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1、武漢科技大學(xué)碩士學(xué)位論文炭材料用煤瀝青熱解縮聚研究姓名:吳碧英申請(qǐng)學(xué)位級(jí)別:碩士專(zhuān)業(yè):化學(xué)工藝指導(dǎo)教師:許斌20061108武漢科技大學(xué)碩士學(xué)位論文第l頁(yè)摘要通過(guò)TGA對(duì)炭材料用煤瀝青粘結(jié)劑的熱失重過(guò)程進(jìn)行了研究,分析了煤瀝青粘結(jié)劑的熱解縮聚特征,并對(duì)中溫瀝青和改質(zhì)瀝青的熱解縮聚行為進(jìn)行了對(duì)比分析,研究了升溫速率對(duì)煤瀝青熱解縮聚的影響,發(fā)現(xiàn)快速升溫使煤瀝青組分更多地分解逸出,不利于提高煤瀝青的結(jié)焦值。針對(duì)煤瀝青熱解縮聚反應(yīng)特點(diǎn),建立了煤瀝青熱解縮聚反應(yīng)動(dòng)力學(xué)的DAEM模型和Coats.Redfern模型,其表達(dá)式分別為:
2、-n
3、爿乩『警1+0.∞,s一言和tnt塵筍Hn等一寺·對(duì)武鋼中溫瀝青和改質(zhì)瀝青的熱解縮聚動(dòng)力學(xué)過(guò)程進(jìn)行探索性分析研究,在不同煤瀝青揮發(fā)分組分轉(zhuǎn)化率下,中溫瀝青和改質(zhì)瀝青l(xiāng)n(h/T2)對(duì)1/T的關(guān)系曲線(xiàn)具有很好線(xiàn)性相關(guān)性,兩類(lèi)煤瀝青熱解動(dòng)力學(xué)都屬于一級(jí)反應(yīng)。采用DAEM模型對(duì)煤瀝青熱解縮聚研究顯示,中溫瀝青熱解縮聚反應(yīng)活化能為75~127kJ/mol,改質(zhì)瀝青熱解縮聚反應(yīng)活化能為60~140kJ/mol,中溫瀝青和改質(zhì)瀝青的熱解縮聚反應(yīng)活化能隨著煤瀝青熱分解轉(zhuǎn)化率的增加而呈單調(diào)增大趨勢(shì)。煤瀝青熱分解前期階段,煤瀝青熱解
4、縮聚反應(yīng)所需的反應(yīng)活化能逐漸緩慢增大,并且中溫瀝青熱解縮聚反應(yīng)所需的反應(yīng)活化能要高于改質(zhì)瀝青相應(yīng)的反應(yīng)活化能。煤瀝青熱解的后期階段,煤瀝青熱解反應(yīng)活化能隨熱分解轉(zhuǎn)化率增加而急劇增大,并且在此階段改質(zhì)瀝青所需要的反應(yīng)活化能要高于中溫瀝青相應(yīng)值。采用Coats.Redfem模型對(duì)煤瀝青熱解縮聚研究顯示,中溫瀝青熱解縮聚反應(yīng)活化能為31~38kJ/mol,改質(zhì)瀝青熱解縮聚反應(yīng)活化能為29~39kJ/mol。隨著升溫速率的加快,中溫瀝青和改質(zhì)瀝青的反應(yīng)活化能均呈增大的趨勢(shì)。關(guān)鍵詞:TGA;煤瀝青粘結(jié)劑;熱解縮聚反應(yīng);動(dòng)力學(xué)分析;
5、DAEM模型;Coats.Redfern模型:活化能第1I頁(yè)武漢科技大學(xué)碩士學(xué)位論文AbstractTheprocessesofthermalweightlossofcoal—tarpitcharestudiedbymeansofTGA.Thecharacteristicsofpyrolysiscondensationofcoal—tarpitchareanalyzed.Thecharacterofpyrolysiscondensationofmediumpitchiscomparedwiththatofmodified
6、pitch.Theinfluencesofheatingrateonthepyrolysiscondensationofcoal—tarpitchesareinvestigated.Itisfoundthatrapidheatingresultsinmoreconstituentsofcoal—tarpitchesevolvingandisunfavourabletotheenhancementofcokingvalueofcoal—tarpitches.Accordingtothecharacteristicsofth
7、epyrolysiscondensationreactions,theDAEMandCoats—Redfernmodelsofpyrolysisreactionkineticsofcoal·tarpitcheshavebeenestablished.Themodelexpressionsareasfollow:-n【糾乩【警】+o-s。伊而E。nd·nc掣Hn等一言Underdifferentvolatileconversionratesofcoal.tarpitches,In(h/1"z)incorrelationCH
8、IVeiscorrelatedwith1/Tverywell.Itisfoundthatthepyrolysisofcoal—tarpitchesarefirstorderreaction.AccordingtoDAEMmodelcalculation,theactivatederiergiesofpyrolysisreactionsofmediumpitchandmodifiedpitchare75~127kJ/moland60~140lO/molseparately.Theactivatedenergiesofpyr
9、olysisreactionsofcoal—tarpitchesincreasewiththeupgradeofvolatileconversionrates.Infirststageofpyrolysis,theactivatedenergiesofpyrolysisreactionsofcoal-tarpitch