**2. Materials and methods**

### **2.1 Origin of materials**

The rice husk originates from the Muriaé region, in the state of Minas Gerais (Brazil) where it is widely grown and easy to obtain biomass. The banana peel was obtained in fairs of the city of Teófilo Otoni – MG (Brazil), these fairs are supplied by small producers of all region of the Mucuri Valley.

### **2.2 Preparation of biomass**
