甲烷气氛下铁基催化剂对低阶煤温和液化的影响

针对煤直接液化的高温高压苛刻反应条件和高昂的氢气成本问题,通过降低煤液化反应温度、压力和更换供氢气氛等方法来优化工艺过程。选用四种铁基催化剂研究低阶煤在甲烷气氛下温和液化的反应特性,研究结果表明：神华黑山长焰煤HS在温度350℃、初始压力3 MPa的甲烷气氛下液化产物为轻质气体、液化油和沥青质;以FeSO₄为催化剂时沥青质的产率最高达到8.03%,并将煤液化的转化率提升了6.10%;以FeS为催化剂时油气产率提升了3.48%;助剂硫元素的加入对煤液化反应总转化率的提升有着重要作用;Fe粉、Fe+S和FeS催化剂的加入有助于提升煤液化油中单环芳烃的含量。     

秸秆与兖州煤共液化反应条件的研究

在高压反应釜内,以四氢萘为供氢溶剂,Fe2O3＋S为催化剂,研究了温度、反应时间、初始氢压、配比对兖州煤与秸秆共液化的影响。结果表明,提高反应温度,转化率、油产率增加;延长反应时间对转化率、油产率的影响较小;升高初始氢压,转化率、油产率刚开始增加,6 MPa以后增幅趋缓;在m（秸秆）∶m（兖州煤）=0.5∶9.5时,共液化的油产率为60.45%,比兖州煤单独液化的油产率提高了4.17%;在m（兖州煤）∶m（秸秆）=9.5∶0.5,440℃,8 MPa,90 min的条件下,共液化转化率和油产率达到最大,分别为83.58%和63.1%。     

神华煤直接液化性能及固体酸催化可行性研究

利用微型压热釜考察了气氛、温度、氢气初压及煤溶剂比等工艺条件对神华煤直接液化转化率和产物分布的影响,结合神华煤的溶剂抽提性能和产物表征,系统地研究了神华煤加氢液化性能,并通过与FeS和FeS＋S等催化剂对比实验,初步探讨了SO2^2-／MxOy型固体酸催化煤加氢液化的可行性．结果表明,神华煤中以非共价键作用结合的小分子化合物含量较低,煤中的羟基主要位于大分子骨架结构中;神华煤具有良好的液化性能,400℃,煤／四氢萘比为1：2,SO4^2-／ZrO2为催化剂时最高转化率达到76．3％,气氛、初压、液化温度及煤溶剂比对液化转化率具有较大影响,较高温度及强的供氢体系有利于提高煤的转化率及油气产率．三种催化剂的催化活性顺序为：FeS〈FeS＋S〈SO4^2-／ZrO2,其中SO4^2-／ZrO2固体酸不仅具有良好的液化转化率,而且油气收率高,值得进一步研究开发．     

高惰质组分五彩湾煤直接液化性能研究

以新疆五彩湾煤为研究对象,进行了煤质和热解分析,考察了溶煤比、反应时间、氢初压和反应温度对其加氢液化效果的影响.结果表明,尽管五彩湾煤惰质组含量高达81.5%,镜质组最大反射率达到0.73%,挥发分低于37%,H/C仅为0.59,但在氢初压仅为6.0MPa,溶煤比1.75和反应时间60min条件下,其最佳液化温度为450℃,油产率和转化率分别达到55.20%和76.76%,仍然具有良好的液化性能.     

新疆淖毛湖煤加氢液化特性及液化产物中氢的分布规律

以新疆淖毛湖煤和四氢萘为原料,在2L高压釜中进行加氢液化实验,开展新疆淖毛湖煤直接液化过程调控研究,考查了温度、压力、时间及催化剂对氢耗、气产率、转化率、油产率和沥青类物质产率的影响规律,探讨了复杂多相体系液化产物中氢的分布规律,揭示了煤直接加氢液化反应与氢分布规律的内在联系.结果表明:在420℃,15MPa和60min的反应条件下,淖毛湖煤的转化率为94%,油产率为65%,是适宜直接液化的优良煤种;氢较均匀地分布在淖毛湖煤加氢液化的轻质产物(水、150℃馏分油、150℃～260℃馏分油和260℃～350℃馏分油)中,在350℃重质馏分油中分布最高,接近30%;氢在液化产物中的分布与加氢液化反应效果呈现出正相关特征.     

飞灰对五彩湾煤低压直接液化性能影响研究

在溶煤比为2.75∶1,氢初压为6.0MPa和反应时间为60min条件下,考察了温度、飞灰加入量、CoSO4和NiSO4用量及其加入方式等因素对五彩湾煤直接液化性能的影响.结果表明,在给定的条件下,在飞灰加入量为3%(daf,质量分数)和温度为415℃时,可获得最大油产率为64.59%;当CoSO4和NiSO4与飞灰和煤样机械混合加入时,对液化油产率和转化率产生负效应;当NiSO4和CoSO4浸渍担载加入时,油产率分别达到68.01%和66.58%.尽管煤质分析结果表明该煤样加氢液化性能较差,但以飞灰、CoSO4和NiSO4为催化剂时,还是获得了良好的液化效果.     

溶胀煤制备及煤加氢液化性能的研究

在自然和微波条件下,对五彩湾煤进行溶胀处理,进行煤质、电镜、热解、煤的结构-化学指数分类、加氢液化产率和液化残渣热解的分析。实验结果表明:五彩湾煤自然溶胀煤样和微波溶胀煤样的层状和裂纹显著增加,失重量明显增大。煤加氢液化测试结果表明,在氢初压6.0 MPa、溶煤比1.75:1、反应温度450℃和反应时间60 min条件下,气产率由原煤的9.7%,降低到两种溶胀煤均在3.4%左右;油产率由原煤的55.2%,提高到自然溶胀煤的70.1%和微波溶胀煤的74.0%;转化率由原煤的76.8%,增加到自然溶胀煤的82.1%和微波溶胀煤的84.8%。可见,经过溶胀处理,煤加氢液化效果显著。     

Mo修饰的钼铁复合催化剂及其煤直接液化催化性能

分别在Fe催化剂制备的沉淀、氧化和干燥阶段引入Mo合成了五种Mo修饰的钼铁复合催化剂,调控了Mo和Fe的结合形式。利用XRD、SEM、TEM、BET、XRF、XPS和H₂-TPR对催化剂进行表征,在500 ml高压釜内进行神华上湾煤的直接液化实验。结果表明,钼铁协同催化作用促进了氢的活化和煤的分解,Mo修饰的复合催化剂的煤直接液化活性明显提高。Mo在催化剂表层分布有利于活性氢在工业循环溶剂和沥青类物质中的传递,促进沥青转化为油。Mo与Fe共沉淀会影响铁氧化物晶体形成和生长,使晶粒尺寸下降,比表面积和可还原度升高。Mo从氨水中引入形成均匀分散的小晶粒Mo-Fe复合化合物,液化油产率提高4.4%。浸渍引入Mo不改变铁氧化物结构,但Mo富集于催化剂表面提高了与反应物的碰撞概率,液化油产率提高5.0%。     

兖州煤与木质素共液化反应性的研究

采用单因素法,以四氢萘为供氢溶剂,以Fe2O3和S为催化剂,在高压釜内,研究了配比、温度、反应时间和初始氢压对兖州煤与木质素共液化反应性的影响.结果表明,在液化中适量添加木质素可提高兖州煤的液化反应性.综合考虑实验条件和经济成本,得到共液化的最佳工艺条件为:兖州煤:木质素(质量比)=9:1,440℃,60min,8MPa,在此条件下转化率与油产率分别为86.8%与62.9%.     

神府煤的液化性能及其重质产物结构表征

利用管式高压反应釜,以四氢萘为溶剂、FeS和S为催化剂,对神府煤进行了加氢液化研究,考察了催化剂、反应温度和反应气氛等因素对煤液化性能和产物组成分布的影响,同时对液化产物进行了红外光谱、元素分析以及酸性含氧官能团等结构表征。结果表明,FeS+S催化神府煤液化的最高四氢呋喃(THF)抽提率和油+气收率分别为69.5%和35.9%;未加催化剂时,神府煤液化THF抽提率和油+气收率都是最低的。     

煤炭直接液化残渣加氢研究进展

在煤炭直接液化生产过程中,会产生占液化原煤质量30％左右的液化残渣。它是一种高碳、高灰和高硫的物质,主要由未转化的煤、液化中间产物、无机矿物质以及煤液化催化剂组成。煤炭直接液化残渣有很高的利用价值,无论从经济角度还是环保角度出发,都需要对残渣进行利用,这也是煤炭直接液化工业化必须解决的问题。综述了煤炭直接液化残渣的来源、组成、性质、加氢研究现状及应用等。     

乙炔羰基化合成丙烯酸甲酯的研究

以乙炔、一氧化碳和甲醇为原料,卤化镍为主催化剂,羰基化合成丙烯酸甲酯,考察其在不同的反应温度、反应初始压力、原料配比、反应时间和催化剂用量下对反应结果的影响,确定最优的工艺条件。实验表明：以甲醇为溶剂,在185℃左右和5．2～5．5MPa的条件下,n（甲醇）：n（乙炔）：n（CO）=5．5～6．2：1：1,催化剂用量0．85wt％～0．9wt％,反应4～5h,丙烯酸甲醣的收率（相对乙炔）达到90％以上。     

从低阶煤直接制取苯类产品的项目研究

基于市场对粗苯的需求,进行以低阶煤为原料直接制取粗苯的研究。我国低变质程度煤炭资源丰富,且储量巨大,选择性地对某些低阶煤在一定的溶剂、催化剂、温度、压力条件下加氢液化,可得到含芳香烃较高的油品,经过重整精馏可进一步得到苯、甲苯、二甲苯等产物。初步探讨了低阶煤加氢液化制粗苯的工艺过程和过程条件。     

Thermochemical liquefaction characteristics of microalgae in sub- and supercritical ethanol

Thermochemical liquefaction characteristics of Spirulina, a kind of high-protein microalgae, were investigated with the sub- and supercritical ethanol as solvent in a 1000 mL autoclave. The influences of various liquefaction parameters on the yields of products (bio-oil and residue) from the liquefaction of Spirulina were studied, such as the reaction temperature (T), the S/L ratio (R₁, solid: Spirulina, liquid: ethanol), the solvent filling ratio (R₂) and the type and dosage of catalyst. Without catalyst, the bio-oil yields were in the range of 35.4 wt.% and 45.3 wt.% depending on the changes of T, R₁ and R₂. And the bio-oil yields increased generally with increasing T and R₂, while the bio-oil yields reduced with increasing R₁. The FeS catalyst was certified to be an ideal catalyst for the liquefaction of Spirulina microalgae for its advantages on promoting bio-oil production and suppressing the formation of residue. The optimal dosage of catalyst (FeS) was ranging from 5-7 wt.%. The elemental analyses and FT-IR and GC-MS measurements for the bio-oils revealed that the liquid products have much higher heating values than the crude Spirulina sample and fatty acid ethyl ester compounds were dominant in the bio-oils, irrespective of whether catalyst was used.     

Catalytic hydrogen transfer due to FeSO4 and Co&z.sbnd;Mo in coal liquefaction

The liquefaction behaviour of a Kentucky coal was studied in batch autoclave experiments at 410 °C under either a H₂ or a N₂ atmosphere (≈ 13.8 MPa) for reaction times of up to 2 h. To understand the catalytic roles of FeSO₄ and a Co&z.sbnd;Mo catalyst in coal liquefaction and to assess the feasibility of using FeSO₄ as a model for coal pyrites, effects of impregnation of the coal with FeSO₄ and direct charges of a Co&z.sbnd;Mo catalyst on coal liquefaction and tetralin dehydrogenation were examined. Both catalysts increase the conversion to benzene-soluble material by 7–10%, and improve the selectivity values for conversion to oil and gas. In addition they are also active in the dehydrogenation of tetralin. The dehydrogenation activities of these catalysts correlate with their catalytic activities during coal liquefaction. Analyses of the mean chemical structures and the product distributions of the coal-derived liquid from liquefaction in H₂ and in N₂ atmospheres indicate that:

1. (1) H-transfer from tetralin is the only major mechanism of coal liquefaction; and

2. (2) both pyrrhotite, generated in-situ from FeSO₄, and Co&z.sbnd; Mo catalyst can provide a major liquefaction mechanism by catalysing the H-transfer from the donor solvent to the coal or the coal-derived liquid.

     

Hydrogenation of heavy liquids from a direct coal liquefaction residue for improved oil yield

For hydrogenation of heavy liquids in direct coal liquefaction residue (DCLR) within the direct coal liquefaction (DCL) process, heavy liquids in a DCLR derived from a bench-scale Shenhua DCL process using Shenhua coal are evaluated under two conditions. One simulates the coal liquefaction conditions of the Shenhua plant in the presence of a Fe-based Shenhua catalyst; the other one simulates the online hydrotreating conditions in the presence of a NiMo/Al₂O₃ catalyst. The results show that the heavy liquids of DCLR can be hydrogenated under these two conditions yielding less heavy products; hydrogenating the heavy liquids under the online hydrotreating conditions is more effective than that under the coal liquefaction conditions; the preasphaltene fraction is a main problem that yields non-soluble materials under these hydrogenation conditions. The results suggest that hydrogenation of toluene soluble and tetrahydrofuran soluble fractions of the DCLR under the coal liquefaction and online hydrotreating conditions is feasible, but their conversion to lighter products are inapparent under the coal liquefaction conditions, and elimination of the formation of tetrahydrofuran insoluble fraction in the online hydrotreator should be considered.