The main wastes of oil refining are heavy petroleum residues (mazuts, vacuum gasoils, sludges) in which the bulk of oil heteroatomic and mineral components is concentrated. For example, resources of sludge upon refining of West Siberian oil amounts to 23% of oil refined. To refine heavy petroleum residues into light overhead products (petrol and diesel fractions) they use in world practice methods as follows:
fluid cracking (thermoform-type cracking in fluidized bed);
flexicoking (coking with further gasification);
catalytic cracking or hydrocracking after preliminary deasphaltization and demetallization;
high-temperature vapor oxygen gasification;
donor solvent cracking (processes of Lurgi, Galf Canada, Petro-Canada, Exxon и and others).
All these processes are performed upon high pressure from 3.5 to 30 МPа and temperature up to 460С with presence of specially prepared hydrogen donor and exclusively with gross outgo of expensive catalytic agents.
The specialists from TTU Ltd. developed a technology for heavy petroleum residues recycling along with slates of any genetic types in plants of UTT-3000 types upon practically atmosphere pressure and temperature up to 490С without external catalyst agents and hydrogen donors. Required conditions for sludge thermal cracking are provided in the cylindrical reactor of the UTT-3000 plant by means of warming of sludge up to the temperature of cracking, mixing it with slate which contains natural catalyst agents in the form of aluminum silicates and donor hydrogen additive agents from vapor gas mixture (a product of sludge pyrolysis) as well as sulfur as natural activating agent of thermal cracking and oxides of alkaline-earth metals. There is no necessity in preliminary deasphaltization and demetallization. The output of useful products of thermal cracking amounts up to 73% of sludge mass.
The technology is protected by the patent of the Russian Federation No. 2338773 with a priority 19.06.2007 recorded in the State Register of Inventions of the Russian Federation on 20/11/2008.