Biodiesel which is a renewable resource is assumed as an alternative to conventional diesel fuel, such as, straight vegetable oil, animal oil/fats, tallow and waste cooking oil. Biodiesel can be blended with petro-diesel in different proportions based on the required application. It has many interesting properties such as it is produced from a renewable domestic source, its biodegradability, and potential to reduce exhaust emissions.
Recently, biodiesel attracts more attention due to petro-diesel price continuous and sharp increasing, and also due to the growing awareness to the environmental negative consequences caused by using conventional resources. Unfortunately, a major obstacle in the commercialization of biodiesel production from edible vegetable oil is its high production cost, which is due to the higher cost of edible oil. However, waste cooking oil, which is less expensive than edible vegetable oil, is a promising alternative to edible vegetable oil.
The most common way to produce biodiesel is through transesterification, which is the reaction of triglyceride oil with an alcohol to form esters (biodiesel) and glycerol using alkali-chemical catalysis. Then the biodiesel is separated from the glycerol and purified.
Therefore, the main objective of this project is to produce biodiesel from waste cooking oil through transesterification method. In this content, three main factors affecting the yield of biodiesel were investigated. First the alcohol to oil molar ratios (1:1 , 2:1and 3:1), second the catalyst type which are sodium hydroxide, potassium hydroxide and sodium methoxide and finally the catalyst concentration (0.2%, 0.5% and1%). The properties of biodiesel product must be measured according to American Society and Material Testing (ASTM) test methods and compared to the standard one. The biodiesel yield was calculated for each sample and it was founded that the most acceptable yield was 78.57% at specific variables which are( 3:1 Methanol to oil molar ratio, 0.5% NaOH) Moreover, biodiesel was blended with petro-diesel fuel with percentage of B0, B5, and B10 (0%, 5%, and 10% biodiesel by volume respectively) , and exhaust gas temperature, CO concentration, and NOx concentration have been measured using combustion analyzer model 500, the B0 results were taken as a reference for comparing biodiesel achieved results .
It was founded that , as biodiesel percentage increases the NOx concentration have been increased ,such as ( Bo=23 ppm, B5=79ppm ,B10=83 ppm).Also CO emissions was increased with increasing percentage of biodiesel like (B5=142 ppm ,B10= 146 ppm) .comparing with petro -diesel (B0) ,the bio diesel has less CO emissions (B0=306 ppm, B5=111,B10 =128).
It is possible to produce biodiesel from recycled waste oils comparable in quality to that of virgin vegetable oil biodiesel with an added attractive advantage of being lower in price. Thus, biodiesel produced from recycled frying oils has the same possibilities to be utilized.
The main concluded points were:
1.
Acceptable yield can be achived at ( 3:1 M/O ,5%NaOH)
2.
*biodiesel can be produced by trnsestirification using soyabean oil
- Exhaust temp increased which is an indicator about thermal efficiency improvement
- the produced biodiesel contributes in CO emission reduction .
5.
Nox emission has increased to alevels higher than the average biodieemiss