A method for ex-situ soil thermal desorption

Abstract

The invention discloses an ex-situ oil thermal-desorption method. According to the invention, soil to be repaired is preheated by using heat of bottom residues of a biomass circulating fluidized bed boiler through a heat pipe heat exchange manner, then, pollutants in the soil are desorbed by using heat of circulating ash of the biomass circulating fluidized bed boiler through a direct heat exchange manner, meanwhile, the fertility of repaired soil is improved by using active ingredients in the circulating ash, and gaseous pollutants generated by desorption are introduced into the boiler to be incinerated and decomposed. On the basis of waste heat of the bottom residues of the boiler, thermal desorption of soil is realized, meanwhile, the fertility of soil is improved by blending active ingredients, and volatile pollutants generated by desorption are conveyed into the boiler to be incinerated directly, so that secondary pollution is avoided.

Description

technical field

[0001] The invention relates to an ex-situ soil thermal desorption method, which belongs to the technical field of soil pollution control. Background technique

[0002] Soil thermal desorption is one of the effective methods for remediating polluted soil. It is a process of heating organic pollutants in the soil to a high enough temperature to separate them from the soil through direct or indirect heating. Obviously, soil thermal desorption requires a lot of heat, and the gaseous pollutants after desorption need to be purified by special equipment before being discharged into the atmosphere. Therefore, the actual soil thermal desorption method often has problems such as high equipment energy consumption, complex equipment structure, and expensive operation costs.

[0003] The biomass circulating fluidized bed boiler is a typical equipment for the horizontal function expansion of circulating fluidized bed boilers. This equipment can not only process straw-lik...

Examples

Embodiment Construction

[0029] This embodiment is carried out on the premise of this technical solution, and the detailed implementation and operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0030] This embodiment provides a soil heterotopic thermal repair method, the object of action is the soil polluted by a petrochemical enterprise, the specific method is as follows:

[0031] (1) The bottom slag from the biomass circulating fluidized bed boiler with a temperature of 700-800°C is transferred to a heat pipe by direct heat exchange (the initial feed water temperature is 15-25°C), so that the feed water in the heat pipe is heated Turn into water vapor to obtain bottom slag after first-level cooling, the temperature is about 400-500 °C;

[0032] (2) carry out fluidization with the secondary air of 150~180 ℃ drawn from the biomass circulating fluidized bed boiler and the bottom slag after the first-level cooling obtained in step...

technical field

[0001] The invention relates to an ex-situ soil thermal desorption method, which belongs to the technical field of soil pollution control. Background technique

[0002] Soil thermal desorption is one of the effective methods for remediating polluted soil. It is a process of heating organic pollutants in the soil to a high enough temperature to separate them from the soil through direct or indirect heating. Obviously, soil thermal desorption requires a lot of heat, and the gaseous pollutants after desorption need to be purified by special equipment before being discharged into the atmosphere. Therefore, the actual soil thermal desorption method often has problems such as high equipment energy consumption, complex equipment structure, and expensive operation costs.

[0003] The biomass circulating fluidized bed boiler is a typical equipment for the horizontal function expansion of circulating fluidized bed boilers. This equipment can not only process straw-lik...

Examples

Embodiment Construction

[0029] This embodiment is carried out on the premise of this technical solution, and the detailed implementation and operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0030] This embodiment provides a soil heterotopic thermal repair method, the object of action is the soil polluted by a petrochemical enterprise, the specific method is as follows:

[0031] (1) The bottom slag from the biomass circulating fluidized bed boiler with a temperature of 700-800°C is transferred to a heat pipe by direct heat exchange (the initial feed water temperature is 15-25°C), so that the feed water in the heat pipe is heated Turn into water vapor to obtain bottom slag after first-level cooling, the temperature is about 400-500 °C;

[0032] (2) carry out fluidization with the secondary air of 150~180 ℃ drawn from the biomass circulating fluidized bed boiler and the bottom slag after the first-level cooling obtained in step...