Gasification reactor with discrete reactor vessel and grate and method of gasification

• US 10,611,973 B2
• Filed: 06/18/2019
• Issued: 04/07/2020
• Est. Priority Date: 01/30/2012
• Status: Active Grant

• Current Assignee: Aries Gasification, LLC
• Original Assignee: Aries Gasification, LLC
• Inventors: Bull, Douglas R., Patten, Ross M., Cairney, Paul, Cox, Gerald M., Jepson, William P.
• Primary Examiner(s): Akram, Imran
• Application Number:
  US16/445,118
• Publication Number:
  US 20190359903A1
• Time in Patent Office: 294 Days
• CPC Class Codes: B01J 2208/00893 Feeding means for the reactants
• CPC Class Codes: B01J 2208/00902 Nozzle-type feeding elements
• CPC Class Codes: B01J 2208/00991 Disengagement zone in fluidised-bed reactors
• CPC Class Codes: B01J 8/1809 Controlling processes
• CPC Class Codes: B01J 8/1827 the fluidising gas being a reactant
• CPC Class Codes: C02F 11/10 by pyrolysis
• CPC Class Codes: C02F 11/121 by mechanical de-watering
• CPC Class Codes: C02F 11/13 by heating
• CPC Class Codes: C10J 2300/0909 Drying
• CPC Class Codes: C10J 2300/0916 Biomass
• CPC Class Codes: C10J 2300/0923 Sludge, e.g. from water treatment plant
• CPC Class Codes: C10J 2300/0956 Air or oxygen enriched air
• CPC Class Codes: C10J 2300/1643 Conversion of synthesis gas to energy
• CPC Class Codes: C10J 2300/1807 Recycle loops, e.g. gas, solids, heating medium, water
• CPC Class Codes: C10J 3/466 Entrained flow processes
• CPC Class Codes: C10J 3/482 Gasifiers with stationary fluidised bed
• CPC Class Codes: C10J 3/84 with means for removing dust or tar from the gas
• CPC Class Codes: C10K 1/026 by centrifugal forces cyclones B04C
• CPC Class Codes: Y02P 20/129 Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
• CPC Class Codes: Y02W 10/40 Valorisation of by-products of wastewater, sewage or sludge processing
• CPC Class Codes: Y10T 29/49 : Method of mechanical manufacture

Abstract

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.

Claims

1. A gasification reactor comprising:

a discrete reactor vessel which is cylindrical in shape having a bottom with an inverted cone section;

a freeboard section comprising the top half of the reactor vessel, said freeboard section having a diameter of at least 57 inches;

a fluidized bed in a bed section within said reactor vessel located beneath the freeboard section, said fluidized bed having a diameter of at least 45 inches;

at least one fuel feed inlet located beneath the freeboard section, said inlet configured to feed a fuel into said reactor vessel at a fuel feed rate during steady-state operation of the gasifier;

a gas distributor located within the inverted cone section comprising a flue gas and air inlet that feeds flue gas and air to an array of nozzles whereby the flue gas and air are directed into the fluidized bed in the bed section; and

an ash grate positioned beneath the bottom of the discrete reactor vessel.

2. The reactor of claim 1, further comprising at least one inlet for a natural gas and air mixture.

3. The reactor of claim 1, further comprising at least one inlet for addition of an inert media.

4. The reactor of claim 1, further comprising an outlet for agglomerates;

and an outlet for producer gas.

5. The reactor of claim 1, wherein the freeboard section is configured to provide particle entrainment out of the reactor.

6. The reactor of claim 1, wherein the freeboard section has a diameter greater 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 (0.33 ft/s) and 3 m/s (9.84 ft/s).

7. A method of gasification comprising:

Supplying fuel through at least one inlet into a gasification reactor;

Introducing a fluidizing agent through at least one inlet into the gasification reactor;

Distributing the fluidizing agent within the reactor; and

Producing the outflow of producer gas through a top portion of the gasification reactor,

Said gasification reactor comprising;

a discrete reactor vessel which is cylindrical in shape having a bottom with an inverted cone section;

a freeboard section comprising the top half of the reactor vessel, said freeboard section having a diameter of at least 57 inches;

a fluidized bed in a bed section within said reactor vessel located beneath the freeboard section, said fluidized bed having a diameter of at least 45 inches;

at least one fuel feed inlet located beneath the freeboard section, said inlet configured to feed a fuel into said reactor vessel at a fuel feed rate during steady-state operation of the gasifier;

a gas distributor located within the inverted cone section comprising a flue gas and air inlet that feeds flue gas and air to an array of nozzles whereby the flue gas and air are directed into the fluidized bed in the bed section; and

an ash grate positioned beneath the bottom of the discrete reactor vessel.

8. The method of claim 7, wherein the thermochemical conversion process occurs with an oxygen-to-fuel equivalence ratio between 0.1 and 0.5.

9. The method of claim 7, wherein a superficial velocity of producer gas inside the freeboard section during steady state operation is between 0.1 m/s (0.33 ft/s) and 3 m/s (9.84 ft/s).

10. The method of claim 7, wherein a thermochemical conversion process occurs within the reactor at a temperature between 900°

F. (482.2°

C.) and 1700°

F. (926.7°

C.).

11. The method of claim 7, further comprising the step of using a cyclone separator to separate material exhausted from said reactor into producer gas and ash.