Fragmentation and diffusion model for coal pyrolysis

Numerical simulation of coal pyrolysis with Tar and Gas products prediction

“…[12] A similar approach to the tar fractions calculation is also used to describe the production rate of gaseous products. In the case of gases, each fragment of gas (symbolized by subscribe h) was calculated as a function of chemical species (symbolized by subscribe j), and functional groups (symbolized by subscribe l) follows the equation:…”

“…[12] As the number of chemical species and functional groups is more than one, the simultaneous integration of Eqn (3) was solved by simultaneous matrix arrangement.…”

“…[2,12,[19][20][21] The main gaseous secondary reactions include the following homogeneous and heterogeneous reactions:…”

“…[6] There are many mathematical models that are currently available to predict the composition of the coal pyrolysis with broad range of precision and correctness, for example. [7][8][9][10][11][12][13][14][15] Based on the chemical reaction, the mathematical models can be grouped into single first-order reaction model (SFOR) and complex reaction model scheme (CRS). While the first model was purely empirical chemical reaction approaches, the second model combines chemical reactions models and volatile matter diffusion inside the coal pores.…”

“…Chen and He have tested the accuracy of the three different models: those of FG-DVC (group-depolymerization, vaporization, and cross-linking), chemical percolation model for devolatilization, (CPD) and FD, for three different types of coal with maximum particle diameter of 30 µm at temperature of 1023 K and showed that FD model was predicting better among others. [12] However, the previous FD model that has been built recently did not consider the temperature gradient across the radius of the coal particle. The temperature gradient and heating rate influenced the product yield for each species during the pyrolysis.…”