Production of nanoporous sorbents by partial steam-air conversion of charcoal

A D Nikitin,A F Ryzhkov,G I Khudyakova

doi:10.1088/1742-6596/1128/1/012073

Abstract

An effective sorbent is activated carbon having a developed nanoporous structure with an average pore diameter about 2-4 nm. Perspective method of activated carbon production is the partial steam conversion of the coal bed in boiler furnaces of power plants. The additional thermal energy is produced by burning the syngas. The aim of this work is to study the co-production of activated carbon and syngas by partial steam-air conversion of charcoal. Due to the presence of oxygen in the flow, intensification of conversion occurs. In the laboratory bed reactor, the mass loss curves and the syngas composition were obtained at temperatures of 800°C and 900°C. Two zones with different reaction mechanisms were identified on the height of the bed. The reactions between carbon and steam shift toward hydrogen formation in the oxygen zone. The dependence of the porous structure of the activated carbon on the conversion degree of the raw material is obtained. The maximum of micropores is formed at a conversion degree of 0.5. The material and energy balance of the partial conversion in the laboratory reactor was estimated.

Highlights

One of the global problems of our time is the increase in anthropogenic pollution of the environment
The average compositions of the syngas remained constant throughout each experiment and practically coincided at temperatures of 800°C and 900°C
Despite the oxygen presence in the amount of up to 15% required for complete combustion of the fuel, the proportion of macropores is not large

Summary

Introduction

One of the global problems of our time is the increase in anthropogenic pollution of the environment. In addition to the developed fields of activated carbon (AC) application – water purification, desulfurization of natural and industrial gases, heavy metal compounds capture [1, 2] , new technologies are being developed: mercury removal from flue gases in power plants [3,4,5] and CO2 capture [6]. The producing activated carbon in boiler furnaces of power plants is a perspective method. It is partial steam conversion of the coal bed due to heating from the burning of the main fuel with afterburning of the exuding syngas that is used to receive additional thermal energy [8, 9]

Objectives

Results

Conclusion