Multilayer rotary kiln based small granular material destructive distillation method

Abstract

The invention relates to a multilayer rotary kiln based small granular material destructive distillation method. The method comprises the following steps: adding oil shale granules (with the granularity of 0-20mm) with the water content of below 5% to a bunker from a kiln head, sending to the inner cylinder of a rotary kiln by a spiral conveying device, heating the material in the inner cylinder to 500DEG C through the circulation of high temperature hot flue gas (with the temperature of 700DEG C) from a hot blast stove in an annular channel between an outer cylinder and the inner cylinder to pyrolyze the oil shale material in order to generate a destructive distillation gas and semicoke, and carrying out purifying recovery on the destructive distillation gas to obtain gas and shale oil; and adding the semicoke into the annular channel from the inner cylinder, allowing the semicoke to run along a direction opposite to the material running direction in order to carry out heat exchange of the material in the inner cylinder and absorb the waste heat of the semicoke, discharging parts of the semicoke from the stove, and adding a small amount of the semicoke to the inner cylinder for the mixing of the small amount of the semicoke with a normal temperature mixture in order to further utilize the waste heat of the semicoke. The method has the advantages of simple technology, low energy consumption, no pollution, high product quality, realization of the industrial large-scale production, and easy large-area popularization.

Description

Technical field [0001] The invention relates to a method for dry distillation of small particle materials based on a multilayer rotary kiln. Background technique [0002] As a supplementary and alternative energy source for petroleum, oil shale is rich in oil shale resources in my country. At present, the processes used for dry distillation of oil shale are divided into solid heat carrier dry distillation and gas heat carrier dry distillation. However, most dry distillation processes at home and abroad can only dry distillation of particles with a diameter of 20mm or more. Small particles below 20mm have small particles, small space between materials and poor air permeability. The heat and temperature required for dry distillation cannot be uniformly transferred to the materials, which is easy to cause Blocking of the furnace and coking make the dry distillation furnace unable to operate normally, so small oil shale is discarded, and the resource waste rate reaches more than 20%...

AI Technical Summary

Problems solved by technology

[0004] There are three typical techniques for carbonization of small particle oil shale in foreign countries. One is the ATP furnace (Alberea-Taciuk Processor) in Australia. This device is a solid heat carrier rotary carbonization furnace with huge equipment, complex structure and power consumption Large, unstable operation, often shut down for maintenance, the operating rate is only about 50%, and the longest continuous operation was only 96 days

One is the Galoter furnace in Estonia, which can process 0-25mm oil shale, with a processing capacity of 3000t / d. The problem with the equipment is that the operation rate is not high, the proportion of heavy oil is large, there are mechanical operations, oil and gas Dust removal and flue gas dust removal and other issues

The third is the Tosco-II oil shale dry distillation technology developed by Tosco Corporation of the United States, which is used to process small particle oil shale. This system uses ceramic balls as the heat carrier, and the oil recovery rate reaches 90%. The problems with this equipment are: : High investment in equipment, large amount of maintenance, low thermal efficiency, and the latent heat (fixed carbon) in oil shale semi-coke is not utilized

In the past two years, there are two kinds of small particle retort devices researched in China. One is the DG technology of Dalian University of Technology, which uses solid as the heat carrier; Carbon technology, powdery oil shale and high-temperature gas heat carrier contact, fluidized dry distillation, but the oil shale needs to be crushed to a particle size below 0.3mm, and the equipment process is complex

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