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《水熱改性對(duì)褐煤熱轉(zhuǎn)化過程中污染物釋放與遷移規(guī)律影響-研究》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在教育資源-天天文庫。
1、萬方數(shù)據(jù)浙江大學(xué)碩士學(xué)位論文摘要褐煤的脫水提質(zhì)技術(shù)能夠提高煤炭利用效率、降低能耗損失,已經(jīng)成為低品質(zhì)煤大規(guī)模利用的重點(diǎn)發(fā)展方向。水熱改性作為一種高效、實(shí)用的脫水提質(zhì)手段成為研究的熱點(diǎn)問題。本文就水熱改性對(duì)三種低品質(zhì)煤熱轉(zhuǎn)化過程中氮、硫污染物釋放及遷移影響規(guī)律進(jìn)行了研究。首先采用高溫高壓反應(yīng)釜對(duì)準(zhǔn)東煙煤、伊敏褐煤、昭通褐煤進(jìn)行了200。C、250℃、300。C的水熱改性實(shí)驗(yàn),獲取改性后煤樣。發(fā)現(xiàn)水熱改性確實(shí)大幅度脫除了煤中水份,提高了低位燃燒熱值。(1)利用X射線光電子能譜技術(shù)(XPS)對(duì)水熱改性前后三種煤種
2、氮、硫元素的賦存形態(tài)進(jìn)行了研究,利用ⅫSPEAK分峰軟件進(jìn)行氮、硫元素的分峰擬合。發(fā)現(xiàn)水熱改性確實(shí)破壞了煤中氮、硫?qū)m能團(tuán)結(jié)構(gòu),使得煤中的N.5向N.6或者N-Q發(fā)生轉(zhuǎn)化,多環(huán)芳烴結(jié)構(gòu)的N.Q向N.6轉(zhuǎn)化,煤分子邊緣的N.Q向N—X轉(zhuǎn)化;硫醇硫醚、亞砜、砜類硫可能會(huì)向噻吩轉(zhuǎn)化,硫醇硫醚可能向硫鐵礦硫轉(zhuǎn)化,同時(shí)可能存在著砜類、亞砜類硫向硫酸鹽硫轉(zhuǎn)化的過程。(2)利用快速熱解儀器.質(zhì)譜色譜聯(lián)用儀(Py—GC/MS)對(duì)三種低品質(zhì)煤改性前后快速熱解時(shí)含氮、硫大分子揮發(fā)份的釋放特性進(jìn)行了研究,發(fā)現(xiàn)水熱改性影響了煤改性前
3、后氮、硫大分子的種類和釋放含量。將氮、硫大分子揮發(fā)份歸類后發(fā)現(xiàn),水熱改性影響了揮發(fā)份中含氮物質(zhì)如胺類、酰胺類、肟類、腈類、唑類,含硫物質(zhì)如硫醇硫醚類等的釋放特性。(3)利用管式爐實(shí)驗(yàn)平臺(tái)對(duì)三種低品質(zhì)煤改性前后熱解、燃燒過程中含氮、硫雜質(zhì)的污染物釋放特性進(jìn)行了研究。水熱改性使得熱解過程中準(zhǔn)東煤及昭通煤含氮、硫污染物的釋放減少,使得伊敏煤含氮污染物釋放增加、含硫污染物釋放減小。水熱改性使得燃燒過程中準(zhǔn)東煤含氮污染物釋放減少,含硫污染物釋放增大,伊敏煤含氮污染物釋放增大、含硫污染物釋放減小,昭通煤NO釋放量增大,
4、SOz第一釋放峰降低第二釋放峰升高。關(guān)鍵詞:低品質(zhì)煤;水熱改性;XPS;快速熱解;GC/MS;氮、硫污染物萬方數(shù)據(jù)浙江大學(xué)碩士學(xué)位論文ABSlRACTABSTRACTDehydrationtechnologiesoflignite,whichcanimprovecoalutilizationefficiencyandreduceenergylosses,havebecomeafocusofthelarge—scaleuseoflowqualitycoal.Asahi曲一efficiencyandpracti
5、caldewateringmethod,hydrothermaltreatmenthasbecomeahotresearchissue.Influencelawofhydrothermaltreatmentonnitrogenandsulfurpollutantsreleaseandmigrationofthreekindsoflowqualitycoalduringthermalconversionprocesshasbeenstudiedinthispaper.First,Zhundongbitumin
6、ouscoal,YmainligniteandZhaotonglignitewerehydrothermaUymodifiedat200"C,250。Cand300。Cbyusinghigh—heatandhigh-pressurereactionkettle.Resultsshowedthathydrothermaltreatmentgreatlyremovedthemoistureincoalandimprovedthelow-levelcombustioncalorificvalue.(1)X·ray
7、photoelectronspectroscopytechnologywasadoptedtobetteranalyzethespeciesofnitrogenandsulfurinrawcoalandhydrothermal—modifiedcoal.XPS-peak-differentation-imitatinganalysisWasperformedbyusingtheXPSPEAKpointspeaksoftware.Resultsshowedthathydrothermaltreatmentba
8、dlydestroyedmicro-structuresandfunctionalgroupsofnitrogenandsulfurincoal,bringingaboutphenomenonsthatN-5structureconvertedtoN一6orN—Q.N-QofpolycychcaromatichydrocarbonconvertedtoN-6andN—Qinedgeofcoalmoleculeco