煤层气催化裂解制备纳米洋葱碳及其应用研究

发布时间：2018-03-22 08:27

本文选题：煤层气　切入点：零排放催化裂解　出处：《太原理工大学》2017年博士论文　论文类型：学位论文

【摘要】：中国煤层气(CBM)资源储量丰富(已探明储36.8万亿立方米),排世界第三位,但煤层气综合利用却相当滞后。煤层气的主要成分是甲烷,甲烷催化裂解后一方面可以提供丰富的氢能源,另一方面又可通过一定的催化手段使裂解后的纳米碳变为极具潜在应用价值的新型碳材料(如纳米洋葱碳CNOs、石墨烯Graphene、纳米碳管CNTs等)。对煤层气催化裂解制备氢气和纳米碳材料已成为了众多研究者研究的热点。纳米洋葱碳以其独特的物理和化学结构已经引起了研究机构的重视,尤其是其独特的0维结构、小的直径(10 nm)、高导电率以及相对于1维纳米管和2维石墨烯而言比较容易分散。CNOs被认为在能源材料、耐高温/耐磨材料、磁性存储媒介材料、超导材料、生物材料、润滑油抗摩剂和低温离子液体电解液活性材料等方面具有广阔的应用前景。甲烷催化裂解制备氢气及纳米碳材料的研究已相对成熟,而对于煤层气催化裂解研究相对较少,本文在甲烷催化裂解的基础上,通过自行设计的“零排放催化裂解制碳-产氢-发电”系统,以煤层气为碳源,采用改进高温水蒸气处理不锈钢载体工艺并担载催化剂,用化学气相沉积法高选择性地合成了纳米洋葱碳。系统地从理论上分析了反应系统的能量效率,采用TPR手段对不锈钢网催化剂载体催化活性进行了分析并优化了制备方法,研究并优化了纳米洋葱碳的纯化方法,最后分析探讨了纳米洋葱碳在超级电容器、电化学传感器及在润滑油中的极压抗摩特性。研究结果表明:(1)通过理论计算得出,发明设计的“零排放催化裂解制碳-产氢-发电”系统,催化裂解温度为800℃时,整个系统净能量产出为20.2%;(2)通过高温水蒸气工艺处理不锈钢网载体,提高不锈钢网比表面积(4.45m2/g)近8倍,以此担载催化剂,经H2气900℃还原1.5h后在800℃下催化裂解煤层气,转化效率达到70%左右;替代H2还原过程,以催化剂经过煤层气热裂解后产生的氢气在线自还原后进行裂解反应,其催化裂解效率达到88%,接近理论转化率(91.3%),且持续裂解60小时后无下降趋势;(3)催化剂具有高的选择性,裂解制备纳米碳90%以上是石墨化程度高的圆球状CNOs,粒径在5~200nm,是内嵌催化剂颗粒的CNOs与中空CNOs的混合物。通过“酸洗-500℃氧化-再酸洗”的工艺,可以将内嵌催化剂移除,纳米洋葱碳的回收率不足50%。通过磁学性能分析发现,内嵌催化剂CNOs具有铁磁性,可通过“酸洗-磁选”将内嵌催化剂CNOs与中空CNOs有效分离。(4)纳米洋葱碳与super-p按照比例1:0、1:3、1:5和0:1加入到超级电容器电极材料中,以TEA-BF4为电解液组装超级电容器并测试其电化学性能发现,CNOs取代super-p以后其比容量达到142.31F/g,提高近17.14%,且经过1000转循环的循环稳定性有所提高。(5)通过旋转圆盘(SDP)制备了CNOs-M(M=Pt,Au)CNOs-Pt/GCE和CNOs-Au电化学传感器,并分别对甲醛和葡萄糖进行电化学检测。结果表明,CNOs-Pt/GCE对甲醛具有好的电化学反应活性,相对高的灵敏度和精确度。CNOs-Au传感器能很好的检测葡萄糖并表现出相应时间快,稳定性高和再生性能好,能够用于血液葡萄糖检测。(6)纳米洋葱碳在润滑油中具有较好的油溶性,饱和油溶量为0.1wt%,加入量0.01wt%以下时基本不影响原油品的表观颜色,纳米洋葱碳含量在0.002wt%以上时,表现出优异的极压抗磨性能,且随着加入量的增加抗磨性能增加。
[Abstract]:China coalbed methane (CBM) reserves (proven reserve of 36 trillion and 800 billion cubic meters), ranked third in the world, but the comprehensive utilization of coal seam gas is lagged behind. The main component of coal-bed methane is methane, catalytic cracking of methane could provide a hydrogen rich, on the other hand, by means of nanometer catalyst after cleavage of the carbon carbon materials as a new variable has the potential application value (such as carbon nano onion CNOs, graphene Graphene, carbon nanotubes CNTs). Catalytic cracking of methane gas in the preparation of hydrogen and carbon nano materials has become a hotspot for researchers to study. Carbon nano onions with its unique physical and chemical the structure has attracted research organizations, especially its unique 0 dimensional structure, small diameter (10 nm), high conductivity and relative to the 1 dimensional nanotubes and 2 dimensional graphene is relatively easy to disperse.CNOs is considered in the energy. The material, high temperature resistance / abrasion resistant material, magnetic storage media materials, superconducting materials, biological materials, has a wide application prospect of lubricating oil anti-wear agent and low temperature ionic liquid electrolyte active materials. The catalytic pyrolysis of methane on the preparation of hydrogen and carbon nano materials has been relatively mature, and for the study of catalytic cracking of methane relative less, based on the catalytic decomposition of methane on the self-designed "zero emission of catalytic cracking for carbon - hydrogen - generating system, with coal-bed gas as carbon source, using the improved high temperature steam treatment process and stainless steel carrier supported catalyst by chemical vapor deposition of high selective synthesis of nano onion carbon. Systematically from the theoretical analysis of the energy efficiency of the reaction system, the stainless steel net catalyst carrier catalytic activity was analyzed and the preparation method are optimized by TPR method, research and optimization of the Na Purification method of carbon onions meters, finally analyzed the carbon nano onions in super capacitor, electrochemical sensor and in lubricating oil extreme pressure antiwear properties. The results show that: (1) obtained by theoretical calculation, the design of the invention of "zero emissions of catalytic cracking for carbon - hydrogen generating system, catalytic the pyrolysis temperature is 800 degrees centigrade, the whole system of net energy output was 20.2%; (2) by high temperature water vapor treatment technology of stainless steel net carrier, improve the stainless steel net surface area (4.45m2/g) nearly 8 times, which supported catalyst by H2 gas at 900 1.5h reduction after the catalytic pyrolysis of coal seam gas at 800 DEG C, transformation efficiency can reach 70%; instead of the H2 reduction process, the catalyst after pyrolysis of hydrogen generated on-line coalbed methane pyrolysis self reduction, catalytic efficiency reached 88%, close to the theoretical conversion rate (91.3%), and declined after 60 hours without cracking Potential; (3) catalyst has high selectivity, cracking of preparation of the nano carbon 90% is a high degree of graphitization of spherical CNOs, 5~200nm in diameter, is a mixture of catalyst particles embedded in CNOs and CNOs. Through the process of "hollow oxidation and acid pickling -500 C", can be embedded in the catalyst removed. The recovery rate of less than 50%. of the carbon nano onions by magnetic properties analysis, embedded CNOs has a ferromagnetic catalyst, can be embedded in CNOs catalyst and hollow CNOs effective separation through "pickling separation". (4) carbon nano onions and super-p according to the ratio of 1: 0,1:3,1:5 and 0:1 added to the electrode material of super capacitor, TEA-BF4 super capacitor electrolyte assembly and test its electrochemical properties of CNOs substituted super-p later found that the specific capacity reached 142.31F/g, increased by nearly 17.14%, and after 1000 cycles to cycle stability was improved. (5) by spin The rotating disk (SDP) to prepare CNOs-M (M=Pt, Au) CNOs-Pt/GCE and CNOs-Au electrochemical sensors were electrochemical detection of formaldehyde and glucose. The results show that CNOs-Pt/GCE has good electrochemical activity of formaldehyde, a relatively high sensitivity and accuracy of.CNOs-Au sensor can detect glucose well and show the corresponding time soon high stability and good regeneration performance, can be used for blood glucose detection. (6) carbon nano onions with good oil solubility in lubricating oil, saturated oil quantity is 0.1wt%, amount of 0.01wt% when the basic does not affect the original oil apparent color, carbon nano onions in the above 0.002wt%, showing excellent extreme pressure and antiwear performance, and with the increase of the amount of wear resistance increased.

【学位授予单位】：太原理工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TQ127.11;TB383.1

【相似文献】