**2.2 Torrefaction**

Torrefaction is the one of the clean thermal treatments of biomass. Further, torrefaction actively removes the moisture content from biomass, however, similarly improves the efficiency of subsequent thermochemical conversion methods [12]. Biomass that has been torrefied has a number of superior quality over raw biomass, including higher grindability, lower hydrophobicity, higher heating value, and pelletization properties [13]. In the process of torrefaction, several factors influence their performance, such as, torrefaction temperature, holding time, heating rate, environment, moisture content, particle size [14]. **Figure 3** illustrates general flow chart of torrefaction process.
