Abstract
Feed stock cost and NOX emission are the major barriers for commercialization of biodiesel. Waste cooking oil is well identified as one of the cheapest feed stocks for biodiesel production. This chapter reduces NOX emission of waste cooking oil biodiesel. Test fuel blends are prepared by mixing diesel (20 to 50 v/v%), butanol (5 v/v%), and waste cooking oil biodiesel (45 to 75 v/v%). Fuel properties of waste cooking oil biodiesel are enhanced due to addition of diesel and butanol. Brake specific energy consumption of the blends is higher than diesel fuel. Harmful emissions like carbon monoxide, nitrous oxide, and smoke opacity are lower for blends than diesel fuel. Increasing biodiesel concentration in blend also reduces hydrocarbon emission to a significant extent. The obtained results justify the suitability of proposed cheap blends for diesel engine emission reduction.
TopIntroduction
Diesel engines occupy an important role in industrial, agricultural and transportation sectors (Ceramicrotaryengines, (2019)). However, continuous rise in diesel fuel price along with harmful gas emissions during its combustion have forced nations around the globe to look for alternate clean fuels (Rahman et al. (2014)). Emissions from diesel engines can be reduced by fuelling them with vegetables oils instead of fossil diesel fuel. Long term operation of diesel engines with raw vegetable oils reduces durability of engine components (Ramadhas et al., (2004); Shahid and Jamal (2008); Basinger et al. (2010)). Durability problems can be avoided if viscosity of vegetable oils is reduced by converting them into their ester forms/bio-diesel (Meher et al. (2006); Agarwal et al., (2007)). Biodiesel production cost can be reduced by utilizing non-edible oils, animal fats and used oils as feed stocks instead of edible oils (Ma and Hanna (1999); Bousbaa et al., (2012)). Among these feed stocks, used/waste oils are cheap, readily available and in addition their storage stability properties are very well studied (Knothe and Steidley (2009)). In biodiesel-based fuels NOX emissions will be higher. In this chapter, the effort taken to reduce NOX emission is presented.
The major objectives of the work are listed below:
- 1.
Conversion of waste cooking oil into biodiesel
- 2.
Preparation of diesel-butanol-waste cooking oil biodiesel blends
- 3.
Assessment of diesel-butanol-waste cooking oil biodiesel fuel properties
- 4.
Impact assessment of fuel blends on diesel engine performance and emissions
Key Terms in this Chapter
Engine Emissions: Exhaust gases released from engine after combustion of fuel inside engine chamber.
Flash Point: Flash point is the minimum temperature at which a liquid fuel forms ignitable vapor mixture with the air near its surface. It gives an indication on the ease of flammability of fuel.
Calorific Value: Amount of energy released when 1 kg of fuel is burned.
Waste Cooking Oil: Oil discarded after frying edible items.
Cloud Point: Cloud point is the temperature at which saturated fatty acids in biodiesel begins to separate when biodiesel is cooled and the fuel looks cloudy. Lower cloud point is always preferred.
Cetane number: Cetane number of the test fuel is the volume percent of n-hexadecane (cetane number 100) in a mixture of n-hexadecane and 1-methylnaphthalene (cetane number 0) that gives similar ignition delay as test fuel.
Pour Point: Pour point is the temperature at which biodiesel ceases to flow or loses its flowing properties. Cloud and pour point are essential for identifying suitable locations for applicability of particular biodiesel.
Trans-esterification: Trans-esterifcation is the process in which triglyceride reacts with alcohol in the presence/absence of catalyst to produce esters (biodiesel) and glycerol. Non-catalyst trans-esterifcation requires high temperature and pressure.
Viscosity: Viscosity refers to resistance offered by adjacent layers of fluid during its flow. Viscosity is an important fuel property which gives an idea of spray characteristics of fuel and overview of ease of combustion.