Method to upgrade heavy oil in a temperature gradient reactor (TGR)
A method of upgrading heavy oil in which the heavy oil is preheated to above a boiling point of water to remove water as steam and lighter fractions as vapors. The heavy oil passes downwardly through a series of sequential horizontal heat gradients in a temperature gradient reactor. A temperature of each sequential heat gradient progressively increases so that lighter fractions of the heavy oil vaporize with minimal cracking and heavier heavy oil fractions continue to fall by force of gravity downwards. As they pass through further sequential heat gradients of progressively increasing temperature, they tend to crack into lighter fractions in the presence of nascent hydrogen. Coke, formed from heavier heavy oil fractions generated and deposited on a fluidized catalytic bed a bottom of the temperature gradient reactor, is fluidized with superheated steam. The superheated steam generates the nascent hydrogen required to promote hydrogen reactions by indirect heated steam reforming and water-gas shift reactions.
1. A method of upgrading heavy oil, comprising:
preheating the heavy oil to above a boiling point and below a cracking temperature to remove a water stream as steam and a first fraction comprising a first set of lighter hydrocarbons as vapours;
passing the heavy oil downwardly through a series of sequential horizontal heat gradients in a temperature gradient reactor, with a temperature of each sequential heat gradient progressively increasing so that a second fraction comprising a second set of lighter hydrocarbons of the heavy oil vaporizes and a third fraction comprising a set of heavier heavy oil hydrocarbons continues to fall by force of gravity downwards where, as the third fraction passes through further sequential heat gradients of progressively increasing temperature, at least a portion of the third fraction cracks into a fourth fraction comprising a third set of lighter hydrocarbons in the presence of nascent hydrogen;
fluidizing a coke bed with superheated steam, the coke bed being formed from a portion of the third fraction and deposited on a fluidized catalytic bed positioned at a bottom of the temperature gradient reactor, the superheated steam generating the nascent hydrogen by indirect heated steam reforming and water-gas shift reactions, the third fraction further comprising organo-metals, wherein the organo-metals catalyse a cracking and a hydrogenation of the heavier heavy oil fractions in the presence of the nascent hydrogen; and
capturing the first, second and fourth fractions of the heavy oil which are vaporized.
2. The method of claim 1 , wherein the step of preheating the heavy oil comprises heating the heavy oil to a temperature of less than 350 degrees Celsius.
3. The method of claim 1 , wherein the step of preheating of the heavy oil is performed by passing the heavy oil through a heat exchanger.
4. The method of claim 1 , wherein a first temperature gradient of the temperature gradient reactor is up to 350 degrees Celsius.
5. The method of claim 1 , wherein the organo-metals provide a continuous addition of catalyst and the rate of generation of hydrogen is controlled by controlling temperatures in order to control coke formation in the fluidized catalytic bed.
6. The method of claim 1 , wherein the sequential horizontal heat gradients in the temperature gradient reactor are provided by two or more internal cooling sources.
7. The method of claim 1 wherein the fluidized catalytic bed at the bottom of the temperature gradient reactor is concurrently heated and mixed vigorously.
8. The method of claim 1 , wherein the fluidized catalytic bed at the bottom of the temperature gradient reactor is heated by a combustion unit embedded in the fluidized catalytic bed.
9. The method of claim 7 , wherein the heating and mixing is performed by a radiated acoustic pressure provided by resonance tubes immersed in the fluidized catalytic bed and powered by a pulse combustor.
10. The method of claim 1 , where the heavy oil is heated and processed in an increasing temperature gradient provided by the temperature gradient reactor, with a mass of heavy oil being heated decreasing as the temperature of the temperature gradient increases.
11. The method of claim 1 , wherein the temperature gradient reactor comprises a series of fractionation trays and provides distillation, hydro-cracking and steam reforming functions.
12. The method of claim 1 , wherein a catalyst regeneration loop is provided to draw spent catalyst from the temperature gradient reactor, regenerate the catalyst and then mix the regenerated catalyst into a feed stream entering the temperature gradient reactor.
13. The method of claim 1 , wherein the temperature gradient reactor comprises two fluidized catalytic beds, one of which is primarily to promote hydro-cracking and another of which is primarily to promote hydrogen generation.
14. The method of claim 11 , wherein the temperature gradient reactor comprises contact channels that can process heavy oil having solids content greater than five percent.
15. The method of claim 14 , wherein the temperature gradient reactor comprises internal baffles which define angled surfaces that are angled in relation to horizontal such that solids tend to slide down the angled surfaces by force of gravity.