Method for retorting carbonaceous particles
AssigneeMarathon Oil Company
InventorLaVaun S. Merrill, Jr.
Life of this patent
Estimating the term…
Abstract
In this process carbonaceous materials in a wide range of particles size are heat treated in a substantially vertical gravity retort through which heated gasses flow upwardly. The particles are graded by size and fed into the retort with the largest particles being inserted into an upper portion of the retort, and in preferred embodiments, with progressively smaller particles being inserted into progressively lower portions of the retort so that the residence time of each of the particles in the retort is substantially directly proportional to the size and mass of the particles. This process allows high throughput of the material while reducing the amount of entrained small particles which flow up with the heated gas, thus reducing pressure drop in the retort system.
Claims13
In the method of thermolytically treating solid particles having a range of particle sizes in a substantially vertical gravity feed gas heated retort, said retort having an upper portion and a lower portion including a heated gas inlet, wherein substantially all of said particles are substantially continuously downwardly nonturbulently flowing in said retort due to the effect of gravity while being heated with continuously upwardly flowing heated gases, said gases flowing upwardly from said gas inlet at a nonfluidizing rate relative to said particles, wherein the improvement comprises reducing pressure drop in said retort and maintaining the residence time in said retort of each said solid particle directly proportional to the size of each said solid particle by:
- obtaining at least two portions of to-be-treated particles including a first portion which includes the largest to-be-treated particles while substantially excluding the smallest particles, substantially all the to-be-treated particles in said first portion having a particle size of at least one inch (2.5 cm), and a second portion including substantially all of the smallest to-be-treated particles, substantially all of the to-be-treated particles in said second portion having a particle size less than 1 inch (2.5 cm);
- inserting said first portion including said largest particles into an upper portion of said retort;
- and
- inserting the second portion including said smallest particles into a lower portion of said retort at a vertical location below where said first portion is inserted.
Dependencies are inferred from the claim text.