**3. The torrefaction technology**

Torrefaction is a recently well-known technology to upgrade biomass for combustion and gasification applications. It is a thermal pre-treatment technology carried out at atmospheric pressure in the absence of oxygen. Torrefaction of biomass can be described as a mild form of pyrolysis that occurs at temperatures between 200 and 300°C [4]. During torrefaction, the more easily combustible components of biomass (i.e. hemicelluloses) are decomposed first and most vigorously, through carbonization. Only minor decomposition of lignin and cellulose occur at torrefaction temperatures but rate of decomposition depends on the type of biomass [14]. Their chemical structure is changed but no significant mass losses occur [15, 16]. The solid uniform product that is produced has a very low moisture content, high heating value [17] and less hydrophilic compared to the untreated biomass to fresh biomass [1]. Furthermore, the fibrous and tenacious nature of the biomass is reduced, resulting in a brittle material that can easily be comminuted into smaller particles [18].

is being considered as a feedstock for bioethanol. Very few studies have reported the use of

Development of Torrefaction Technology for Solid Fuel Using Renewable Biomass

http://dx.doi.org/10.5772/intechopen.76100

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Agricultural wastes such as rice husks are now used as a source of energy that helps advance the agriculture industry, particularly on rice mechanization and post production operations. The Philippines produces an average of 2 million metric tons of rice husks annually. A kilo of rice husk basically contains about 3000 kcal of heat energy and can provide sufficient amount of clean gaseous fuel when gasified. Converting this available biomass waste into energy by gasification can provide about 25 pJ of energy which can be utilized for various heat and power applications, especially in rice farming and rural-based

Dried coconut leaves were collected in a coconut farm in Calauan, Laguna (CALABARZON, Region IV-A). Cogongrass and rice husks were collected from Puerto Princesa, Palawan [5]. The dried biomass was air dried and cut into small pieces. The cut biomass was stored in

The thermal behaviors of dried coconut leaves [4, 5], cogongrass [5] and rice husks [5] (about 5.769 mg milled using a Thomas Willey mill) were investigated at the Polymer Materials Laboratory at the Institute of Chemistry, College of Science, University of the Philippines, Dilijan, Quezon City using a TGA Q50 (TA Instrument). The heating program consisted on a 5 min hold at 30°C, ramp up to 800°C at a heating rate of 10°C/min, and then the weight difference was recorded as a function of temperature profile. Nitrogen was used as a purging gas

The calorimetric experiments were performed using the raw and torrefied biomass. About 1 g size sample was placed in a nickel crucible introduced into a Parr 1356 Oxygen Combustion Bomb Calorimeter. The experiments were performed at 25°C. The bomb was filled with oxygen at a filling pressure of 30 atm. The calorimeter was placed in an isothermal-jacket with an air-gap separation of 10 mm between all surfaces. The calorimeter was filled with two liters of de-ionized water. The fuel was ignited through external electric connections. Temperature of this water was measured to 10−4°C at intervals of 10 s at the start of ignition to calculate the

cogongrass as a renewable energy source.

operations [24].

**5. Methodology**

**5.1. Sample production of biomass**

plastic containers at room temperature.

**5.2. Characterization of the raw biomass**

*5.2.1. Thermogravimetric analysis (TGA)*

at a flow rate of 50 ml/min [4].

heating value for each sample [4].

*5.2.2. Heating value*
