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1.
Hydrogen amplification from simulated hot coke oven gas (HCOG) was investigated in a BaCo0.7Fe0.2Nb0.1O3−δ (BCFNO) membrane reactor combined with a Ru-Ni/Mg(Al)O catalyst by the partial oxidation of hydrocarbon compounds under atmospheric pressure. Under optimized reaction conditions, the dense oxygen permeable membrane had an oxygen permeation flux around 13.3 ml/(cm2·min). By reforming of the toluene and methane, the amount of H2 in the reaction effluent gas was about 2 times more than that of original H2 in simulated HCOG. The Ru-Ni/Mg(Al)O catalyst used in the membrane reactor possessed good catalytic activity and resistance to coking. After the activity test, a small amount of whisker carbon was observed on the used catalyst, and most of them could be removed in the hydrogen-rich atmosphere, implying that the carbon deposition formed on the catalyst might be a reversible process.  相似文献   

2.
焦炉煤气甲烷重整制氢热力学分析和实验研究(英文)   总被引:1,自引:0,他引:1  
对焦炉煤气甲烷部分氧化重整热力学进行分析,考察反应温度、CH4/O2摩尔比及水蒸气加入量等因素对重整性能的影响,并分析焦炉煤气原始氢含量对其部分氧化重整性能的影响.分析结果表明甲烷转化率均随CH4/O2摩尔比和水蒸气加入量的增大以及反应温度的升高而增大.在CH4/O2摩尔比1.7-2.1,温度825-900℃及压力1.01×105Pa的反应条件下,可得较好重整性能;甲烷转化率,氢及一氧化碳的选择性分别为91.0%-99.9%,87.0%-93.4%和100%-107%,重整后得到的氢量增大到原始氢量的1.95-2.05倍,每摩尔焦炉煤气消耗的热量仅为2.94J,同时得出在CH4/O2摩尔比2,温度825-900℃及1.01×105Pa条件下,往焦炉煤气内添加体积分数为2%-4%的水蒸气时重整性能得到较大提高;重整后甲烷转化率、氢及一氧化碳选择性分别由92.6%、87.2%、104%增大到98.6%、96.4%、107%.并在BaCo0.7Fe0.2Nb0.1O3-δ透氧膜反应器上研究NiO/MgO固溶体催化剂焦炉煤气部分氧化重整性能.结果表明该重整反应效果较好,于875℃下获得16.3mL.cm-2.min-1透氧量,95%甲烷转化率及80.5%氢和106%一氧化碳选择性.且所得实验结果与热力学分析结果符合较好,表明NiO/MgO固溶体催化剂有较好的催化重整性能.  相似文献   

3.
The performance of LiNi/r-Al2O3 catalysts modified by rare earth metal oxide (La2O3 or CeO2) packed on BCFNO membrane reactor was discussed for the partial oxidation of methane (POM) in coke oven gas (COG) at 875 ◦C. The NiO/r-Al2O3 catalysts with different amounts of La2O3 and CeO2 were prepared with the same preparation method and under the same condition in order to compare the reaction performance (oxygen permeation, CH4 conversion, H2 and CO selectivity) on the membrane reactor. The results show that the oxygen permeation flux increased significantly with LiNiREOx/r-Al2O3 (RE = La or Ce) catalysts by adding the element of rare earth especially the Ce during the POM in COG. Such as, the Li15wt%CeO29wt%NiO/ -Al2O3 catalyst with an oxygen permeation flux of 24.71 ml·cm−2·min−1 and a high CH4 conversion was obtained in 875 ◦C. The resulted high oxygen permeation flux may be due to the added Ce that inhibited the strong interaction between Ni and Al2O3 to form the NiAl2O4 phase. In addition, the introduction of Ce leads up to an important property of storing and releasing oxygen.  相似文献   

4.
采用溶胶-凝胶法制备了MgO和SiO2的二元复合氧化物载体, 通过浸渍法制得NiO/MgxSi1-xOy催化剂, 并使用Brunauer-Emmett-Teller(BET)吸附、载射线衍射(XRD)、透射电子显微镜(TEM)等对其进行表征. 以甲苯和萘的混合物作为高温焦炉煤气中焦油组分的模型化合物, 在固定床反应器中进行高温焦炉煤气中焦油组分催化裂解的研究. 结果表明, 催化剂的焙烧温度、反应空速以及载体中Mg和Si的原子比对反应活性有很大的影响. 在反应温度800 益、水碳摩尔比为0.7的条件下, 10%(w)NiO/Mg0.80Si0.20Oy催化剂能将甲苯和萘完全转化为CO、CH4等小分子气体, 显示出很好的催化活性、稳定性以及好的抗积炭性能.  相似文献   

5.
在高压气流床反应装置上对东胜煤快速加氢热解制取焦油试样 ,研究了热解温度对焦油主要组分的影响 ,并与高温焦炉焦油进行比较。实验表明 :加氢热解焦油的液态烃得率达 1 5 %以上 ,是高温焦炉焦油得率的二倍 ;油馏分高 ,沥青质少 ;酚类化合物和纯缩合多环芳烃含量高 ,脂肪烃含量低 ,纯缩合多环芳烃烷基衍生物组成较简单。加氢热解改善了焦油的品质 ,提高了得率。  相似文献   

6.
煤气部分返回炼焦过程焦炭脱硫   总被引:3,自引:2,他引:3  
将半焦中的硫区分为无机硫和有机硫,在不同气氛和温度下进行脱硫实验;计算煤气返回对焦炉温度的影响和模拟炼焦过程返回煤气在炭化室的分布。结果表明:增加氢气浓度对有机硫和无机硫的脱除都有利,但是温度升高并不总是有利于脱硫;氢气脱硫效果要好于甲烷和一氧化碳;指出了炼焦后期在焦炉煤气返回之前预热煤气可以减少对炉温的影响,但是煤气的预热温度不能太高,否则甲烷裂解容易堵塞管道;煤气的最佳返回时机是在焦炭中孔隙分布较为均匀之时。  相似文献   

7.
采用溶胶凝胶法制备了La0.6Sr0.4NixCo1-xO3钙钛矿催化剂,并测试了该催化剂在焦炉煤气CO2重整反应中的性能.通过X射线衍射、N2吸附脱附、程序升温还原、扫描电镜、透射电镜和热重-微分扫描量热等方法对催化剂进行了表征.结果表明,溶胶凝胶法合成的La0.6Sr0.4NixCo1-xO3催化剂形成了钙钛矿结构的固溶体.着重考察了钙钛矿催化剂焙烧温度和A位Ni的掺杂含量对其催化性能和反应后积碳的影响.结果表明: La0.6Sr0.4NixCo1-xO3钙钛矿催化剂在反应中生成了活性金属Ni, Co颗粒和La2O2CO3,这些组分对催化剂的活性和稳定性起关键性的作用,并且能够抑制积碳的形成;焦炉煤气中的富氢气体具有抑制甲烷裂解反应发生的作用,从而减少催化剂的积碳.  相似文献   

8.
采用分步浸渍法制备了MgO-Al2O3负载的Ni基催化剂, 并运用N2吸附、载射线衍射(XRD)、透射电子显微镜(TEM)等手段进行表征. 该催化剂用于甲苯或萘为焦油模拟化合物的高温焦炉煤气(COG)的常压加氢裂解反应, 并考察了H2浓度、H2S对催化剂活性的影响. 结果表明: 催化剂还原后, 表面形成均匀分散、直径为8-14 nm的金属Ni纳米颗粒; 在较低的水碳摩尔比(nH2O/nC=0.28)时, 甲苯就能完全转化并选择性地加氢裂解形成CH4, 测试的时间内(480 min), 催化剂没有明显的失活和积炭现象, 显示出好的反应活性、稳定性和耐硫能力. 制得的Ni/MgO-Al2O3催化剂有望应用于较低水含量(10%-15%(φ, 体积分数))的高温焦炉煤气中焦油的直接转化.  相似文献   

9.
高选择性氧化环己烷(CHA)制备环己酮和环己醇(KA油)具有重要的工业价值和应用前景. 本文提出采用间歇电沉积法制备纳米MnOx催化剂负载多孔管式钛膜,构建电催化膜反应器(ECMR)催化氧化环己烷制备环己醇和环己酮. 利用场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)和电化学工作站等表征手段对催化剂的结构与性能进行表征. 结果表明,间歇电沉积法制备的催化剂为纳米花球状γ-MnO2. 与基体钛膜相比,MnOx/Ti膜电极具有更优的电化学性能和传质性能. 此外,以MnOx/Ti电催化膜为阳极,不锈钢网为阴极构建ECMR. 当环己烷初始浓度30 mmol·L-1、反应温度30oC、停留时间34.3 min、电流密度2.3 mA·cm-2等条件下,ECMR环己烷转化率达25.6%,KA油总选择性高于99%. 同时,ECMR重复使用8次后表现较高催化稳定性.  相似文献   

10.
 采用共沉淀-水热法合成了一系列 Ni/MgAl(O) 催化剂. 用甲苯和萘的混合物作为焦油模型化合物, 在固定床反应器上研究了该催化剂直接催化转化具有较低水蒸气/碳摩尔比的高温焦炉煤气中焦油为小分子气体的反应. 考察了催化剂组成、水蒸气/碳摩尔比和反应条件等对催化剂性能的影响. 结果表明, Mg/Al 摩尔比为 3 时 Ni/MgAl(O) 催化剂表现出最优的催化性能. 在 700~800 oC 和水蒸气/碳摩尔比为 0.68 的反应条件下, 15%Ni/Mg3Al(O) 催化剂能将甲苯和萘完全转化为 CO 和 CH4 等小分子气体. 在反应气中引入 0.05% H2S(摩尔分数) 气体的实验表明, 该催化剂在焦油催化转化反应中具有较好的抗硫能力. 另外, 在催化剂中加入少量 Pt 助剂能显著提高催化剂活性.  相似文献   

11.
磷酸三丁酯萃取脱硫废液中硫氰酸根的初步研究   总被引:2,自引:0,他引:2  
焦炉煤气含污染物H_2S 5g/m~3-8gm~3、HCN1g/m~3-2.5g/m~(3[1]),目前主要用催化氧化-氨水吸收法(NH_3-OMC)工艺处理.由此产生的脱硫脱氰废液中主要含有NH_4SCN、(NH_4)_2S_2O_3等无机盐,其中,SCN~-及S_2O_3~(2-)浓度均影响脱硫催化剂的效率,规定其总浓度不得超过250g/L.  相似文献   

12.
在三相淤浆床-固定床反应装置中,研究含氮合成气直接合成二甲醚。使用双功能混合催化剂,粒度为0.15 mm~0.18 mm。在220 ℃~260 ℃、3.0 MPa~7.0 MPa、空速1 000 mL·g-1·h-1时考察了温度、压力及两种反应器中催化剂的装填比例对CO转化率及二甲醚选择性的影响。结果表明,一氧化碳转化率随反应压力的增加而提高,随着温度升高二甲醚的选择性变化不大,CO转化率的升高较明显,因此在催化剂活性适宜的温度范围内,该反应装置可以采用较高的反应温度。当260 ℃、7.0 MPa、三相床与固定床中催化剂比例为1∶1时,CO的转化率可达84.5%,二甲醚的选择性为78.7%。淤浆床-固定床反应装置具有操作稳定性好、CO转化率高的优点。催化剂在该装置中反应370 h活性没有明显下降。  相似文献   

13.
A porous layer open tubular (PLOT) column has been used for monitoring the light hydrocarbons and permanent gases produced in coking plants. The method, which offers a simple alternative to traditional multi column techniques, entails a single injection on to a Carboplot 007 capillary column and simultaneous thermal conductivity and flame ionization detection. The simplified approach proposed is restricted to coke oven gas analysis: application to other gas mixtures has not been considered. The reliability of this procedure compares favorably with that of traditional methods; the technique is also much less time-consuming: seven individual gases can be determined on-line every fifteen minutes. Primary and secondary gas standards were used to determine response curves for the gases. The method also facilitates reliable calculation of heat values associated with the burning of the fuel gas mixtures.  相似文献   

14.
Hydrogen production by catalytic reforming of simulated hot coke oven gas (HCOG) with toluene as a model tar compound was investigated in a fixed bed reactor over Ni/Mg(Al)O catalysts. The catalysts were prepared by a homogeneous precipitation method using urea hydrolysis and characterized by ICP,BET, XRD, TPR, TEM and TG. XRD showed that the hydrotalcite type precursor after calcination formed (Ni,Mg)Al2O4 spinel and Ni-Mg-O solid solution structure. TPR results suggested that the increase in Ni/Mg molar ratio gave rise to the decrease in the reduction temperature of Ni2+ to Ni0 on Ni/Mg(Al)O catalysts. The reaction results indicated that toluene and CH4 could completely be converted to H2 and CO in the catalytic reforming of the simulated HCOG under atmospheric pressure and the amount of H2 in the reaction effluent gas was about 4 times more than that in original HCOG. The catalysts with lower Ni/Mg molar ratio showed better catalytic activity and resistance to ceking, which may become promising catalysts in the catalytic reforming of HCOG.  相似文献   

15.
石油焦高温气化反应性   总被引:5,自引:4,他引:5  
常压,1 200 ℃~1 500 ℃,在自制管式反应器中,以二氧化碳为气化介质,研究了石油焦以及石油焦与后布连煤焦掺混后形成的混合焦的气化反应性,借助于XRD分析了高温处理后石油焦与煤焦在碳结构有序化方面的区别。研究结果表明,当碳转化率高于0.7,气化超过1 300 ℃,石油焦的反应速率出现急骤下降,气化温度越高,相应石油焦速率下降越快。混合焦气化反应性既不同于纯石油焦也不同于纯煤焦。随石油焦掺入比变化而改变的拐点主要源于石油焦与煤焦的反应性之间差异。较高转化率下出现的拐点,主要源于石油焦本身随气化温度提高导致气化速率下降。XRD测定显示,高温处理后石油焦中碳有序化程度要明显高于煤焦。高气化温度下石油焦碳结构发生明显有序化是导致其反应活性急剧下降的重要原因。  相似文献   

16.
针对中国乙烯、丙烯等低碳烯烃生产原料供需日益尖锐的矛盾和重质油利用技术的不足,提出焦炭与重质油共气化联产烯烃技术。阐述了焦炭与重质油共气化联产烯烃的技术原理及过程设计,并以固定床为反应器,焦炭和常压渣油为原料进行实验模拟。结果表明,当裂解温度为750℃~800℃,停留时间τ<0.5s时,渣油在焦炭介质中裂解,其低碳烯烃含量最高;渣油在模拟气化裂解区、750℃下裂解时,得到出口气体中低碳烯烃(C2H4+C3H6)、烷烃(CH4+C2H6)及合成气(H2+CO)的体积分数分别为20%、28%及46%。应用扫描电镜观察了焦炭介质表面上结焦生成物的形貌,发现通氧气后结焦生成物残留量较少。实验模拟结果证明,焦炭与重质油共气化技术可以制备低碳烯烃并联产合成气,且能有效地解决重质油裂解造成的结焦问题。  相似文献   

17.
Non‐oxidative methane conversion over Fe©SiO2 catalyst was studied for the first time in a hydrogen (H2) permeable tubular membrane reactor. The membrane reactor is composed of a mixed ionic–electronic SrCe0.7Zr0.2Eu0.1O3?δ thin film (≈20 μm) supported on the outer surface of a one‐end capped porous SrCe0.8Zr0.2O3?δ tube. Significant improvement in CH4 conversion was achieved upon H2 removal from the membrane reactor compared to that in a fixed‐bed reactor. The Fe©SiO2 catalyst in the H2 permeable membrane reactor demonstrated a stable ≈30 % C2+ single‐pass yield, with up to 30 % CH4 conversion and 99 % selectivity to C2 (ethylene and acetylene) and aromatic (benzene and naphthalene) products, at the tested conditions. The selectivity towards C2 or aromatics was manipulated purposely by adding H2 into or removing H2 from the membrane reactor feed and permeate gas streams.  相似文献   

18.
A low dead volume oxygen scrubbing system was introduced in a commercially available liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) interface to enhance the analytical capability of the system. In the LC/IRMS interface carbon from organic samples is converted into CO(2) inside the mobile phase by wet chemical oxidation using peroxodisulfate (Na(2)S(2)O(8)). After passing the hot reaction zone, surplus oxygen (O(2)) remains dissolved in the liquid phase. Both CO(2) and O(2) diffuse through a transfer membrane into the helium carrier and are transferred to the mass spectrometer. The presence of O(2) in the ion source may have detrimental effects on measurement accuracy and precision as well as on filament lifetime. As a remedy, a new on-line O(2)-removing device has been incorporated into the system.The new O(2) scrubber consists of two parallel hot copper reduction reactors (0.8 mm i.d., active length 120 mm) and a switch-over valve between them. One reactor is regenerated using He/H(2) while the other is actively scavenging O(2) from the gas stream. The capacity of each reduction reactor, expressed as usage time, is between 40 and 50 min. This is sufficient for a single LC run for sugars and organic acids. A further increase of the reduction capacity is accompanied by a peak broadening of about 100%. After switching to a freshly reduced reactor the oxygen background and the delta(13)C values of the reference gas need up to 500 s to stabilize. For repeated injections the delta(13)C values of sucrose remain constant (+/-0.1 per thousand) for about 3000 s. The long-term stability for measurements of sucrose was 0.11 per thousand without the reduction oven and improved slightly to 0.08 per thousand with the reduction oven. The filament lifetime improved by more than 600%, thereby improving the long-term system stability and analytical efficiency. In addition the costs per analysis were reduced considerably.  相似文献   

19.
粒径对煤在H2/Ar等离子体中热解的影响   总被引:10,自引:1,他引:10  
对粒径在H2/Ar等离子体煤热解制乙炔中的影响进行了研究,得到了煤的粒径与煤的裂解程度(转化率)、乙炔收率、乙炔在产品气体中摩尔分数和反应器壁结焦的关系,并且在考虑各种因素的制约下,对如何选择最佳粒径和粒径分布的问题进行了讨论。根据煤等离子体热解制乙炔反应器壁结焦的机理和煤粒径是影响反应器内结焦的重要因素,提出了进料粒径双峰分布缓解煤等离子体热解制乙炔装置结焦的新方法,实验证明该方法可行。  相似文献   

20.
When a methanol reforming–membrane reactor is employed as a hydrogen generator for proton exchange membrane fuel cell (PEMFC), three important aims should be simultaneously achieved in one process, which are methanol conversion improvement, high hydrogen recovery, and high CO removal efficiency. To achieve the aims, we investigated five different configurations of a membrane reactor (a methanol reforming–microporous membrane (MMi) reactor, methanol reforming–mesoporous membrane (MMe) reactor, methanol reforming–mesoporous membrane–water–gas shift (MMeW) reactor, methanol reforming–macroporous membrane (MMa) reactor and methanol reforming–macroporous membrane–water–gas shift (MMaW) reactor). As a result, the MMi reactor was not suitable for a hydrogen carrier of PEMFC due to low hydrogen recovery. The MMe and MMa reactor showed low CO removal efficiency due to low permselectivity of the mesoporous and macroporous membrane. In contrast, the MMeW and MMaW reactor gave simultaneously methanol conversion improvement, high hydrogen recovery, and high CO removal efficiency in one process. The low CO removal efficiency due to low permselectivity of the mesoporous and macroporous membrane was significantly enhanced by the water–gas shift reaction in the permeate side of the MMeW and MMaW reactor. In addition, based on the reaction results in the MMi, MMe and MMa reactor, it was confirmed that methanol conversion in a membrane reactor system is higher as a membrane used in a membrane reactor has higher total permeance difference (∑permeance of products − ∑permeance of reactants).  相似文献   

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