Influence of gasification agent parameters on the efficiency of high-temperature staged pulverized coal gasification process

Gasification is usually regarded as a typical type of clean coal technologies due to its low specific emissions and low gas cleaning costs. The possibility of combining energy and chemical production (primarily the synthesis of liquid hydrocarbons and oxygenates, hydrogen) on the basis of a single thermochemical process opens up the prospects of environmentally friendly multi-product plants capable of the chemical energy storage and export. Efficient gasification processes require high temperatures, which can be achieved in different ways (reducing the proportion of inert, preheating). Using different mathematical models (based on equations of chemical equilibrium and diffusional kinetics), operation modes of a high-temperature staged gasifier are studied in a wide range of conditions. As a result of these calculations, the main characteristics of the gasification process (characteristic temperatures, the composition of the generator gas) and their dependence on the control parameters (specific consumption of the steam; initial air temperature; fuel distribution over the stages; initial oxygen concentration) are determined. Given the kinetic and technological limitations, the paper identifies efficient gasification modes, the use of which is possible for promising power plants.