Mechanical recovery methods

A. Lewis, I. Singsaas, B. O. Johannesen, and A. B. Nordvik, Key Factors that Control the Efficiency of Oil Spill Mechanical Recovery Method, MSRC Technical Report Series 95-038, Marine SpiU Response Corporation, Washington, DC, 1995. 

The increasing trend of oil and gas activities in the Arctic offshore has raised major concerns about oil spills and their impacts on the Arctic s ecologically sensitive environment. To decrease the severity of such impacts, oil spill clean-up technologies are developed as passive barriers to oil spills. Various techniques are available for removal of offshore oil spills, such as in-situ burning, use of dispersants, and mechanical methods. Oil skimmers are one of the essential categories of mechanical recovery methods that generally are used in combination with containment booms (Fingas 2011, Potter et al. 2012). 

A considerable percentage (40% - 85%) of hydrocarbons are typically not recovered through primary drive mechanisms, or by common supplementary recovery methods such as water flood and gas injection. This is particularly true of oil fields. Part of the oil that remains after primary development is recoverable through enhanced oil recovery (EOR) methods and can potentially slow down the decline period. Unfortunately the cost per barrel of most EOR methods is considerably higher than the cost of conventional recovery techniques, so the application of EOR is generally much more sensitive to oil price. 

Micromechanical theories of deformation must be based on physical evidence of shock-induced deformation mechanisms. One of the chapters in this book deals with the difficult problem of recovering specimens from shocked materials to perform material properties studies. At present, shock-recovery methods provide the only proven teclfniques for post-shock examination of deformation mechanisms. The recovery techniques are yielding important information about microscopic deformations that occur on the short time scales (typically 10 -10 s) of the compression process. 

The interfacial rheologic properties are extremely sensitive parameters toward the chemical composition of immiscible formation liquids [1053]. Therefore comparison and interpretation of the interfacial rheologic properties may contribute significantly to extension of the spectrum of the reservoir characterization, better understanding of the displacement mechanism, development of more profitable enhanced and improved oil-recovery methods, intensification of the surface technologies, optimization of the pipe line transportation, and improvement of the refinery operations [1056]. 

The plants are hand-cut, mowed, or pulled in developing coimtries, while mechanized harvesting methods are imder investigation in the United States. Ribboning machines are sometimes used to separate the fiber-containing bark before retting for recovery of the kenaf strands. For pulping, the kenaf is shredded or hammermilled to 57-cm pieces, washed, and screened. 

The recovery system may affect the amount of product recovered, the convenience of the subsequent purification steps and the quality of the final product. Cell separation from the fermentation broth is the preliminary step of the recovery method. In order to recover the PHA granules, it is necessary to rupture the bacterial cell and remove the protein layer that coats the PHA granules. Alternatively, the PHA has to be selectively dissolved in a suitable solvent. Generally, two methods are usually utilized for the recoveiy and purification of PHAs from cell biomass, which include PHA solubilization or non-polymer cellular material (NPCM) dissolution. The majority of the PHA recovery method is performed using a solvent extraction process mainly by chloroform and methanol. Modifying the cell wall s permeability and then PHA dissolution in the solvent are the mechanisms for PHA extraction. 

In order to apply the most suitable FOR procedure, one thus needs the knowledge of the various physicochemical data of the reservoir. Steam injection reduces the viscosity of oil (due to higher temperature), thus helping the increased production. The addition of polymers gives rise to higher viscosity of the water phase (used for pushing the oil). More recently, there have been some recovery methods where microbial applications have been applied in FOR (Banat, 1995 Bryant and Lockhart, 2(X)2 Donaldsen, 1991 Jimoh, 2012). The microbial FOR is comphcated and the exact mechanism is... 

Ahmed, T. 2010. Reservoir Engineering Elandbook, 4th ed. Boston Gulf Professional Publishers. This book explains the fundamentals of reservoir engineering and their practical applications in conducting a comprehensive field study (from Preface, p. xv). Divided into 17 chapters., the coverage includes reservoir fluid behavior and properties, fundamentals of reservoir fluid flow, oil and gas well performance, oil recovery mechanisms, and methods for the prediction of oil reservoir performance. 

An interesting feature of the Russian process is the two-step method employed for the complete recovery of arsenic from solution waste-streams. In the first step, which is similar to the recovery method used in the Thylox process, the solution is heated to 70°C (158 F), and arsenic sulfide is precipitated by the addition of 75% sulfuric acid. The precipitate is separated from the liquid by filtration, dissolved in aqueous sodium carbonate, and returned to the circulating solution-stream. The clear liquid is then passed to the second step where it is made alkaline with sodium carbonate solution and treated with a solution of ferric sulfate. In this operation the small amount of arsenic remaining in the solution after the first step is fixed and precipitated as ferric arsenite and arsenate. The precipitate is finally removed by filtration, and the filtrate, which contains about 10 to 20 ppm of arsenic, is either discarded or processed for recovery of thiosulfate. Wooden tanks lined with acid-resistant materials are used in both steps of the arsenic-recovery operation. Each tank is sized for a solution residence time of 4 hr and provided with a mechanical agitator. 

The treatments used to recover nickel from its sulfide and lateritic ores differ considerably because of the differing physical characteristics of the two ore types. The sulfide ores, in which the nickel, iron, and copper occur in a physical mixture as distinct minerals, are amenable to initial concentration by mechanical methods, eg, flotation (qv) and magnetic separation (see SEPARATION,MAGNETIC). The lateritic ores are not susceptible to these physical processes of beneficiation, and chemical means must be used to extract the nickel. The nickel concentration processes that have been developed are not as effective for the lateritic ores as for the sulfide ores (see also Metallurgy, extractive Minerals recovery and processing). 

There are advantages and disadvantages in both processes the solvent process requires no special equipment but uses an excess of benzene whose recovery adds to the cost of the product. The bad mill method uses no excess benzene but requires special equipment which has frequent mechanical problems. 

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