Effect of synthetic antioxidants on storage stability of calophyllum inophyllum biodiesel

Biofuels, especially biodiesels derived from renewable sources, are becoming increasingly important because of environmental and energy concerns. However, biodiesels composed of long chain unsaturated fatty acid esters are prone to oxidation. One such biodiesel is non-edible high acid value Calophyllum inophyllum oil-based biodiesel produced through a two-stage esterification process and one-stage transesterification process. In this study, the oxidation stability of biodiesel treated with three prominent antioxidants, namely pyrogallol, propyl gallate and tert-butylhydroxyquinone was evaluated. The induction period of biodiesel with or without antioxidant was measured according to the EN14112 standard using a Rancimat instrument. Antioxidants were added at 500 ppm, which in general improved the induction period. The samples were kept for 70 days and different properties that change during storage, namely induction period, density and kinematic viscosity were monitored. For all samples, oxidation stability decreased and kinematic viscosity increased because of the formation of oxidation products. Pyrogallol showed the best effect in retaining oxidation stability of Calophyllum inophyllum biodiesel

Current state and perspectives on transesterification of triglycerides for biodiesel production

Triglycerides are the main constituents of lipids, which are the fatty acids of glycerol. Natural organic triglycerides (viz. virgin vegetable oils, recycled cooking oils, and animal fats) are the main sources for biodiesel production. Biodiesel (mono alkyl esters) is the most attractive alternative fuel to diesel, with numerous environmental advantages over petroleum-based fuel. The most practicable method for converting triglycerides to biodiesel with viscosities comparable to diesel fuel is transesterification. Previous research has proven that biodiesel–diesel blends can operate the compression ignition engine without the need for significant modifications. However, the commercialization of biodiesel is still limited due to the high cost of production. In this sense, the transesterification route is a crucial factor in determining the total cost of biodiesel production. Homogenous base-catalyzed transesterification, industrially, is the conventional method to produce biodiesel. However, this method suffers from limitations both environmentally and economically. Although there are review articles on transesterification, most of them focus on a specific type of transesterification process and hence do not provide a comprehensive picture. This paper reviews the latest progress in research on all facets of transesterification technology from reports published by highly-rated scientific journals in the last two decades. The review focuses on the suggested modifications to the conventional method and the most promising innovative technologies. The potentiality of each technology to produce biodiesel from low-quality feedstock is also discussed

Study on stability, fuel properties, engine combustion, performance and emission characteristics of biofuel emulsion

This study reviewed papers related to biofuel emulsion, principally assessing the use of biofuel emulsion. The discussion is focused mainly on three active areas of emulsified biofuel, namely, exploration of various factors affecting the preparation of stable emulsion and its fuel properties, investigation of the effect of water concentration on physicochemical properties of fuel, and observation of the improvement and degradation of combustion, performance, and emission characteristics and the possible methods to enhance these characteristics. (c) 2015 Elsevier Ltd. All rights reserved

Effect of antioxidant on the oxidation stability and combustion-performance-emission characteristics of a diesel engine fueled with diesel-biodiesel blend

Alexandrian laurel or Calophyllum inophyllum oil is recently considered one of the most anticipated nonconsumable or nonedible biodiesel sources. An attempt has been made in this study to increase the oxidation stability and investigate the engine performance, emission, and combustion characteristics of a diesel engine by adding 1% (by vol.) of two antioxidants, such as 2,6-Di-tert.-butyl-4-methylphenol and 2,2'-methylenebis (4-methyl-6-tert-butylphenol), in higher percentages of C. inophyllum biodiesel (CB30) with diesel fuel (B0). The experiment was performed on a single-cylinder, water-cooled, direct-injection diesel engine for this purpose. The addition of both antioxidants increased the oxidation stability without significantly changing other physicochemical properties. Results also show that the antioxidants enhanced the start of combustion of biodiesel, which resulted in a short ignition delay. The peak pressure and the peak heat release rate during premixed combustion phase of pure CB30 and its modified blend with antioxidant were higher than those of B0. Both antioxidant blends showed higher brake power, higher brake thermal efficiency, and lower brake specific fuel consumption than pure CB30. Both antioxidants significantly reduced NOX emission; however, CO, HC, and smoke opacity were slightly higher than those of CB30. Based on this study, Alexandrian laurel or C inophyllum biodiesel blend (CB30) with antioxidant can be used as an alternative fuel in a diesel engine without modifications. (C) 2015 Elsevier Ltd. All rights reserved

Response surface methodology approach for optimization of biosorption process for removal of Hg(II) ions by immobilized Algal biomass Coelastrella sp.

Currently, adsorption stands as a viable technique for the effective removal of pollutants such as heavy metals from water. Within this research endeavor, adapted green algae (Coelastrella sp.) have been harnessed as a sustainable and environmentally conscious adsorbent, employed in the removal of Hg(II) ions from a simulated aqueous solution via employment of an Airlift bioreactor. The analysis of the attributes of adsorbent was conducted through the utilization of Fourier transform infrared (FTIR) spectroscopy. The examination of residual concentrations of Hg(II) ions in the treated solution was accomplished through the utilization of atomic absorption spectroscopy (AAS). The impact of various experimental factors, including the duration of contact (ranging from 10 to 90 minutes), initial concentrations of Hg(II) ions (ranging from 500 to 2000 μg/l), quantity of adsorbent introduced (ranging from 0.1 to 0.7 g per 250 ml), temperature variations (ranging from 20 to 40 °C), and airflow velocity (ranging from 200 to 300 ml/min), was systematically examined. For the optimization of adsorption efficiency, MINITAB 18 software was employed. The equilibrium data was subjected to analysis using the Langmuir, Freundlich, and Temkin isotherm models. Employing the framework recommended by MINITAB 18, the optimal parameters for adsorption were identified as 2000 μg/l for initial concentration, 90 minutes for contact time, 40 °C for temperature, and 300 ml/min for airflow rate. The Langmuir equation yielded the highest adsorption capacity, measuring 750 μg/g at a temperature of 40 °C

Effects of flame-plane wall impingement on diesel combustion and soot processes

This work aims to assess the effects of flame-wall impingement on the combustion and soot processes of diesel flames. For this work, experimental measurements were performed in a constant-volume combustion chamber (CVCC) at ambient conditions that are representative of compression-ignition engines. The characteristics of impinging and free flames were compared at two identical ambient and injector conditions (20.8 kg/m³ ambient density, 6 MPa ambient pressure, 1000 K bulk temperature, 15 and 10 vol% ambient O₂ concentration, and 100 MPa injection pressure). To simulate flame-wall impingement, a flat plane steel wall, normal to the injector axis, was initially placed at 53 mm from nozzle, but was varied from 53 to 35 mm during the experiments. Under the test conditions of this work, it was found that wall impingement resulted in lower soot temperature and soot content, in addition to a loss of momentum for the wall jet. The results also revealed that decreasing impingement distance from the nozzle resulted in reduced soot temperature and soot level for the wall jet. The reduced soot content observed for the wall jet appeared to be mainly driven by enhanced mixing. Flame transparency modeling was also performed to assess the uncertainties of two-color measurements for flame-plane wall impingement. The analysis indicated that the derived soot temperature and concentration values would be affected by the actual temperature profiles, rendering the technique useful to reveal trends, but not reliable for absolute soot concentration measurements.I.M. Rizwanul Fattah, Ho L. Yip, Zhiyuan Jiang, Anthony C.Y. Yuen, Wei Yang, Paul R. Medwell, Sanghoon Kook, Guan H. Yeoh, Qing N. Cha

Emission and performance improvement analysis of biodiesel-diesel blends with additives

Abstract This experimental investigation evaluates the comparative improvement of palm biodiesel-diesel blend (20 palm biodiesel-80 diesel) with the help of ethanol, n-butanol and diethyl ether as additives regarding emission and performance characteristics. The improved blends consisted 80 diesel, 15 palm biodiesel and 5 additive. Use of additives prominently improved brake power, decreased {BSFC} (brake specific fuel consumption) and increased {BTE} (brake thermal efficiency). Diethyl ether showed highest 6.25 increment of brake power, 3.28 decrement of {BSFC} and about 4 increment of {BTE} than 20 palm biodiesel-diesel blend when used as additive. Other two additives also showed interesting improvement regarding performance. All the blends with additives showed decreased {NO} and {CO} emission but {HC} emission showeda slight increment. However, this experiment reveals comparative suitability of these three additives on improving biodiesel-diesel blend