Potential of fat, oil and grease (FOG) for biodiesel production: A critical review on the recent progress and future perspectives

Abstract Biofuels are the promising alternative to exhaustible, environmentally unsafe fossil fuels. Algal biomass is attractive raw for biofuel production. Its cultivation does not compete for cropland with agricultural growing of food crop for biofuel and does not require complex treatment methods in comparison with lignocellulose-enriched biomass. Many microalgae are mixotrophs, so they can be used as energy source and as sewage purifier simultaneously. One of the main steps for algal biofuel fabrication is the cultivation of biomass. Photobioreactors and open-air systems are used for this purpose. The formers allow the careful cultivation control, but the latter ones are cheaper and simpler. Biomass conversion processes may be divided to the thermochemical, chemical, biochemical methods and direct combustion. For biodiesel production, triglyceride-enriched biomass undergoes transetherification. For bioalcohol production, biomass is subjected to fermentation. There are three methods of biohydrogen production in the microalgal cells: direct biophotolysis, indirect biophotolysis, fermentation.

Review: Biofuel production from plant and algal biomass

Selection Criteria and Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Advanced Spark-Ignition Engines

\n Vegetable oils have been used as a feedstock for fatty acid methyl ester (FAME) production. The high cost of neat vegetable oil and its impact on food security have necessitated its replacement as a feedstock for FAME by used vegetable oil, also known as waste cooking oil (WCO). This study compares the properties and fatty acid (FA) compositions of samples of neat vegetable oil with those of samples of WCO, collected from restaurants and takeaway outlets at the point of disposal. The samples were subjected to property determination and pyrolysis gas chromatography mass spectrometer (PYGCMS) analysis. Analysis showed that degree of usage and the type of food items originally fried in the oil substantially affected its properties and FA composition. Density of neat vegetable oil varied between 904.3 and 919.7 kg/m3 and of WCO between 904.3 and 923.2 kg/m3. The pH of neat vegetable oil varied between 7.38 and 8.63 and of WCO between 5.13 and 6.61. The PYGCMS analysis showed that neat palm oil contains 87.7% unsaturated FA and 12.3% saturated FA, whereas neat sunfoil contains 74.37% saturated FA and 25% polyunsaturated FA. Generally, neat vegetable oils consisted mainly of saturated FAs and polyunsaturated FAs, whereas the WCO contained mainly of saturated FAs and monounsaturated FAs. This research confirms the suitability of WCO as feedstock for FAME.

Comparative study of properties and fatty acid composition of some neat vegetable oils and waste cooking oils

Recently, the interest in converting waste cooking oils (WCOs) to raw materials has grown exponentially. The driving force of such a trend is mainly represented by the increasing number of WCO applications, combined with the definition, in many countries, of new regulations on waste management. From an industrial perspective, the simple chemical composition of WCOs make them suitable as valuable chemical building blocks, in fuel, materials, and lubricant productions. The sustainability of such applications is sprightly related to proper recycling procedures. In this context, the development of new recycling processes, as well as the optimization of the existing ones, represents a priority for applied chemistry, chemical engineering, and material science. With the aim of providing useful updates to the scientific community involved in vegetable oil processing, the current available technologies for WCO recycling are herein reported, described, and discussed. In detail, two main types of WCO treatments will be considered: chemical transformations, to exploit the chemical functional groups present in the waste for the synthesis of added value products, and physical treatments as extraction, filtration, and distillation procedures. The first part, regarding chemical synthesis, will be connected mostly to the production of fuels. The second part, concerning physical treatments, will focus on bio-lubricant production. Moreover, during the description of filtering procedures, a special focus will be given to the development and applicability of new materials and technologies for WCO treatments.

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Available Technologies and Materials for Waste Cooking Oil Recycling

High cost of edible feedstocks, food vs fuel debate, threat of deforestation, environmental pollution, damage to wildlife habitat, etc has shifted the attention of researchers to the generation of biodiesel from waste or used frying oil. This paper reviews recent researches on the performance and emission characteristics of waste cooking oil methyl ester in an unmodified conventional compression ignition engine. The general consensus among most authors is that the use of waste cooking oil methyl ester was found to result in increased brake specific fuel consumption, brake thermal efficiency and higher exhaust gas temperature when compared with petroleum-based diesel fuel. Most authors reported that diesel engines fuelled with pure biodiesel emitted less carbon monoxide, carbon dioxide, particulate matter and unburnt hydrocarbon but higher nitrogen oxide compared with diesel fuel. The oxygenated nature and other fingerprints of the biodiesel were responsible for the outcomes of the tests. However most of the research were not carried out in substantial compliance with established performance regulations and emission protocols.

A review of the performance and emissions of compression ignition engine fuelled with waste cooking oil methyl ester

Biodiesel's renewability, universal accessibility and milder impact on the environment has positioned it as a potential fuel of choice for transport prime movers going forward. Biodiesel's unique fuel chemistry while conferring some advantage, has shown some mismatch between it and the current compression ignition (CI) combustion strategy. Computational as well as experimental research on biodiesel combustion are presently, in large part, geared toward resolving this mismatch. Numerical property prediction, as a more efficient and cost effective tool was implemented here to determine the thermo-physical and transport properties of biodiesel derived from moringa, jatropher and waste restaurant oil. Primary and secondary experimental data obtained in accordance with biodiesel standard ASTM D6751 were used to validate the scheme. The average relative deviation (ARD) for most key properties fell within acceptable limit (≤5%). Obtaining higher computational fidelity was observed to correlate with improved accuracy in determining the free fatty acid (FFA) composition of the different component and group contribution of the biodiesel mixture.

http://ieeexplore.ieee.org/iel7/7464594/7466693/07466718.pdf

A property prediction scheme for biodiesel derived from non-edible feedstock

Given the challenges of renewability, affordability, and sustainability that ultra-low sulfur diesel (ULSD) fuel and first-generation biodiesel currently face, a niche clearly exists for biodiesel sourced from waste cooking oil. Exploring these potentials requires insights into a range of properties as well as performance and emission characteristics. Real-time experimental determination of fatty acid methyl ester (FAME) properties, engine performance and emissions of compression ignition (CI) engines fuelled with unblended FAME is technical, time-consuming, expensive, and requires sophisticated laboratory infrastructure, unlike numerical prediction techniques. Emerging trends and consensus indicate that utilization of numerical simulation and prediction techniques are cost-effective, less laborious, innovative, and flexible. Although FAME properties, engine performance, and emissions have been accurately predicted via various numerical techniques in the recent past, important gaps such as using numerical approaches to determine the optimal FAME mix still exist. The objective of this study was to review the numerical techniques employed in predicting FAME properties, engine performance and emissions of CI engine and investigate whether an optimal FAME candidate can be unearthed through these numerical prediction techniques. This review reports that the outcomes of these numerical predictions agree with experimental data and fall within acceptable average relative deviation but a precise approach to determining an optimal FAME candidate was not achieved. The use of numerical tools like MATLAB and computational fluid dynamics (CFD) in amalgamation with some new measurement techniques including high-speed cameras to accurately predict FAME properties, engine performance, emission characteristics and gain access to the activities in the combustion chambers, were highlighted. These high capacity modeling tools, high-speed cameras, and techniques can be used to accurately forecast an optimal FAME mix to improve engine performance, meet emission benchmarks and advanced engine research, if well harmonized.

Prediction of Properties, Engine Performance and Emissions of Compression Ignition Engines Fuelled with Waste Cooking Oil Methyl Ester - A Review of Numerical Approaches

E. I. Onuh

Papers

A review of the performance and emissions of compression ignition engine fuelled with waste cooking oil methyl ester

A property prediction scheme for biodiesel derived from non-edible feedstock

Prediction of Properties, Engine Performance and Emissions of Compression Ignition Engines Fuelled with Waste Cooking Oil Methyl Ester - A Review of Numerical Approaches