FLUIDIZED BED BIOGASIFIER AND METHOD FOR GASIFYING BIOSOLIDS

摘要

A fluidized bed biogasifier is provided for gasifying biosolids. The biogasifier includes a reactor vessel and a feeder for feeding biosolids into the reactor vessel at a desired feed rate during steady-state operation of the biogasifier. A fluidized bed in the base of the reactor vessel has a cross-sectional area that is proportional to at least the fuel feed rate such that the superficial velocity of gas is in the range of 0.1 m/s (0.33 ft/s) to 3 m/s (9.84 ft/s). In a method for gasifying biosolids, biosolids are fed into a fluidized bed reactor. Oxidant gases are applied to the fluidized bed reactor to produce a superficial velocity of producer gas in the range of 0.1 m/s (0.33 ft/s) to 3 m/s (9.84 ft/s). The biosolids are heated inside the fluidized bed reactor to a temperature range between 900° F. (482.2° C.) and 1700° F. (926.7° C.) in an oxygen-starved environment having a sub-stoichiometric oxygen level, whereby the biosolids are gasified.

主权项

1. A method for gasifying biosolids obtained from sewage sludge, comprising:
receiving biosolids in a fluidized bed biogasifier, the biogasifier having:
a reactor vessel;a freeboard section having a diameter of at least 57 inches and a height of at least 10 feet;a feeder for feeding biosolids into said reactor vessel, said feeder being configured to feed said biosolids into said reactor vessel at a biosolids fuel feed rate during steady-state operation of the biogasifier; anda fluidized bed in a bed section of said reactor vessel, said fluidized bed having a diameter of at least 45 inches;wherein the freeboard section has a greater diameter than the fluidized bed,and further wherein a ratio of a height of the bed section of the reactor vessel to a depth of the fluidized bed is 1.5; introducing gas to said fluidized bed reactor; and heating and reacting said biosolids inside said biogasifier, whereby biosolids are gasified.