Acetone Prospect as an Additive to Allow the Use of Castor and Sunflower Oils as Drop-In Biofuels in Diesel/Acetone/Vegetable Oil Triple Blends for Application in Diesel Engines

Abstract

The present paper investigates the feasibility of using acetone (ACE) in triple blends with fossil diesel (D) and straight vegetable oils (SVOs) as alternative fuel for diesel engines. In this respect, ACE is selected as an oxygenated additivedue to its favorable propertiesto be mixed with vegetable oils and fossil diesel. In fact, the very low kinematic viscosity allows reduces the high viscosity of SVOs. ACE’s oxygen content, low autoignition temperature, and very low cloud point and pour point values highlight its possibilities as an additive in D/ACE/SVO triple blends. Moreover, ACE can be produced through a renewable biotechnological process, an acetone–butanol–ethanol (ABE) fermentation from cellulosic biomass. The SVOs tested were castor oil (CO), which is not suitable for human consumption, and sunflower oil (SO), used as a standard reference for waste cooking oil. The viscosity measurement of the ACE/SVO double blend was considered crucial to choose the optimum proportion, which better fulfilled the specifications established by European standard EN 590. Moreover, some of the most significant physicochemical properties of D/ACE/SVO triple blends, such as kinematic viscosity, cloud point, pour point, and calorific value, were determined to assess their suitability as fuels. The blends were evaluated in a conventional diesel generator through the study of the following parameters: engine power, smoke emissions, and fuel consumption. Despite the low calorific value of ACE limits its ratio in the mixtures due to engine knocking problems, the experimental results reveal an excellent performance for the blends containing up to 16-18% of ACE and 22-24% of SVO. These blends produce similar engine power as to fossil diesel, but with slightly higher fuel consumption. Considerable reductions in emissions of air pollutants, as well as excellent cold flow properties are also obtained with these triple blends. In summary, the use of these biofuels could achieve a substitution of fossil diesel up to 40%, independently on the SVO employed.

Evaluation of Dimethyl Carbonate as Alternative Biofuel. Performance and Smoke Emissions of a Diesel Engine Fueled with Diesel/Dimethyl Carbonate/Straight Vegetable Oil Triple Blends

“…where C is the constant of the calibrated viscometer, provided by the manufacturer (0.037150 (mm 2 /s)/s at 40 • C) and t is the flow time, i.e., the time (seconds) that a known volume of liquid takes to pass, under action of gravity, between two marks indicated on an instrument [18][19][20][21]. The maximum absolute error in the viscosity measurements is 1.1% and that in the density measurements is 0.7%.…”

“…The flow properties at low temperatures were measured following the same procedure as described in previous works [18,19]. EN 23015/ASTM D2500 and ISO 3016/ASTM D97 were the standard methods followed for cloud point (CP) and pour point (PP), respectively.…”

“…A study of power output, brake-specific fuel consumption and smoke emissions was carried out in a diesel engine-electrogenerator set fueled with the proposed fuel blends, in order to analyze their efficiency. An experimental methodology that has been previously reported was followed [18][19][20][21] and the technical specifications of the employed engine are collected in Table 2. Likewise, the experimental methodology is illustrated in Figure 1.…”

“…Generally, the use of oxygen-rich compounds as viscosity improvers allows to a better combustion process and reduced emissions. In this sense, light vegetable oils (orange, camphor, eucalyptus and pine oil) [10][11][12][13] and lower (methanol and ethanol) [14][15][16] and higher alcohols (1-propanol, 2-propanol, isobutanol, 1-butanol, 2-butanol and 1-pentanol) [16,17], as well as other renewable oxygenated compounds (diethyl ether, acetone, ethyl acetate, diethyl carbonate and so on) [18][19][20][21] have recently been described as viscosity reducers of SVOs. Overall, the exhaust emissions were significantly reduced with the use of these blends, resulting in a similar or slightly lower engine performance than that exhibited by conventional diesel.…”

Outlook for Direct Use of Sunflower and Castor Oils as Biofuels in Compression Ignition Diesel Engines, Being Part of Diesel/Ethyl Acetate/Straight Vegetable Oil Triple Blends

“…In addition to gasoline, diethyl ether (DEE) [16] and acetone (ACE) [17] have been employed as effective LVS of CO and SO, in triple blends with diesel. Both additives can be obtained from ethanol which, in turn, can be obtained from biomass, making the process more sustainable.…”