A two-stage heat treatment method for soil heavy metal remediation plants coupled with medium-temperature gasification and high-temperature chemical chains

Abstract

The invention discloses a two-section type thermal treatment method for soil heavy metal repairing plants with coupling of medium-temperature gasification and high-temperature chemical chains. Primarygasification of repairing plants is achieved in a medium-temperature gasification reactor to obtain a rough combustible gas, and meanwhile, most heavy metals can be migrated and immobilized in residues; in a high-temperature reduction reactor, secondary gasification reforming of the rough combustible gas can be achieved through lattice oxygen of an oxygen carrier, meanwhile, immobilization adsorption of heavy metals by the oxygen carrier is achieved, and efficient capturing of heavy metals in the repairing plants is achieved together with bottom residue enrichment; in an oxidation reactor, oxidation regeneration of the oxygen carrier after oxygen loss can be achieved; and by using a separator and a return feeder, oriented separation of three components, namely a gasified combustible gas,oxygen carrier granules and residual carbon granules, and recycling of the oxygen carrier and the residual carbon granules, can be achieved. With coupling of medium-temperature gasification and high-temperature chemical chains, gradient utilization of energy and reforming upgrading of gasification products can be achieved, a high-quality synthesis gas can be obtained, meanwhile, efficient capturing of the heavy metals in the repairing plants can be achieved, and harmless and resource utilization of the soil heavy metal repairing plants can be achieved.

Description

technical field [0001] The invention relates to a heat treatment method for soil heavy metal restoration plants in the field of energy and environmental protection, in particular to a two-stage heat treatment method for soil heavy metal restoration plants coupled with medium-temperature gasification and high-temperature chemical chains. Background technique [0002] As an emerging technology, phytoremediation is developing rapidly in the field of heavy metal management. With the large-scale promotion and application of phytoremediation technology, the problem of post-harvest disposal of phytoremediation plants has arisen as the times require. If no suitable post-production disposal technology is developed, the enriched heavy metals will return to the environment, which will not only cause waste of manpower, material and financial resources, but also cause secondary pollution to the environment. [0003] Traditional post-harvest treatment methods for restoration plants inclu...

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Problems solved by technology

It can be seen that the traditional chemical looping gasification method will not be conducive to the enrichment of heavy metals to the bottom slag, which will affect the recovery rate of heavy metals

[0007] (2) The migration and transformation rules of heavy metals under chemical looping gasification atmosphere are complex: direct gasification of repair plant chemical looping, the process includes not only the primary gasification reaction of fuel and gasification agent, but also gasification products and oxygen The secondary gasification reaction of solids, the reaction atmosphere is richer, and the reaction process is more variable, which will inevitably lead to further complexity of the migration and transformation mechanism of heavy metals, which will easily cause heavy metals to escape into the environment along with flue gas and fly ash

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