Method for starting up a system for treating waste by hydrothermal oxidation

1. Process for starting up a system intended for the oxidation of organic bodies present in an aqueous effluent, said system comprising a tubular body ( 10 ) into the inlet ( 12 ) of which said aqueous effluent can be injected at a pressure P 1 corresponding to at least the critical pressure of said aqueous effluent, said tubular body ( 10 ) having a first zone ( 16 ) extending said inlet ( 12 ), a second zone ( 18 ) into which an oxidising composition can be injected, and an outlet ( 14 ),

said process comprising the steps of:

providing to said first zone ( 16 ) of said tubular body ( 10 ), a first quantity of thermal energy Q 1 , which is capable of raising the temperature of said aqueous effluent passing through said tubular body ( 10 ) from an initial temperature to a higher intermediate temperature T 1 , which is below a temperature at which said organic bodies oxidize and

providing a definite quantity of a combustible mixture which is capable of reacting at a temperature lower than an oxidation temperature of the organic bodies and of which at least a first part can react at said intermediate temperature T 1 to provide a second quantity of thermal energy Q 2 raising the temperature of said aqueous effluent to a reaction temperature T 2 and is injected into said tubular body ( 10 ) at said pressure P 1 between said inlet ( 12 ) and said zone ( 16 ) of said tubular body ( 10 ) in such a way that injection of said oxidising composition into said second zone ( 18 ) brings about reaction of at least a second part of said combustible mixture providing a third quantity of energy Q 3 at said outlet ( 14 ) from said tubular body ( 10 ), a fraction of said third quantity of energy Q 3 being applied to said first zone ( 16 ) of said tubular body ( 10 ) to raise the temperature of the aqueous effluent passing through it at least from said initial temperature to said intermediate temperature T 1 .

2. The process of claim 1 , further comprising stopping providing of said first quantity of energy Q 1 to said first zone ( 16 ) of said tubular body ( 10 ) when said fraction of said third quantity of energy Q 3 is equal to at least Q 1 .

3. The process of claim 2 , further comprising stopping an injection of said combustible mixture and injecting said aqueous effluent at the inlet ( 12 ) to said tubular body ( 10 ) when said fraction of said third quantity of energy Q 3 is equal to at least the sum of Q 1 and Q 2 such as to raise the temperature of the fluid passing through said tubular body ( 10 ) from said initial temperature to said reaction temperature T 2 .

4. The process of claim 1 , wherein said combustible mixture comprises a combustible material and an oxidising agent in substoichiometric proportion so that a first portion of said combustible material reacts with said oxidising agent when said combustible mixture is raised to said temperature T 1 to provide said second quantity of energy Q 2 and the second portion of said combustible material reacts with said oxidising composition.

5. The process of claim 4 , wherein said combustible material and said oxidising agent are capable of releasing a quantity of energy in excess of 3 megaJoules per mole of molecules of combustible material.

6. The process of claim 4 , wherein said combustible material has an activation energy of less than 1 kiloJoule per mole of molecules of said combustible material.

7. The process of claim 4 , wherein said oxidising agent is hydrogen peroxide.

8. The process of claim 1 , wherein said combustible material comprises glucose.

9. The process of claim 1 , wherein said second quantity of energy Q 2 which said combustible mixture is capable of providing represents between 40 and 80% of the sum of Q 1 and Q 2 .

10. The process of claim 1 , wherein said combustible mixture is injected into the inlet ( 12 ) of said tubular body ( 10 ).

11. Process for starting up a system intended for the oxidation of organic bodies present in an aqueous effluent, said system comprising a tubular body ( 10 ) into the inlet ( 12 ) of which said aqueous effluent can be injected at a pressure P 1 corresponding to at least the critical pressure of said aqueous effluent, said tubular body ( 10 ) having a first zone ( 16 ) extending said inlet ( 12 ), a second zone ( 4 ) into which an oxidising composition can be injected, and an outlet ( 14 ),

said process comprising the steps of:

providing to said first zone ( 16 ) of said tubular body ( 10 ), a first quantity of thermal energy Q 1 capable of raising the temperature of a aqueous effuent passing through the tubular body ( 10 ) from an initial temperature to a higher intermediate temperature T 1 ;

providing a definite quantity of a combustible mixture capable of reacting at a temperature lower than an oxidation temperature of the organic bodies and of which at least a first part can react at said intermediate temperature T 1 to provide a second quantity of thermal energy Q 2 raising the temperature of said fluid to a reaction temperature T 2 and is injected into said tubular body ( 10 ) at said pressure P 1 between said inlet ( 12 ) and said zone ( 16 ) of said tubular body ( 10 ) in such a way that injection of said oxidising composition into said second zone ( 18 ) brings about reaction of at least a second part of said combustible mixture providing a third quantity of energy Q 3 at said outlet ( 14 ) from said tubular body ( 10 ), a fraction of said third quantity of energy Q 3 being applied to said first zone ( 16 ) of said tubular body ( 10 ) to raise the temperature of the fluid passing through it at least from said initial temperature to said intermediate temperature T 1 ;

stopping providing of said first quantity of energy Q 1 to said first zone ( 16 ) of said tubular body ( 10 ) when said fraction of said third quantity of energy Q 3 is equal to at least Q 1 ; and

stopping an injection of said combustible mixture and injecting said aqueous effluent at the inlet ( 12 ) to said tubular body ( 10 ) when said fraction of said third quantity of energy Q 3 is equal to at least the sum of Q 1 and Q 2 such as to raise the temperature of the fluid passing through said tubular body ( 10 ) from said initial temperature to said reaction temperature T 2 .

12. The process of claim 11 , wherein said combustible mixture comprises a combustible material and an oxidising agent in substoichiometric proportion so that a first portion of said combustible material reacts with said oxidising agent when said combustible mixture is raised to said temperature T 1 to provide said second quantity of energy Q 2 and the second portion of said combustible material reacts with said oxidising composition.

13. The process of claim 11 , wherein said combustible material and said oxidising agent are capable of releasing a quantity of energy in excess of 3 megaJoules per mole of molecules of combustible material.

14. The process of claim 11 , wherein said combustible material has an activation energy of less than 1 kilojoule per mole of molecules of said combustible material.

15. The process of claim 11 , wherein said oxidising agent is hydrogen peroxide.

16. The process of claim 11 , wherein said combustible material comprises glucose.

17. The process of claim 11 , wherein said second quantity of energy Q 2 which said combustible mixture is capable of providing represents between 40 and 80% of the sum of Q 1 and Q 2 .

18. The process of claim 11 , wherein said combustible mixture is injected into the inlet ( 12 ) of said tubular body ( 10 ).