**4. Methodology and experimental set-up**

This experiment is making a case for blending of WPPO whose n-alkenes are lower by 25% in auto-ignition, compared to diesel fuel whose n-alkenes are good for auto-ignition. The aromatics, which affect PM emissions, are very low in WPPO blends. According to Refs. [59, 60], WPPO consists of iso-alkanes, n-alkanes, and olefins in the region of 27, 25, and 9%, respectively, with over 30% content being undefined due to complicated and complex chemical bond structures. However, aromatic cyclo-alkanes (naphthalene) and aromatics poor in auto-ignition were also found to be 40% by volume [61]. Blending was preferred to improve the low pour point to improve the cold starting characteristics of WPPO. Second, blending with ethanol was introduced to improve the fuel spray characteristics; ethanol is soluble and miscible in WPPO blends. Third, blending contributed to the reduction of the viscosity of WPPO biodiesel, thus further improving spray characteristics.

**45**

**Table 3.**

**Table 2.**

*Experimental engine specifications.*

*List of equipment used in the experiment.*

*Effects of Biodiesel Blends Varied by Cetane Numbers and Oxygen Contents on Stationary Diesel…*

The experiment used a naturally aspirated four-cylinder diesel engine power generator, water cooled, direct injection, Iveco engine, in the Mechanical Engineering Department Laboratory, University of Kwazulu-Natal in Durban, South Africa. Using a defined flow rate of particles, PM emissions were detected by photoelectric measurement. Both the mass flow of the PM particles and the fuel were calculated as the sum of inlet air and fuel mass flow rate, and the result expressed in gram per kWh. To help in the analysis of the engine, pressure sensors and crankshaft position sensors and encoders were used. The aim of these sensors was to provide the

in-cylinder pressure in relation to the crankshaft position variation.

**Parameters Position value** Ignition type 4 (Stroke)DICI Number of cylinders 4 in-line Cooling medium Water Manufacturer Iveco Revolutions per minute 2000 Brake power 43.40 kW @ 2000 Cylinder bore 104 mm Piston stroke 115 mm Compression ratio 17:1 Connecting-rod length 234 Engine capacity 2500 cc Dynamometer make 234 Injection timing 12 bTDC ֯ Maximum torque 206.9 Nm @ 1500 Injection pressure 250–272 Bar

**Property Equipment Standard** Kinematic viscosity SVM 4000 (Anton Paar, UK) ASTM D445 Flash point NPM 550 (Norma lab, France) ASTM D93 Oxidation stability 900 Rancimat (Metrohm, Switzerland) ASTM D14112 CP/PP NTE 500 (Norma lab, France) ASTM D2500 Carbon residue NMC 440 (Norma lab, France) ASTM D4530 Total sulfur 5000 MULTI-EA (AJ Germany) ASTM D5433 Calorific value C 2500 basic calorimeter (IKA, UK) ASTM D240 Density SVM 3500 (Anton Paar, UK) ASTM D1298

PM AVL smoke meter — Gaseous emissions Gas analyzer (MEXA 7000) Germany —

*DOI: http://dx.doi.org/10.5772/intechopen.92569*

**4.1 Engine tests**

*Effects of Biodiesel Blends Varied by Cetane Numbers and Oxygen Contents on Stationary Diesel… DOI: http://dx.doi.org/10.5772/intechopen.92569*
