Experimental study on influence of dominant fatty acid esters in engine characteristics of waste beef tallow biodiesel

Abstract

Biodiesel is regarded as the most promising renewable biofuel which can satisfy the worldwide energy demand through its robust net energy output with less impact on environment and also an effective alternative or supplement for existing diesel fuel for powering Compression Ignition engines. This present study aims to compare the performance, combustion and emission characteristics of beef tallow biodiesel with its dominant fatty acid esters and their influence on these characteristics. Ethyl stearate, ethyl palmitate and ethyl oleate were identified as dominant fatty acid esters available in a composition of 14.78, 37.36 and 25.17%, respectively. Two set of samples were prepared for testing purpose and were classified as (i) blend samples and (ii) ester samples, with plain diesel as base fuel. The maximum cylinder pressure was found to be in the range between 67 and 71 bar for all the samples and heat release rate was found to be highest for B20 blend. Slight decrease in efficiency along with marginal increase in fuel consumption was a result of long chained fatty acid esters (stearate and oleate esters) whereas increase in CO 2 emission and decrease in NO X emission were because of higher oxygen content, cetane number and degree of unsaturation in the ester molecule.

Effect of Dominant Fatty Acid Esters on Emission Characteristics of Waste Animal Fat Biodiesel in CI Engine

“…For emission characteristics study, a set of test samples namely: Biodiesel Blend, Oleate Blend, palmitate blends, and stearate blend, were prepared by blending waste fat biodiesel, ethyl oleate, ethyl palmitate, ethyl stearate with plain diesel, which was also taken as reference blend. The volume of ester/biodiesel sample for preparing the necessary blend was calculated using Equation 1 (Srinivasan et al, 2019):…”

“…The emission levels were determined based on undiluted measurement by passing the engine exhaust gas inside the flue gas analyser directly from exhaust manifold, where IR sensors sensed the concentration of oxides of carbon, nitrogen and Hydrocarbon emissions in it as electrical signals and were manipulated into numerical data using suitable software. Table 3 outlines the technical specifications of Kirloskar Engine TV1 and AVL DI GAS 444 N (five gas analyser) (Srinivasan et al, 2019). Figure 2 portrays the schematic diagram of test engine setup.…”

“…Based on availability of characterized fatty acid esters, the numbers of carbon, hydrogen and oxygen molecules were calculated and molecular formula of waste fat biodiesel was formulated as C 19 H 37 O 2 . Following that, Stoichiometric airfuel ratio was calculated from the quantity of air, N AIR (in terms of mols), required for completely combusting of one mol of biodiesel, determined using Equation (3) (Srinivasan et al, 2019), derived from balanced equation Equation 2of Carbon, hydrogen and oxygen molecules available in the fuel (Sarkar, 1974):…”

“…Similarly, Srinivasan et al (2019) studied the role of fatty acid esters in influencing the engine characteristics of waste beef tallow biodiesel. Based on characterization, ethyl oleate, ethyl palmitate, and ethyl stearate were characterized as the dominant fatty acid ethyl esters and played a significant role in deciding the engine characteristics of biodiesel.…”

Molecular Study on Dominant Fatty Acid Esters Characterized from Waste Beef Tallow Biodiesel – A Quantum Computational Approach

“…Numerous studies on biodiesel related to its: theoretical and experimental optimization of reaction and its parameters [8], mathematical modeling of reaction and reactors [9], thermalphysicochemical properties [10], comprehensive engine characteristics study [11], unconventional applications like biodegradation of crude oil [12] have been carried out to understand its viability as successful replacement for diesel fuel in terms of global scale commercialization. Interestingly, the fatty acid esters present in the biodiesel imparts a significant role in deciding its overall thermal & physicochemical properties [13] and engine characteristics [14]. Hence, understanding its molecular and quantum properties would help the researchers to understand its subatomic behavior which holds key for mathematical modeling of its reaction kinetics and combustion chemistry; and this can be achieved by carrying out quantum computational study on biodiesel molecules.…”