Coal gasification in a spouted bed

Abstract

Low Btu gas has been produced by gasifying coal in a spouted bed reactor. Coal of size 0.8‐3.6 mm is fed continuously to a 0.15 m diameter spouted bed of inerts and gasified using mixtures of steam and air. Tests of the process with Western Canadian coals of free swelling index 0, 4 and 7 are reported. Gases of heating value to 3.61 MJ/m3 were produced at coal throughputs of 0.188 kg/m2s with the reactor operating at atmospheric pressure and temperatures to 930°C. Characteristics of the spouted bed gasifier are presented and results compared to commercial moving and fluidized bed systems. A simple mathematical model based on the two‐region spouted bed model of Mathur and Lim is used to predict the effect on steam utilization of bed composition, bed height and diameter, and particle size.

Behavior of fine particles in a spouted bed consisting of fine and coarse particles

“…On a employe des mesures de retention moyenne des particules sur une section droite et de la vitesse locale des particules pour interpreter la diminution de vitesse d'ilutriation le long du franc-bord. On a aussi employe le concept connu de hauteur de desengagement.spouted bed consisting of inert particles has recently A been utilized for both combustion (Khoshnoodi and Weinberg, 1978) and gasification (Foong et al, 1980,…”

Coal gasification in a jet‐spouted bed

“…In all runs at gasification temperatures up to 1 150"C, the temperatures of the whole bed were maintained within rt 50°C of the average. This was nearly the same value as in a single-stage, conventional spouted bed gasifier operated at about 900°C (Foong et al, 1980(Foong et al, , 1981. The uniformity of the temperature in the whole bed reflects not only the wellmixed condition of the particles in each stage but also the appropriate oxygen feeding method employed in this gasifier.…”

“…It has been reported that the coal feed rate is most critical in deciding the smoothness of a run when caking coal is gasified (Foong et al, 1980). In the present work, however, trouble-free operation was achieved at a maximum bed temperature up to 1 150°C over the experimental range of the coal feed rate, i.e.…”

“…oal gasification processes operated in the dry ash mode C employ various types of reactors including fixed, moving, fluidized and conventional spouted beds. Although each reactor has its own advantage (Foong et al, 1980), there is a common limitation in gasification temperature to avoid incurring ash clinkering troubles. This limitation results in a lower performance of these gasifiers than that of an entrained bed gasifier operated in the wet ash mode (Fujinami et al, 1988).…”

Pyrolysis of western canadian coals in a spouted bed

“…Alternately, by pulverizing the coal, an entrained reactor may be used in which voidage is sufficiently high to avoid agglomeration (Chang et al, 1980). Prior work in our laboratories had shown that gasification of highly caking coals could be carried out without agglomeration if a spouted bed of inerts was used (Foong et al, 1980). In this work a similar approach was used for pyrolysis.…”