function [sim] = AdsorptionPackedBed(grid, param)

% Define the number of differential equations

    grid.Ne = grid.N - 2 + grid.N;


    C0 = zeros(grid.Ne,1);
    tspan = [1.0 3.0];


    [t, c] = ode15s(@(t,c) APBModel(t, c, grid, param), tspan, C0);

    sim.t = t;
    sim.c = c;