Process for pseudohydrostatic feeding of solids into a reactor

In a method for the continuous reaction of pulverized coal with gases or vapors at a pressure of at least 80 psi, and including shutdown of the operation as required the improvement comprising continuously feeding said pulverized coal into a reaction zone utilizing the pseudohydrostatic pressure of a fluidized column which is of a height of at least 200 feet and includes additions of fluidizing gas at selected points of the column, by passing said pulverized coal downwardly through said column at a descent velocity of the pulverized coal in the column which is greater than the ascent velocity of the fluidizing gas relative to the pulverized coal, the average velocity of the fluidizing gas in the column being between 0.01 and 0.1 feet per second relative to the fluidized coal and the descent velocity of said coal being at least 1 foot per second, said method further including removing excess gas below the top of said column during said shutdown and further comprising controlling the feed rate at the bottom of said column by throttling the flow of coal, a pressure reduction of up to 5 percent of absolute being effected by said throttling.