铁基催化剂对将军庙煤低压直接液化性能影响

以将军庙煤为研究对象,催化剂用量按活性金属元素计为3%(wtCoaldaf)、反应温度T=420℃、反应时间τ=75min、溶煤比S/C=2/1和氢初压PH2=6.5MPa条件下,首先,以油产率为目标,Fe2O3为主催化剂,S为助催化剂,通过考察S/Fe对煤样直接液化性能的影响,确定了最佳S/Fe=1/1。其次,在S/Fe为1/1和上述反应条件下,考察了一系列铁基催化剂对煤样液化性能的影响。结果表明,以油产率为目标,其活性由高到低为:Fe2O3/S油溶性Fe3O4/S油溶性Fe3O4(中试)/S飞灰/S纳米Fe3O4/S黄铁矿/Fe2O3油酸铁/SFeSO4/SFe(NO3)3/Sβ-FeOOH/SFeCl3/S还原铁粉/SFeS。最后,将Fe2O3/S与MoO3/S、FeSO4/S与NiSO4/S和CoSO4/S分别进行了比较。结果表明:Fe2O3/S比MoO3/S更能促进沥青质向油的转化;FeSO4/S与NiSO4/S和CoSO4/S三者油产率相差甚小,均约67%。故此,Fe2O3/S的催化活性最好。     

惰质组含量对上湾煤液化性能的影响

对不同惰质组分含量的上湾煤样进行了高压釜煤液化实验。在反应温度440～465℃,氢初压7～11 MPa条件下,研究了5种不同惰质组含量的上湾煤的液化性能。结果表明:在反应温度为440～465℃内,随着温度的升高,除惰质组含量最高的5号煤样在温度高于465℃时转化率开始下降以外,其余不同惰质组含量的4种煤的转化率、油产率、气产率和氢耗均随着温度的升高而增加,沥青烯产率随温度的升高而减小;随着氢初压的增加,不同显微组含量的煤的转化率和油产率增加,沥青烯产率减小。惰质组含量越高,煤的转化率和油收率越低。     

超声波辐射下溶胀改善煤液化性能的研究

以山东兖州局的北宿煤 ( BS)、兴隆庄煤 ( XLZ)、枣庄局的柴里煤 ( CL)等为研究用煤 ,首先在自然条件下使用吡啶溶剂进行原煤样的溶胀 ,然后利用超声波仪 ,在 40 k Hz和 5 0 0 W辐射功率和室温的条件下 ,进行超声波辐射作用下的吡啶溶剂溶胀 .经过对脱除溶剂后溶胀煤的加氢液化实验、低温干馏焦油产率测定、挥发分产率测定及体积溶胀率的测定 ,结果表明该三种原煤具有良好的可溶胀性能 ,溶胀煤均具有良好的加氢液化性能 .在 H2 冷态压力 8.2 MPa,40 0℃ ,Fe SO4·7H2 O和升华 S作催化剂、反应 1 .5 h的液化实验条件下 ,自然溶胀煤的液化油产率比原煤增加 1 2%～ 2 5 % ,北宿溶胀煤的液化油产率达到 69.76% .辐射溶胀后的溶胀煤与自然溶胀煤比较 ,在如上所述同样的液化条件下 ,兴隆庄煤的液化油产率增加了 2 2 % ,并且煤的总转化率也增加了 .实验数据表明 ,对于以提高煤加氢液化反应活性为目的的研究 ,当超声波辐射的频率和功率一定时 ,辐射时间对于改善煤样加氢液化的性能存在着最适宜值 ,这一最适宜值与煤的变质程度有直接关系 .     

新疆西沟煤超临界醇解及对其液化性能的影响

以新疆阜康西沟煤为研究对象,考察了甲醇(MET)和洗油(WO)混合溶剂下的醇解条件,醇-碱体系下的醇解行为及醇解残渣的液化性能,并与煤样直接液化结果进行对比.结果表明:θ=320℃,t=60min,m(solvent)∶m(coal)=10∶1,mMET∶mWO=8∶2为适宜的醇解条件,此条件下,醇解率为21.8%.进一步加入NaOH或CaO作为醇解催化剂,当碱煤比=0.8∶1时,醇解率分别为51.3%和27.4%.以洗油为供氢溶剂,对醇解残渣进行直接液化,并与原煤样直接液化的结果进行对比,煤样直接液化的总液体产率为62.3%,而无碱醇解、CaO醇解和NaOH醇解产物的总液体产率依次为71.0%,72.7%,83.2%,分别提高了8.7%,10.4%和20.9%.同时,对醇解产物进行了FTIR,TG-DTG和SEM表征,对催化醇解与煤样直接液化的气体产物进行了GC分析.     

胶体磨制备煤浆及粒径对直接液化性能的影响

以新疆将军庙煤样为研究对象,四氢萘为制浆、供氢溶剂,使用胶体磨湿磨制浆,考察了研磨时间对煤浆粒径的影响.通过激光粒度仪表征可得:磨煤1h,2h,3h和4h的主要粒径分布范围分别为8 000nm~10 800nm(2 000目~1 000目),2 400nm~2 900nm(6 000目~5 000目),800nm~1 200nm(18 700目~12 500目)和500nm~1 250nm(30 000目~12 000目).低压直接加氢液化实验结果表明,随煤样粒径减小,煤粉粒子间因团聚现象油产率反而下降,在其他液化条件都相同的条件下,200目煤样油产率为75.24%,1 340目煤样的油产率为59.96%.但对1 340目煤浆进行超声处理,其油产率提高到80.04%,增加了20%.     

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。     

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。     

煤直接液化残渣与神东煤共热解特性研究

实验选用500 g级基于热重系统热解装置研究了神华液化残渣与神东煤共热解特性。结果表明,在反应器侧壁温度为200～600℃区间内,同一时刻,随着液化残渣配比的增加,热解胶质层比例增加,热解过程中传热加剧,煤样中心温度逐渐升高;液化残渣配比为20%时,煤样中心温度最高。液化残渣配比由0%增加至25%时,热解总失重量逐渐减小,焦油收率逐渐升高,热解特性趋好。当液化残渣比例由10%增加至25%时,半焦粘结加剧,3～6 mm粒级产率由51.99%降至34.03%,大于6 mm粒级占比由39.82%增加到57.06%;当液化残渣配比达到20%时,有一半以上的半焦粒度增加。     

微波溶胀对五彩湾煤直接液化影响的研究

采用NMP/CS(2体积比1︰1)混合溶剂,在微波辐射下对五彩湾煤进行溶胀处理,并将原煤和微波溶胀煤样进行对比表征和加氢液化实验,考察了液化反应温度、反应气氛、溶胀剂对液化效果的影响。结果表明:微波溶胀后,煤样孔隙结构显著增加,结构发生变化。在液化条件是温度450℃、氢初压6.0 MPa、溶煤比1.75︰1和反应时间60 min,油产率和转化率分别是原煤55.02%和76.76%,微波溶胀煤74.03%和84.78%。     

低压下新疆黑山煤直接液化工艺性能研究

以新疆黑山煤样为对象,采用正交实验设计法,在低压下考察了初压、反应时间、反应气氛和溶煤比四个因素及它们之间的交互作用对其液化性能影响,结果表明:在给定的其他条件下,黑山煤在初压6 MPa,反应60 min,纯氢和溶煤比2:1时,油产率达到52.06%,转化率为76.51%,就油产率而言,溶煤比和反应气氛高度显著影响,反应初压一般影响,反应时间无影响,四个因素间的三种交互作用可忽略,降低初压到6 MPa,黑山煤仍具有理想的直接液化工艺性能.     

内旋式移动床煤热解新工艺开发及试验

采用2t/d外热内旋式移动床热解试验装置,通过控制反应器物料热解区及粉尘沉降气室区的温度,研究了内旋式移动床工艺温度分布对13mm以下神木煤热解产物产率及性质的影响规律。结果表明：物料热解温度控制为650℃和700℃时,煤料均实现了较好热解,半焦挥发分V_daf降低至10.36%～11.95%;相同物料热解温度,提高粉尘沉降气室温度后,辐射传热作用增强,半焦和焦油产率降低,煤气产率升高;在物料热解温度700℃,粉尘沉降气室温度500℃时,焦油收率Tar_d最高,为7.44%;物料热解温度为650℃,焦油模拟蒸馏360℃以下馏分含量为63.3%～72.0%,物料热解温度700℃时为67.5%～72.2%;相同物料热解温度,提高粉尘沉降气室温度后,焦油中轻油组分减少,洗油和沥青质含量增加,煤气中氢气含量增加;粉尘沉降气室温度达到550℃时,挥发物二次反应作用明显强于450℃和500℃;各工艺条件下,焦油中喹啉不溶物含量均低于1%,最低为0.51%。     

神华上湾煤恒温阶段直接液化反应动力学

为考察神华上湾煤的直接液化性能及反应动力学,以加氢蒽油-洗油混合油作为溶剂、负载型FeOOH作为催化剂,在0.01 t·d^-1煤直接液化连续实验装置上考察了不同反应温度（435~465℃）、不同停留时间（7~110 min）下液化产品组成的演变规律。研究发现,随着煤的裂解及加氢反应的进行,煤及沥青类物质（PAA）收率不断减小,重质液化产物逐步向轻质液化产物转化。当反应温度为455℃、停留时间为90 min时,煤转化率为90.41%（质量分数（,油收率为61.28%（质量分数（。随着反应条件进一步苛刻,油收率下降。基于上湾煤直接液化反应特性及其产物收率变化规律建立了11集总煤直接液化反应动力学候选模型,以BFGS优化算法对实验数据搜索、选优,确定了动力学模型参数。检验结果表明所建立的动力学模型可用于恒温阶段直接液化行为的模拟计算。     

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.     

Liquefaction of bituminous coal at moderate temperatures

Coal hydrogenation was investigated in the temperature range 275 to 325 °C in order to minimize the number of thermal side reactions that take place. Gas-phase hydrogen was used in batch experiments without an added donor solvent, to avoid the additional analytical complexities introduced by such a solvent. It was found that significant oil yields (up to 72% of the daf coal) can be obtained from the hydrogenation of bituminous coal at 325 °C. Furthermore, at this temperature, the data indicate that cleavage of certain C---O bonds may have an important role in oil formation. The metal surfaces of the liner and impeller of the autoclave had a strong catalytic effect on the liquefaction reactions under these conditions. The oil yield was 48% when the metallic surfaces were exposed and only 19% when these components were coated with glass. Catalysis by nickel, applied as nickel acetate impregnated into the coal, gave higher overall conversion, lower oil yield, and a more saturated oil product than catalysis by the autoclave surfaces.     

Solvolytic liquefaction of coals with a series of solvents

Solvolytic liquefaction of coals of different rank was studied with a variety of solvents at 370–390 °C under nitrogen in order to elucidate the role of solvent in coal liquefaction of this kind and to find a suitable solvent for the highest yields of liquefaction. The yield was found to depend strongly upon the nature of the coal as well as the solvent under these conditions. Pyrene and a SRC-BS pitch were excellent solvents for Miike coal, which was fusible with high fluidity at these temperatures. However, the former was less efficient for Itmann and Taiheiyō coals which were fusible at a higher temperature and non-fusible, respectively. The mechanism of solvolytic liquefaction is discussed, including nature of coal and solvent at reaction temperatures, in order to understand the properties required for high yields with non-fusible coals in solvolytic liquefaction. It is found that for liquefaction with a high yield if the coal is non-fusible, solvolytic reaction should take place between solvent and coal, so giving a liquid phase of low viscosity at the reaction temperature. The solvolytic reaction may be one of hydrogen transfer when SRC-BS is used as the solvent.     

Approach for promoting liquid yield in direct liquefaction of Shenhua coal

Single and multi-stage liquefaction of Shenhua (SH) bituminous coal and re-liquefaction of its liquefaction residue (SHLR) were carried out in an autoclave reactor to investigate the essential approach for promoting oil yield and conversion in SH coal direct liquefaction (SHDL). The multi-stage liquefaction includes pretreatment, keeping the reactor at 250 °C for 40 min before heating up to the reaction temperature, and two-stage liquefaction processes consisting of low temperature stage, 400 °C, and high temperature stage, 460 °C. The results show that the pretreatment has slight effect on oil yield and conversion of SHDL, especially for liquefaction at 460 °C. There is a positive function of two-stage liquefaction in shortening reaction time at high temperature. Increasing ratio of solvent to SHLR can promote the oil yield and abate reaction condition in SHLR re-liquefaction, that is, it can promote the conversion from preasphaltene and asphaltene to oil. The primary factor to inhibit coal liquefaction is the consumption of hydrogen free radical (H·) from solvent or H₂ and condensation of free radicals from coal pyrolysis after a period of reaction. So the essential approach for increasing oil yield and conversion of SHDL is to provide enough H· to stabilize the free radicals from coal pyrolysis.     

超细FeS对五彩湾煤直接液化性能的影响

以硫酸亚铁为铁源,硫化钠为沉淀剂,采用液相沉淀法合成了超细FeS催化剂。以四氢萘为溶剂,反应温度430℃、氢初压6.0 MPa、反应时间60 min、溶煤比2∶1条件下,探讨超细FeS催化剂对五彩湾煤直接液化性能的影响。结果表明：硫酸亚铁基超细FeS粒子形貌均一,呈细棒状;五彩湾煤直接液化实验的油产率、液化率和转化率,以2.0%（wt,以活性金属元素计,相对于干燥无灰煤,下同）超细FeS为催化剂的实验分别达到56.15、73.29和81.21%（wt,相对于干燥无灰煤,下同）,高于相同条件下,以3.0%分析纯Fe2O3为催化剂的实验产率（分别是44.00、49.33和62.05%）。     

煤炭直接液化油收率极限理论及其应用

首次建立了煤炭直接液化油收率极限理论,在指定的液化试验装置上,当催化剂、助催化剂和试验条件一定时,可以确定煤种的低限油收率和高限油收率,从而阐明了煤种进行直接液化主反应的限度,掌握煤种的低限油收率和高限油收率可以识别煤炭直接液化催化剂性能,最大限度地降低前沥青烯和沥青烯等液化反应中间产物的产率,就可以获得接近高限油收率的液化油收率。     

固体酸催化新疆褐煤直接加氢液化研究

为了实现褐煤温和加氢液化联产高附加值酚类化学品,研制了1种新型固体酸催化剂,可以弥补反应条件缓和带来的褐煤大分子结构单元桥健断裂的裂解性能不足,进行了固体酸催化剂的物性表征和活性评价,考察了催化剂类型对褐煤温和加氢液化性能和产物分布的影响规律,探讨了固体酸催化剂用于褐煤温和加氢液化的可行性,并与传统液化进行了比较。结果表明:固体酸催化剂粒径减小,出现了强酸中心,在430℃和15 MPa反应条件下,转化率和油产率与传统液化相当,低级酚产率增加了1.5%,气产率降低近4%,这种固体酸催化剂有利于实现褐煤加氢液化的节能减排增效和产品结构优化,是一种值得关注和深入研究的煤直接加氢液化催化剂。     

Liquefaction of Yallourn brown coal at low pressures and rapid heating rates

Liquefaction of Yallourn brown coal in solvents at high temperature for short contact times and low pressures has been studied. Very high asphaltene yields are achieved with hydrogen-donating solvents (hydrogenated Ashland pitch A240, hydrogenated anthracene oil, and hydrogenated pyrene). For hydrogenated pyrene, yields of almost 90% were obtained during reaction at 450°C for 10 min or at 510°C for 1 min. The average molecular weight of the asphaltene found was 270, with 40 wt% being accounted for by three-and four-ring polynuclear hydrocarbons. The effect of liquefaction temperature, time, and solvents on the asphaltene yield have been examined to clarify the properties required for the solvent under the present conditions used. The behaviour of the asphaltene during pyrolysis and hydrotreatment has also been studied. Some mechanistic aspects of high-temperature, short contact time liquefaction are discussed with regard to the reactivities of the brown coal and the solvents.