Journal of Mechanical Science and Technology 32 (6) (2018) 2947~2957 www.springerlink.com/content/1738-494x(Print)/1976-3824(Online) DOI 10.1007/s12206-018-0551-8 Performance, emission and combustion characteristics of CI dual fuel engine powered by diesel/ethanol and diesel/gasoline fuels † Arkadiusz Jamrozik * , Wojciech Tutak, Michał Gruca and Michał Pyrc Institute of Thermal Machinery, Czestochowa University of Technology, 42-201 Czestochowa, Armii Krajowej 21 Av., Poland (Manuscript Received December 4, 2017; Revised February 15, 2018; Accepted March 13, 2018) ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Abstract The effects of gasoline/diesel and ethanol/diesel on combustion, fuel economies and exhaust emissions of dual fuel direct injection die- sel engine were experimentally investigated. Tests were carried out based on a direct injection engine at a constant engine speed of 1500 rpm and full load. The results showed that with the fraction of gasoline and ethanol increasing, ignition delay was noticed. Operating parameters of dual fuel engine powered with gasoline were at the same level as for engine powered by pure diesel fuel. In case of power- ing by ethanol the values of thermal efficiency and indicated mean effective pressure increased (about 13 %) with increase of ethanol fraction up to 55 %. For maximal analyzed gasoline fraction specific NO x (nitrogen oxide) emission increased by 2.7 times, but for etha- nol the increase was lower and it was by 2.5-times compared to reference values obtained for an engine powered by pure diesel fuel. Regarding THC (total hydrocarbons) emission up to 45 % of ethanol or gasoline energetic fraction no significant increase in specific THC emissions was noted. With the increase in ethanol and gasoline fraction in combustion process causes lower CO (carbon monoxide) emission. It turns out that it is possible to co-combustion of gasoline in a compression-ignition internal combustion engine. Keywords: Dual fuel; Combustion; Ethanol; Gasoline; Ignition delay ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 1. Introduction Compression ignition engines are responsible for consump- tion of large quantities of global fossil fuels and additionally for large harmful emissions. Despite this, these engines are still used in various applications due to their high fuel- efficiency and reliability. Thus, many researches are seeking renewable and clean alternative fuels [1-3]. In recent years works on novel combustion modes have been conducted that can be used in diesel engines [4]. Now, the researches are carried out towards fuel economy (low CO 2 emission) and reducing harmful emission [5, 6]. The main problem is the reduction of NO x and soot emissions. In compression ignition engines the conditions which are conducive to reducing NO x emissions favor soot emissions and vice versa. Low tempera- ture combustion concepts are a focus of study nowadays as a method to avoid the NO x -soot trade-off existing with conven- tional diesel combustion. One most promising strategy is known as reactivity controlled compression ignition because of its high thermal efficiency and the ultra-low nitrogen oxides and soot emissions [7, 8]. In practice, there are two ways of co-combustion of alternative fuel and diesel fuel. The first way is to produce a blend of diesel with alternative fuel and then bring the mixture of fuels to the engine, using a typical supply system for a compression ignition engine. Other mode is injection of the alternative fuel into the intake manifold of IC (internal combustion) engine and then ignition of near to homogeneous air-fuel mixture by injection dose of diesel fuel. This mode requires the addition of an injector, along with a separate fuel tank, lines and controls. The biggest advantage of this solution is the flexibility of the power system because the engine can switch from dual fuel to diesel fuel operation. The diesel engine can operate with diesel fuel only [9]. Ethanol fuel is one of the most common alternative fuels co-combusted with diesel or biodiesel fuel [10, 11]. Ethanol can be produced from any plant which contains sugar or other components which can be converted into sugar, such as starch or cellulose in the fermentation, distillation and dehydration process [12]. Ethanol is less toxic than gasoline and methanol, and is not carcinogenic. Bioethanol can be derived from a wide range of carbohydrates of general formula (CH 2 O) n . It is used as a blend or using dual fuel technology. Many investiga- tions have studied the influence of blending various oxygen- ates additives with diesel or biodiesel fuel on engine perform- ance and emission characteristics of compression ignition engine. The most investigated, in recent years, oxygenates are alcohols such as ethanol [13-15]. On the basis of these papers * Corresponding author. Tel.: +48 343250543, Fax.: +48 343250555 E-mail address: jamrozik@imc.pcz.czest.pl † Recommended by Associate Editor Jeong Park © KSME & Springer 2018