleaginous feedstocks and distinct chemical reactions that can be efficiently catalyzed by lipases, which make them quite attractive in the context of Green Chemistry. Thereby, this review describes different aspects of biolubricants by detailing their main applications, properties, uses, and potential feedstocks such as vegetable oils. In this review, chemical modification of their structures using different routes has been highlighted in order to overcome a few limitations for direct application of oleaginuous feedstocks as biolubricants. It also depicts the progress of enzymatic catalysis and immobilization protocols for preparing heterogenous biocatalysts (immobilized lipases), once it is a promising route to obtain a variety of biolubricants based on recent studies described in available literature. Furthermore, future prospects and challenges for enzymatic biolubricant production on an industrial scale are also reviewed.

Combustion investigation of ternary blend mixture of biodiesel/n-butanol/diesel: CI engine performance and emission control

Abstract: This study aims to analyze the effects of a novel ternary blend of n-butanol and castor oil methyl ester (COME) with petro-diesel on combustion, engine performance and emission characteristics of four stroke single cylinder diesel engine and to obtain optimum blending proportion which can simultaneously reduce UHC, CO, and NOx without affecting engine performance. A quick and simple approach involving a single zone combustion model coupled with double and triple Wiebe functions has been successfully applied to analyze combustion behavior of binary and ternary fuel blends respectively. Neat diesel was used as a baseline fuel to compare combustion, performance and emission characteristics with binary and ternary fuel blends (B30, B20Bu10, B10Bu20 and B15Bu15). Apparent heat release rate (AHRR) calculated from the model is in good agreement (RMSE ≤ 1.33) with experimental values. Peak AHRR values (J/°CA) for fuel blends B30, B20Bu10, B15Bu15, B10Bu20 and neat diesel were found to be 26.1, 29.4, 32.7, 37.1, and 36.1 respectively. The ignition delay period was not affected for B30 blend however it was observed to be increased by 2.89–3.35°CA for n-butanol blended fuels. Results of B30 fuel blend showed reduction in BTE by 1–3% with increase in greenhouse gas emissions. The results of ternary fuel blend (B15Bu15) showed improvement in engine performance characteristics whereas NOx emission was reduced in the range of 20–60% compared to B30. Detrimental effect on engine performance, emission characteristics and combustion behavior was observed for B10Bu20. Therefore, B15Bu15 was considered as an optimum fuel blend.

A comprehensive review of the selection of natural and synthetic antioxidants to enhance the oxidative stability of biodiesel

Abstract: Achievement of sustainable development goals emphasizes alternative fuel strategies posing biodiesel production from plant and animal matter stressing long-chain fatty acid esters. Biodiesel production from renewable energy sources are largely preferred owing to its environment friendly and cost effective economic benefits. Nevertheless several limitations hurdle the efficiency of harnessing the maximal usage render the complexities to be rectified for advancing efficacy of biodiesel. Major issue posing severe hazard can be attributed to the ageing process namely oxidation that positively influence the engine performance and negatively alters storage capabilities. Chemical reactions after iterative chain modifications result in free radicals accumulation ameliorating ease of use in biodiesel. Hence, oxidative stability remains the prominent mechanism for enhancing the compatibility of biodiesel employing suitable antioxidants either natural or synthetic for optimally arresting the chain reactions thereby abating culmination of free radicals. The aim of this review was to analyze and compare the crucial role of natural and synthetic antioxidants in preventing the ageing process of biodiesel. Comparative analysis of the antioxidants that significantly escalates oxidative stability of biodiesel over the last two decades are assessed along with the strategic methodology are scrutinized for apprehending biodiesel stability subsequently based on oxidative stability.