Assessing the potential and limitations of heavy oil upgrading by electron beam irradiation

Radiation technology can economically overcome principal problems of heavy oil processing arising from heavy oil??????s unfavorable physical and chemical properties. This technology promises to increase considerably yields of valuable and environmentally satisfying products of thermal cracking; to simplify complexity of refinery configuration; and to reduce energy expenses of thermal cracking. Objectives of the present study are: ?????? Evaluate heavy oil viscosities with respect to absorbed dose and effect of different solvents on the viscosity of irradiated crude oil by comparing selected physical properties of irradiated samples to a non-irradiated control group; ?????? Investigate effect of e-beam radiation on the yields of light fractions comparing yields of radiation-thermal cracking to yields of conventional thermal cracking. The viscosity was used as an indicator of the change in the molecular structure of hydrocarbons upon irradiation. We found that the irradiation of pure oil leads to the increase of the molecular weight calculated from the Riazi-Daubert correlation. Thus, irradiation up to 10 kGy resulted in a 1.64% increase in the molecular weight, 20 kGy ?????? 4.35% and 30 kGy ?????? 3.28%. It was found that if irradiated oil was stored for 17 days, its viscosity increased by 14% on average. The irradiation of samples with added organic solvent in the following weight percentages 10, 5, 2.5wt.% resulted in the increase in the viscosity by 3.3, 3.6 and 14.5%, respectively. The irradiation of the sample with added distilled water also resulted in an increase in the viscosity. This increase mainly happened because the thermal component was absent in the activation energy and hydrogen, produced from radiolysis of solvent and water molecules in mixture with crude oil, and was not consumed by hydrocarbon molecules and no reduction in molecular size occurred. Implementation of radiation to the thermal cracking increased yields of light fractions by 35wt.% on average compared to the process where no radiation was present. The last chapter of this thesis discusses a profitability of installation the hypothetical radiation-thermal visbreaking unit. The calculation of profitability was performed by a rate of return on investment (ROI) method. It showed that implementation of radiation-thermal processing resulted in an increase of ROI from 16 to 60%.