System and process for preparing synthetic gas through co-gasification of coal and biomass

Abstract

The invention provides a system and a process for preparing synthetic gas through co-gasification of coal and biomass. The system comprises a feeding device, a gasifier body and a gasifying medium generation device, wherein the gasifier body consists of a lower dense-phase region and an upper dilute-phase region; a multi-air-chamber air distribution device is arranged at the bottom of the dense-phase region and is connected with an outlet of the gasifying medium generation device; the feeding device is connected with the gasifier body at the junction of the dense-phase region and the dilute-phase region; a deslagging device is connected at a slag outlet between the multi-air-chamber air distribution device and the gasifier body; the upper side wall of the dilute-phase region is provided with a synthetic gas outlet; the gasifying medium generation device comprises an oxygen enrichment preparation device and / or a steam generation device; a taper or inverted taper air distribution mode is adopted by the multi-air-chamber air distribution device. According to the system and the process, the co-gasification of the coal, lignocellulose and municipal domestic waste can be effectively realized, and the synergistic effect of the coal and the biomass is effectively utilized; the system and the process have the advantages of wide raw material adaptability, high gasification speed, little deslagging carbon residue, easiness in controlling over pollutants and the like.

Description

technical field [0001] The invention relates to the technical field of carbon-based solid fuel gasification, in particular to a system and process for preparing synthesis gas through co-gasification of coal and biomass. technical background [0002] At present, China has entered a period of high energy intensity in the accelerated development of industrialization. The "coal-based" energy structure is difficult to change in a short period of time. The adverse effects of environmental pollution and greenhouse gas effects caused by the traditional use of coal (combustion) have become increasingly prominent. Clean coal technology represented by gasification technology has gradually attracted the attention of countries all over the world and has become the focus of competition in the energy field. [0003] Compared with coal, biomass raw materials have the characteristics of high volatile matter, low fixed carbon content, high oxygen-to-carbon ratio, and low ash, nitrogen, and su...

AI Technical Summary

Problems solved by technology

[0006] At present, most of the existing coal and biomass co-gasification processes and devices are based on the addition of biomass on the basis of existing coal gasifiers. Due to the diversity of biomass types and the complexity of properties, existing invention patents are mostly aimed at relatively single There are many types of biomass, and most of them have not considered the pretreatment methods for different types of biomass. In addition, the existing co-gasification fluidized bed reactor has problems such as poor process adaptability and complicated gasifier control.

[0007] Existing fluidized bed co-gasification reactors mainly include single fluidized bed gasification reactor and double fluidized bed gasification reactor. For single fluidized bed gasification reactor, uniform air distribution is often used, and materials are mixed in the furnace The degree is greatly affected by the characteristics of raw materials; in addition, in the Chinese patent disclosure of "a biomass and coal mixed fluidized bed gasification method and its device" with the publication number CN1557919A, the whole process is divided into air combustion and water vaporization Two stages, the control system is more complicated, which increases the complexity of operation

For the dual fluidized bed gasification reactor, the gasification process and the combustion process are carried out in two fluidized beds respectively to increase the operational complexity

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