Effects of palm biodiesel and blends of biodiesel with organic acids on metals

Modeling localized corrosion in biofuel storage tanks

This work aims to model the influence of biofuels on localized "pitting" corrosion that occurs at the bottom of atmospheric storage tanks. To achieve this purpose, an electro-chemical phase-field model is proposed to include the extra chemical reaction due to the presence of organic acids in an electrolyte solution. The resulting set of nonlinear coupled partial differential equations is numerically integrated by means of finite element methods with a twofold aim: tracking the evolution of the metal/electrolyte interface and predicting the corrosion rates observed when either single or multiple interacting pits are formed in the bottom of a carbon steel tank. The results obtained in the case of single pit, which exhibited a good quantitative agreement with recent experimental data, can be summarized as follows: the presence of organic acids led to higher corrosion rates in comparison with conventional fuels; the corrosion rate is a two-stage process; the dependence of the pit depth as a function of time; and the solid potential, which can be successfully described via a double power law. For multiple interacting pits, the larger corrosivity associated to biofuels was further amplified and the long-time behavior of pit growth gave rise to a "band" behavior, with the major role being played by the number of pits rather than the initial spacings among them. Thus, the proposed model can be employed as a sophisticated tool to predict and quantify the real hazards associated with the release of pollutants in the environment, as well as to optimize the maintenance strategies based on an improved risk-based inspection planning.

Applications Characteristics of Different Biodiesel Blends in Modern Vehicles Engines: A Review

Two main aspects of the transportation industry are pollution to the environment and depletion of fossil fuels. In the transportation industry, the pollution to the environment can be reduced with the use of cleaner fuel, such as gas-to-liquid fuel, to reduce the exhaust emissions from engines. However, the depletion of fossil fuels is still significant. Biodiesel is a non-toxic, renewable, and biodegradable fuel that is considered an alternative resource to conventional diesel fuel. Even though biodiesel shows advantages as a renewable source, there are still minor drawbacks while operating in diesel engines. Modern vehicle engines are designed to be powered by conventional diesel fuel or gasoline fuel. In this review, the performance, emissions, combustion, and endurance characteristics of different types of diesel engines with various conditions are assessed with biodiesel and blended fuel as well as the effect of biodiesel on the diesel engines. The results show that biodiesel and blended fuel had fewer emissions of CO, HC, and PM but higher NOx emissions than the diesel-fuelled engine. In the endurance test, biodiesel and blended fuel showed less wear and carbon deposits. A high concentration of wear debris was found inside the lubricating oil while the engine operated with biodiesel and blends. The performance, emissions, and combustion characteristics of biodiesel and its blends showed that it can be used in a diesel engine. However, further research on long-term endurance tests is required to obtain a better understanding of endurance characteristics about engine wear of the diesel engine using biodiesel and its blends.

Improving the sustainability of biodiesel by using imidazolium-based ionic liquid

Corrosion of biodiesel-filled fuel tanks has become a major problem in the use of biodiesel as a new green energy source. The ionic liquid 1-Hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ was used to control corrosion of C-steel in non-edible biodiesel to resolve this problem. The anti-corrosion and antioxidant properties of the [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ were characterized using weight loss, electrochemical impedance spectroscopy, total acid number measurements beside SEM and EDX analysis. The findings show that [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ plays an important role in preventing C-steel corrosion in biodiesel with an efficiency close to 99 percent. The adsorption capability and antioxidant properties of [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ are the major contributors to the ionic liquid's anti-corrosion properties. We anticipate that this work will help to sustainable expand the use of biodiesel as a renewable energy source.

Catalyst and Elemental Analysis Involving Biodiesel from Various Feedstocks

The world is currently faced with the depletion of fossil fuel energy sources and their use is associated with environmental pollution. This has triggered the need to seek alternative energy sources that are renewable, sustainable and environmentally benign. Biodiesel, an alternative fuel of interest, is obtainable from biomass feedstocks. In existing biodiesel fuel, there are concerns that it is a contaminant due to its elemental contents, which over time also affect its quality. This study aimed to investigate the influence of a bifunctional catalyst on the conversion of free fatty acids and the elemental composition of biodiesel obtained from waste oils of sunflower and palm feedstocks. The synthesised catalyst was characterised using BET, XRD, FTIR and SEM while ICP-OES and Rancimat were used for elemental contents and oxidation in feedstocks and biodiesels. The effect of Cu, Zn and Fe metals on the stability of synthesised biodiesel was further studied. The catalyst showed characteristics of bifunctionality with improved textural properties necessary for the conversion of high free fatty acids feedstocks to biodiesel, despite increasing Ca content within the produced biodiesel. Sunflower biodiesel showed superior fuel quality, although palm biodiesel had more oxidation stability. An increase in the concentration of metals decreased the induction period, with Cu and Fe being more effective than Zn metal.

A Study on the Corrosion Characteristics of Internal Combustion Engine Materials in Second-Generation Jatropha Curcas Biodiesel

The corrosiveness of biodiesel affects the fuel processing infrastructure and different parts of an internal combustion (IC) engine. The present study investigates the corrosion behaviour of automotive materials such as stainless steel, aluminium, cast iron, and copper in 20% (B20) and 30% (B30) by volume second-generation Jatropha biodiesel using an immersion test. The results were compared with petro-diesel (B0). Various fuel properties such as the viscosity, density, water content, total acid number (TAN), and oxidation stability were investigated after the immersion test using ASTM D341, ASTM D975, ASTM D445, and ASTM D6751 standards. The morphology of the corroded materials was investigated using optical microscopy and scanning electron microscopy SEM), whereas the elemental analysis was carried out using energy-dispersive X-ray spectroscopy (EDS). The highest corrosion using biodiesel was detected in copper, while the lowest was detected in stainless steel. Using B20, the rate of corrosion in copper and stainless steel was 17% and 14% higher than when using diesel, which further increased to 206% and 86% using B30. After the immersion test, the viscosity, water content, and TAN of biodiesel were increased markedly compared to petro-diesel.