P. S. T. Sai
Indian Institute of Technology Madras, India
Title: Modeling and simulation of coal gasification in internally circulating fluidized bed
Biography
Biography: P. S. T. Sai
Abstract
Coal gasification is one of the best ways to convert the char into the synthesis gas. This process has proved to be very effective in Internally Circulating Fluidized Bed (ICFB) gasifier. In ICFB, there occurs gas bypassing from draught to annulus region and vice versa. In the present work, the effects of gas bypassing through the orifices on product gas compositions in both annulus and draught tube is studied following the modeling reported in literature.
The same modeling is applied to a coal of inferior quality and the conversion and product gas compositions at different temperatures and the effects of various parameters are studied. The number of circulations a particle should undergo, total gas yield and solid circulation rate inside the reactor is studied at different temperatures for different conversion levels. In addition, the effects of coal feed rate, particle size, and O2 to coal and H2O to coal mass ratio is studied on number of circulations, total gas yield and solid circulation rate.
The optimum operating conditions are also obtained to achieve a specified conversion with minimum number of circulations and maximum gas yield per kg of coal per pass through sequential optimization. For a mixture of particle of different sizes, the conversion and product gas composition in annulus region are studied and compared with uniform size particles. The product gas composition depends strongly on operating parameters such as O2/coal and H2O/coal mass ratio and gas bypassing values through the orifice.
Figure 1: Composition of product gas in annulus region at different temperatures