Fluid bed incineration of wastes containing alkali metal chlorides

• US 3,907,674 A
• Filed: 04/24/1974
• Issued: 09/23/1975
• Est. Priority Date: 04/24/1974
• Status: Expired due to Term

• Current Assignee: Elliott J. Roberts, Peter Allen Angevine
• Original Assignee: Elliott J. Roberts, Peter Allen Angevine
• Inventors: Roberts, Elliott J., Angevine, Peter Allen
• Primary Examiner(s): Wyse, Thomas G.
• Assistant Examiner(s): Castel, Benoit
• Application Number:
  US05/463,655
• Time in Patent Office: 517 Days
• Field of Search: 210/63,67,71,152,68,20 432/15,28,2 423/481,482,552,334,332,331,328,327,659.5F 110/28J,8F
• US Class Current: 588/320
• CPC Class Codes: B01J 8/32 with introduction into the fluidised bed of more than one kind of moving particles
• CPC Class Codes: F23G 2209/10 Liquid waste
• CPC Class Codes: F23G 5/30 having a fluidised bed
• CPC Class Codes: Y02W 10/40 Valorisation of by-products of wastewater, sewage or sludge processing
• CPC Class Codes: Y10S 423/16 Fluidization

Abstract

Combustible waste materials containing alkali metal chlorides and sulfur and/or sulfates are incinerated in a fluid bed reactor by a process in which formation of low melting eutectics is avoided. The temperature of the fluid bed is maintained substantially above the vapor saturation temperatures of the alkali metal chlorides so that they are to a great extent carried out with the combustion gases. By insuring the presence of sufficient reactive silica and a sufficiently high temperature, alkali metal sulfates can be prevented from accumulating. Any sticky alkali metal silicate glasses which tend to form are prevented from causing defluidization by insuring the presence of sufficient CaO, MgO, Fe2O3 and/or Al2O3 so that the glass is converted into high melting silicate compounds.

Claims

1. A PROCESS FOR FLUID BED INCINERATION, IN THE PRESENCE OF SULFUR OR SULFUR-CONTAINING COMPOUNDS, OF AN AQUEOUS COMBUSTIBLE ORGANIC WASTE STREAM CONTAMINATEED WITH AT LEAST ONE ALKALI METAL CHLORIDE, COMPRISING THE STEPS OF:

1.FLUIDIZING A BODY OF PARTICULATE MATERIAL IN A REACTION CHAMBER BY PASSNG AN UPWARDLY FLOWING STREAM OF AIR THERETHROUGH,

2. maintaining the fluidized body at a temperature in the range from about 800*C up to about 1,000*C to burn the organic material,

3. INTRODUCING FNELY DIVIDED SIO2 IN AN EFFECTIVE AMOUNT OF UP TO 3% BY WEIGHT, BASED ON THE WATER CONTENT OF SAID

4. discharging the gaseous and solid reaction products from the reaction chamber for disposal or further treatment.

5. The process of claim 4 in which Al2O3 is added in an amount such that the weight ratio of Al2O3/Na is at least 2.22 where Na is the water-insoluble sodium in the fluidized bed.

6. The process of claim 4 in which Fe2O3 is added in an amount such that the weight ratio of Fe2O3/Na is at least 3.48 where Na is the water-insoluble sodium in the fluidized bed.

7. The process of claim 4 in which MgO is added in an amount such that the weight ratio of MgO/Na is at least 1.74 where Na is the water-insoluble sodium in the fluidized bed.

8. The process of claim 5 in which CaO is added in an amount such that the weight ratio if CaO/Na is at least 2.43 where Na is the water-insoluble sodium in the fluidized bed.

9. The process of claim 8 in which CaO is added in an amount such that the weight ratio of CaO/Na is at least 3.65 where Na is the water-insoluble sodium in the fluidized bed.

10. A process for fluid bed incineration, in the presence of sulfur or sulfur-containing compounds, of an aqueous combustible organic waste stream contaminated with at lEast one alkali metal chloride, comprising the steps of:

11. The process of claim 10 wherein the fluidized body is maintained at a temperature in the range from about 850*C up to about 950*C.

12. The process of claim 11 wherein the fluidized body is composed of sand.

13. The process of claim 12 wherein said gaseous and solid reaction products include HCl and sulfate compounds.