Current available refining and upgrading technology has many drawbacks. Among these, the most critical is the application of heat at an elevated temperature to crack large molecules. Not only can this create an array of environmental pollutants, but the non-specificity of applying energy for bond scission is not economical. Under specific conditions, ultrasound energy can create cavitation centers which result in instantaneously high temperature and pressure. At the interface of oil and water, the free radicals created or induced by cavitation are regulated through membrane-mimetic chemistry principles. It is anticipated that this ultrasoundassisted chemical process will be more specific for bond cleavage and thus reduce waste by-products formed.
This new technology has been developed and proven to recover the upgraded lighter fuels from asphaltenecontaining fossil fuel sources. Sources involved are paving asphalt, heavy oil, coal liquids and bitumens. Using aqueous fuel source emulsions at ambient temperature and pressure at 20 KHz frequency and 20-600 W/cm2 power of sonication, the asphaltene can be converted to resin and gas oil fractions. The new process unit is anticipated to be in modular form, flexible in capacity and functions, and amenable to skid-mounting for transportation. Also the unit can be attached to existing facilities for refinery waste treatment.
In refining application, the total hydrogen demand is substantially reduced since part of the hydrogen supply can be derived from water. An initial estimated energy cost is ﹩0.25/bbl, based on a 20000 bpd (3200 m3/d) plant. This operation cost, plus the low capital cost, and many environmental advantages, will make this refining process unique.
Almost every upgrading and refining process involves some alteration or separation of the heaviest fraction of petroleum, asphaltene. Some of the practices involve: thermal scission of bonds of asphaltene at elevated temperature (delayed coking, thermal cracking); use of chemicals to terminate the free radial reactions after homolytic clevage (catalytical cracking, hydrocracking); conversion of asphaltene into other products (hydrogenation, solvent refining, visbreaking) or separation of asphaltene by some economic means (deasphaltene). All these conversions are carried out under high temperature (> 400 OC) and high pressure (- 2000 psig). Some drawbacks of the conventional methods are: strained and limited reaction vessel materials, too much hydrogen is used as a chemical beyond safety considerations; fugitive pollutions appear as byproducts in high temperature processing; non-specificity of the thermal energy applied is wasteful. Since the heterocyclic and metal components in petroleum represents only
