Investigation on the performance and emissions profile of CI engine using cashew nut shell pyro oil–toluene–diesel blends

Abstract

Abstract This article examines the prospects of using toluene added cashew nut shell pyro oil–diesel blends as alternative fuels in CI engine. Effects of adding fixed proportion (by vol.) of toluene (TU) to various cashew nut shell pyro oil (CPO)–diesel (D) blends on the performance and exhaust emission characteristics of a direct injection, single cylinder, water cooled, naturally-aspirated, constant speed run, 4-stroke CI engine were investigated under varied brake power conditions. Tested fuels were neat diesel, CPOT5 (5% CPO + 5% TU + 90% D), CPOT10 (10% CPO + 5% TU + 85% D) and CPOT15 (15% CPO + 5% TU + 80% D). CPO was extracted through a lab-scale fast pyrolysis apparatus. Fuel samples were prepared and characterized according to ASTM standards. Owing to the features like low sensitivity, impressive anti pinging, etc., presence of toluene in an optimal CPO-diesel blend was expected to promote the engine characteristics. Set of experiments were conducted for each fuel mixture and the respective in-cylinder pressure, fuel consumption, exhaust emission levels, temperatures were recorded. At the rated power output condition, CPOT5 fuel had shown 1.67% increased brake thermal efficiency, 5% reduced brake specific fuel consumption, almost 3% reduced exhaust gas temperatures as well as reduced the exhaust emissions such as HC (from 91 to 87 ppm), CO (from 0.1 to 0.08%), NOx (from 458 to 426 ppm), smoke levels (from 72 to 69 BSN). CPOT5 showed improved combustion characteristics like reduced ignition delays and combustion durations, increased rates of cylinder pressure rise and heat release. However, overall attained improvements in the engine parameters were found to be not up to the mark which makes the chances of using CPOT5 as best alternative to diesel feeble. Article highlights The Cashew nut shells agro-waste is efficiently converted into an alternative fuel. Effect of adding toluene to pyro oil – diesel blends in CI engine is examined. Engine performance is improved marginally with 1.6% higher brake thermal efficiency (BTE) and 5% lower brake specific fuel consumption (BSFC). Reductions in CO, HC, NOx and smoke emissions are observed. Reduced Ignition delay and combustion durations, increased rate of pressure rise, and increased HRR are observed.