Isothermal Drying Kinetic Study of Spent Coffee Grounds Using Thermogravimetric Analysis

Figure 1

SEM images of dry spent coffee grounds particles. (b) The SEM image for spent coffee grounds particles registered at magnitude 1000x and indicates a “sponge-like” aspect. Based on this image, pore sizes were measured and found to vary between 8 ± 0.08 μm and 17 ± 0.17 μm, with an average value of 12.4 ± 0.12 μm. Zein et al. have also reported in the literature pores with dimensions up to 30 μm for dry spent coffee grounds [18]. Le et al. also reported values for spent coffee grounds pore size not exceeding 30 μm [19].