Formulation of multi-purpose grease from waste cooking oil, spent bleaching earth and fume silica /
Mohd Khairul Nizam Mohd Zuhan
- xix, 178 pages : illustrations ; 30 cm. + 1 CD-ROM
Thesis (Master of Engineering (Chemical)) -- Universiti Malaysia Pahang – 2013
Includes bibliographical references
Substantial amount of spent bleaching earth (SBE) and waste cooking oil (WCO) was discarded every year and this has created impact to the environment and economy. The use of these wastes as a value-added product will reduce its dangerous potential and is beneficial to the economy. In this study, a new multi-purpose grease formulated using industrial waste which is the WCO as base oil, SBE as thickener and fumed silica (FS) as an additive. The grease was formulated by manipulating the percentage (w / w) of WCO, SBE and FS. Tests were carried out by measuring the grease penetration test (ASTM D 217), dropping point (ASTM D 2265), copper strip corrosion testing (ASTM D 4048), thermal stability, oxidation stability (ASTM D 942), friction co-efficient and wear scar diameter to evaluate the performance of grease. The results show about 20 % to 35 % of WCO and 80 % to 65 % of the SBE is needed to produce grease with NLGI grade of 1, 2 and 3. The addition and the increase of the % of a certain amount of FS in grease would require the amount of WCO to increase from 20 % to 66 %. In oil separation test, the grease without FS show oil separation ranged from 0.30 % to 1.98 %. The addition of FS reduces the oil separation of 0 % to 1.16 %. The oxidation stability of grease shows pressure loss of 533kPa and 538kPa for different grease sample, the grease showed no dropping point at temperatures above 350 ˚C, 51 % decomposition at temperatures above 900˚C and 61% decomposition of the grease is formulated with present of FS. Corrosion test shows the results of 1b (slightly corrosive). The structure of grease depends on the percentage of the main ingredients and at higher concentration of SBE, the grease is brittle, stiff and black or dark-brown coloured, at high concentration of FS the structure is buttery, sticky and lightly brownish coloured. At a higher percentage of SBE, grease formulated shows the structure of a harder, dark or dark-brown. At the high percentage of FS grease structure is buttery, sticky, soft and brown. Grease tribology properties were evaluated by four ball wear and extreme pressure (EP) testers ; the average friction co-efficient for SBE-WCO samples is 0.095 and 0.082 while 0.11 for the grease formulated with FS addition. In conclusion, the SBE, WCO and FS used successfully applied in formulating grease. Grease and the % of composition plays an important role in determining the performance and stability of the grease.