用加壓熱水預處理山毛櫸樹(shù)粉生產(chǎn)燃料乙醇的初步研究

第24卷第3期農業(yè)工程學(xué)報VoL 24 No.32008年3月Transactions of the CSAEMar.2008219用加壓熱水預處理山毛櫸樹(shù)粉生產(chǎn)燃料乙醇的初步研究呂欣2,坂志朗’,董明盛',陳曉紅',姜梅(1南京農業(yè)大學(xué)食品科技學(xué)院,南京219500:2.京都大學(xué)大學(xué)院能源研究科,京都府6068501,日本)摘要:采用間歇式加壓熱水實(shí)驗裝置,研究了加壓熱水用于山毛櫸樹(shù)粉的分離規律,探討了不同溫度、處理時(shí)間對生物質(zhì)分離的影響。當溫度低于200℃時(shí),隨著(zhù)溫度升高和反應時(shí)間延長(cháng),木粉溶解量、木糖濃度和糠醛濃度均逐漸升高,而葡萄糖濃度和5-羥甲基糠醛濃度則較低。但當溫度高于200℃時(shí),生物質(zhì)溶解量基本不隨反應時(shí)間的變化而變化,葡萄糖濃度隨反應時(shí)間延長(cháng)逐漸增加,木糖濃度則隨著(zhù)反應時(shí)間的延長(cháng)而下降,糠醛濃度則隨著(zhù)反應時(shí)間的延長(cháng)基本不變甚至略有下降,5羥甲基糠醛濃度則隨著(zhù)反應時(shí)間的延長(cháng)而增大。關(guān)鍵詞:燃料乙醇;加壓熱水;預處理;降解;生物質(zhì);生物質(zhì)能中圖分類(lèi)號:S216;X3821文獻標識碼:A文章編號:1002-6819(2008)-3021904呂欣,坂志朗,董明盛,等.用加壓熱水預處理山毛櫸樹(shù)粉生產(chǎn)燃料乙醇的初步研究[J]農業(yè)工程學(xué)報,2008,24(3)219-222.La Xin, Shiro Saka, Dong Mingsheng, et al. Preliminary investigation on hot-compressed water pretreatment of Japanese beechowder for fuel-ethanol production[J]. Transactions of the CSAE, 2008, 24(3): 219-222. (in Chinese with English abstract)0引言分離特性的研究還鮮有報道。本文探討了加壓熱水預處理溫度及時(shí)間對生物質(zhì)分離特性的影響隨著(zhù)對高油價(jià)及能源可持續性的擔心,生物質(zhì)能源被越來(lái)越多地關(guān)注,其中由于乙醇作為燃料可以直接添1材料和方法加到汽油中,而被廣泛研究12。傳統的乙醇生產(chǎn)方法主1.1材料要采用糧食作物(如玉米)為原料,對糧食安全的擔心山毛櫸樹(shù)粉,粉碎并過(guò)1mm篩,用乙醇一苯(1:2)促使人們將目光投向農林廢棄物、生活垃圾等生物質(zhì)原法萃取,得到脫脂木粉,105℃下干燥至恒重,備用。脫料。生物質(zhì)要轉化為液體燃料,首先需要物理或者化學(xué)脂樹(shù)粉含纖維素45%,半纖維素29%和木質(zhì)素26%的方法進(jìn)行預處理,而后酶水解為單糖,再進(jìn)一步用發(fā)1.2加壓熱水處理酵的方法來(lái)獲取乙醇。采用如圖1所示反應裝置進(jìn)行生物質(zhì)加壓熱水反應。然而,生物質(zhì)是復雜的纖維素、半纖維素和木質(zhì)素反應管(材料 Inconel-625)有效體積5mL,配熱電偶測定反的聚合物,三種大分子通過(guò)氫鍵、范德華力等連接而形應管內溫度。約150mg木粉加入反應管中,而后加入4成穩定結構,天然條件下十分穩定,因而需要采用預處mL蒸餾水(HPLC級),油浴加溫,研究溫度范圍160~理技術(shù)將生物質(zhì)碳水化合物分離。已有的預處理方法有220℃,反應時(shí)間3~75min反應時(shí)間從反應管內溫度酸處理、堿處理、蒸汽爆破、熱水、氨爆破等,其中酸達到設定溫度起開(kāi)始計算,反應完成后迅速用冷水冷卻。水解的研究最為廣泛和深入。但由于這些方法存在成本、水解物發(fā)酵抑制、環(huán)境污染等問(wèn)題,亟待新的環(huán)境溫度傳感器友好、高效的預處理方法。超臨界流體是溫度和壓力同時(shí)高于其臨界值的流體,其中水作為反應介質(zhì),在超臨界條件下特殊的性質(zhì)溫度顯示器引起了廣泛關(guān)注6。生物質(zhì)在超臨界水中的變化研究也電加熱器日益增多,但其中氣化生物質(zhì)的研究報道較多01而對于在低于超臨界條件下,加壓熱水預處理過(guò)程中生物質(zhì)電磁攪拌收稿日期:200707-19修訂日期:2007-1204YH中國煤化工支置示意圖作者簡(jiǎn)介:呂欣(1975-),男,上海人,博士,主要從事生物質(zhì)能的研CNMHGfor hot-compressed究,南京南京農業(yè)大學(xué)食品科技學(xué)院,219500water treatment of biomassmailxinlusyu@yahoo.com農業(yè)工程學(xué)報2008年1.3分析方法高,葡萄糖單體產(chǎn)生速率加快;但隨后由于葡萄糖降解,反應后,用1mL微量取樣器從反應管中取02mL反應生成5HMF或其他降解產(chǎn)物l12,葡萄糖濃度逐漸下樣品,放入超濾離心管(045 um Millipore filter tube)降離心分離(5000r/min,1min),分離所得濾液放入HPLC樣品瓶用于HPLC分析。采用 Shimadzu lc10A高效液相色譜系統, RID/UV雙檢測器, Shodex Sugar KS-801210℃.1.9MPa( Showadenk)液相色譜柱,采用外標法定量葡萄糖、木糖、200℃,16MPa糠醛和5-羥甲基糠醛,進(jìn)樣量10μL。測定條件為:流190℃,13MF姹20動(dòng)相:水;流速:1mL/min;柱溫:80℃180℃,10MPa170℃,08MF反應后,將反應管內反應液抽濾,所得殘渣置于160℃,06MP105℃干燥箱干燥至恒重,稱(chēng)量。木粉溶解百分比的計算木粉溶解百分比(w%)=(加入反應管中木粉量殘渣量)/加入反應管中木粉量×100%反應時(shí)間/min2結果與分析圖2加壓熱水處理后木粉溶解百分比Fig 2 Water-soluble percentages after hot-compressed在溫度160~220℃,反應時(shí)間3~75mn范圍內water treatment考察了不同溫度和反應時(shí)間條件下,木粉溶解百分比的變化情況。如圖2所示,隨溫度升高和時(shí)間延長(cháng),木粉20℃,23MPa經(jīng)加壓熱水處理后水溶解部分百分比逐漸增加,但當溫210℃,19MPa200℃,1MP度高于210℃時(shí),木粉溶解百分比隨反應時(shí)間變化不顯190℃,13MPa著(zhù),采用SPS110進(jìn)行相關(guān)性分析,160~220℃范圍內180℃,10MPa反應時(shí)間與木粉溶解百分比的相關(guān)系數分別為:09170℃,08MPa(160℃),0.62(170℃),0.42(80℃),0.56(190℃),0.31(200℃),0.53(210℃),0.35(220℃),可以看出只有160℃5時(shí),木粉溶解百分比與反應時(shí)間顯著(zhù)相關(guān),而高溫條件下相關(guān)性不顯著(zhù),即高溫條件下,木粉溶解百分比與處圖3水溶解部分中葡萄糖濃度理時(shí)間不相關(guān)。此外,隨著(zhù)溫度的升高,木粉溶解量差Fig 3 Glucose concentration in water-soluble異逐漸縮小。210℃平均溶解量為41.6%,220℃平均溶解portion after hot-compressed water treatment量42.4%,僅增加0.8%;而160℃平均溶解量11.4%,170℃則達到287,增加17.3%即,在研究的溫度范圍內,溫220℃,23MPa度每提高10℃,木粉溶解增加量逐漸減小。從圖2還可210℃,1.9MPa℃,16MP以看出,160℃條件下,最大木粉溶解百分比僅為20%且190℃,13MPa反應時(shí)間長(cháng)(75min),因而本文后續研究對該溫度沒(méi)有180℃.10MP進(jìn)一步考察。另外,除160℃以外,170~220℃范圍內,170℃.08MPa木粉溶解百分比在15min后基本不變。由于延長(cháng)反應時(shí)間,糖類(lèi)等物質(zhì)會(huì )進(jìn)一步降解,從而影響后續的發(fā)酵過(guò)程,一方面降低了糖的收率,另一方面,產(chǎn)生的降解物質(zhì)會(huì )抑制微生物的發(fā)酵過(guò)程?；谝陨戏治?本文后續圖4水溶解部分中木糖濃度重點(diǎn)分析和考察了反應溫度170~220℃,反應時(shí)間3~Fig 4 Xylose concentration in water-soluble portionafter hot-compressed water treatment15min水溶解部分的糖類(lèi)及降解產(chǎn)物的變化。如圖3所示,當溫度低于200℃時(shí),生物質(zhì)中纖維素如圖4所示,當溫度低于200℃時(shí),隨反應溫度及時(shí)糖苷鍵基本不斷裂,因而葡萄糖濃度低,在反應時(shí)間范間的H中國煤化工,15mn木糖濃度圍內,濃度低于025g;但當溫度高于200℃時(shí),隨反達最應時(shí)間延長(cháng),纖維素在加壓熱水作用下糖苷鍵斷裂而釋著(zhù)反CNMHG0℃時(shí),木糖濃度隨木糖濃度放單體葡萄糖,葡萄糖濃度顯著(zhù)增加,210℃,9min達2.2l!gL,15mi則下降至0.64gL;而在220℃,3min到最大值1.54gL,隨后葡萄糖濃度基本不變。而當溫度最大木糖濃度僅為146gL,并逐漸下降,15min時(shí)降至為220℃時(shí),6min即可達最大值147gL,即隨著(zhù)溫度升0.17gL。根據上面分析,在高于200℃的條件下,木糖第3期呂欣等:用加壓熱水預處理山毛樺樹(shù)粉生產(chǎn)燃料乙醇的初步研究221更易發(fā)生降解反應,且溫度越高降解反應越劇烈。采用加壓熱水處理,與傳統的化學(xué)方法(酸法、堿法等)相比,該方法無(wú)化學(xué)添加劑,是一種綠色、環(huán)保的新預220℃,23MPa處理技術(shù)。本研究以加壓熱水為手段,探索了用于木粉·200℃,1.6MPa預處理的基本規律。當溫度低于200℃時(shí),隨著(zhù)溫度的升190℃,3MPa高和反應時(shí)間的延長(cháng),木粉溶解量、木糖濃度和糠醛濃1.0 MPa度均逐漸升高,而葡萄糖濃度和5-羥甲基糠醛濃度則較0. 8 MPa低。但當溫度高于200℃時(shí),木粉溶解量基本不隨反應時(shí)間的變化而變化,木糖濃度則隨著(zhù)反應時(shí)間延長(cháng)而下降反應時(shí)間/min糠醛濃度則隨著(zhù)反應時(shí)間的延長(cháng)基本不變甚至有略有下圖5水溶解部分中糠醛濃度降,5-羥甲基糠醛濃度則隨著(zhù)反應時(shí)間的延長(cháng)而逐漸增Fig 5 Furfural concentration in water-soluble大。從增加木糖得率、防止分解反應以及后續乙醇發(fā)酵portion after hot-compressed water treatment的角度考慮,宜采用低于200℃的加壓熱水處理生物質(zhì)如圖5所示,當溫度低于200℃時(shí),糠醛的濃度隨著(zhù)溫度升高和時(shí)間延長(cháng)而升高,但當溫度高于200℃時(shí),糠[參考文獻][1] Jens R. Rostrup-Nielsen. Making fuels from biomass []醛濃度基本不隨反應時(shí)間而變,210℃,平均糠醛濃度為Science,2005,308(3):1421-1422091gL;220℃,平均糠醛濃度也為091g/L,且隨反應(2] Alexander E Farrel, Richard J Pelvin, Brian T Turner,ra時(shí)間延長(cháng)略有下降。Ethanol can contribute to energy and environmental goals U]Science,2006,311(27):50[3] Arthur J Ragauskas, Charlotte K Williams, Brian H Davison,220℃,23MPaet al. The path forward for biofuels and biomaterals U]210℃,19MPaScience,2006,31127:484-489200℃,16MPa[4] Nathan Mosier, Charles Wyman, Bruce Dale, et al. Feature1.3 MPaof promising technologies for pretreatment of lignocellulosicbiomass []. Bioresource Technology, 2005, 96: 673-686170℃,08MPa[5] Martyn Poliakoff, Peter King. Phenomenal fluids [] Nature,2001,412(12):1256] Marr R, Gamse T. Use of supercritic反應時(shí)間/minprocesses including new developments-a review []Fig6水溶解部分中5-羥甲基糠醛濃度[7 Digby D Macdonald, Leo B Kriksunov. Probing the chemicalFig 6 5-HMF concentration in water-soluble portionand electrochemical properties of Scwo systems []after hot-compressed water treatmentElectrochimica Acta, 2001, 47: 775-790.如圖6所示,當溫度低于200℃時(shí),5羥甲基糠醛的【81 Zheng Fang Phase behavior and oxidation of organic wastesin supercritical water Doctor thesis)[D]. McGill University,濃度很低,最大值僅為01gL(200℃,15min)。但當Canada, 2003溫度高于200℃時(shí),5-羥甲基糠醛的濃度迅速升高,并隨9] Millot N,xinB, Pighini C,eal. Hydrothermal synthesis of著(zhù)反應時(shí)間的延長(cháng)而增大,210℃,15min達最大值0.64nanostructured inorganic powders by a continuous processgL;220℃時(shí),9min即可達最大值0.80gL。即,高溫under supercritical conditions []. Joumal of the European下葡甘露聚糖糖苷鍵斷裂,生成葡萄糖單體,進(jìn)而生成Ceramic Society,2005,25(12):2013-2016[10] Yukihiko Matsumura, Tomoaki Minowa, Biljana Potic, et al.5羥甲基糠醛。糖類(lèi)單體高溫下,首先降解為對發(fā)酵有抑Biomass gasification in near-and super-critical water: Status制作用的呋喃類(lèi)化合物(如糠醛和羥甲基糠醛)31,若and prospects [] Biomass and Bioenergy, 2005, 29: 269繼續升高溫度,這些化合物還會(huì )進(jìn)一步降解為有機酸等小分子物質(zhì)。進(jìn)一步,隨著(zhù)溫度的升高,木質(zhì)素來(lái)源芳 11] Wei Feng, Heder J van der Kooi, Jakob de Swaan Arons香族降解物質(zhì)也將顯著(zhù)增加,而這類(lèi)物質(zhì)對發(fā)酵也有明Biomass conversions in subcritical and supercritical water:顯抑制作用151。除可能的抑制作用外,由于糖類(lèi)降解導中國煤化工thermodynamic analysisg,2004,43:1459致低糖收率,進(jìn)而降低乙醇發(fā)酵產(chǎn)率,因而考慮發(fā)酵過(guò)CNMHG程,采用較低溫度較為有利[123 Masaru Watanabe, Yuichi Aizawa, Toru lida, et al.3結論reactions within the heating period and the effect ofthe reactions in hot compressed water]預處理技術(shù)一直是生物質(zhì)能源研究的熱點(diǎn)和難點(diǎn)Carbohydrate Research, 2005, 340: 1931-1939農業(yè)工程學(xué)報[13] Berta Sanchez, Juan Bautista. Effects of furfural and [15] Klinke H B, Thomsen A B, Ahring B K. Inhibition of5-hydroxymethylfurfural on theethanol-producing yeast and bacteria by degradation productsSaccharomyces cerevisiae and biomass production fromproduced during pre-treatment of biomass [] ApplliedCandida guilliermondii). Enzyme and MicrobialMicrobiology Biotechnology, 2004, 66: 10-26Technology,1988,10:315-318[16] Kruse A, Dinjus E. Hot compressed water as reaction medium[14] Boyer L J, Vega J L, Klasson K T, et al. The effects of furfuralnd reactant-2: Degradation reactions []. J ofon ethanol production by Saccharomyces cerevisiae in batchFluids,2007,41:361-379culture U]. Biomass and Bioenergy, 1992, 3(1): 41-48Preliminary investigation on hot-compressed water pretreatmentof Japanese beech powder for fuel-ethanol productionLu Xin',2, Shiro Saka, Dong Mingsheng, Chen Xiaohong, Jiang Mei(1. College of Food Science and Technology, Nanying Agricultural University, Nanjing 210095, China;2. Graduate School of Energ,, Kyoto University, Kyoto 606-8501, Japan)Abstract: The effects of temperature and reaction time on dissolution of Japanese beech powder by hot-compressedwater treatment were investigated. When the temperature was lower than 200C, water-soluble portion, xyloseconcentration and furfural concentration increased with the increase of temperature, while glucose concentration and5-HMF concentration were lower. When temperature was higher than 200C, water-soluble portion did not varyignificantly with reaction time prolonged. Glucose concentration increased with reaction time prolonged while xyloseconcentration decreased with reaction time prolonged. Furfural concentration did not vary or even decrease a little withon time prolonged while 5-HMFtime prolongedKey words: fuel-ethanol; hot-compressed water; pretreatment; decomposition; biomass; bioengergy中國煤化工CNMHG