3.1.1. Lignite

The characterization of lignite, supplied by Technische Universität Darmstadt (TUDA), and its particle size distribution, are reported in Table 2 and Figure 2, respectively. The particle size analysis was performed with a Malvern Mastersizer 2000.

**Table 2.** Proximate and ultimate analysis of lignite.

**Figure 2.** Particle size distribution of lignite.

Figure 2 shows that lignite has a bimodal particle size distribution, meaning that there are two main particle diameters: a high content of particles with a smaller diameter (around 70 μm) and another relevant fraction of particles with a larger diameter (around 600 μm). The d3,2 diameter of lignite given by the particle size analysis is 44.08 μm.

As the average diameter of the feedstock particles is very small, working with the filter candle in the freeboard of the gasifier is recommended, in order to avoid the entrainment of lignite particles outside of the reactor with the gas flow.

#### 3.1.2. Olivine before Tests

The particle size analysis of olivine before the gasification tests is reported in Figure 3.

**Figure3.**Particlesize distributionofolivine.

The d3,2 diameter of olivine given by the particle size analysis is 316.75 μm.
