Fabrication, Characterization and Oil Spill remediation Properties of Exfoliated Graphite
Open Access
- Author:
- Moustafa, Ahmed Mohamed Abdel-hakim
- Graduate Program:
- Civil Engineering
- Degree:
- Master of Engineering
- Document Type:
- Master Thesis
- Date of Defense:
- April 03, 2009
- Committee Members:
- Fred Scott Cannon, Thesis Advisor/Co-Advisor
Fred Scott Cannon, Thesis Advisor/Co-Advisor - Keywords:
- Exfoliated graphite
oil spills - Abstract:
- Severe damages frequently occur each year worldwide due to the effect of oil spills, where crude oil is considered as one of the most aggressive liquids to the environment especially when accidentally spilled in large amounts. Suez Canal, Egypt, was one of the water sheds that suffered from the impact of crude oil spill especially the one dated December 14, 2004 10,000 tons of spilled crude oil. The aim of this research was to synthesize, test and develop a sorbent material capable of adsorbing crude oil spilled from water. Previous studies showed that exfoliated graphite (EG) is a promising material that can be used to adsorb hydrocarbon compounds. However, finding the proper way to utilize the EG is still a challenging problem. Also, the effect of some parameters such as temperature and type of the crude oil has not been widely investigated. The research herein had the following goals: (1) assess the effect of the exfoliation temperature on the sorption efficiency and the properties of the product; (2) assess and compare the effect of two different exfoliation time on the sorption efficiency and the properties of the product; and (3) find an applicable form of the exfoliated graphite for the oil spill remedy application. To this end, the exfoliation time was found to have a great impact on the exfoliation volume and consequently on the crude oil sorption capacity, where the rate of expansion increases gradually and then decreases until the exfoliation temperature reaches 800 0C. After this temperature, there is no significant impact for the exfoliation time, however the exfoliation volume continues to increase with a very low rate. Also, the exfoliated graphite density was found to decrease gradually from 44 g/l at 400„aC to 3.10 g/l at 1000„aC for the samples exfoliated for 60 seconds, and from 45.44 g/l at 300„aC to 3.31 g/l at 1000„aC for the samples exfoliated for 120 seconds. The x-ray diffraction (XRD) for the graphite exfoliated for 60 seconds showed that the sulfur still exists in the exfoliated sample at 950„aC. However, there no sulfur was detected after exfoliation at 1000„aC with the XRD data did not show any sulfur content for the tested samples exfoliated for 120 seconds starting from 650„aC. On the other hand, SEM/EDS detected sulfur content in all the samples exfoliated for 60 s and 120 s, which decreases as the exfoliation temperature increases, even after exfoliation for 120 s at 1000„aC. The maximum sorption capacity achieved is ~ 82 (kg of oil/kg of sorbent) which is about double the capacity of any other natural sorbent material reported so far. It was expected that the sorption capacity would increase with increasing the atmospheric temperature, however an interesting finding was that there is a minimal effect of atmospheric temperature on the sorption capacity of the exfoliated graphite when tested for Pennsylvania crude oil sorption. It was found also that the applicability of the EG is greatly modified by using fiber glass as a packaging material giving a maximum adsorption capacity of ~ 68 kg of crude oil per kg of the new composite material introducing the maximum sorption capacity for the applicable form of the exfoliated graphite.