A Ferromagnetic Sorbent System for Oil Spill Recovery (1976)

ABSTRACT A unique development project has evolved from the author's earlier laboratory research into the use of ferromagnetic sorbents for oil spill recovery and control. (Turbeville,1973.) Recent efforts to improve the quality of ferromagnetic sorbents have shown that the problems normally associated with sorbent systems of oil spill recovery can be virtually eliminated. It is now possible to produce a reusable ferromagnetic polyurethane foam product in less than ten minutes by using, a new one-component mix polymer (Hypol) which was developed by W. R. Grace Company. In addition to being a recycleable, oil-absorbing foam, the ferromagnetic properties of the product provide a "handle" for its removal from a water surface. A 24-foot portable oil spill recovery unit incorporating magnetic principles is being developed by the University of South Florida and Gulf Tampa Drydock Company with partial support from the Florida Sea Grant Program. This prototype recovery unit is expected to be ready for initial in situ testing by September1976. Details of the ferromagnetic sorbent concept and principles by which the recovery unit functions are discussed with the aid of figures and tables. Sorbent requirements, oil recovery rates and operational costs are projected on the basis of laboratory experiments. INTRODUCTION Ferromagnetic sorbents will transform a maritime oil spill into a highly buoyant, magnetizable surface layer which can be recovered by magnetic means. Laboratory experiments, conducted and reported by the author (Turbeville, 1973), reveal the properties of ferromagnetic sorbents made with small polystyrene spheres. More recent work with a new one-component polyurethane polymer (Hypol) developed by W. R. Grace Company has provided a method for quickly producing a reusable, sponge-like ferromagnetic foam which should greatly reduce the costs and logistics problems normally associated with sorbent systems of oil spill recovery. A development project which incorporates magnetic principles into a recovery system was started in January 1976 by the University of South Florida jointly with Gulf Tampa Drydock Company. The work is partially supported by the Florida Sea Grant Program. FERROMAGNETIC SORBENTS The use of polyurethane foam as a sorbent material for oil spill recovery has been studied extensively by the Shell Development Company of Houston (Oxenham et al., 1973) and similar work is currently under way at the Navy's civil engineering laboratory at Port Hueneme, California. Much of Shell's earlier work provides a resource of information which has been very useful in the planning of the magnetic recovery system which is now under development in Tampa. Shell's researchers developed a two-component liquid mix concept wherein large sheets of polyurethane foam were formed on the deck of a recovery barge. These pancake-shaped sheets were shreaded, disseminated over an oil spill and recovered with a conveyor type harvester. Their foam was of low tensile strength and suffered loss of buoyancy after a few passes through their system resulting in sinking and, consequently, a high loss rate of foam from the foam cycle.