Influence Of Pellet Size Research Articles

Influence of pellet size on product yields and syngas composition during solar-driven high temperature fast pyrolysis of biomass

The growing interest in syngas production from biomass has extended research towards solar-driven pyrolysis taking place at high temperature and heating rate, due to its high efficiency and environmental advantages. The aim of this work is to experimentally study and compare the effect of pellet size (5, 10 and 15 mm height) on product yields (liquid, char and gas), gas composition (H2, CO, CO2, CH4) and tar secondary reactions during fast solar pyrolysis of sawdust pellets (800, 1200 and 1600 °C and heating rates of 10 and 50 °C/s). Additionally, the influence of pellet height on syngas quality is analyzed by parameters such as H2/CO, CH4/H2 ratios, mechanical gas efficiency and carbon conversion efficiency, focused on methanol production. An analysis based on characteristic times and dimensionless numbers is also performed to estimate the rate-controlling phenomena. Experimental results showed that, for temperatures below 1200 °C, there were no significant differences in the gas yield for the three pellet heights. However, the gas product distribution was influenced by the pellet size even at 800 °C. A further increase in temperature emphasized the influence of the pellet height on both gas yield and gas composition. Therefore, it can be argued that, in order to improve the gas yield and the quality of the syngas, the fast pyrogasification of large particles is advisable.

Evaluation of the leaching of florfenicol from coated medicated fish feed into water

Florfenicol is one of the most-used antimicrobial agents in global fish farming. Nevertheless, in most countries, its use is not conducted in accordance with good practices. The aim of this work was to evaluate the leaching of florfenicol from coated fish feed into the water. Analytical methods were developed and validated for the quantitation of florfenicol in medicated feed and water by UHPLC-MS/MS. Florfenicol residues in the water were quantified after 5- and 15-min exposures of the medicated feed in the water at 22 and 28 °C and at pH 4.5 and 8.0. The influence of pellet size and three coating agents (vegetable oil, carboxymethylcellulose, and low-methoxylated pectin) on the leaching of the drug was also assessed. Pellet size, coating agent, water temperature, and time of exposure significantly (p < 0.05) affected florfenicol leaching, while water pH did not interfere with the leaching. Coating with vegetable oil was the most efficient method to reduce florfenicol leaching, while coating with carboxymethylcellulose presented the highest leaching (approximately 60% after 15 min at 28 °C). Thus, the coating agent has a significant effect on the florfenicol leaching rate and, consequently, on the necessary dose of the drug to be administered. Moreover, it is worth mentioning that higher florfenicol leaching will pose a greater risk to environmental health, specifically in terms of the development of bacteria resistant to florfenicol. Additional studies are needed with other polymers and veterinary drugs used in medicated feed for fish farming.

Iron ore pellet drying assisted by microwave: A kinetic evaluation

ABSTRACTDrying is a critical process step to achieve excellent pellet quality in pelletizing process. The complexity and energy consumption toward moisture removing, especially for highly hydrated iron ore, increased the need for breakthrough enhancements to this process. The present study has evaluated kinetics parameters of the moisture release from iron ore green pellet using energy transmitted through microwave (frequency of 2.45 GHz). The influence of pellet size and output power on the moisture effective diffusivity (Deff) and the drying activation energy (Ea) were evaluated. The results make possible to compare the cutting-edge approach with traditional convective drying. Pellet physical quality was investigated through the green crushing strength (GCS), which shows smooth reduction in earlier stages, however not affecting the final dry GCS results. Bonded hematite reduction and calcination of goethite was identified at the microstructure through reflected light microscopy, SEM showed micro cracks formation in several grains.

Influence of Pellet Size on Quality and Microstructure of Iron Ore Pellets

During the induration of pellets, temperature and oxygen partial pressure influence the formation of different phases and microstructure. With increasing the pellet size, these thermo-chemical conditions vary across its cross section. The time difference between the oxidation of the pellet surface and the core increases with increasing pellet size, i.e. the oxidation takes place under different conditions resulting in different phases and microstructure. In this study commercial pellets of different sizes (8–16 mm) were studied for their physical, mechanical and metallurgical properties. Pellets in the size range of 10–12.5 mm showed superior properties. Electron and optical micro structural studies with image analysis revealed that hematite content, pore density, amount and distribution of silicate melt of different sized pellets are different and distinctly affect the pellet quality. SEM-EDX analysis and X-ray mapping techniques revealed that Mg has a specific distribution pattern across the cross section of the pellet.

Influence of pellet size on rat's hoarding behavior

The body weight threshold for hoarding behavior of rats is routinely used as a means to discern an animal's body weight regulation. We explored whether the size of food pellets would modify hoarding and the hoarding threshold. In Experiment 1, we offered the rats either large (ca. 5 g) or small (ca. 2 g) food pellets on alternate days while keeping their body weights within a narrow range when they were not in the hoarding sessions. The hoarding threshold was not influenced, by food size (312±32 g small and 298±13 g large pellets, N.S.). On the other hand, the relationship between hoarded food and body mass significantly differed between small and large pellets (ratio of 2.7). Because such a ratio was similar to that of the respective pellet weights, this suggests that the more the rat is deprived of food, the more willing it is, in a predetermined manner, to move about in search of food. Experiment 2 verified this hypothesis: instead of weighing the food hoarded, we counted the number of pellets hoarded. The slopes of the regression lines were similar in both cases, when the pellets were counted and when the hoarded food was weighed. Results showed no significant differences between these two approaches, suggesting that the weight of hoarded food is a good indicator of the number of trips from home to food in the hoarding experiment.

Influence of pellet size on growth performance in nursery pigs and growth performance, nutrient digestibility, and stomach morphology in finishing pigs (1996)

Pellet size (i.e., 3/32 in., 5/32 in., 5/16 in., and 1/2 in. diameter) had little effect on growth performance during the early stages (d 0 to 5) of the nursery phase. However, the 5/32 in. diameter pellets supported the best efficiencies of gain during the overall nursery (d °to 29) and finishing phases.; Swine Day, Manhattan, KS, November 21, 1996

Influence of pellet size on extraction rate of rice bran oil

Influence of pellet size on extraction rate of rice bran oil

The influence of pellet size and density on the intake by calves of dried grass pellets given as supplements to hay

ABSTRACTHigh (1·31 kg/1) or medium-density (1·17 kg/1) dried grass pellets of 9, 12 or 18 mm diameter were given to British Friesian male calves of 7 to 14 weeks of age as supplements to chopped hay (Experiment 1). Pellets were given ad libitum but with access limited to two periods of 1½ h per day, and hay was given ad libitum for the remaining 21 h. In Experiment 2, high (1·34 kg/1) or medium-density (1·14 kg/1) dried grass pellets of 18 mm diameter were given to British Friesian male calves of 26 to 30 weeks of age. Pellets were given as supplements to chopped hay as in Experiment 1.There was no effect of pellet size or density on total intake of organic matter or live-weight gain by calves in either experiment. With the exception of animals given pellets of 12 mm diameter in Experiment 1, animals in both experiments consumed less pellets of high density than of medium density, but they were able to compensate for low pellet intake by eating more hay.The coefficients of variation for intake were higher in Experiment 1 than in Experiment 2, and higher for the intake of pellets than for total intake. There was a progressive increase in the intake (g organic matter/kg M0·75 per day) by calves in Experiment 1, whereas in Experiment 2 intake increased for the first 10 days and then remained constant. On average the proportion of pellets and hay consumed did not change in Experiment 1, but in Experiment 2 the proportion of pellets in the feed consumed increased from 53·5 to 60·6%.