System and method for comprehensively utilizing gasification ash

Abstract

The invention discloses a method for comprehensively utilizing gasification ash. The method comprises the following steps: 1) the gasification ash is preliminarily dehydrated to obtain concentrated ash; 2) the concentrated ash is further dehydrated and dried by exchanging heat with a gasification heat carrier medium to obtain dry ash with a low water content; and 3) the dry ash is combusted and reused. The invention also discloses a system using the method for comprehensively utilizing gasification ash. The system comprises a concentrating system, a drying system and a combustion system; and the concentrating system reduces water in the gasification ash and increases the relative content of residual carbon in the gasification ash, the concentrated ash is further dried and dehydrated by using excess heat carried by the gasification heat carrier medium in the drying system, and then the product is sent to the combustion system and is combusted and reused. The method and the system have the advantages of full utilization of the waste heat of a gasification device, recycling of the residual carbon in the ash, increase of the overall heat utilization efficiency of the device, reductionof the ash treatment cost and the adverse impact on the environment, and good economic and environmentally-friendly benefits.

Description

technical field [0001] The invention relates to the technical field of gasification slag treatment, in particular to a gasification ash comprehensive utilization system and method for a solid fuel gasification device. Background technique [0002] So far, gasification is still the most effective way to use hydrocarbon fuels such as coal in a large-scale, efficient and clean manner, and it is also a leading technology for related chemical processes. The fuels used include generalized hydrocarbon fuels such as coal, petroleum coke, asphalt, biomass and even garbage. [0003] The gasification reaction is a partial oxidation reaction of coal or other fuels with oxygen in the gasifier to generate high-pressure crude synthesis gas and gasification ash. Gasification slag is divided into gasification coarse slag and gasification fine slag (or slag), the gasification coarse slag generally contains 5-20% carbon (weight ratio, dry basis), and moisture content is 40-60% (weight ratio ...

AI Technical Summary

Problems solved by technology

Therefore, the use of direct landfill treatment can not achieve reduction and resource utilization, and it is necessary to set up a landfill slag field in accordance with environmental protection regulations and requirements. The slag field design is complex, occupies a large area, requires high investment, and easily leads to secondary pollution. At the same time, it is also necessary to consider the problem of returning the leachate from the slag field to the device for reprocessing

[0006] 2. Since there is still a certain amount of residual carbon (generally 10-40%, weight ratio) in the gasification ash, landfill treatment makes this part of the heat unusable, so the overall energy utilization efficiency is low; and because it contains The high content of residual carbon also greatly limits the way of reusing slag, such as building materials and roadbed materials, etc.

Since the general flash gas pressure is not high and contains a small amount of acid gas and ammonia, the excess flash gas needs to be cooled by circulating water, resulting in increased consumption of circulating water

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