Thermogravimetric assessment for combustion characteristic of torrefied pellet biomass from agricultural solid waste

Abstract

This present paper is focused on the investigation of combustion characteristics of torrefied pellet biomass from agricultural waste. Four biomass pellet samples such as sugarcane bagasse, Napier grass, Palm Empty Fruit Bunches, and Cassava stem were torrefied in a designed cylinder tubular pyrolysis reactor. The reactor was set up under 30 min of residence time, and the temperature reaction was varied at 200, 250, and 300 °C in an inert atmosphere. The torrefied products were then characterized in terms of their psychochemical properties such as proximate, ultimate, calorific value, and combustion properties. The combustion properties of raw and torrefied biomass pellets during the combustion process were investigated by the thermogravimetric analyzer Exstar SII TG/DTA7300. The samples were heated at an ambient temperature up to 800 °C at a constant heating rate of airflow at 10 °C/min in airflow. The results showed that the moisture content and volatile matter of torrefied pellets decreased by 2 to 5% and 8 to 14%, subsequently. Otherwise, the fixed carbon content is up to three times higher than the raw material. The study conclusively that torrefaction can also able to enhance combustion performance in terms of ignition and burnout temperature, ignition and burnout index, and combustion rate. The results shows that, the ignition and burnout temperatures of torrefied pellets are higher than raw material. The ignition and combustion index of torrefied pellets are lower than raw material, and the torrefied pellets have a longer burning time and a higher combustion temperature.

Near-Infrared Spectroscopy Modeling of Combustion Characteristics in Chip and Ground Biomass from Fast-Growing Trees and Agricultural Residue

“…TGA is a destructive yet an effective method for studying the thermal behavior of biomass and for evaluating the combustion performance indices [3]. The TGA investigation is based on the mass loss of biomass samples during the entire experimental duration [21]. The combustion setting in TGA (TG 209 F3 Tarsus, Netzsch, Germany), with a microbalance sensitivity of 0.1 µg resolution, is programmed to simulate biomass direct combustion in air, i.e., with oxygen (99.7%) and nitrogen (99.99%) in a 1:4 ratio.…”

“…This typically takes place within a temperature range of 35-140 • C. The second stage involves devolatilization and its combustion, which occurs at temperatures around 150-405 • C and is characterized by a rapid loss of mass. The third stage involves the char combustion, during which the rate of mass loss decreases and gradually slows down until the sample eventually turns into ash [21].…”

“…TGA has also been instrumental in studying the ignition behavior of straw pellets [18] and investigating ignition and burnout in bamboo and sugarcane bagasse [19]. Furthermore, TGA has been utilized to analyze the combustion characteristics of various biomass pellet types, including rubberwood sawdust pellets, teak sawdust pellets, eucalyptus bark pellets, cassava rhizome pellets [20], as well as agricultural solid waste torrefied pellets [21] and briquettes [15]. These studies collectively provide valuable insights into the reactivity, flammability, and thermal properties of these biomass materials, exhibiting their potential as fuels and their role in sustainable energy solutions.…”

“…A high D f signifies complete combustion, leaving minimal unburned fuel or ash content [19,22]. A higher D i and D f indicate greater reactivity of the biomass, making it more suitable and flammable as a fuel [21]. The peak temperature is the point on the TGA curve at which the rate of weight loss of biomass due to combustion is at its maximum.…”