矽粉對稻殼灰分碳熱還原氮化反應之影響研究｜國立中央大學博碩士論文系統

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研究生：	王勇謀 Yung-Mou Wang
論文名稱：	矽粉對稻殼灰分碳熱還原氮化反應之影響研究 The Carbothermal Reduction and Nitridation of Rice Husk Ash with Silicon Powder Addition
指導教授：	張奉文 Feg-Wen Chang
口試委員:
學位類別：	碩士 Master
系所名稱：	工學院 - 化學工程與材料工程學系 Department of Chemical & Materials Engineering
畢業學年度：	91
語文別：	中文
論文頁數：	94
中文關鍵詞：	氮化矽、碳熱還原、矽粉、稻殼灰分、氮化反應
外文關鍵詞：	Carbothermal Reduction, Silicon Nitride, Nitridation, Rice Husk Ash, Silicon Powder
相關次數：	點閱：14 下載：0
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摘要
本研究以矽粉為添加劑，在氮氣環境下進行熱解後稻殼灰分的碳熱還原反應，探討矽粉添加劑對反應產物的形態、反應速率等影響，並深入研究矽粉添加劑於反應中所扮演的角色。研究中使用直立式管狀高溫爐系統，由反應前後的重量變化求得稻殼灰分的轉化率，以探討各項操作變數對反應的影響。
而在操作變數方面包括：氮氣流率、矽粉添加量、樣品載量、顆粒大小及反應溫度等。研究中並做各種物性分析如：感應耦合電漿質譜分析儀 (ICP-MS)、元素分析儀 (EA)、比表面積測定儀 (BET)、X-射線繞射儀 (XRD)、掃描式電子顯微鏡 (LV-SEM) 等來提供各項實驗結果的佐證。
實驗結果顯示，稻殼經由水洗、酸洗及熱解前處理後，由EA分析得C/SiO2莫耳數比為3.72 。BET特性分析得其比表面積為235m2/g，並由等溫曲線中，了解稻殼灰分為一種多孔性物質的毛細管凝結現象。產物方面，利用XRD分析得知反應產物為氮化矽，且隨添加量的增加，特徵峰強度更強。增大氮氣流率下，可增加稻殼灰分的轉化率，但當氮氣流率大於400 ml/min時，對於轉化率影響較不明顯。添加矽粉後可以增加稻殼灰分的轉化率，添加1wt %以上則轉化率增加幅度變小。減小稻殼灰分粉粒直徑可增加其轉化率。反應溫度對提高轉化率影響甚為顯著。另由LV-SEM顯示產物氮化矽為鬚晶狀結構，且隨添加量的增加產物分布更為均勻。在化學反應控制區內，反應的活化能為478.5 kJ / mol。

Abstract
The carbothermal reduction and nitridation of rice husk ash with silicon powder addition was investigated by weight change measurement. The reaction were carried out in a vertical reaction tube heated by a tubular furnace. In this study, the operating variables have been discussed included: nitrogen flow rate, amount of silicon powder addition in the reactant, grain size, sample weight and reaction temperature. The analysis of this experiment is conducted by element analysis (EA), inductively coupled plasma-mass spectrometer (ICP-MS), BET surface area, X-ray diffraction (XRD) and scanning electron microscope (SEM).
The experimental results indicated that the conversion of rice husk ash is increased with an increasing nitrogen flow rate and the effect is not appreciable when the flow rate exceeds 400ml/min. The conversion of rice husk ash is increased with an increasing amount of silicon powder addition in the reactant. Reducing the grain size of rice husk would accelerate the reaction rate. Moreover, the reaction rate and the conversion of rice husk ash is significantly increased with higher reaction temperature. The reaction product is fibrous shape a-Si3N4 with silicon addition. In the chemical reaction controlled region, the activation energy of the reaction is 478.5 kJ/mol when silicon powder addition is 1wt %.

目 錄
中文摘要	I
英文摘要	III
目錄	IV
圖索引	VI
表索引	IX
符號說明	X
第一章 緒論	1
第二章 文獻回顧	7
2.1 稻殼灰分的性質與製備程序	8
2.2 氮化矽的形態結構	13
2.3 稻殼灰分的碳熱還原氮化反應	15
第三章 理論背景	21
3.1 氮化矽生成機構及熱力學上的分析	21
3.2 動力學上的分析	26
3.3 轉化率的計算	29
第四章 實驗部份	33
4.1 藥品及氣體	33
4.2 儀器設備	33
4.3 試樣的前處理	36
4.4 氮化反應系統	41
4.5 試樣的成分分析	44
4.6 試樣的物性分析	45
4.7 實驗流程概要和操作變數	50
第五章 結果與討論	52
5.1 試樣物性的分析結果	52
5.2 稻殼灰分還原條件的探討	67
5.3 反應動力學的研究	76
5.4 氮化矽生長機構的探討	81
第六章 結論	84
參考文獻	86
附錄 實驗數據	90
圖 索 引
Figure 2-1 Section of the crystal structure Si3N4, view approximately along C. (Lange, 1991)	14
Figure 3-1 The process of a reaction of a porous solid reactant with a gas to form a porous solid product.	28
Figure 4-1 Manually operated hydraulic press	34
Figure 4-2 Schematic diagram of the apparatus for the acid leaching of rice husk	38
Figure 4-3 Schematic diagram of the apparatus for pyrolysis of rice husk.	40
Figure 4-4 Schematic diagram of the apparatus for the nitridation system	42
Figure 4-5 Schematic diagram of the function for X-ray diffractometer.	48
Figure 4-6 The flow chart of the nitridation of RHA/C/Si mixture	51
Figure 5-1 Adsorption isotherm of BET of RHA/C	54
Figure 5-2 BET plot of RHA/C	56
Figure 5-3 X-ray diffractogram of RHA/C.	57
Figure 5-4 X-ray diffractogram of nitrided specimen without Si addition (nitridation at 1698K for 4h)	58
Figure 5-5 X-ray diffractogram of nitrided specimen with 1wt % Si
addition (nitridation at 1698K for 4h)..	59
Figure 5-6 X-ray diffractogram of nitrided specimen with different wt % Si addition (nitridation at 1698K for 4h)	61
Figure 5-7 X-ray diffractogram of nitrided specimen with different reduction temperature (nitridation with 1wt % Si addition for 4h).	62
Figure 5-8 Scanning electron micrographs of the specimen (a) RHA/C (x600) (b) RHA/C (x2000) (c) nitridation pellet without Si addition at 1698K for 4h (x600) (d) nitridation pellet without Si addition at 1698K for 4h (x2000).	63
Figure 5-9 Scanning electron micrographs of the specimen (a) nitridation pellet with 1wt % Si addition at 1698K for 2h (x2000) (b) nitridation pellet with 1wt % Si addition at 1698K for 4h (x2000) (c) nitridation pellet with 1wt % Si addition at 1698K for 2h (x600) (d) nitridation pellet with 1wt % Si addition at 1698K for 2h (x600).	65
Figure 5-10 Scanning electron micrographs of the specimen (a) nitridation pellet with 1wt % Si addition at 1658K for 4h (x600) (b) nitridation pellet with 1wt % Si addition at 1658K for 4h (x2000) Scanning electron micrographs of the specimen (c) nitridation pellet with 5wt % Si addition at 1698K for 4h (x600) (d) nitridation pellet with 5wt % Si addition at 1698K for 4h (x2000)	66
Figure 5-11 The effect of nitrogen flow on the nitridation of sample (Si addition: 1wt %, sample weight: 0.25g , grain size: 25-38mm , temperature: 1698K, reaction time: 4h, pellet-forming pressure: 1.5x106 kPa)	68
Figure 5-12 The effect of Si powder addition on the nitridation of sample (N2 flow rate: 400ml/min, sample weight: 0.25g, grain size: 25-38mm, temperature: 1698K, reaction time: 4h, pellet-forming pressure: 1.5x106 kPa)	70
Figure 5-13 The effect of grain size on the nitridation of sample (N2 flow rate: 400ml/min, Si addition: 1wt %, sample weight: 0.25g, temperature: 1698K, reaction time: 4h, pellet-forming pressure: 1.5x106 kPa)	72
Figure 5-14 The effect of sample weight on the nitridation of sample (N2 flow rate: 400ml/min, Si addition: 1wt %, grain size: 25-38mm, temperature: 1698K, reaction time: 4h pellet-forming pressure: 1.5x106 kPa)	74
Figure 5-15 The effect of reaction temperature on the nitridation of sample (N2 flow rate: 400ml/min, Si addition: 1wt %,
sample weight: 0.25, grain size: 25-38mm, reaction time:
4h, pellet-forming pressure: 1.5x106 kPa)	75
Figure 5-16 Evaluation of the initial nitridation rate at different reduction temperature	78
Figure 5-17 Arrhenius plot showing the temperature dependence of initial nitridation rate of sample (Si addition: 1wt %, pellet-forming pressure: 1.5x10-6kPa, N2 flow rate: 400mi/min, sample weight: 0.25g, grain size:25-38mm)	80
表 索 引
Table 1-1 Physical properties of Si3N4 material. (Lange et al., 1991)	3
Table 1-2 The various methods for the synthesis of Si3N4	4
Table 2-1 Organic constituent of rice husk. (Patel et al., 1987)	.9
Table 2-2 Chemical analysis of raw rice husk. (Patel et al., 1987)………………………………………………….…...10
Table 5-1 Ultimate element analysis of rice husks after pyrolysisa.	.53
Table 5-2 The ICP-MS analysis and element analysis of RHA after carbon removal	53
Table A-1 Effect of nitrogen flow rate on the nitridation of sample	90
Table A-2 Effect of Si added on the nitridation of sample.	91
Table A-3 Effect of Grain size on the nitridation of sample.	92
Table A-4 Effect of sample weight on the nitridation of sample.	93
Table A-5 Effect of reaction temperature on the nitridation of sample……………………………………………………....94

                                

參考文獻
Badrak. S. A., T. S. Bartnitskaya, and I. M. Baryshevskay, et al.,
“Thermodynamic calculations for the assessment of possible ways of formation of silicon nitride”, Porohk. Metall., 9, 66 (1981).
Blumenthal J. I., M. J. Santy and F. A. Burns, AIAA J., 4, 1053 (1966).
Chen, J. M. and F. W. Chang，"The chlorination kinetics of rice husk ", Ind. Eng. Chem. Res., 30 , 2214 (1991).
Cho Y. M. and J. A. Charles, “Synthesis of nitrogen ceramic powders by carbothermal reduction and nitridation Part 1 silicon nitride “, Mater. Sci. and Tech., 7, 289 (1991).
Chong-Min Wang and F. L. Riley, “Structural nano-defects in a-silicon nitride“, Journal of the European Ceramic Society.,16, 679-683 (1996).
Durham B. G., Marlyn J. Murtha and George Burnet, “Si3N4 by the carbothermal ammonolysis of silica ”, Adv. Ceram. Mater., 3(1), 45 (1988).
Durham S. J. P., K. Shanker, and R. A. L. Drew, “Carbothermal synthesis of silicon nitride: effect of reaction conditions “, J. Am. Ceram. Soc., 74(1), 31 (1991).
Durham S. J. P., K. Shanker, and R. A. L. Drew, “Silicon nitride particle formation during carbothermal reduction “, P.313 in ceramic powder processing science. Edited by H. hausner, G. Messing, and S. Hirano. Deutsche Keramische Gesellschaft, Koln, FRG, (1989).
Durham S. J. P., K. Shanker, and R. A. L. Drew, “ Thermochemistry of the Si-O-N-C system with relation to the formation of silicon nitride “, Can. Metall. Q., 30(1), 39-43 (1991).
Ekelund, M. and B. Forslund, “Carbothermal preparation of silicon nitride: influence of starting material and synthesis parameters “, J. Am. Ceram. Soc., 75(3), 532-539 (1991).
Ekelund, M. and B. Forslund, “Reactions whthin Quartz-Carbon Mixtures in a Nitrogen Atmosphere “, J. Eur. Ceram. Soc., 9(2), 107-119 (1992).
Fiqusch V. and T. Licko, “Synthesis of silicon nitride powder by carbothermal nitriding of silica “, P.157 in high tech ceramics. Edited by P.Vincenzini. Elsevier, Amsterdam, The netherlands, (1987).
Han W., S. Fan, Q. Lee, B. Gu, X. Zhang, and D. Yu, “Synthesis of silicon nitride nanorods using carbon nanotube as a template”, Appl. Phys.Lett., 71(16), 2271-2273 (1998).
Hanna, S. B., B. A. L. Mansour, A. S. Taha, and H. M. A. Abd-allah,“silicon carbide and nitride from rice hulls III – formation of silicon nitride “, Br. Ceram. Trans. J., 84, 18 (1985).
Hendry A. and K. H. Jack, In Special Ceramics (edited by P. Popper). P.199 Br.Cer. Res. Assoc., Stoke on Trent (1975).
Hirosaki N., Y. Akimune, and M. Mitomo, “Effect of grain-growth of beta-silicon nitride on strength, weibull modulus, and fraacture –toughness“, J. Am. Ceram. Soc., 76(7), 1892 (1993).
Ibrahim, D. M. and S. A. EL-Hemaly, “Thermal treatment of rice-husk ash : effect of time firing on pore structure and crystallite size”, Thermochimica Acta., 37, 347 (1980).
Inoue H., K. Komeya and A. Tsuge, ”Synthesis of silicon nitride powder from silica reduction “, Comm. of the Amer. Ceram. Soc., December, C-205 (1982).
Jack K. H., “In progress of nitrogen ceramic “, Edited by F. L. Riely. Martins Nijhoff Publishers, Boston, P.465 (1983).
Koc R., and S. Kaza, ”Synthesis of α-Si3N4 from carbo coated silica by carbothermal reduction and nitridation”, J. Eur. Ceram. Soc., 18, 1471-1477 (1998)
Komeya K. and H. Inoue, “Synthesis of the a form silicon nitride from silica “, J. Mater. Sci.Lett., 10, 1243 (1975).
Komeya K., H. Inoue and T. Ohta, US Patent 4117095 (1978).
Krishnarao R. V., M. M. Godkhindi, P. G. Mukunda and M. Chakraborty, “Direct pyrolysis of raw rice husks for maximization of silicon carbide whisker formation ”, J. Am. Ceram. Soc., 74, 2896 (1991).
Kubaschewski O., E. L. L. Evans, and C. B. Alcock, “Tables “ in Metallurgical Thermochemistry Volume 1, Raynor, G. V., Eds, Pergamon: Oxford (1967).
Kumar B., and M. M. Godkhindi, “Studies on the formation of SiC, Si3N4 and Si2N2O during pyrolysis of rice husk”, J. Mater. Sci. Lett., 15, 403-405 (1996).
Lee J. G., PHD thesis, University of Utah, (1976).
Lee D. D., S. J. L. Kang, G. Petzow, D. N. Yoo,” Effect of alpha-beta (beta’) phase-transition on the sintering of silicon-nitride ceramics ”, J. Mater. Pro. Tech., 73(3), 767 (1990).
Lencart-Silva F., and J. M. Vieira, ”Carbothermal reduction and nitridation of silica : nuclei planar growth controlled by silicon monoxide diffusion on the reducer surface”, J. Eur. Ceram. Soc., 18, 1471-1477 (1998).
Licko T., V. Figusch, and J. Puchyova, “Synthesis of silicon nitride by carbothermal reduction and nitriding of silica : control of kinetics and morphology”, J. Eur. Ceram. Soc., 9, 219-230 (1992).
Liou, T. H. and F. W. Chang, “The nitridation kinetics of pyrolyzed rice husk”, Ind. Eng. Chem. Res., 35, 3375 (1996).
Liou, T. H. ,F. W. Chang, and J. J. Lo, “Pyrolysis kinetics of acid-leached rice husk” , Ind. Eng. Chem. Res., 36, 568 (1997).
Magnus E., “Preparation of silicon nitride powder by carbothermal reduction of silica in a nitride atmosphere “, Chem. Commum., 4, 58 (1991).
Mansour, N.A.L. and Hanna, S. B. “Silicon carbide and nitride from rice hulls-II. Effect of iron on the formation of silicon carbide “, Trans. J. Br. Ceram. Soc. 78(6), 132 (1979).
Moulson A. J., “Review: reaction-bonded silicon nitride: its formation and properties “, J. Mater. Sci., 14, 1017 (1979).
Rahman I. A., F. L. Riley, “The control of morphology in silicon nitride powder from rice husk “, J. Eur. Ceram. Soc., 5, 11-22 (1989).
Schwartz M. M., “Powder”, in “Handbook of Structural Ceramics ”, 4, 43 (1992).
Szekely J., J. M. Evans, and H. Y. Sohn, “Reactions of porous solids “, in gas-solid reaction, Academic: New York (1976).
Weimer A. W., J. R. Cassiday, D. W. Susnitzky, C. K. Black, “Carbothermal nitridation synthesis of a-Si3N4 powder from pyrolysed rice hulls ”, J. Mater. Sci., 31, 6005 (1996).
Weimer A. W., A. E. Glenn, W. S. David, R. B. Donald, W. M. Jeffrey, “Mechanism and kinetics of the carbothermal nitridation synthesis of a-silicon nitride “, J. Am. Ceram. Soc., 80(11), 2853 (1997).
Weimer A. W., “Effect of si metal addition to C-SiO2 precursors for synthesizing Si3N4 by carbothermal nitridation”, J. Mater. Ceram. Soc., 17(2), 123-125 (1998).
Weimer A. W., R. K. Bordia, “Processing and properties of nanophase SiC/ Si3N4 composites“, Composites: Part B 30, 647-655 (1999).
Zhang, Shi-Chang, W. R. Cannon, “Preparation of silicon nitride from Silica “, J. Amer. Ceram. Soc., 67(10), 691 (1984).
Zhuang, Y., J. Wang, and W. Li, “Synthesis of a-silicon nitride (Si3N4) powder from carbothermal reduction “, Chem. Abstr., 115, 55156d (1991).
劉宗宏，二氧化矽/碳粉和稻殼灰分氮化反應動力學之研究，國立中央大學博士論文 (1995)。

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