Indonesia is one of the largest coconut-producing countries in the world.The utilization of coconut shell waste into briquettes will increase the selling value and become a great export opportunity.However,the effect ...Indonesia is one of the largest coconut-producing countries in the world.The utilization of coconut shell waste into briquettes will increase the selling value and become a great export opportunity.However,the effect of adhesives on the quality of coconut shell charcoal briquettes made using screw extruder machine has not been widely studied.This study aims to determine the effect of adhesive type on the quality of coconut shell charcoal briquettes.The process of fabricating briquettes in this study included crushing,mixing,blending,pressing,and drying.In the mixing process,3 types of adhesives were used,namely tapioca flour(Briquette_1),cassava flour(Briquette_2),and modified cassava flour(Briquette_3)with a concentration of 5%of the weight of coconut shell charcoal powders.The quality of the resulting briquettes and commercial briquettes will be evaluated by moisture content,ash content,volatile matter,fixed carbon,calorific value,density,compressive,and drop test testing.The results of this research showed that the type of adhesive had a significant effect on the quality of the briquettes produced.Specimen Briquette_1 had better quality than commercial briquettes(Briquette_4)and other briquette specimens.The test results showed that Briquette_1 produced briquettes with better compressive strength and friability than the other specimens,at 6.95 N/mm^(2) and 4.44%,respectively.The moisture content,ash content,fixed carbon,and calorific value of Briquette_1 have met the requirements set by the Indonesian National Standard(SNI)number 01-6235-2000.Meanwhile,the volatile matter content and density of Briquette_1 are by the standards of Japan and the United States America(USA).展开更多
In this study, composite briquettes were prepared using gravity dust and converter sludge as the main materials; these briquettes were subsequently reduced in a tube furnace at 1000-1300℃ for 5-30 min under a nitroge...In this study, composite briquettes were prepared using gravity dust and converter sludge as the main materials; these briquettes were subsequently reduced in a tube furnace at 1000-1300℃ for 5-30 min under a nitrogen atmosphere. The effects of reaction temperature, reaction time, and carbon content on the metallization and dezincification ratios of the composite briquettes were studied. The reduced com- posite briquettes were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy-dispersive spectroscopy （EDS）. The results show that the gravity dust and converter sludge are combined into the composite briquettes and a reasonable combination not only improves the performance of the composite briquettes, but also leads to the reduction with no or little reductant and flux. As the re- action temperature is increased and the reaction time is extended, the metallization and dezincification ratios of the composite briquettes in- crease gradually. When the composite briquettes are roasted at 1300℃ for 30 rain, the metallization ratio and dezineification ratio reaches 91.35% and 99.25%, respectively, indicating that most of the iron oxide is reduced and the zinc is almost completely removed. The carbon content is observed to exert a lesser effect on the reduction process; as the C/O molar ratio increases, the metallization and dezincification ra- tios first increase and then decrease.展开更多
HyperCoal was prepared from low-rank coal via high-temperature solvent extraction with N-methylpyrrolidone as an extraction solvent and a liquid-to-solid ratio of 50 mL/g in a high-temperature and high-pressure reacto...HyperCoal was prepared from low-rank coal via high-temperature solvent extraction with N-methylpyrrolidone as an extraction solvent and a liquid-to-solid ratio of 50 mL/g in a high-temperature and high-pressure reactor. When HyperCoal was used as a binder and pulverized coal was used as the raw material, the compressive strength of the hot-pressed briquettes(each with a diameter of 20 mm and mass of 5 g) under different conditions was studied using a hot-pressing mold and a high-temperature furnace. The compressive strength of the hot-pressed briquettes was substantially improved and reached 436 N when the holding time period was 15 min, the hot-pressing temperature was 673 K, and the HyperCoal content, was 15 wt%. Changes in the carbonaceous structure, as reflected by the intensity ratio between the Raman G-and D-bands(IG/ID), strongly affected the compressive strength of hot-pressed briquettes prepared at different hot-pressing temperatures. Compared with cold-pressed briquettes, hot-pressed briquettes have many advantages, including high compressive strength, low ash content, high moisture resistance, and good thermal stability; thus, we expect that hot-pressed briquettes will have broad application prospects.展开更多
Melina wood torrefied at 260℃ for 60 min was agglomerated with lean grade coal fines into composite briquettes using pitch as binder.Torrefied biomass(3%-20%)and coal fines(80%-97%)were blended together to produce th...Melina wood torrefied at 260℃ for 60 min was agglomerated with lean grade coal fines into composite briquettes using pitch as binder.Torrefied biomass(3%-20%)and coal fines(80%-97%)were blended together to produce the composite briquettes under a hydraulic press(28 MPa).The briquettes were cured at 300℃.Density,water resistance,drop to fracture,impact resistance,and cold crushing strength were evaluated for the composite briquettes.The proximate,ultimate,and calorific value analyses were carried out according to different ASTM standards.Microstructural studies were carried out using scanning electron microscope and electron probe microanalyzer equipped with energy dispersive x-ray.Fourier Transform Infrared Spectrophotometer(FTIR)was used to obtain the functional groups in the raw materials and briquettes.The density of the composite briquettes ranged from 0.92 to 1.31 g/cm^(3) after curing.Briquettes with<10%torrefied biomass has good water resistance index(>95%).The highest cold crushing strength of 4 MPa was obtained for briquettes produced from 97%coal fines and 3%torrefied biomass.The highest drop to fracture(54 times/2 m)and impact resistance index(1350)were obtained for the sample produced from 97%coal and 3%torrefied biomass.The fixed and elemental carbons of the briquettes showed a mild improvement compared to the raw coal.The peaks from FTIR spectra for the briquettes shows the presence of aromatic C=C bonds and phenolic OH group.The composite briquettes with up to 20%torrefied biomass can all be useful as fuel for various applications.展开更多
文摘Indonesia is one of the largest coconut-producing countries in the world.The utilization of coconut shell waste into briquettes will increase the selling value and become a great export opportunity.However,the effect of adhesives on the quality of coconut shell charcoal briquettes made using screw extruder machine has not been widely studied.This study aims to determine the effect of adhesive type on the quality of coconut shell charcoal briquettes.The process of fabricating briquettes in this study included crushing,mixing,blending,pressing,and drying.In the mixing process,3 types of adhesives were used,namely tapioca flour(Briquette_1),cassava flour(Briquette_2),and modified cassava flour(Briquette_3)with a concentration of 5%of the weight of coconut shell charcoal powders.The quality of the resulting briquettes and commercial briquettes will be evaluated by moisture content,ash content,volatile matter,fixed carbon,calorific value,density,compressive,and drop test testing.The results of this research showed that the type of adhesive had a significant effect on the quality of the briquettes produced.Specimen Briquette_1 had better quality than commercial briquettes(Briquette_4)and other briquette specimens.The test results showed that Briquette_1 produced briquettes with better compressive strength and friability than the other specimens,at 6.95 N/mm^(2) and 4.44%,respectively.The moisture content,ash content,fixed carbon,and calorific value of Briquette_1 have met the requirements set by the Indonesian National Standard(SNI)number 01-6235-2000.Meanwhile,the volatile matter content and density of Briquette_1 are by the standards of Japan and the United States America(USA).
基金financially supported by the National Natural Science Foundation of China(No.U1260202)the National Basic Research Priorities Program of China(No.2012CB720401)the State Key Laboratory of Solid Waste Reuse for Building Materials
文摘In this study, composite briquettes were prepared using gravity dust and converter sludge as the main materials; these briquettes were subsequently reduced in a tube furnace at 1000-1300℃ for 5-30 min under a nitrogen atmosphere. The effects of reaction temperature, reaction time, and carbon content on the metallization and dezincification ratios of the composite briquettes were studied. The reduced com- posite briquettes were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy-dispersive spectroscopy （EDS）. The results show that the gravity dust and converter sludge are combined into the composite briquettes and a reasonable combination not only improves the performance of the composite briquettes, but also leads to the reduction with no or little reductant and flux. As the re- action temperature is increased and the reaction time is extended, the metallization and dezincification ratios of the composite briquettes in- crease gradually. When the composite briquettes are roasted at 1300℃ for 30 rain, the metallization ratio and dezineification ratio reaches 91.35% and 99.25%, respectively, indicating that most of the iron oxide is reduced and the zinc is almost completely removed. The carbon content is observed to exert a lesser effect on the reduction process; as the C/O molar ratio increases, the metallization and dezincification ra- tios first increase and then decrease.
基金financially supported by the NationalNatural Science Foundation of China (No. 51574023)the National Key Research and Development Program ofChina (No. 2016YFB0600701)
文摘HyperCoal was prepared from low-rank coal via high-temperature solvent extraction with N-methylpyrrolidone as an extraction solvent and a liquid-to-solid ratio of 50 mL/g in a high-temperature and high-pressure reactor. When HyperCoal was used as a binder and pulverized coal was used as the raw material, the compressive strength of the hot-pressed briquettes(each with a diameter of 20 mm and mass of 5 g) under different conditions was studied using a hot-pressing mold and a high-temperature furnace. The compressive strength of the hot-pressed briquettes was substantially improved and reached 436 N when the holding time period was 15 min, the hot-pressing temperature was 673 K, and the HyperCoal content, was 15 wt%. Changes in the carbonaceous structure, as reflected by the intensity ratio between the Raman G-and D-bands(IG/ID), strongly affected the compressive strength of hot-pressed briquettes prepared at different hot-pressing temperatures. Compared with cold-pressed briquettes, hot-pressed briquettes have many advantages, including high compressive strength, low ash content, high moisture resistance, and good thermal stability; thus, we expect that hot-pressed briquettes will have broad application prospects.
基金This research was funded by The World Academy of Science(TWAS),FR:3240287331,Italy and The Council of Scientific and Industrial Research(CSIR FUND:P-81-1-09),India.
文摘Melina wood torrefied at 260℃ for 60 min was agglomerated with lean grade coal fines into composite briquettes using pitch as binder.Torrefied biomass(3%-20%)and coal fines(80%-97%)were blended together to produce the composite briquettes under a hydraulic press(28 MPa).The briquettes were cured at 300℃.Density,water resistance,drop to fracture,impact resistance,and cold crushing strength were evaluated for the composite briquettes.The proximate,ultimate,and calorific value analyses were carried out according to different ASTM standards.Microstructural studies were carried out using scanning electron microscope and electron probe microanalyzer equipped with energy dispersive x-ray.Fourier Transform Infrared Spectrophotometer(FTIR)was used to obtain the functional groups in the raw materials and briquettes.The density of the composite briquettes ranged from 0.92 to 1.31 g/cm^(3) after curing.Briquettes with<10%torrefied biomass has good water resistance index(>95%).The highest cold crushing strength of 4 MPa was obtained for briquettes produced from 97%coal fines and 3%torrefied biomass.The highest drop to fracture(54 times/2 m)and impact resistance index(1350)were obtained for the sample produced from 97%coal and 3%torrefied biomass.The fixed and elemental carbons of the briquettes showed a mild improvement compared to the raw coal.The peaks from FTIR spectra for the briquettes shows the presence of aromatic C=C bonds and phenolic OH group.The composite briquettes with up to 20%torrefied biomass can all be useful as fuel for various applications.
