Preliminary Study of Microwave Irradiation Towards Oil Palm Empty Fruit Bunches Biomass

In this study, torrefaction via microwave irradiation was introduced towards oil palm empty fruit bunches (EFB) samples. The samples of 10 g was fed into the quartz type crucible inside the microwave with the power input limit to 385 W. Continous nitrogen up to 50 ml/min were induced and promoted the non oxidative atmosphere in the closed crucible. This proved the increased of energy properties as high 23.6 MJ/kg for torrefied samples comparable to raw 14.8 MJ/kg. On the result of proximate analysis, fixed carbon shows the increase trends whereby the volatile matter decreased. Torrefaction has been found to improve the energy properties of oil palm EFB biomass as a fuel.

Simulating Thermal State of High-Temperature Ceramic Samples

Developing high-velocity atmospheric aircraft equipped with ramjet engines, which use atmospheric air as the oxidizer, is an important component of aerospace technology prospects. These craft may be employed to quickly deliver payloads over intercontinental distances and as boosters for spacecraft injection into orbit. A characteristic feature of high-velocity atmospheric aircraft is a presence of sharp aerofoil edges subjected to highly oxidative airflow. This means that actual implementation of numerous hypersonic atmospheric aircraft projects largely depends on whether it is possible to develop materials that could remain stable in an oxidative atmosphere at temperatures of 2000--2500 °C. We estimated the thermal state of a structural component in the shape of a blunted wedge made out of promising refractory ceramics under flight conditions at an altitude of 22 km and a velocity of Mach 7

Thermal Conversion of Pine Wood and Kinetic Analysis under Oxidative and Non-Oxidative Environments at Low Heating Rate

Atmosphere is one of the most significant factors in the thermal decomposition of biomass. In domestic or industrial biomass boilers, ambient oxygen concentration varies through time, which means that the reaction will change from pyrolysis to combustion. In this way, to analyze and compare each thermochemical conversion process, a simple analytical method, the non-isothermal thermogravimetric analysis, is carried out under oxidative (air) and non-oxidative (argon) environments at 10 °C/min and as a function of different flow rates (2 to 150 mL/min). Additionally, this work was complemented by a kinetic analysis considering a first-order reaction to each conversion stage and using the Coats–Redfern method. The effect of the atmosphere on the thermal decomposition behavior was evident. It was observed that the thermal decomposition of pine wood particles varied from three to two stages when the oxidative or inert atmosphere was applied. The presence of oxygen changes the mass loss curve mainly at high temperature, around 350 °C, where char reacts with oxygen. The maximum mass loss rate from experiments with the oxidative atmosphere is 15% higher than in an inert atmosphere, the average char combustion rate is approximately 5 times higher and the heat released reaches levels 3.44 times higher than in an inert atmosphere. Ignition and combustion indexes were also defined, and results revealed that particles are ignited faster under oxidative atmosphere and that, on average, the combustion index is 1.7 times higher, which reinforces the more vigorous way that the samples are burned and how char is burned out faster in the experiments with air. Regarding the kinetics analysis, higher activation energies, and consequently, lower reactivity was obtained under the oxidative atmosphere for the second stage (~125 kJ/mol) and under the inert atmosphere for the third thermal conversion stage (~190 kJ/mol).

A study on the biomass wastes' combustion process and their biochar

Peanut shells (PS) and sugar canes (SC) constitute an attractive and an energetic biomass source in Morocco since they are renewable, abundant and available. this work seeks to study the thermal decomposition of these biomass samples and their derived solid biofuel under oxidative atmosphere, and it also attempts to determine their kinetic and thermodynamic combustion parameters . The solid biofuel samples were produced by slow pyrolysis at a temperature of 400°C. Based on the TGA results, the biomass combustion process goes through three stages which are the evaporation of moisture, devolatilization and char formation. For the biochar, it takes two steps that corresponds to the evacuation of water and to the coal combustion. Kinetic parameters of each step are evaluated using Coats-Redfern method, and the thermodynamic parameters are calculated. The results have shown that biochar is less reactive than its original biomass, and that the biomass samples are the most reactive ones in the coal oxidation stage. We have also found that the biomass samples present a different combustion process. These results are useful for the configuration and the design of feasible systems for the conversion of this biomass into energy.