Combustion, performance and emissions characteristics of a biogas fuelled diesel engine with fish biodiesel as pilot fuel

Abstract

Environmental concerns and reduction in the availability of petroleum fuels have driven interest in the search for alternative fuels for IC engines. In order to overcome the problems associated with the use of petroleum based diesel fuels, a renewable and eco-friendly biofuel can be used for partial replacement of diesel fuels. Hence in this work, feasibility of using fish oil biodiesel was investigated. The important fuel properties were evaluated. Experimental tests were carried out to evaluate the performance, emissions and combustion characteristics. A single cylinder 10 HP, constant speed, water cooled diesel engine was used for experimentation with B20 fish diesel as fuel. This study expanded to achieve diesel equivalent performance from diesel engines with maximum replacement of diesel with renewable fuels. In this context the study analysed the influence of B20 fish biodiesel as a pilot fuel in a biodiesel biogas dual fuel engine. The results of dualfuel mode operation study are compared to those for B20 diesel operation at identical engine settings. Further for baseline comparison, the results of biodiesel and dual fuel mode of operation are compared to those of standard diesel run. Experiments were performed at various load conditions from 0 to 100% of maximum load at a constant speed of 1500 rpm. In general, B20 fish biodiesel is compatible with diesel in terms of performance and combustion characteristics. The exhaust emissions like CO and HC were significantly less, and NO x is slightly higher, than diesel fuel at all engine load conditions. Dual fuel mode of operations shows lower thermal efficiency and higher fuel consumption for other fuel mode of test run at all ranges of engine loads. Significantly lower in NO x and smoke capacity and HC, CO concentrations were considerably higher for dual fuel mode as compared to other fuels. In dual fuel mode, peak pressure and heat release rate were slightly higher compared to diesel and biodiesel mode of operation for all engine loads.

Investigations into the Combined Effect of Mahua Biodiesel Blends and Biogas in a Dual Fuel Engine

“…For B20, thermal efficiency escalated by 2.96% at 20 N-m load, in contrast with pure diesel. Ramesha et al [22] provided a justification stating the attributed quality of biodiesel having rich oxygen content and a truncated ignition delay leading to more thermal energy production during combustion. Figure 2b,c tend to analyse the alterations in BTE, by entrainment of methane and biogas, respectively, both at 0 lpm, 8 lpm and 12 lpm flow rates.…”

“…Oxygen available in biodiesel also helps provoke better combustion. As seen from Figure 5b,c, it is deduced that the introduction of methane and biogas with biodiesel (B20) as pilot fuel in the dual fuel mode shows a sharp rise in HC emissions due to less air inducted and inefficient combustion resulting in rich mixture formation [22]. Another reason might be the high heat of vaporization leading to flame quenching [25].…”

“…In the dual fuel condition portrayed in Figure 6b,c, the induction of methane and biogas releases obnoxious amounts of CO, with methane induction showing dominant behaviour with the maximum value reaching up to 0.378% at 12 lpm. CO emissions spiked due to increased induction of methane and biogas diminishing the oxygen content in the cylinder [22]. Biogas is considered convenient in dual fuel with the maximum value of CO, reaching only up to 0.193%.…”

“…Ramesha et al [22] reported the combustion, performance and emission characteristics of a biogas fuelled CI engine using fish oil as pilot fuel. Brake thermal efficiency of dual fuel engine was found to be very low due to higher fuel consumption and low combustion temperature.…”

Experimental Study of Gas Flow and Combustion in Biogas Generators

“…A premixed laminar flame is the basis of the premixed turbulent combustion model, which provides a detailed chemical reaction that occurs during combustion research dynamics [16][17][18]. It is also an important means to clarify the combustion mechanism.…”