2013 1(12)

SIMULATION OF TWO STAGE GASIFIER FOR CONVERSION OF COAL AND SLUDGE IN THE FLOW OF SUPERHEATED STEAM

Bogomolov A.R.¹, Alekseev M.V.¹, Sorokin A.L.¹, Pribaturin N.A.¹, Kagakin E.I.², Shevyrev S.A.²

¹ Institute of Thermophysics SB RAS, Novosibirsk, Russia
² Kuzbass State Technical University, Kemerovo, Russia

Introduction

Increase of extraction and enrichment of coal leads to increased amount of waste of coal industry. The waste contains significant organic components in the amount of economically beneficial to use, but not quite suitable for processing with the use of existing traditional technologies. Therefore, of great importance is the development of technology of nonfuel use of organic part of low-grade coals and wastes of coal-mining industry. Gasification using of superheated water vapor is one of the technologies of processing of such materials with high humidity and ash content. The advantage of using of superheated water vapor as active agent is confirmed by recent foreign studies. Extensive experimental studies are needed for development of industrial technology of gasification. The volume of these studies can be considerably reduced when combined the experimental studies with the numerical modeling of process steam reforming.

Purpose

The present work is focused on the numerical modeling of steam gasification of coal in a two-stage gasifier.

Method

Processes of drying, carbonization and steam reforming of carbonized raw materials subsequently proceed at steam gasification. Earlier authors carried out numerical simulation of steam gasification of coal and sludge in the flow of superheated steam in a joint course of all these processes in one stage gasifier. The simulation results showed that the combination of processes of drying, carbonization and steam reforming in one stage gasifier is not effective. To improve the performance of steam gasification of carbon containing materials the development of two-stage technology is more perspective. Processes of drying and carbonization of coal and sludge proceed at the first stage of technology. Steam conversion of carbonized product obtained in the first stage proceeds at the second stage technology. Modeling of two-stage gasifier with thermal power of steam flow 50 kW for each stage was carried out. Properties of slurry coal of CP «Berezovskaja» were selected for modeling gasification.

Results

The dependence of the completeness of gasification on the relationship of the mass flow rate of steam and the processed material is studied. Comparison of single-stage and two-stage variants of technology is carried out. The obtained results can be used for designing an industrial installation.

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