本文選題：生物質(zhì)焦油 + 重整　； 參考：《大連理工大學(xué)》2015年碩士論文

【摘要】：生物質(zhì)焦油是生物質(zhì)在熱解氣化過程中產(chǎn)生的一種粘稠、成分復(fù)雜、含氧量高、具有刺激性氣味的黑色副產(chǎn)物。焦油的存在不僅影響設(shè)備正常運(yùn)行,而且會(huì)對(duì)環(huán)境和人體健康造成嚴(yán)重危害,進(jìn)而影響生物質(zhì)熱解氣化技術(shù)的產(chǎn)業(yè)化發(fā)展。催化法是高效去除生物質(zhì)焦油的重要手段,傳統(tǒng)的催化法雖然能夠有效分解焦油組分,但是因其存在的焦油轉(zhuǎn)化率低、催化劑抗積碳性能差、失活快及氫產(chǎn)率低等問題,限制了其在熱解氣化領(lǐng)域的廣泛應(yīng)用。針對(duì)如何提高焦油的去除效率及解決催化劑易積碳失活等問題,本研究提出了利用鎳基催化劑進(jìn)行生物質(zhì)焦油催化重整制氫的方法。通過熱重分析法研究生物質(zhì)焦油熱解和燃燒過程的動(dòng)力學(xué)特性,Py-GC/MS分析產(chǎn)物分布規(guī)律；制備高效、穩(wěn)定的泡沫陶瓷鎳基催化劑；改變實(shí)驗(yàn)反應(yīng)條件,揭示獲得最大產(chǎn)氫率的最佳工況條件；通過部分氧化方法實(shí)現(xiàn)催化劑原位再生,保證催化劑對(duì)焦油的長(zhǎng)效催化。本文開展研究工作具體如下：(1)利用熱重分析法研究了生物質(zhì)焦油在不同升溫速率下的熱化學(xué)過程。研究發(fā)現(xiàn),生物質(zhì)焦油熱解失重過程可以分為三個(gè)階段：揮發(fā)階段,一次熱解階段和二次熱解階段。在不同升溫速率下,熱重曲線具有類似的趨勢(shì),隨著升溫速率的增加,TG和DTG曲線向高溫區(qū)移動(dòng),焦油熱解溫度升高。生物質(zhì)焦油熱解動(dòng)力學(xué)符合一級(jí)動(dòng)力學(xué)反應(yīng),根據(jù)阿倫尼烏斯公式計(jì)算熱解區(qū)動(dòng)力學(xué)參數(shù)可知,一次熱解反應(yīng)的活化能為33.48-50.27kJ/mol,二次熱解反應(yīng)的活化能為39.18-44.20 kJ/mol。生物質(zhì)焦油燃燒失重規(guī)律與熱解過程類似,在高溫區(qū)燃燒過程有明顯的失重,燃燒階段的活化能為79.77-124.25kJ/mol,遠(yuǎn)大于熱解過程。Py-GC/MS分析結(jié)果表明,在不同熱解溫度下,焦油熱解產(chǎn)物都主要以芳香族類和酮類物質(zhì)為主,并且隨著熱解溫度的升高,酮類物質(zhì)含量明顯增多,芳香族化合物明顯減少。(2)以泡沫陶瓷為載體,采用浸漬法制備了鎳基泡沫陶瓷催化劑。結(jié)合SEM和XRD分析方法考察了鎳基活性組分,煅燒溫度,催化劑負(fù)載量等因素對(duì)催化劑活性的影響。結(jié)果表明,當(dāng)鎳源為Ni(NO3)2·6H2O,煅燒溫度為700℃,催化劑負(fù)載量為3.50±0.2%時(shí),制得的鎳基泡沫陶瓷催化劑對(duì)焦油催化重整制氫反應(yīng)具有較高的活性和較好的穩(wěn)定性。(3)采用固定床反應(yīng)器進(jìn)行生物質(zhì)焦油催化重整制氫實(shí)驗(yàn),主要考察了反應(yīng)溫度,S/C,空氣當(dāng)量(ER)和再生催化劑四個(gè)因素對(duì)焦油催化重整制氫的影響。結(jié)果表明,當(dāng)反應(yīng)溫度為500-900℃, S/C比為0-4,ER為0時(shí),氫產(chǎn)量在28.29-105.28g H2/kg tar。但隨著空氣當(dāng)量的增加,氫產(chǎn)量不斷下降。SEM和XRD分析表明,在部分氧化過程中,催化劑活性組分通過燃燒積碳實(shí)現(xiàn)原位再生,而且催化劑再生后仍保持較高的活性。生物質(zhì)焦油和重整油的GC/MS分析結(jié)果表明,活性組分鎳促進(jìn)了鏈烴化合物和苯環(huán)支鏈上C-C鍵、C-O鍵斷裂以及雜環(huán)類化合物發(fā)生開環(huán)反應(yīng)。
[Abstract]:Biomass tar is a kind of black by-product produced by pyrolysis and gasification of biomass with complex composition, high oxygen content and irritating smell. The existence of tar will not only affect the normal operation of the equipment, but also cause serious harm to the environment and human health, and then affect the industrialization development of biomass pyrolysis gasification technology. Catalytic method is an important method to remove biomass tar efficiently. Although the traditional catalytic method can decompose tar components effectively, it has some problems such as low tar conversion, poor resistance to carbon deposition, fast deactivation and low hydrogen yield. Its wide application in the field of pyrolysis and gasification is limited. Aiming at how to improve the removal efficiency of tar and to solve the problem of catalyst deactivation easily, the method of catalytic reforming of biomass tar for hydrogen production using nickel based catalyst was put forward in this paper. The kinetic characteristics of pyrolysis and combustion of tar were studied by thermogravimetric analysis. The distribution of products was analyzed by Py-GC / MS. The high efficient and stable nickel based foam catalyst was prepared, and the reaction conditions were changed. The optimum conditions for obtaining the maximum hydrogen yield were revealed, and the in-situ regeneration of the catalyst was realized by partial oxidation to ensure the long-term catalytic performance of the catalyst for tar. The thermochemical process of biomass tar at different heating rates was studied by thermogravimetric analysis (TGA). It is found that the pyrolysis process of biomass tar can be divided into three stages: volatilization stage, primary pyrolysis stage and secondary pyrolysis stage. The thermogravimetric curves show a similar trend at different heating rates. With the increase of the heating rate, the TG and DTG curves move to the high temperature region, and the tar pyrolysis temperature increases. The kinetics of biomass tar pyrolysis accords with the first-order kinetic reaction. According to the kinetic parameters of the pyrolysis region calculated by Arrhenius formula, the activation energy of the first pyrolysis reaction is 33.48-50.27kJ / mol, and the activation energy of the secondary pyrolysis reaction is 39.18-44.20kJ / mol / mol. The law of mass loss in biomass tar combustion is similar to that in pyrolysis process. The activation energy of combustion stage is 79.77-124.25kJ / mol, which is much larger than that of pyrolysis process. Py-GC / MS analysis shows that at different pyrolysis temperatures, the activation energy of biomass tar combustion is 79.77-124.25kJ / mol, which is much higher than that of pyrolysis process. The pyrolysis products of tar are mainly aromatics and ketones, and with the increase of pyrolysis temperature, the contents of ketones increase obviously, and the aromatic compounds decrease obviously. Nickel-based foam ceramic catalyst was prepared by impregnation method. Combined with SEM and XRD analysis, the effects of nickel based active components, calcination temperature and catalyst loading on the activity of the catalyst were investigated. The results show that when the nickel source is Ni(NO3)2 _ 6H _ 2O, the calcination temperature is 700 鈩，

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