Maximizing the Recycling of Iron Ore Pellets Fines Using Innovative Organic Binders (1)
This research work focuses on the practicality of using organic binders for the briquetting of pellet fines. The developed briquettes were evaluated in terms of mechanical strength and reduction behavior with hydrogen. A hydraulic compression testing machine and thermogravimetric analysis were incorporated into this work to investigate the mechanical strength and reduction behavior of the produced briquettes. Six organic binders, namely Kempel, lignin, starch, lignosulfonate, Alcotac CB6, and Alcotac FE14, in addition to sodium silicate, were tested for the briquetting of pellet fines. The highest mechanical strength was achieved using sodium silicate, Kempel, CB6, and lignosulfonate. The best combination of binder to attain the required mechanical strength even after 100% reduction was found to be a combination of 1.5 wt.% of organic binder (either CB6 or Kempel) with 0.5 wt.% of inorganic binder (sodium silicate). Upscaling using an extruder gave propitious results in the reduction behavior, as the produced briquettes were highly porous and attained pre-requisite mechanical strength.
Effects of Feeding Speed and Temperature on Properties of Briquettes from Poplar Wood Using a Hydraulic Briquetting Press（2）
The investigation of the effect of densification parameters on briquette quality is necessary for process optimization. This study investigates the influence of die temperature (100, 120, 140 °C) and feeding speed (2.4, 2.9, 3.3 mm s−1) on the quality of briquettes produced from poplar using a hydraulic biomass briquetting machine. The density of the briquettes ranged between 746.7 and 916.8 kg m−3, the mechanical durability ranged from 97.4 to 98.4%, and the water resistance index was between 91.6 and 96.1%. The results show that the temperature was statistically significant (p < 0.05) on the density, mechanical durability and water resistance of biomass briquettes. The feeding speed was statistically significant (p < 0.05) on the density and water resistance. The interaction of temperature and feeding speed was statistically significant (p < 0.05) on all properties considered. The results obtained in this study are useful for optimizing the quality of briquettes produced using the hydraulic piston press.
Effects of Feeding Speed and Temperature on Properties of Briquettes from Poplar Wood Using a Hydraulic Briquetting Press
Biomass has a high potential to contribute towards resolving the energy deficit. Processing biomass into solid fuels enhances its use in various bioenergy conversion technologies. The quality of densified biomass depends on several variables.The investigation of the effect of densification parameters on briquette quality is necessary for process optimization. This study investigates the influence of die temperature and feeding speed on the quality of briquettes produced from poplar using a hydraulic biomass briquetting machine.
Identification of Optimal Binders for Torrefied Biomass Pellets (3)
This section introduces inorganic binders, compares binders, and come to a conclusion that organic binders are more suitable for torrefied energy pellets, and The most promising binders are lignin, biomass tar, tall oil pitch, and lime. Hydrated lime is the best inorganic binder.
Identification of Optimal Binders for Torrefied Biomass Pellets (1)
The pretreatment of biomass through torrefaction is an effective means of improving the fuel quality of woody biomass and its suitability for use in existing facilities burning thermal coal. Densification of torrefied biomass produces a fuel of similar energy density, moisture content, and fixed carbon content to low-grade coals. Additionally, if the torrefaction conditions are optimized, the produced torrefied pellet will be resistant to weathering and biological degradation, allowing for outdoor storage and transport in a manner similar to coal. In untreated biomass, lignin is the primary binding agent for biomass pellets and is activated by the heat and pressures of the pellet extrusion process. The thermal degradation of lignin during torrefaction reduces its binding ability, resulting in pellets of low durability not suitable for transportation. The use of a binding agent can increase the durability of torrefied pellets/briquettes through a number of different binding mechanisms depending on the binder used. This study gives a review of granular binding mechanisms, as they apply to torrefied biomass and assesses a variety of organic and inorganic binding agents, ranking them on their applicability to torrefied pellets based on a number of criteria, including durability, hydrophobicity, and cost. The best binders were found to be solid lignin by-product derived from pulp and paper processing, biomass tar derived from biomass pyrolysis, tall oil pitch, and lime.
Effect of the Mixer Design Parameters on the Performance of a Twin Paddle Blender: A DEM Study (2)
In this paper, the DEM simulations were performed to examine the particle blending in a twin paddle blender containing cohesion-less, mono-disperse spherical particles. The developed DEM model in our previous research was employed to investigate the influences of the impeller configurations (paddle’s angle, gap, and width) on the performance of the mixer. In order to characterize the mixer’s performance, RSD values were calculated in each case.
Effect of the Mixer Design Parameters on the Performance of a Twin Paddle Blender: A DEM Study (1)
The design parameters of a mixing system have a major impact on the quality of the final product. Therefore, identifying the optimum parameters of mixing systems is highly relevant to various industrial processes dealing with particulate flows. However, the studies on the influences of the mixer’s design features are still insufficient. In this study, the Discrete Element Method (DEM) is used to examine the impact of paddle angle, width, and gap on the mixing performance of a twin paddle blender. The mixing performance and particle flow are assessed using the relative standard deviation (RSD) mixing index, velocity field, diffusivity coefficient, granular temperature, the force acting on particles, and the mixer’s power consumption. The mixing performance is highest for a paddle angle of 0° at the cost of the highest forces acting on particles. The paddle width is indicated as a critical factor for achieving better mixing quality. In contrast, the powder mixing efficiency and the mixer’s power consumption are not significantly affected by the paddle gap. The results regarding the power consumption denote that the mixer using the paddle angle of 60° has the minimum power consumption. Moreover, increasing the paddle width results in the enhancement of the mixer’s power consumption.
Modeling and Experimental Study of Ore-Carbon Briquette Reduction under CO–CO2 Atmosphere (2)
Modeling predictions and experimental results indicated that the CO–CO2 atmosphere significantly influences the final reduction degree of the briquette. Increasing the reduction temperature did not increase the final reduction degree but was shown to increase the carbon that was consumed by the oxidative atmosphere. The influence of the CO–CO2 atmosphere on the briquette reduction behavior was found to be insignificant in the early stage but became considerable in the later stage; near the time of the briquette reaching its maximum reduction degree, both iron oxide reduction and metallic iron re-oxidation were able to occur.