Fig 1: ROSE© reduces contaminant levels in Deasphalted Oil
The ROSE® (Residuum Oil Supercritical Extraction) process is a very efficient solvent-extraction option for recovering higher value products from resids. ROSE® units yield deasphalted oils that are excellent feedstocks for fluid catalytic crackers and hydrocrackers, as well as recover resins and asphaltenes that have a variety of uses. State-of-the-art technology, coupled with extensive experience in the engineering and construction of ROSE® units, puts KBR, a worldwide technology licensor of the process, at the forefront of resid processing by super critical solvent extraction.
Fig 2: ROSE© Simplified Block Flow Diagram
ROSE® technology is based on the use of a light, readily available paraffinic solvent to extract deasphalted oil from a feedstock rich in asphaltenes. The solvent is separated from the deasphalted oil in the downstream deasphalted oil separator, then recovered and recycled. Solvent selection is based on the desired deasphalted oil purity and yield for a given feedstock. The ROSE unit includes a deasphalted oil stripper and an asphaltene stripper for final recovery and recycling of dissolved solvent from the two effluent streams. (see Fig. 2)
The many economic benefits of the ROSE® process are the result of recovering the extraction solvent as a supercritical fluid. The recovered solvent is recycled through heat exchangers to recapture a major portion of the energy necessary to achieve supercritical solvent recovery. This can significantly reduce capital and operating costs.
Commercial ROSE® units have demonstrated overall savings of up to 50 percent compared to conventional solvent-extraction processes that use evaporation, compression and condensation. By eliminating the need to evaporate a major portion of the extraction solvent, the size and complexity of the ROSE® unit is reduced. This, in turn, can lead to reduced investment costs and further energy savings.
ROSE® units can upgrade very heavy crudes, process resid from tar sand bitumen, and extract valuable products from thermally degraded petroleum products, shale oil and coal liquefaction residues.
A ROSE® unit can be designed to yield deasphalted oils ranging from lube-oil blending stock to fluid catalytic cracker feedstock, depending on the solvent selected for the extraction.
Further flexibility is possible by designing the unit to generate two, three or more products. A two product ROSE® unit makes deasphalted oil and a heavy product. The three product unit produces deasphalted oil and separates the heavy product into resins and asphaltenes, further improving the refinery's ability to meet market demand for asphalts and other specialty products.
Deasphalted oil is a relatively clean product, substantially lower in metals and carbon-residue contaminants than the resin and asphaltene fractions. Deasphalted oil is readily processed in a downstream fluid catalytic cracker or hydrocracker.
Resins, an intermediate fraction, act as a peptizing agent to maintain a homogeneous solution of asphaltenes, resins and oils to produce stable asphalt with desired properties. Resins also can be hydrotreated, catalytically or thermally cracked, or coked to produce more valuable products.
Asphaltenes, the heaviest components of crude oil, are friable solids at ambient temperature, with Ring and Ball Softening Point test results ranging from 160-400ºF. These can be blended with other refinery streams to produce high grade road asphalt, fuel oil, and pelletized for use in cement and steel plants. In addition, asphaltenes can be gasified to produce hydrogen, steam, and power.
Resins and asphaltenes are used as fuel blending components, ore reductants, fuel for cement kilns and power generation, carbon enrichers in casting molds, drilling mud additives and blending components in paving- and roofing-grade asphalts. The ROSE® process enables the refiner to make specification asphalts from crudes not normally considered asphalt crudes. Blending of asphalts and products from the ROSE® process can improve asphalt properties. Also, a ROSE® unit can dig deeper than vacuum distillation to produce specification asphalts from poor asphalt crudes.