USE OF A MIXTURE OF CARBON DIOXIDE AND NITROGEN AS AN INERTING AND FLOW MEDIUM IN POWDER INJECTION SYSTEMS FOR USE IN PULVERIZED COAL GASIFICATION UNDER PRESSURE

摘要

The invention relates to a powder injection system for use in pulverized coal gasification under pressure, which system comprises a reservoir (BK) for stocking the pulverized coal, a plurality of powder injection tubes (SES) and a metering unit (DG). According to the invention, a mixture of nitrogen N₂ / carbon dioxide CO₂ is fed to the components that are at operating pressure, namely the powder injection tube and the metering unit, as the inerting and flow medium or fluidizing medium. The nitrogen N₂ / carbon dioxide CO₂ mixture-carrying components are heated in such a manner that the temperature is above the threshold of the diphase range. The method according to the invention allows reduction of the nitrogen content in the product gas, which nitrogen is caused by the powder injection system, especially when used in pulverized coal gasification under pressure to produce a synthesis gas for the production of different hydrocarbons.