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"ABSTRAKThis research aims to study on the impact of temperature, reaction time and particle size of biomass on the property of calorific value in 3 types of raw biomass including palm branches, balm fibres and palm shell, and to forecast the calorific value equations to study the impacts of palm branch, palm fibre and palm shells calorific values. The experiment was carried out by grinding all raw biomass to be sized of 3 mm with a weight of 10 g each, then treated them in the reactor under the torrefaction temperature of 220 oC, 260 oC and 280 oC with a range of time at 20, 40 and 60 minutes. After that, all torrefied biomass were analyzed of their calorific values by means of ultimate analysis and proximate analysis. The study presented its result that the maximization of temperature and reaction time made the calorific value higher. The ultimate analysis showed the calorific value of palm branches is higher than the calorific value of palm shells and palm fibers showed indifferent values for both analyses. However, the proximate analysis found palm shell possessed the highest calorific value."

"ABSTRAKPenelitian torrefaksi bonggol jagung telah dilakukan untuk mempelajari pengaruh laju alir nitrogen terhadap yield dan komposisi bonggol jagung yang dihasilkan melalui proses torrefaksi. Pengaruh laju alir nitrogen diteliti dengan memvariasikan laju alir nitrogen sebesar 0,3 L/min, 0,5 L/min, dan 0,7 L/min dengan masing-masing variasi laju alir nitrogen dilakukan pada 3 variasi suhu torrefaksi, yaitu 250oC, 275oC, dan 300oC. Proses torrefaksi berlangsung di reaktor tubular dengan holding time 20 menit, heating rate 10oC/menit, dan total massa umpan 15 gram. Identifikasi pengaruh laju alir nitrogen dilakukan dengan menganalisis bonggol jagung hasil torrefaksi dengan menggunakan karakterisasi FTIR, Ultimate, dan Thermogravimetri Analysis (TGA). Hasil penelitian ini menunjukkan bahwa terdapat pengaruh laju alir nitrogen terhadap yield dan komposisi bonggol jagung hasil torrefaksi. Semakin besar laju alir nitrogen maka yield dari bonggol jagung hasil torrefaksi akan semakin kecil. Semakin besar laju alir nitrogen, kandungan oksigen dalam bonggol jagung hasil torrefaksi akan semakin berkurang dan kandungan karbonnya meningkat. Kandungan oksigen setelah torrefaksi menurun hingga 38% pada saat suhu torrefaksi 300oC dengan laju alir nitrogen sebesar 0,7 L/min sementara kandungan karbonnya meningkat hingga 44% bila dibandingkan dengan bonggol jagung umpan torrefaksi, rasio C/O meningkat dari 0,95 menjadi 2,19 dan rasio C/H meningkat dari 6,9 menjadi 13,99. Berdasarkan karakterisasi FTIR seiring semakin besar laju alir nitrogen maka gugus fungsi fenol, guaiacol, catechol, dan ether akan semakin tinggi. Data karakterisasi TGA menunjukan bahwa laju alir nitrogen tidak berpengaruh terhadap suhu pirolisis dari bonggol jagung yang sudah ditorrefaksi. Suhu torrefaksi adalah faktor yang mempengaruhi dari suhu pirolisis bonggol jagung yang sudah ditorrefaksi.

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ABSTRACTTorrefaction of corn cobs has been carried out to study the effect of nitrogen flow rate on yield and torrefied corn cobs composition produced through torrefaction. The effect of nitrogen flow rate was investigated by varying the nitrogen flow rate by 0,3 L/min, 0,5 L/min, and 0,7 L/min with each nitrogen flow rate variation performed on 3 torrefaction temperature variations are 250oC, 275oC, and 300oC. Torrefaction process takes place in a tubular reactor with a holding time of 20 minutes, a heating rate of 10oC/ minute, and a total feed mass of 15 grams. Identification of the effect of nitrogen flow rate was carried out by analyzing the torrefaction corn cobs using FTIR, Ultimate, and Thermogravimetric Analysis (TGA) characterizations. The results of this study indicate that nitrogen flow rate affects yield and torrefied corncobs composition. The greater the nitrogen flow rate, the lower is the yield of torrefied corn cobs. The greater the flow rate of nitrogen, the lower is the oxygen content in the corn cobs and the higher is the carbon content. The oxygen content after torrefaction decreased up to 38% when the torrefaction temperature was carried out at 300oC with a nitrogen flow rate of 0.7 L/min while the carbon content increased by 44%, the C/O ratio increased from 0,95 to 2,19 and the C/H ratio increased from 6,9 to 13,99. Based on FTIR characterization, increasing nitrogen flow rate increases the functional groups furan, phenol, guaiacol, catechol, and ether. Based on the TGA characterization, the nitrogen flow rate did not affect the pyrolysis temperature of the torrefied corn cobs. Torrefaction temperature is a factor that influences the pyrolysis temperature of torrefied corn cobs."

"Torrefaction, which is used to improve the properties of sugarcane bagasse as fuel in pulverised fuel combustion and as carbon feed in gasification, is a low heating rate pyrolysis of biomass carried out at a temperature of 200–300oC, at an atmospheric pressure, and in an inert environment. In the present work, sugarcane bagasse was torrefied at heating rates of 3, 6, and 10oC/minute, respectively, to achieve a final temperature of 275oC and after the final temperature was reached, hold times of 0 and 15 minutes, respectively occurred at a constant temperature of 275oC for a heating rate of 6oC/minute. The physical characteristics of torrefied sugarcane bagasse samples to be determined were a particle size distribution accomplished by grinding, hydrophobicity by allowing the samples to absorb moisture from the ambient air, and pellet hardness of the sample pellets. The torrefaction results show that increasing heating rate and hold time reduced the cellulose content of the sugarcane bagasse to as low as between 5.35% to 10.61% by weight composition, respectively. As the lignin content increased, the sample pellets resulted in better hardness in comparison to that measured on raw sugarcane bagasse. As the hemicellulose content increased, the samples, after grinding and stronger hydrophobicity, produced a higher fraction of smaller particle sizes. The maximum weight fraction of particles in these samples with sizes smaller than 105 µm achieved was 83.43% weight in contrast to 0.62% weight in raw sugarcane bagasse. The maximum water absorption by the samples in 3 hours was 1.28% weight in contrast to 8.02% weight by raw sugarcane bagasse. The results indicate that torrefaction is able to improve sugarcane bagasse physical characteristics, which are favourable for biomass pelletization, storage and transportation."

"Interest in using biomass energy as an alternative to fossil fuels has advanced in recent years. This study aimed to assess the effects of torrefaction on the quality of pyrolysis products. Oil palm biomass, such as empty fruit bunches (EFB), mesocarp fiber (MF) and palm kernel shell (PKS) were either untreated (untorrefied) or torrefied (treated), and subsequently pyrolyzed. The experiment’s conditions for torrefaction were set to be a 220°C temperature, a 10°C/min heating rate, and 30 minutes holding time, and for pyrolysis they were set to a 650°C temperature, 20°C/min heating rate and 2 hours holding time. The nitrogen flow rate of 2L/min was maintained for both experiments. The results revealed that the torrefaction pretreatment improved the heating value of the torrefied biomass to 18–21 MJkg-1 from the previous value of 16–19 MJkg-1 for the untorrefied biomass. During torrefaction, the PKS showed a high solid yield of 95% due to high lignin content. The higher heating value (HHV) of the biochar and bio-oil derived from untorrefied and torrefied biomass were between 26–30 MJkg-1 and 16–17 MJkg-1 for the former, and 28–31 MJkg-1, and 17–20 MJkg-1 for the latter. The maximum HHV of 31.2 MJkg-1 was obtained from torrefied PKS biochar. The pyrolysis of torrefied biomass gave higher quality biochar and bio-oil compared to untorrefied biomass. The bio-oil acquired from the pyrolysis of the torrefied sample is less acidic and has a higher calorific value in comparison with the bio-oil obtained from the untorrefied sample. MF and PKS have demonstrated a superior outcome after torrefaction. In this way, the PKS and MF were identified as better biomass for torrefaction and pyrolysis compared to EFB."

"Deposit ampas tebu di Indonesia yang mencapai 8,5 juta ton per tahun menjadikan biomassa ini potensial untuk dikembangkan sebagai sumber energi alternatif. Perbaikan sifat ampas tebu sebagai bahan bakar padat dilakukan dengan torefaksi, yaitu proses pretreatment termokimia terhadap biomassa yang dilakukan pada suhu 200?300oC, tekanan atmosfer, dan lingkungan yang inert. Ampas tebu ditorefaksi sampai suhu 275oC dengan variasi laju pemanasan sebesar 3, 6, dan 10oC/menit dan variasi waktu penahanan suhu selama 0 dan 15 menit. Analisis yang dilakukan untuk mengetahui karakteristik fisik ampas tebu adalah kandungan lignoselulosa, distribusi ukuran partikel, sifat hidrofobik, dan kekerasan pellet. Kenaikan laju pemanasan dan waktu penahanan suhu mengurangi kandungan hemiselulosa ampas tebu sampai di bawah 6% dan menaikkan kandungan ligninnya sampai di atas 83%. Seiring peningkatan kandungan lignin, kekerasan pellet ampas tebu juga meningkat, yaitu sampai 29,22 pada skala durometer Shore D. Seiring penurunan kandungan hemiselulosa, ampas tebu bersifat lebih mudah dihancurkan dan hidrofobik. Distribusi partikel yang berukuran lebih kecil dari 105 μm pada ampas tebu yang ditorefaksi adalah sebanyak 67%, sedangkan pada ampas tebu yang tidak ditorefaksi hanya 0,62%. Penyerapan air oleh ampas tebu yang ditorefaksi hanya sebanyak 1,3%, sedangkan pada ampas tebu yang tidak ditorefaksi sampai 8,02%. Hasil ini menunjukkan bahwa torefaksi dapat memperbaiki karakteristik fisik ampas tebu.

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Sugarcane bagasse waste in Indonesia reaching 8.5 million tons per year is potential to be developed as an alternative energy source. Torrefaction, which is used to improve the properties of sugarcane bagasse as a solid fuel, is a thermochemical pretreatment of biomass carried out at a temperature of 200?300oC, atmospheric pressure, and inert environment. Sugarcane bagasse is torrefied at 275oC with the heating rate variation of 3, 6, and 10oC/minute and hold time variation of 0 and 15 minutes. Characterizations conducted to determine the physical characteristics of sugarcane bagasse are lignocellulosic content, particle size distribution, hydrophobicity, and pellet hardness. The increasing heating rate and hold time will reduce the hemicellulose content of sugarcane baggase to lower than wt-6% and increase the lignin content to higher than wt-83%. As the lignin content increases, the sugarcane bagasse pellet will have better hardness, i.e. 29.22 on a durometer Shore D scale. As the hemicellulose content increases, sugarcane bagasse will have better particle size distribution and stronger hydrophobic tendency. The particle size distribution of torrefied sugarcane bagasse which is smaller than 105 μm is wt-67% while only wt-0.62% in untorrefied sugarcane bagasse. The water absorbtion of torrefied sugarcane bagasse is wt-1.3% while wt-8.02% in untorrefied sugarcane bagasse. The results indicate that torrefaction is able to improve sugarcane bagasse

physical characteristics."