第34卷第9期太陽能學(xué)報(bào)Vol 34. No 92013年9月ACTA ENERGIAE SOLARIS SINICA文章編號(hào):02540096(2013)09-151406生物質(zhì)炭水蒸氣氣化制取合成氣涂軍令,應(yīng)浩12,吳歡,李琳娜,高一葦,江俊飛(1.中國林業(yè)科學(xué)研究院林產(chǎn)化學(xué)工業(yè)研究所;生物質(zhì)化學(xué)利用國家實(shí)驗(yàn)室;國家林業(yè)局林產(chǎn)化學(xué)工程重點(diǎn)開放性實(shí)驗(yàn)室;江蘇省生物質(zhì)能源與材料重點(diǎn)實(shí)驗(yàn)室,南京210042;2.中國林業(yè)科學(xué)研究院林業(yè)新技術(shù)研究所,北京10001)摘要:在常壓固定床反應(yīng)器中,以生物質(zhì)炭為原料進(jìn)行水蒸氣氣化制取合成氣研究。實(shí)驗(yàn)在溫度800~1000℃和水蒸氣流量0.083~0.285g/( ming char)條件下進(jìn)行,反應(yīng)時(shí)間為15min,研究反應(yīng)溫度和水蒸氣流量對(duì)生物質(zhì)碳轉(zhuǎn)化率、合成氣產(chǎn)率及合成氣組分的影響。研究結(jié)果表明:生物質(zhì)炭水蒸氣氣化具有很高的反應(yīng)活性,氣體產(chǎn)率在0.40~297Lg之間;溫度和水蒸氣流量對(duì)碳轉(zhuǎn)化率和合成氣熱值及組分影響顯著;在反應(yīng)溫度1000℃、水蒸氣流量0.285g/( ming char)時(shí),碳轉(zhuǎn)化率達(dá)到最高值787%;氣體產(chǎn)物主要由H2、CO、CO2和CH4組成,合成氣熱值在89~96M/Nm3之間,合成氣中(H2+CO)在68%-80%之間,(H2CO)在3.1-6.4之間關(guān)鍵詞:生物質(zhì)炭;水蒸氣氣化;合成氣;(H2CO)中圖分類號(hào):TK6文獻(xiàn)標(biāo)識(shí)碼:A0引言研究。綜上所述,氣化溫度、氣化介質(zhì)和氣化壓力等是影響生物質(zhì)炭氣化特性的重要因素。生物質(zhì)資源具有可再生、產(chǎn)量豐富、氮硫含量目前,在生物質(zhì)炭水蒸氣氣化制備合成氣方面低、環(huán)境友好等優(yōu)點(diǎn),其開發(fā)和利用技術(shù)在世界范圍研究報(bào)道甚少。本文嘗試用水蒸氣氣化法將生物質(zhì)內(nèi)已得到廣泛研究。生物質(zhì)氣化/熱解產(chǎn)物除燃炭轉(zhuǎn)化為合成氣,并考查反應(yīng)溫度和水蒸氣流量對(duì)氣和液體外,還有生物質(zhì)炭,開發(fā)利用生物質(zhì)炭對(duì)于合成氣組分、熱值及碳轉(zhuǎn)化率等方面的影響提高生物質(zhì)的利用效率和能源生產(chǎn)的經(jīng)濟(jì)性具有重大意義。作為副產(chǎn)物,生物質(zhì)炭可用于直接燃燒、回1實(shí)驗(yàn)收金屬離子、制備活性炭及生產(chǎn)砌磚等方面23),也1.1原料可用于進(jìn)一步氣化制取燃?xì)?。生物質(zhì)經(jīng)氣化或熱解原料取自江蘇省某生物質(zhì)流化床氣化裝置氣化后脫除揮發(fā)分,因此生物質(zhì)炭與生物質(zhì)相比,具有松木屑后產(chǎn)生的生物質(zhì)炭。生物質(zhì)炭經(jīng)研磨和篩較高的固定碳含量以及較低的揮發(fā)分和氧含量,其分,選用粒徑在0.125-0.250mm之間的部分作為氣化特性與生物質(zhì)氣化特性有明顯差別。實(shí)驗(yàn)原料。原料的物理化學(xué)特性分析包括工業(yè)分近年來,已有學(xué)者對(duì)生物質(zhì)炭的氣化特性進(jìn)行析、元素分析低位熱值、表觀密度等結(jié)果見表1研究。 Chaudhari S T等4對(duì)生物質(zhì)炭水蒸氣從表1可看出,該原料固定碳含量較高、揮發(fā)分氣化制氫/制備合成氣進(jìn)行了研究,結(jié)果所得合成氣較低、灰分含量高、含氧量很低、表觀密度大,適合用H2含量在70%,H2CO在4~15之間,非常適合制于水蒸氣氣化制備合成氣或富氫燃?xì)?。氫或制備合成氣。Fem0oJ等在熱重分析儀內(nèi)1.2實(shí)驗(yàn)裝置對(duì)濕地松炭的CO2氣化反應(yīng)進(jìn)行研究,研究了溫度生物質(zhì)炭水蒸氣氣化實(shí)驗(yàn)在常壓固定床反應(yīng)器和壓力對(duì)CO2氣化反應(yīng)的影響并計(jì)算了反應(yīng)動(dòng)力中進(jìn)行,實(shí)驗(yàn)裝置簡(jiǎn)圖見圖1。該裝置主要由以下學(xué)參數(shù)。 Matsumoto K等6以日本柳杉在氣流床內(nèi)幾部分組成恒流泵(用于計(jì)量和控制所需的水蒸氣氣化后產(chǎn)生的生物質(zhì)為原料,進(jìn)行了氣化動(dòng)力學(xué)流量)水蒸中國煤化立為水蒸氣)橫收稿日期:20110720CNMHG基金項(xiàng)目:林業(yè)公益性行業(yè)科研專項(xiàng)項(xiàng)目(200904062);國家自然科學(xué)基金(30972318)通訊作者:應(yīng)浩(1963-),男,學(xué)士、研究員、碩士生導(dǎo)師,主要從事生物質(zhì)能轉(zhuǎn)化技術(shù)與應(yīng)用方面的研究。hy2478@163.com9期涂軍令等:生物質(zhì)炭水蒸氣氣化制取合成氣1515表1生物質(zhì)炭的物理化學(xué)特性Table 1 Physical and chemical characteristics of biomass-derived char工業(yè)分析/w%元素分析/wt%低位熱值表觀密度揮發(fā)分固定碳灰分12.9475.73l.1522.880.2425.45注:a.干基;b.差分法。氣發(fā)生裝置,恒流泵控制水蒸氣流量在0.2490.854g/min之間;然后,將盛放原料的石英舟迅速放人高溫反應(yīng)區(qū)進(jìn)行水蒸氣氣化反應(yīng)15mn;反應(yīng)產(chǎn)物通過冷凝器,未反應(yīng)的水蒸氣和可凝氣體冷卻10為液體,通過吸收過濾裝置收集反應(yīng)產(chǎn)生的焦油或其他雜質(zhì);最后,純凈的氣體流經(jīng)氣體流量計(jì),計(jì)量合成1.氮?dú)馄?.調(diào)節(jié)閥3.氣體流量計(jì)4.恒流計(jì)量泵氣的生成量,并用氣體采樣袋收集氣體樣品,用于組5水蒸氣發(fā)生器6.高溫管式爐7.反應(yīng)器8冷凝器分分析;實(shí)驗(yàn)結(jié)束后,將石英舟移至低溫區(qū)冷卻,待冷9吸收過濾裝置10濕式氣體流量計(jì)1.氣體采樣與分析系統(tǒng)卻至室溫后取出稱量殘余的生物質(zhì)炭的質(zhì)量。圖1生物質(zhì)炭氣化實(shí)驗(yàn)裝置圖實(shí)驗(yàn)擬在溫度分別為800、850、900950、1000℃CFig. 1 Schematic diagram of the experimental setup for水蒸氣流量為0.083~0.285gH2O/(min· g char)的條steam gasification of biomass-derived char件下進(jìn)行。為了保證數(shù)據(jù)的準(zhǔn)確性,每組實(shí)驗(yàn)至少重向可控溫的高溫管式爐固定床反應(yīng)器(爐管長(zhǎng)復(fù)3次,誤差在3%以內(nèi),取其平均值。110cm,內(nèi)徑50mm,可耐1100℃高溫)、冷凝器(用1.4分析方法于液體產(chǎn)物收集)、焦油吸收和過濾裝置、氣體流量采集的氣體樣品使用島津GC2014進(jìn)行檢測(cè),計(jì)以及氣體樣品采集裝置。載氣為氬氣。氣體中的H2、CO、CO2使用CD5021.3實(shí)驗(yàn)方法柱、氧氯分析柱和TCD檢測(cè)器檢測(cè),其他有機(jī)氣體實(shí)驗(yàn)步驟:每次稱取3g生物質(zhì)炭均勻鋪在石(CH4C2H6、C2H4、C2H2)使用A2O3S柱和FD檢英舟中。啟動(dòng)水蒸氣發(fā)生器和管式爐,將反應(yīng)器加測(cè)器檢測(cè)。熱到實(shí)驗(yàn)所需溫度(800~1000℃),升溫過程中以氣體產(chǎn)量通過濕式氣體流量計(jì)計(jì)量;碳轉(zhuǎn)化率50mL/min的流速向反應(yīng)器中通入氮?dú)?以保持無氧(x,%)和氣體的低位熱值(L,MJNm3)的計(jì)算環(huán)境;達(dá)到實(shí)驗(yàn)溫度后,關(guān)閉氮?dú)鈿庠?并打開水蒸方法見式(1)和式(2)12Y([CO2]+[co]+[CH4]+2×[C2H2]+2×[C2H4]+2×[C2H6])X100%224x[C]LHV=([CO]×126.36+[H2]×10798+[CH4]×358.18+[C2H2]×56.002+[C2H4]×59.036+[C2H6]×63.712)/1000(2)式中,[C]——生物質(zhì)炭中的碳含量;[CO]、[H2]、生物質(zhì)炭中含有的少量揮發(fā)分,同時(shí)伴隨少量揮發(fā)CH4]、[C2H2]、[C2H4]、[C2H]—分別為各組分與炭的氣化反應(yīng)和裂解重整反應(yīng);第二步是揮發(fā)分的體積分?jǐn)?shù),%。分、水蒸氣和生物質(zhì)炭的之間反應(yīng),主要包括C與2結(jié)果與討論水蒸氣的氣化反應(yīng)(4)、CO與水蒸氣的變換反應(yīng)(5)碳素溶解下應(yīng)(6用欄反應(yīng)(7)、甲2.1生物質(zhì)炭水蒸氣氣化反應(yīng)過程烷重整反應(yīng)中國煤化工物的重整反生物質(zhì)炭的水蒸氣氣化反應(yīng)通常可分為兩應(yīng)(9)。兩步CNMH組成了最終步9:第一步是生物質(zhì)炭的熱解反應(yīng)(3),反應(yīng)析出得到的合成氣。1516太陽能學(xué)報(bào)34卷熱解反應(yīng):氣化的反應(yīng)活性很高隨著溫度的升高,氣體產(chǎn)率從CH,O.+alH2+bCO+cCO2+dCH4+eC2,+/H2O0.40Lg增加到2.97L/g,趨勢(shì)與碳轉(zhuǎn)化率相似,可(3)以解釋為是隨著溫度的升高,生物質(zhì)炭與水蒸氣反碳與水蒸氣氣化反應(yīng):應(yīng)(4)~(9)不斷加強(qiáng)的結(jié)果。C+H2o0+H2(4)0.083g(mi水煤氣變換反應(yīng):222g/(min· g char)士0.285g(min· g charCO+H2O一+(5)碳素溶解損失反應(yīng):C+co(61.5甲烷化反應(yīng)C+2H2一→CH4(7)甲烷重整反應(yīng):1000CH4+H2O—÷C0+3H2(8)溫度/℃碳?xì)浠衔镏卣磻?yīng)圖3反應(yīng)溫度對(duì)生物質(zhì)炭水蒸氣氣化氣體產(chǎn)率的影響C, Hm+2nH20-+(2n+m/2)H2 +ncO2(9)Fig. 3 Effects of reactionmperature2.2溫度的影響biomass-derived char in steam gasification反應(yīng)(4)~(9)均為吸熱反應(yīng),故溫度是影響生圖4反映了反應(yīng)溫度對(duì)生物質(zhì)炭水蒸氣氣化制物質(zhì)炭水蒸氣氣化特性的重要因素12。本研究得合成氣熱值的影響。由圖4可發(fā)現(xiàn),合成氣熱值分別在800、850、900、950、1000℃溫度下,考查氣化隨反應(yīng)溫度的升高呈先增大后減小的趨勢(shì),原因是溫度對(duì)碳轉(zhuǎn)化率、合成氣產(chǎn)量、合成氣組分及熱值的在800~900℃時(shí),CO含量明顯增加,CH4與水蒸氣影響的重整反應(yīng)不明顯,熱值提高;高于900℃時(shí),CH反應(yīng)溫度對(duì)生物質(zhì)炭水蒸氣氣化過程碳轉(zhuǎn)化率重整反應(yīng)加強(qiáng),合成氣中CH4含量明顯降低,造成的影響情況見圖2。從圖2中可看出,在相同水蒸熱值減小。氣流量條件下,生物質(zhì)炭的碳轉(zhuǎn)化率隨溫度的升高不斷增大,在溫度為1000℃,水蒸氣流量為0.285g(min· g char)時(shí),碳轉(zhuǎn)化率達(dá)到最大值78.7%,該結(jié)果與 Chaudhari s t等的研究結(jié)果一致。70/+0.083g/(ming char)0222g/(min· g char)0285g/(min· g char6二:9501000溫度/℃圖4反應(yīng)溫度對(duì)生物質(zhì)炭水蒸氣氣化產(chǎn)氣熱值的影響Fig 4 Effects of reaction temperature on low heating value of theroduct gas obtained during steam gasification of溫度/℃Iornass-geny圖2反應(yīng)溫度對(duì)生物質(zhì)炭水蒸氣氣化碳轉(zhuǎn)化率的影響表2列出了不同溫度和水蒸氣流量條件下,生Fig 2 Effects of reaction temperature on carbon conversion of物質(zhì)炭水蒸biomass-derived char in steam gasificatic仝帶組公和(H2CO)的研究結(jié)果。中國煤XO2、CH4及少圖3為反應(yīng)溫度對(duì)生物質(zhì)炭水蒸氣氣化過程合量其他的碳CNMHG可發(fā)現(xiàn),H2和成氣產(chǎn)率的影響情況?？梢钥闯?生物質(zhì)炭水蒸氣CO的含量隨溫度的升高而增大,CO2和CH4的變9期涂軍令等:生物質(zhì)炭水蒸氣氣化制取合成氣l517化趨勢(shì)正好與之相反,原因是隨著溫度的升高,反大可能是碳素熔損反應(yīng)(6)和CH4等碳?xì)浠衔锱c應(yīng)(4)、(6)和(8)逐漸加強(qiáng);同時(shí),合成氣中的水蒸氣的重整反應(yīng)(8)共同作用的結(jié)果。CO2含量(H2+CO)不斷提高,在68%~80%之間;還可觀察隨溫度的升高有所下降,原因是高溫條件下,CO2與到,(H2CO)在3.1~6.4之間,隨著溫度的升高,雖C發(fā)生了碳素熔損反應(yīng)(6),然而,在更高的溫度然H2含量增大,但(H2/CO)卻不斷減小,這主要?dú)w(>90℃)下,CO2的變化并不明顯,該現(xiàn)象可能是結(jié)于CO含量的增加。CO含量隨溫度的升高而增反應(yīng)(5)、(6)、(8)共同作用的結(jié)果。表2不同溫度和水蒸氣流量條件下,合成氣的組分和(H2COTable 2 Results orct gas composition and ( H2/CO)obtained during steam gasification of biomass-derived char atvarious reaction temperatures and steam flow rates水蒸氣流量氣體組成/vol%溫度/℃/g(ming char) [H,] [CO] [ CO2] LCH, [C+1(H,+ CO)/vol% (H2/Co)8000.08353.9227.130.178500.0833.790.023.760.08317.422.960.0275.71l8.742.170.0178.100.08319.2019.590579.013.128000.2223.765.6211.9923.8872.920.22261.1515.5320.823.9500.22260.9616.021.103.810.22261.2017.5120.111.150.030.2859.340.0668.330.28560.2311.5150.71.809000.28561.2521.3395061.5115.43211.85100062.5015.5521.140.800.014.0223水蒸氣流量的影響氣流量有利于提高碳轉(zhuǎn)化率和氣體產(chǎn)率。從圖4可水蒸氣作為生物質(zhì)炭氣化反應(yīng)的氣化劑,是影看出,水蒸氣流量的增大會(huì)造成合成氣熱值的減小,響生物質(zhì)炭水蒸氣氣化反應(yīng)特性的重要因素之這主要是因?yàn)殡S著水蒸氣流量的增大,CO的變換為考查水蒸氣流量對(duì)生物質(zhì)炭水蒸氣氣化過程中碳反應(yīng)和CH重整反應(yīng)加快合成氣中CH,和CO含轉(zhuǎn)化率氣體產(chǎn)率、氣體組分及其熱值等參數(shù)的影量減小而造成的。表2反映出隨著水蒸氣流量的增響在水蒸氣流量為0.083~0.285g/(min· g char)大,H2含量略有增加,而CO含量有所減少,導(dǎo)致的范圍內(nèi)對(duì)生物質(zhì)炭水蒸氣氣化進(jìn)行實(shí)驗(yàn)研究。從(H2CO)提高,在800℃,水蒸氣流量為0.285圖2圖3可看出,在相同溫度下,碳轉(zhuǎn)化率和氣體g( ming char)時(shí),(H2CO)達(dá)到632;水蒸氣流量產(chǎn)率均隨水蒸氣流量的增大而增大;在900℃時(shí),水對(duì)合成氣中(H2+CO)在氣體產(chǎn)物中的比例影響不蒸氣流量從0.083g/(min· g char)增大到0.285明顯。研究結(jié)氣體產(chǎn)率從080Lg增大到17/,因?yàn)樗魵夂铣蓺獠中國煤化工氣化易于生成CNMH(蒸氣流量,調(diào)是反應(yīng)(4)、(5)、(8)、(9)的反應(yīng)物之一,增大水蒸節(jié)合成氣中不同的(H2CO),適用于不同的用途。1518太陽能學(xué)報(bào)對(duì)于(H2/CO)很高的合成氣,可通過提純制氫用作roduction of activated carbons[J]. Journal of Analytical合成氨或氫燃料;對(duì)于(H2/CO)較低的合成氣,可ind Applied Pyrolysis, 2009, 85(1-2): 134-141用于合成醇醚燃料或 Fischer-Tropsch合成1-1;同31 Fernandez-Pereira C, de la Casa J A, Gomez-Barea A,時(shí),合成氣還可直接用作氣體燃料。et al. Application of biomass gasification fly ash for brickmanufacturing[J ]. Fuel, 2011, 90(1):220--2323結(jié)論[4 Chaudhari S T, Dalai A K, Bakhshi NN. Production ofhydrogen and/or syngas(H,+CO)via steam gasification1)在溫度為800~1000℃和水蒸氣流量0.083~of biomass-derived chars[ J ] Energy &Fuels, 20030.285g/( ming char)的條件下,生物質(zhì)炭水蒸氣氣17(4):1062-1067化反應(yīng)活性較高,而且由于原料生物質(zhì)炭的揮發(fā)分[5] Fermoso J, Stevanoy c, Moghtaderi B,etal.High含量低,氣化制得合成氣基本不含焦油,因此非常適pressure gasification reactivity of biomass chars produced用于制備潔凈的合成氣;at different temperatures[J]. Jourmal of Analytical and2)溫度是影響生物質(zhì)炭水蒸氣氣化反應(yīng)的重Applied Pyrolysis, 2009, 85(1-2):287-293要因素,碳轉(zhuǎn)化率和合成氣產(chǎn)率隨溫度升高而增大eno在1000℃和0.285g/( ming char)水蒸氣流量條件Gasification reaction kinetics on biomass char obtained下,生物質(zhì)碳轉(zhuǎn)化率和氣體產(chǎn)率最高,分別可達(dá)到as a by-product of gasification in an entrained-flowgasifier with steam and oxygen at 900-1000C [J]78.7%和297Lg;隨著溫度的升高,H2和CO含量Fuel,2009,88(3):519-527呈上升趨勢(shì),H2含量在1000℃和水蒸氣流量為(7]YanF, Zhang L G,HuZQ,etl. ydrogen-rich gas0.285g/(min· g char)均達(dá)到最高625%;而CO2和production by steam gasification of char derived fromCH4等含量變化呈下降趨勢(shì);合成氣中(H2+CO)cyanobacterial blooms( CDCB )in a fixed-bed reactor比例隨溫度的升高而增大(在68%~80%之間);合Influence of particle size and residence time on gas yield成氣中(H2CO)隨溫度的升高而減小(在3.1~6.4and syngas composition [ J]. 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The study of1] Zhou X P, Wang F, Hu H W, et al. Assessment ofprocess].Fuel,2003,82(7):835-842sustainable biomass resource for energy use in China [13 Lv P中國煤化工tal.Bio- syngas[J]. Biomass Bioenergy, 2011,35(1):1-11[2 Gonzalez J F, Roman S, Encinar J M, et al. Pyrolysis ofCNMHEnergy Conversion and Management, 2007, 48(4)various biomass residues and char utilization for thel132-11399期涂軍令等:生物質(zhì)炭水蒸氣氣化制取合成氣1519[14 He M Y, Xiao B, Hu Z Q, et al. Syngas production4(3):1342-134om catalytic gasification of waste polyethylene: [15] Goransson K, Soderlind U, He J, et al. Review ofInfluence of temperature on gas yield and compositionsyngas production via biomass DFBGs[J]. Renewable[J]. International Journal of Hydrogen Energy, 2009Sustainable Energy Reviews, 2011, 15(1): 482-49PRODUCTION OF SYNTHESIS GAS BY STEAM GASIFICATION OFBIOMASS-DERIVED CHARTu Junling, Ying Hao", Wu Huan, Li Linna, Gao Yiwei, Jiang JunfeiInstitute of Chemical Industry of Forest Products, CAF; National Engineering Lab for Biomass Chemical UtilizationKey and Open Lab on Forest Chemical Engineering, SFA; Key Lab of Biomass Energy and Material, Jiangsu Province, Nanying 210042, China;2. Institute of New Technology of Forestry, CAF, Beying 100091, China)Abstract: Steam gasification of biomass-derived char was studied at atmospheric pressure in a fixed bedreactor Experiments were carried out at 800, 850, 900, 950 and 1000C with different steam flow rates in therange of 0. 083 to 0. 285g/(min g char)and a reaction time of 15min. The effects of temperature and steam flowrate on conversion of char, synthesis gas yield, heat value and its compositions were mainly studied. It has beenfound that biomass-derived char was highly reactive, particularly at high temperature, synthesis gas yield was in therange of 0. 40-2. 97L/g. The results show that steam flow rate and temperature have strong effects on the conversionof char, synthesis gas yield, heat value and its compositions. The conversion of this char was maximum (78. 7%)at1000C with steam flow rates of 0. 285g/( min g char). The product gas obtained was mainly a mixture of H2, COcO,, and CH. Under the present reaction conditions, synthesis gas(H2+Co)prodtsteam gachar was in the range of 68-80mol%. The low heating value of the product gas wasrange of 8.9-9. 6MJ/Nm, and the(H, /Co )was about 3. 1-6. 4. The results suggest that there is a strong potential for producingsynthesis gas from steam gasification of biomass-derived chars.Keywords: biomass-derived char; steam gasification; synthesis gas; (H2/CO)中國煤化工CNMHG