Mo和Ni改性的HZSM-5催化剂对煤热解焦油的改质

考察了Mo和Ni改性的HZSM-5催化剂对煤热解焦油的改质性能,分析了催化改质前后焦油中轻质芳烃分布的变化规律。结果表明,经HZSM-5催化剂褐煤(XM)热解轻质芳烃总量的增加率为220%,这与煤热解产物在HZSM-5催化剂中发生烯烃和烷烃的芳构化以及酚羟基脱除等作用有关。负载活性金属Mo和Ni后,可以有效促进轻质芳烃的生成;Ni对焦油中带脂肪侧链化合物具有更强的裂解作用,而Mo则有利于带侧链化合物如甲苯和二甲苯的形成。焦煤(FX)热解过程中轻质芳烃的释放量分别是XM煤和年轻烟煤(PS)的2.2和2.4倍。经催化改质后,XM煤产物中轻质芳烃产率明显大于PS煤,并接近FX煤;这主要是因为XM煤结构中含有较多的含氧官能团和脂肪结构,在HZSM-5作用下可催化形成轻质芳烃。     

生物质热解制备木醋液及其性质研究

对杉木屑、棉杆、竹屑三种生物质热解制得的木醋液产率、基本理化性质及其有机成分进行了分析研究。结果表明,三种生物质原料在350℃下热解制得的粗木醋液、精制木醋液产率相差不大,相同条件下氯化钾浸渍处理后的杉木屑热解所得的粗木醋液、精制木醋液的产率有所降低。三种原料制得的精制木醋液的理化性质不同,杉木屑木醋液的pH值最小,密度最大,竹屑和棉杆木醋液的有机酸含量相对较高。采用GC-MS对精制木醋液中的有机成分进行了分析,结果表明,杉木屑木醋液中的主要组分为酸类、酚类和酮类化合物,棉杆和竹屑木醋液中的主要组分除这三类有机物质外,还含有相对含量较高的醇类化合物。酸类和酚类化合物在三种木醋液中的相对含量依次是竹屑 >棉杆 >木屑;酮类的相对含量依次是木屑 >棉杆 >竹屑。氯化钾处理后的木屑热解所得的木醋液中主要组分酚类和酮类化合物的相对含量有所降低,酸类化合物的相对含量增加,主要表现为乙酸相对含量的增加。与杉木屑木醋液相比,KCl处理后的杉木屑木醋液中的醇类化合物相对含量增加了1倍左右。     

橄榄石基固体热载体影响褐煤热解产物分布的分析

为了提高固体热载体煤热解工艺中焦油的品质,降低焦油中沸点大于360 ℃的重质组分含量,本实验采用固定床反应器,在450~600 ℃下进行褐煤固体热载体快速热解反应.分析对比了橄榄石基和石英砂固体热载体对褐煤热解产物收率、焦油馏分、气体组成的影响.结果发现,Co能改变煤内部挥发分氢元素的分布,橄榄石负载Co热载体能将焦油中重质组分转化为轻质焦油和热解气.热解温度为550 ℃时,与橄榄石相比,负载Co的橄榄石固体热载体使焦油收率提高了19.2%.与石英砂相比,负载Co的橄榄石固体热载体使焦油中重质组分含量降低了17.0%,轻质组分收率达5.1%,其中,轻油、酚油和萘油分别提高了19.6%、17%和15.2%,气体产物中H₂、CH₄含量下降.     

碱／碱土金属催化松木屑快速热解机制

研究碱／碱土金属（AAEM）对生物质的热解及其热解产物组成的影响规律,可为生物质热解特性研究和热解产物的高效利用提供重要的理论依据。本文以松木屑为原料,将原样进行酸洗,并对酸洗样分别用K、Ca、Na和Mg氯化盐溶液浸渍,在500℃和Ar气氛下对各样品进行快速热解,考察了4种金属离子对松木屑热解产物组成分布的影响规律;通过热重分析考察了各个样品的热解特性;通过对热解生物油的气相色谱／质谱（GC／MS）分析考察了快速热解的焦油成分。研究结果表明：AAEM对松木屑有明显的催化作用,AAEM的存在能够提高热解气体和固体的产率,降低热解焦油的产率;AAEM能够降低热解温度,使热解更加容易进行;快速热解的焦油成分主要有酚类、酮类、醛类、芳烃、醇类、脱水糖类、呋喃类以及酸类,AAEM显著影响焦油产物组成,特别是呋喃类和芳烃的含量会有所增加。本文为优化生物质的热解条件与提高热解生物油品质具有重要意义。     

溶剂溶胀对鄂尔多斯褐煤结构及热解产物分布的影响

采用四种有机溶剂对鄂尔多斯褐煤进行溶胀预处理并在粉-粒流化床上进行快速热解,探究溶胀对褐煤结构及热解特性的影响。采用傅里叶变换红外光谱仪、热重分析仪、气相色谱-质谱联用仪、固体核磁、X射线衍射、全自动化学吸附仪等仪器对溶胀煤及热解产物进行表征。结果表明,非极性溶剂对煤结构影响较小。极性溶剂可以降低褐煤含氧官能团的氢键交联,增加小分子的流动性,增加煤的平均孔径。溶胀后的煤热解焦油和气相产率提高,热解水产率降低。与原煤相比,极性溶剂甲醇、丙酮、四氢呋喃处理煤样的热解焦油产率分别提高了18.88%、26.72%、33.58%,焦油的轻质组分中酚类、单环和双环类芳香烃组分含量明显增加。     

离线热解-热脱附-气相色谱-质谱法用于研究烟草中主要糖类对挥发性成分的影响

提出了离线热解-热脱附-气相色谱-质谱法测定烟草中挥发性成分的方法,并将此方法用于研究烟草中主要糖类化合物(果糖、葡萄糖和蔗糖)对烟草挥发性组分的影响。结果表明:①糖类在高温下裂解,主要生成呋喃类、羧酸类及酯类化合物,不同糖类的裂解产物有较明显差异;②加入蔗糖后,烟草的挥发性成分中醛、酮类和含氮、硫杂环类化合物增加显著;③加入葡萄糖后,醇、酚类和含氧杂环类化合物增加明显;④而加入果糖后,各类化合物增加均较少,其中含氧杂环类化合物含量几乎没有变化。可见糖类物质在热解过程中不仅自身发生氧化还原反应,还与烟草中的成分发生了一系列化学反应,从而显著影响烟气的化学组成。     

麦草半纤维素的快速热裂解实验研究

采用管式炉反应器在550℃~850℃进行了半纤维素的高温快速热裂解实验,以了解其热裂解产物分布及热解规律。结果表明,半纤维素热解三相产物中,气体产物产率最大且随着温度的升高而增加,其主要成分为H₂、CO、CO₂、CH₄ 以及小分子烃类。液相产物中主要是酸类、醇类、呋喃、环戊烯酮类化合物,以及苯酚等芳香化合物,其产率随着温度的升高无明显变化。而焦炭产率则随着温度的升高而降低,且其中残留有大量的有机化合物如醇类、酮类及脱水糖等。     

生物质水热液化和炭化产物特性研究

分别选取稻杆,水葫芦,纤维素和木聚糖（生物质模型化合物）为原料,在反应釜中进行水热液化（300℃,30min）和水热炭化（220℃,4h）实验,对液化产物和炭化产物进行分析。结果表明,稻杆获得重油产率达最大值21.62%。纤维素,木聚糖和水葫芦的重油产率分别为15.00%,11.61%和12.19%。生物质化学组分对其重油产率和组分有着一定的影响。液态产物分别利用总有机碳分析仪（TOC）和气质联用仪（GC-MS）进行测定。表明重质油中主要含有酮类,酚类,醛类,醇类和少量的酸类化合物。利用扫描电镜（SEM）和透射电镜（TEM）对水热炭化固态产物进行了形貌与结构表征,得到具有核壳结构的纳米微球。纤维素,水葫芦和稻杆有着较高的焦炭产率,最后对木聚糖的碳微球形成机理进行初探。     

微拟球藻脂肪热解及对全组分制备生物油的影响

以酸水解法从微拟球藻中提取的粗脂肪为原料,在管式裂解炉中考察不同热解温度下脂肪单组分的热解规律及对微拟球藻全组分各相产率及生物油性能的影响。利用热重分析仪分别考察粗脂肪及全组分的热失重特性,并求出相应的动力学参数。结果表明,脂肪热解能够提高全组分热解有机相产率并改善油品性能。随着温度的升高,粗脂肪与全组分热解后的有机相产率及油品性能的变化趋势相同,且生物油性能均在600℃时达到最佳。经热解,粗脂肪中含氧化合物含量降低,脂肪烃含量显著增加。对比全组分热解,粗脂肪热解后的油品脱氧率及氢、碳元素比例更高,因而增加全组分中脂肪的含量能够促进油品性能的进一步提高。对粗脂肪及全组分的热重数据进行计算,发现两者均满足二级化学反应机理,粗脂肪、全组分的活化能与指前因子分别为64.34 k J/mol与2.94×105min-1,48.13 k J/mol与2.96×103min-1。     

Ni改性HZSM-5催化类煤模型化合物热解研究（英文）

以苯乙醚(PEE)和苯基苄基醚(BOB)为类煤模型化合物,在固定床反应器上研究了它们在镍改性HZSM-5催化剂存在下的催化热解行为。采用浸渍法将镍负载于HZSM-5沸石,对所得催化剂采用XRD、FT-IR、H2-TPR、NH3-TPD进行表征,还研究了还原预处理对催化剂性能的影响。研究表明,Ni O/HZSM-5能显著提高两种模型化合物热解液相产物中酚类化合物的收率。与Ni/HZSM-5相比,Ni O/HZSM-5对苯乙醚热解催化效果更好。     

在Ni/HZSM-5催化剂上低温水蒸汽重整生物油制氢

We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregna-tion method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst composition, reforming temperature and the molar ratio of steam to carbon fed on the stream reforming process of bio-oil over the Ni/HZSM-5 catalysts were investigated in the reforming reactor. The promoting effects of current passing through the catalyst on the bio-oil reforming were also studied using the electrochemical catalytic re-forming approach. By comparing Ni/HZSM-5 with commonly used Ni/Al₂O₃ catalysts, the Ni₂₀/ZSM catalyst with Ni-loading content of about 20% on the HZSM-5 support showed the highest catalytic activity. Even at 450 oC, the hydrogen yield of about 90% with a near complete conversion of bio-oil was obtained using the Ni₂₀/ZSM catalyst. It was found that the performance of the bio-oil reforming was remarkably enhanced by the HZSM-5 supporter and the current through the catalyst. The features of the Ni/HZSM-5 catalysts were also investigated via X-ray diffraction, inductively coupled plasma and atomic emission spectroscopy, hydrogen temperature-programmed reduction, and Brunauer-Emmett-Teller methods.     

餐饮垃圾热解制取生物燃油的实验研究

主要研究温度、餐饮垃圾种类以及催化剂对餐饮垃圾热解所制生物燃油的产率和品质的影响。结果表明,猪肉和米饭的最佳产油温度均为410℃,白菜的最佳产油温度为450℃。米饭、白菜、猪肉的产油率分别为45.02%、25.60%、71.26%。采用氧弹热量计对其热值进行测定,米饭和白菜热解油的高位热值较低,分别为18.30MJ/kg和17.49MJ/kg;而猪肉热解油的高位热值为36.57 MJ/kg, 并且黏稠度较高。催化剂Co-MCM-41的催化效果明显,使餐饮垃圾的产油率由41.99%提高到66.30%,同时使热解油中的含氧化合物明显降低,而烷烃类和烯烃类的含量明显增加,高位热值由30.30MJ/kg提高到32.74MJ/kg。通过物理吸附仪对新制备的和使用一次后再生的催化剂Co-MCM-41进行表征,结果表明,催化剂Co-MCM-41再生后孔容、孔径和比表面积变化不大,性质基本不变,活性依然存在。
     

Enhancement of Bio-based para-Xylene Selectivity in Catalytic Fast Pyrolysis of Cellulose Using a Surface-modified Mg/P/HZSM-5 Catalyst

With the growing consumption of oil, the production of /?-xylene(PX) from renewable biomass has gained significant attention recently. This work demonstrated that cellulose, a main component in lignocellulosic biomass, was directly converted into PX over the Mg/P surface-modified zeolites. The catalysts modified by the incorporation of P2O5 and MgO into HZSM-5(HZ) promoted the isomerization of zw-/o-xylenes to p-xylene. The PX selectivity was greatly enhanced using the modified zeolites due to the deactivation of external surface and the adjustment of pore entrance. In addition, the addition of methanol to cellulose was beneficial to increase the selectivity of xylenes due to the alkylation reactions and the Diels-Alder reactions between cellulose-derived furans and methanol-derived olefins. The highest PX yield of 10.7%(molar fraction) with a high PX selectivity in xylenes(97.1%) was obtained over the 10%Mg/5%P/HZ catalyst. The reaction pathway for the formation ofp-xylene was addressed according to the study of the key reactions and the characterization of catalysts.     

HZSM-5在线提质生物油及催化剂失活机理分析

对不同使用时间的HZSM-5分子筛在线催化提质制取的生物油进行理化特性和成分分析,从生物油品质角度对HZSM-5的催化性能进行评价;并采用TG、BET、XRD、SEM和TEM等方法对失活的HZSM-5催化剂进行表征分析,探讨了HZSM-5催化提质生物油的失活机理,并进行再生研究。研究表明,HZSM-5分子筛可转化生物油中的酸类、醛类和酮类等"非期望"有机物,生成较多"期望"有机物,如酚类和芳烃类物质,降低生物油的氧含量及酸性,提高生物油的热值;HZSM-5使用80 min后,生物油品质明显变差,催化剂活性明显降低;失活催化剂上沉积的焦炭主要呈纤维状,同时,还存在少量石墨状焦炭,焦炭总量达14.12%,且使用过程中催化剂的比表面积和孔容均下降,晶粒的团聚现象加剧,结晶度下降;在催化提质过程中,在孔道内生成的石墨状焦炭及在表面形成的纤维状焦炭大量覆盖活性位点,使得催化剂失活。经550℃再生后,催化剂可恢复催化性能。     

碱处理HZSM-5分子筛在线催化提质生物油

采用NaOH溶液对HZSM-5分子筛进行碱处理,利用XRD、SEM、BET、Py-FTIR四种方法表征改性HZSM-5分子筛,对生物原油有机相、未改性HZSM-5制得生物油有机相与改性HZSM-5制得生物油有机相进行理化特性及成分分析,研究了碱处理HZSM-5分子筛对生物油有机相产物的影响;对使用了120 min的三种失活催化剂进行了热重分析,并对焦炭峰面积进行了积分计算。结果表明,经过碱处理后的HZSM-5分子筛保留了典型的MFI拓扑结构,形成了一定数量的介孔;同时,经碱处理1 h的HZSM-5分子筛催化制得的生物油有机相产物的产率有所增加且理化特性得到提高,其产物中烃类物质的含量显著增加,达到了37.67%,且以单环芳香烃为主;同时改性HZSM-5分子筛对生物油有机相中的酸、醛及酮类物质均有较好的脱除效果,有效地降低了生物油的腐蚀性并提升了生物油的稳定性,热值达到了35.32 MJ/kg;经1 h碱处理的HZSM-5分子筛的总结焦量明显降低。     

Production of liquid bio-fuel from catalytic de-oxygenation: Pyrolysis of beech wood and flax shives

This study presents a detailed analysis of the catalytic de-oxygenation of the liquid and gaseous pyrolytic products of two biomasses (beech wood and flax shives) using different catalysts (commercial HZSM-5 and H-Y,and lab-synthesised Fe-HZSM-5,Fe-H-Y,Pt/Al2O3 and CoMo/Al2O3). The experiments were all conducted in a semi-batch reactor under the same operating conditions for all feed materials. BET specific surface area,BJH pore size distribution and FT-IR technologies have been used to characterise the catalysts,while gas chromatography-mass spectrometry (GC-MS),flame ionisation detection (GC-FID) and thermal conductivity detection (GC-TCD) were used to examine the liquid and gaseous pyrolytic products. It was firstly seen that at higher catalyst-to-biomass ratios of 4∶1,de-oxygenation efficiency did not experience any further significant improvement. FeHZSM-5 was deemed to be the most efficient of the catalysts utilised as it helped reach the lowest oxygen contents in the bio-oils samples and the second best was HZSM-5. It was also found that HZSM-5 and H-Y tended to privilege the decarbonylation route(production of CO),whilst their iron-modified counterparts favoured the decarboxylation one (production of CO2) for both biomasses studied. It was then seen that the major bio-oil components (carboxylic acids) underwent almost complete conversion under catalytic treatment to produce mostly unoxygenated aromatic compounds,phenols and gases like CO and CO2. Finally,phenols were seen to be the family most significantly formed from the actions of all catalysts.     

Utilization of camellia oleifera shell for production of valuable products by pyrolysis

Camellia oleifera shell is used as the feedstock to prepare the valuable products by pyrolysis using microwave heating at 400-800 °C. The yield of pyrolysis product is influenced by pyrolysis temperature, which indicates that high pyrolysis temperature promotes to generate bio-gas and restrains the production of biochar. However, pyrolysis temperature little influences the yield of bio-oil. The main compound of bio-oil is phenols, hydrocarbons, ketones, aldehydes and furans, respectively. While, bio-oil produced at 600 °C has as high as 78 % of phenols, which has potential application in chemical industries. The pyrolysis temperature has significantly influenced the composition and heating value of bio-gas. The maximum heating value of bio-gas is 12.44 MJ/Nm³, which is achieved at 600 °C. The physiochemical properties of biochar are also influenced by pyrolysis temperature. Biochar could be used as an adsorbent to adsorb Ag⁺ from aqueous solution, which is formed the value-added ABiochar composite by reduction. The adsorption and reduction process of Ag⁺ are investigated. While, ABiochar composite can be used as the catalyst for methylene blue degradation. ABiochar composite can be also used in the lithium ion battery cathode material for energy storage.     

MCM-41和HZSM-5协同催化对油菜秸秆热解的影响

以油菜秸秆为原料,采用两种方案分层布置催化剂(HZSM-5/MCM-41和MCM-41/HZSM-5),并与MCM-41和HZSM-5单独催化进行对比,从生物油品质和催化剂耐久性两个角度探究协同催化作用机理;对精制生物油有机相进行理化特性分析,采用FT-IR和GC-MS进行成分分析,对催化剂进行耐久性分析。结果表明,与单独催化相比,协同催化所得精制生物油液相产率略有降低,气相产率升高,精制生物油有机相理化特性进一步提高,其中,MCM-41/HZSM-5协同催化所得精制生物油有机相热值较高,为34.31 MJ/kg;精制生物油有机相中含有多种芳香族类物质和少量的羰基类物质,协同催化较单独催化能产生较多的烃类物质及较少的含氧芳香族类物质,其中,MCM-41/HZSM-5协同催化所得精制生物油有机相中烃类物质含量较高,且以单环芳香烃为主;HZSM-5分子筛在300-800℃有两个失重峰,MCM-41分子筛在300-800℃仅有一个失重峰,表明MCM-41催化剂上沉积的焦炭成分单一,较易去除,且协同催化后分子筛表面沉积的焦炭总含量较少。     

Transformation of Bio-oil into BTX by Bio-oil Catalytic Cracking

Production of benzene, toluene and xylenes (BTX) from bio-oil can provide basic feedstocks for the petrochemical industry. Catalytic conversion of bio-oil into BTX was performed by using different pore characteristics zeolites (HZSM-5, HY-zeolite, and MCM-41). Based on the yield and selectivity of BTX, the production of aromatics decreases in the following order: HZSM-5>MCM-41>HY-zeolite. The highest BTX yield from bio-oil using HZSM-5 reached 33.1% with aromatics selectivity of 86.4%. The reaction conditions and catalystcharacterization were investigated in detail to make clear the optimal operating parameters and the relation between the catalyst structure and the production of BTX.