城市污水污泥催化快速热解制备芳香烃和烯烃

将城市污水污泥干燥处理,在小型热解分析系统中使用沸石分子筛进行催化快速热解实验,研究热解条件对芳香烃和烯烃产率及选择性的影响。结果表明:污泥快速热解产物中,烃类物质和含氮化合物较多,这些组分主要源自污泥中的蛋白质和油脂成分;添加催化剂后,芳香烃和烯烃的产率明显提高;在热解温度500℃、催化温度600℃条件下芳香烃和烯烃的产率分别为24%和19%。另外,污泥中大部分的N、P、Na和K等元素依然保留在炭粉中。     

含油污泥在ZSM-5沸石上催化热解产物特性

采用U型固定床管式炉研究了含油污泥在ZSM-5分子筛催化剂上的热解产物特性。发现在450℃下未使用催化剂热解时,GC-MS和GC测得的油泥热解油产物中的主要成分为烷烃和烯烃,芳烃含量较低;气体产物中主要为短链烃类,氢气产量较少。而在ZSM-5分子筛的催化作用下,热解油中芳香烃产量达到88.4%,气体产物中的氢气产量和短链烃类产量均明显增加。研究了400～550℃之间分子筛对含油污泥的催化效果,发现ZSM-5在500℃时催化效果最佳,油相产率达到65.6%,油相中的沥青质和胶质含量较低,芳香烃产量达到90.9%。通过热重和XPS分析发现分子筛上的积炭主要以多环芳烃焦炭的形式存在。     

含油污泥在ZSM-5沸石上催化热解产物特性

采用U型固定床管式炉研究了含油污泥在ZSM-5分子筛催化剂上的热解产物特性。发现在450℃下未使用催化剂热解时,GC-MS和GC测得的油泥热解油产物中的主要成分为烷烃和烯烃,芳烃含量较低;气体产物中主要为短链烃类,氢气产量较少。而在ZSM-5分子筛的催化作用下,热解油中芳香烃产量达到88.4%,气体产物中的氢气产量和短链烃类产量均明显增加。研究了400~550℃之间分子筛对含油污泥的催化效果,发现ZSM-5在500℃时催化效果最佳,油相产率达到65.6%,油相中的沥青质和胶质含量较低,芳香烃产量达到90.9%。通过热重和XPS分析发现分子筛上的积炭主要以多环芳烃焦炭的形式存在。     

生物质模化物催化热解制取烯烃和芳香烃

采用愈创木酚作为生物质模型化合物,以ZSM-5为催化剂,在固定床反应器中研究了反应温度、质量空速以及分压对热解产物产率、选择性的影响,并考察了催化剂的积炭情况。结果表明,愈创木酚催化热解的主要产物为酚类,其次是芳香烃。温度对产物分布有显著影响。催化剂适量的积炭有利于提高烯烃和芳香烃的产率。根据愈创木酚催化热解反应产物分布,推测其主要反应为脱除甲氧基形成酚类,进一步芳构化形成芳香烃。本文研究结果为研究生物质催化热解反应机理提供了理论依据。     

城市污水污泥低温催化热解制油研究

污泥低温催化热解是一项具有污泥处理与能源回收双重性质的资源化技术。本文采用低温热解技术处理城市污水污泥,比较了在有/无催化剂条件下,停留时间和反应温度对热解产物产率及特性的影响。结果表明,催化剂的使用提高了污泥热解油的产率和品质,降低了产炭率。最大产油率所需的最优温度从450℃下降到400℃,最大产油率从34.53%增加到38.71%。     

环烷基瓦斯油催化裂解反应规律及产品性质

利用提升管催化裂解实验装置研究了加拿大合成原油瓦斯油HGO和LGO的催化裂解反应规律和裂解产品性质。发现总低碳烯烃（乙烯、丙烯和丁烯）产率随反应温度和剂油比的增大存在最大值,随反应时间的延长而减小,随水油比的增大而升高。实验确定了HGO催化裂解的优化反应条件：反应温度620～640℃、剂油比16、反应时间2 s、水油比0.5左右。在此反应条件下,乙烯、丙烯和总低碳烯烃产率分别可达9.0%（质量）,15.8%（质量）和32.6%（质量）。催化裂解汽油馏分、柴油馏分和重油馏分含有大量的芳香烃,其中催化裂解汽油馏分总芳香烃含量在80%（质量）以上,主要是甲苯和C₈芳香烃;催化裂解柴油馏分总芳香烃含量在60%（质量）以上,主要是单环和双环芳香烃;催化裂解重油馏分总芳香烃含量在70%（质量）以上,主要是多环芳香烃。     

利用Py-GC/MS研究温度和时间对生物质热解油的影响

以木粉为原料,在不同反应条件下利用Py-GC/MS装置对其进行快速热解,并对热解油气进行在线检测分析,研究反应温度和热解时间对生物油组成及其产率的影响。结果表明,在400℃条件下生物油组成单一,便于分离和提纯;继续升高温度,生物油组成及其产率均逐步增加;温度高于700℃,有利于轻质类和芳香烃类碳氢化合物的生成。同一反应温度,不同热解时间,生物油组成保持稳定,但各类化合物的产率均发生变化。在反应温度为600℃,反应时间为25 s的条件下,高附加值的苯酚类化合物的产率最高。     

基于Py-GC/MS热解温度对准东煤快速热解焦油产物分布的影响

利用热解-气相色谱/质谱(Py-GC/MS),研究了热解温度对准东煤快速热解的影响,利用分步活化能模型拟合了在高升温速率下Py的失重数据,分析了焦油中的成分随温度的变化规律。结果表明,热解温度持续升高,烯烃含量先缓慢增加再减少,烷烃的含量不断减少,芳香烃含量不断增加。脂肪烃和芳香烃两类产物呈现协调竞争关系,中低温热解有利于不稳定桥的断裂产生烷烃和烯烃;高温热解促进不稳定桥的自发缩聚,使芳香烃迅速增加。苯、甲苯、乙基苯和二甲苯的含量在400～600℃快速上升,600℃以后含量缓慢增加。焦油的高位热值在900℃下达到最高,为308.84 kJ/kg。     

生物质选择性催化热解制备芳香烃的研究进展

芳香烃是一种重要的化工原料,生物质常规热解难以形成大量的芳香烃,但在催化热解条件下可显著提高芳香烃的产率,由此可望提供一种新型的芳香烃制备方法。首先阐述了生物质催化热解生成芳香烃的机理,包括综纤维素经解聚、开环和芳构化等反应生成芳香烃;木质素由小分子酚类生成芳香烃。随后讨论了原料、催化剂、预处理及工艺条件等因素对生物质选择性催化热解生成芳香烃的影响,并提出了生物质热解制备芳香烃工艺参数优化方案。     

催化裂解精制污泥热解油的工艺研究

以扬子污水处理厂的污水和污泥为原料,选取热解反应温度、热解反应时间、催化裂解反应温度和催化剂用量等因素,通过正交试验确定催化裂解精制污泥热解油的最佳工艺条件,并考察以上因素对精制油收率的影响.结果表明,在热解反应温度420℃、热解反应时间60 min、催化裂解反应温度460℃和催化剂用量(以催化剂床层高度表示)3 cm...     

重油催化裂解汽柴油二次裂解性能研究

This paper investigated the secondary cracking of gasoline and diesel from the catalytic pyrolysis of Daqing atmospheric residue on catalyst CEP-1 in a fluidized bed reactor.The results show that the secondary cracking reactivity of gasoline and diesel is poor,and the yield of total light olefins is only about 10%（by mass）.As reaction temperature increases,ethylene yield increases,butylene yield decreases,and propylene yield shows a maximum.The optimal reaction temperature is about 670℃for the production of light olefins.With the enhance- ment of catalyst-to-oil mass ratio and steam-to-oil mass ratio,the yields of light olefins increase to some extent. About 6.30%of the mass of total aromatic rings is converted by secondary cracking,indicating that aromatic hy- drocarbons are not easy to undergo ring-opening reactions under the present experimental conditions.     

Improving hydrocarbons production via catalytic co-pyrolysis of torrefied-biomass with plastics and dual catalytic pyrolysis

To increase the low yield and selectivity of aromatic hydrocarbons during the biomass pyrolysis process, we torrefied the biomass and then co-pyrolyzing with plastics such as high-density polyethylene (HDPE), polystyrene (PS), ethylene-vinyl acetate (EVA) and polypropylene (PP) and also single and dual catalyst layouts were investigated by Py-GC/MS. The results showed that non-catalytic fast pyrolysis (CFP) of raw bagasse (RBG) generated no aromatics. After torrefaction non-CFP of torrefied bagasse (TBG) generated low aromatic yield. Indicating that torrefaction would enhance the proportion of aromatics during the pyrolysis process. The CFP of TBG_200℃ and TBG_240℃ over ZSM-5 produced the total aromatic yield of 1.96 and 1.88 times higher, respectively, compared to non-CFP of TBG. Furthermore, the addition of plastic could increase H/Ceff ratio of the mixture, consequently, increase the yield of aromatic compounds. Among the various torrefied-bagasse/plastic mixtures, the CFP of TBG/EVA (7:3 ratio) mixture generated the highest the total aromatic yield of 7.7 times more than the CFP of TBG alone. The dual catalyst layout could enhance the yield of aromatics hydrocarbons. The dual-catalytic co-pyrolysis of TBG_200℃/plastic (1:1) ratio over USY (ultra-stable Y zeolite)/ZSM-5, improved the total aromatics yield by 4.33 times more than the catalytic pyrolysis of TBG_200oC alone over ZSM-5 catalyst. The above results showed that the yield and selectivities of light aromatic hydrocarbons can be improved via catalytic co-pyrolysis and dual catalytic co-pyrolysis of torrefied-biomass with plastics.     

The influence of catalyst regeneration on the composition of zeolite-upgraded biomass pyrolysis oils

The composition of oils derived from the on-line, low pressure zeolite upgrading of biomass pyrolysis oils from a fluidized bed pyrolysis unit have been investigated in relation to the regeneration of the zeolite catalyst. The catalyst used was H-ZSM-5 zeolite. The gases were analysed by packed column gas chromatography. The composition of the oils before catalysis and after catalyst upgrading were analysed by liquid chromatography fractionation, followed by coupled gas chromatography—mass spectrometry of each fraction. In particular, the aromatic and oxygenated aromatic species were identified and quantified. In addition, the oils were analysed for their elemental composition and molecular weight range using size exclusion chromatography. Before catalysis the biomass pyrolysis oil was highly oxygenated but after catalysis a highly aromatic oil was formed with high concentrations of monocyclic aromatic hydrocarbons. In addition, significant concentrations of polycyclic aromatic hydrocarbons (PAH) were formed. Regeneration of the zeolite catalyst showed that continued regeneration reduced the effectiveness of the catalyst in converting biomass pyrolysis oils to an aromatic product. Elemental analysis of the upgraded oils showed an increase in the oxygen content of the oil with increasing regeneration of the catalyst. The molecular weight range of the oils was found to decrease markedly after catalysis, but continued regeneration of the catalyst increased the molecular weight range of the upgraded oils. Detailed analysis of the uncatalysed oils showed they contained low concentrations of aromatic and PAH species which markedly increased in concentration after catalysis. The overall effect of increasing catalyst regeneration was a decrease in the concentration of aromatic hydrocarbons and PAH. Also as the catalyst was regenerated, the number of methyl groups on the parent single ring aromatic compound or PAH increased. The oxygenated aromatic species in the oil before catalysis were mainly, phenols and benzenediols and their alkylated homologues. After catalysis some of the oxygenated species were reduced and some increased in concentration. A dual mechanistic route is suggested for the formation of aromatics and PAH during the catalytic upgrading of biomass pyrolysis oils: (1) the formation of low-molecular-weight hydrocarbons on the catalyst which then undergo aromatization reactions to produce aromatic hydrocarbons and PAH; (2) deoxygenation of oxygenated compounds found in the non-phenolic fraction of the pyrolysis oils which directly form aromatic compounds.     

基于Py-GC/MS的玉米秸秆快速热解实验研究

以玉米秸秆为原料,利用Py-GC/MS设备在不同热解条件下进行快速热解实验,并对热解气相产物进行在线检测分析,考察了热解时间、热解温度及ZSM-5催化剂对玉米秸秆热解特性及热解产物分布的影响.实验结果表明:热解温度越高,热解反应越充分,且热解温度为550℃时对应的热解产物品质最高,其中芳香族化合物最高达28.3％;随着...     

Fe/生物质焦预重整在Ni基催化重整生物油中的作用

低温预重整能够经济节能地提高Ni基催化剂重整生物油的效果。为研究廉价易得的Fe/生物质焦预重整催化剂对重整效果的影响及机理,设计了Fe/生物质焦催化剂和Ni-Ca/γ-Al₂O₃催化剂不同组合方式在不同的预重整温度（350～600℃）下的重整实验,并用紫外荧光分光光度计（UV）和气相色谱-质谱联用仪（GC-MS）分析重整焦油,用气相色谱仪（GC）对重整气进行定性和定量分析。实验结果表明：Fe/生物质焦优化了预重整产生的挥发分,将原本挥发分中分子量较大的苯系物、萘系物及多环芳香化合物转化为结构简单、更易重整为气体的呋喃类、酚类及非芳香化合物,从而有效提高下段Ni基催化剂重整的合成气（H₂、CO）产率。预重整温度增加能有效抑制积炭生成。另外,Fe/生物质焦在较高预重整温度（550～600℃）下能够抑制Ni基催化剂表面积炭生成。     

硼掺杂活性炭催化生物质与塑料共热解制芳烃

活性炭（AC）由于其发达的孔隙结构和官能团,被用作生物质和塑料催化裂解的催化剂或催化剂载体。然而,AC催化剂的催化活性较低,需对其进行改性处理以提高催化性能。本文利用固定床反应器探究了掺硼活性炭（BAC）催化剂催化玉米秸秆和高密度聚乙烯共热解过程中硼掺杂量、催化剂/原料质量比、共热解温度对产物产率及分布的影响规律。采用BET、FT-IR、NH₃-TPD测试了AC与BAC催化剂的比表面积、孔容、表面官能团及酸性等性能,并采用XRD和XPS对BAC使用前后硼的晶体结构和存在形态进行了表征。结果表明,随着硼掺杂量的增加,BAC催化剂的比表面积和孔径逐渐降低,表面官能团无明显变化,而强弱酸量显著增加。使用后的BAC催化剂中硼主要以B—O键的形式存在,BC₃衍射峰消失,出现了B—C弱衍射峰。随着硼掺杂质量分数从0.5%增至3.0%,单环芳烃的含量先升高后降低,而多环芳烃的含量呈现出与单环芳烃相反的变化趋势。当硼掺杂量为1.0%、共热解温度为600℃和BAC催化剂/原料质量比为1.25时,单环芳烃含量达到最大值44.18%,此时多环芳烃的含量为19.75%。此外,硼的存在能有效抑制焦炭沉积,提高催化剂的寿命。     

磁性MgFe2O4及其核壳催化剂制备与煤热解性能研究

采用溶胶-凝胶法制得MgFe₂O₄前体,经焙烧得到MgFe₂O₄催化剂,再经St?ber法制得核壳结构催化剂MgFe₂O₄@SiO₂和MgFe₂O₄@SiO₂@HZSM-5(MSH),利用VSM、XRD、SEM、FT-IR、N₂物理吸附等手段研究了催化剂的磁性能和结构特征;在固定床反应器上,考察了N₂气氛下磁性催化剂对补连塔富油煤的催化热解特性及回收再生性能。结果表明：MgFe₂O₄为立方尖晶石结构,饱和磁化强度达到181.50 emu/g,具有良好热稳定性能。上述系列磁性催化剂均呈现出良好的催化活性,其中MSH催化活性最好。与非催化热解相比,MSH催化热解焦油产率提高了57.7%,焦油中脂肪烃和苯类含量增加约2倍,稠环芳烃含量下降8.6%~9.8%。采用磁选方法可有效实现催化剂回收,经700℃下焙烧处理,可实现回收催化剂的再生。SiO₂包覆有助于提高核壳结构催化剂的磁热稳定性和催化寿命。