Experimental Study Of Adaptability Of Huainan Coal In Texaco Gasification Technology

The study on ash behaviour of Huainan coals is valuable for estimating the applicability of coal in gasification.Huainan coal can't be used directly in Texaco Gasification technology for its high ash fusion temperature (FT>1500℃). To solve the problem, effect of coal blending and flux addition on ash fusion temperatue, slag viscosity and the properties of coal water slurry (CWS) were studied.The mechanism of mineral transformation and the ash fusion process in reducing conditions were analysed by X-ray diffraction (XRD). The model of Texaco CWS gasification system was established by Aspen Plus. The main conclusions are shown as below.(1)Adding flux and blending coal can decrease the ash fusion temperature efficiently. But adding flux alone needs more additives and increases the ash discharge. The ash fusion temperature of Huainan coal samples can be decreased by blending with much amount of L1, L2 and L3 coals. Combining adding flux with blending coal was perfect because of using Huainan coal largely and meeting the requirements of the process.If the flux was added less than 2% (coal base,%), the amount of huainan coals in blending coals will be more than 50%.(2) The mineral phases in Huainan coal samples generally include kaolinite, quartz, hematite, anhydrite, muscovite and anatase. It is suggested that the high content of kaolinite in Huainan coals shows the high ash fusion temperature. The mullite formed in the heating process was the main reason of the high ash melting temperature of Huainan coals. The structure of aluminosilicate of the main mineral phases in Huainan coals was broken and the intensity of mullite formed was declined at high temperatue by adding flux under reducing atomsphere. Meanwhile the anorthite, hercynite and hematite phases were formed, which reacts with quartz to form a low-melting eutectic mixture to lower the ash fusibility temperature.(3)The water slurry property was almost not influenced by adding flux. Blending coal will increases the slurry viscosity of Huainan coal, the fluidity and stability were little worse with increase of the L1 coal amount.(4) The slag viscosity of Huainan coal can be effectively decreased by flux addition. In the mean time, the slag type changes to glass like slag type.(5)The model of Texaco CWS gasification system was built by simulation software Aspen Plus, which agreed well with the operation data and indicated that the model of coal gasifier was reasonabl. Adding flux and blending coal made consumption of oxygen cut down.The temperature and components of raw syngas were greatly affected by the water slurry concentration and oxygen-coal ratio.This paper provided the introduction of Texaco Furnace and choosing the appropriate sorts of coal for it with good basis and dependable scientific foundation.