ABSTRACT
I. Introduction .............................................................................................178 II. Carbon Materials and Heavy Oils Used .................................................181 III. Sorption Capacity for Heavy Oils .......................................................... 184 A. Exfoliated Graphite .......................................................................... 185 B. Carbonized Fir Fibers ...................................................................... 190 C. Carbon Fibers ................................................................................... 192 D. Charcoals.......................................................................................... 193 E. Summary .......................................................................................... 193 IV. Selectivity of Sorption............................................................................ 195 V. Sorption Kinetics ................................................................................... 198 VI. Cyclic Performance of Carbon Materials for Sorption of Heavy Oils ....206 A. Exfoliated Graphite .......................................................................... 207 B. Carbonized Fir Fibers .......................................................................210 C. Carbon Fiber Felt ............................................................................. 213 D. Summary ...........................................................................................217 VII. Analysis of Recovered Oils .....................................................................218 VIII. Preliminary Experiments for Practical Recovery
of Spilled Heavy Oils ............................................................................. 222 A. Exfoliated Graphite Packed into Plastic Bags.................................. 223 B. Formed Exfoliated Graphite ............................................................ 226 C. Heavy Oil Sorption from Contaminated Sand ................................. 226 D. Sorption of Heavy Oil Mousse ......................................................... 228 IX. Concluding Remarks .............................................................................. 230 A. Comparison among Carbon Materials ............................................. 230 B. Comparison with Other Materials ................................................... 233 Acknowledgments ............................................................................................. 234 References ......................................................................................................... 234
There have been a number of oil spill accidents in the world. In March 1989, an oil tanker accident occurred in Alaska and about 3.6 × 104 tons of heavy oil was spilled, which caused serious damage to the environment [1], and the situation was reported to be serious even 10 years later [2]. A number of tanker accidents can be pointed out, such as the oil spill of about 26 × 104 tons off Angora in May 1991, the wide spread of about 9 × 104 tons of spilled oil in the North Sea in January 1993, the collision of two tankers and the resulting serious disturbance of ship transport with about 2 × 104 tons of oil spilled in the Strait of Malacca in October 1997, the serious disaster on the coast of western France in December 1999, the contamination by 70 × 104 L of heavy and diesel oils that caused anxiety about the survival of ancient species in the Galapagos Islands in January 2001, and the stranding of a tanker on the coast of Spain, with about 4 × 104 tons of oil spilled in November 2002. In addition to these accidents, which were mainly due to nasty weather, the demolition of storage tanks in Kuwait during the 1991 Gulf War spilled a large amount of heavy oil into the sea. Another possibility for oil pollution of the ocean occurs during oil rig drilling.
