**2. Value addition technologies**

#### **2.1 Pyrolysis**

In pyrolysis, the organic material and volatiles present in the biomass undergo an irreversible thermochemical decomposition reaction to produce biofuels. Pyrolysis technologies can be classified as slow, flash, and fast [1]. The fast heating rate and short vapor residence times result in rapid exit of the volatile hydrocarbon vapors from the reactor and condensation into bio-oil, whereas slow pyrolysis results in greater biochar production due to increasing of carbonization of biomass due to slow heating rate and longer vapor residence time [11]. However, slow pyrolysis is the prominent technique than others to produce biochar. The remaining pyrolysis techniques enable the production of bio-oil and gases. A flow chart of pyrolysis is present in **Figure 2**.

**Figure 2.** *A simple flow chart of pyrolysis process.*
