High pressure physicochemical properties of biodiesel components used for spray characteristics in diesel injection systems

Heat capacities of fatty acid methyl esters from 300 K to 380 K and up to 4.25 MPa

“…Heat capacities of fatty acid alkyl esters are required for establishing enthalpy balances and the development of thermodynamic models for biodiesels [5,6]. To the best of our knowledge, there are only five sets experimental data for the heat capacities of fatty acid alkyl esters which have more than 8 carbon atoms in the fatty acid group: Deshpande et al [7] reported the heat capacity of methyl tetracaprate at 298 K; Van Bommel et al [8] reported the molar heat capacities of 13 fatty acid methyl esters from 5 K to 350 K; Zaitsau et al [9] reported the molar heat capacities of ethyl caprate from 5 K to 370 K; Pauly et al [10] reported the molar heat capacities of 7 saturated fatty acid methyl esters and 5 unsaturated fatty acid methyl esters from 250 K to 390 K; Dzida et al [11,12] reported the molar heat capacities of ethyl octanoate, ethyl caprate, ethyl laurate and ethyl tetracaprate from 285 K to 343 K. These experimental data are all measured at atmospheric pressure. For the isobaric heat capacities of methyl or ethyl esters of fatty acids at high pressure, no experimental data were reported, only Dzida et al [10,11,13] to 380 K and at pressures from 0.1 MPa to 4.25 MPa were measured with a flow calorimeter.…”

Function K - As a Link Between Fuel Flow Velocity and Fuel Pressure, Depending on the Type of Fuel

“…The author also determines the bulk modulus for pressures of up to 400 bar and provides a comparative overview of results obtained by simulation. Dzida et al [24,25] measure the speed of sound at temperatures of 293-318 K and pressures from 1 to 1010 bar, the density at the atmospheric pressure, and calculate it at pressures of up to 1010 bar. Payri et al [26] experimentally determine the speed of sound at pressures from 150 to 1800 bar and temperatures from 298 to 343 K. Two pressure sensors are placed in a 12 m long "high pressure tube" (with the internal diameter of 2.5 mm) at the distance of 8.22 m from each other.…”

“…Measuring at the atmospheric pressure and temperatures from 293 to 343 K, Freitas et al [27] determine the speed of sound for different fuels and use the data to calculate and predict the acoustic characteristics of other biodiesel fuels [28]. Daridon et al [29] present the data for several different fuels where the speed of sound is measured at the atmospheric pressure and the range of temperatures from 283 to 373 K. For the same pressures and with the approach used in [24,25], Ţarska et al [30] determine the speed of sound for the biodiesel produced from coconut and palm oil. Lopes et al [31] vary the fuel temperature from 298 to 353 K at the atmospheric pressure and determine the fuel speed of sound by measurement, with a presentation of data from the literature on the experimental values of the speed of sound for biodiesels of different origin (and some other alternative fuels).…”

Avaliação físico-química dos óleos de babaçu (Orbignya speciosa) e coco (Cocos nucifera) com elevado índice de acidez e dos ácidos graxos (C6 a C16)

“…Dentre as diversas fontes renováveis de biomassa utilizados na indústria, principalmente no setor alimentício, destacam-se as palmeiras, babaçu (Orbinya speciosa) e coqueiro (Cocos nucifera) [1]. Estas frutífeiras, em modo geral, possuem óleos de composições químicas bastante semelhantes, como é o caso da amêndoa de babaçu e a polpa do coco que são compostas por mais de 60% de óleo, predominantemente de ácidos graxos de cadeia carbônicas intermediárias (C6 a C16), dentre os quais 40 a 55% é de ácido láurico, que corresponde a 12 átomos de carbono na sua constituição [2,3]. Este ácido, ao contrario de outros ácidos, possui apenas ligações simples entre carbonos [4].…”