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 fluidized bed biogasifier for gasifying biosolids obtained from sewage sludge, comprising:
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; and a fluidized bed in a base 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 such that a superficial velocity range of gas inside the freeboard section during steady state operation is between 0.1 m/s (0.33ft/s) and 3 m/s (9.84ft/s), 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.