当前煤层气利用的主要方式是直接燃烧，该过程会产生大量温室气体（CO2）排放，且会造成稀缺资源的低附加值利用。为实现煤层气的高附加值利用，拟通过在煤中原位添加醋酸纤维和KOH活化的方法制备一种醋酸纤维/煤基分级多孔炭材料，并将其应用于煤层气直接裂解制氢，不仅可以获得高纯氢气，还能得到一定数量的纳米碳材料。醋酸纤维/煤基分级多孔炭在制备过程中需要考虑温度、碱碳质量比、溶剂量和其他碳源添加量对制备过程和转化率的影响，利用Design-expert软件对试验方案进行优化设计。通过响应曲面法和部分试验数据对各影响因素与转化率的关系进行分析，建立相应拟合回归方程，得出理论最优解。通过将最优解与试验结果进行对比分析，验证Design-expert软件在多因素多水平条件下的预测可靠性，同时也阐明最优条件下炭材料催化裂解煤层气的机理。结果表明，温度和碱碳质量比是醋酸纤维/煤基分级多孔炭制备过程的最大影响因素，建立相关因素与转化率之间的拟合回归方程并求出理论最优解。理论最优解与试验值之间的最大误差为3.05%，说明Design-expert软件对制备过程的优化准确可靠。醋酸纤维/煤基分级多孔炭催化裂解煤层气较原煤炭材料具有高的转化率和稳定性，前者反应后表面生成大量碳球，而后者表面则生成少量碳纤维和大量碳球。

The current utilization of coal-bed methane is direct combustion, which will generate a large amount of greenhouse gas (CO2) emissions, and will also result in the use of scarce resources with low added value. In order to realize the high value-added utilization of coal-bed methane, it was proposed to prepare a cellulose acetate/coal-based graded porous carbon material by coal in-situ added cellulose acetate and KOH activation, and it was applied to the direct cracking of coal-bed methane to produce hydrogen. It not only can produce high-purity hydrogen, but also a certain amount of nano-carbon materials can be obtained. In view of the influence of temperature, alkali-to-carbon ratio, solvent amount and other carbon source addition on the preparation process and conversion rate in the preparation process of cellulose acetate/coal-based graded porous carbon, it was planned to use the Design-expert software to optimize the design of the experimental program. The relationship between each influencing factor and the conversion rate was analyzed by the response surface method and some experimental data, the corresponding fitting regression equation was established, and the theoretical optimal solution was obtained. Through comparing and analyzing the experimental value, the reliability of Design-expert software under multi-factor and multi-level conditions was verified, and the mechanism of carbon material catalytic cracking coal-bed methane under optimal conditions also was clarified. The results show that temperature and alkali-to-carbon ratio are the most influential factors in the preparation process of cellulose acetate/coal-based hierarchical porous carbon. The fitting regression equation between the relevant factors and the conversion rate is established and the theoretical optimal solution is obtained. The theoretical results are compared with the experimental results, the maximum error between the results is 3.05%, indicating that the Design-expert software is accurate and reliable in the optimization of the preparation process. The cellulose acetate/coal-based hierarchical porous carbon catalytic cracking coal-bed methane has a higher conversion rate and stability than the original coal material. After the reaction, the former produces a large number of carbon balls on the surface, while the latter produces a small amount of carbon fibers and a large number of carbon balls on the surface.

0 引言

1 试验材料与方法

   1.1 试验材料

   1.2 试验设计

   1.3 催化剂制备

   1.4 催化剂评价和表征

2 结果与讨论

   2.1 基于正交试验的Design-expert分析 

   2.2 Design-expert响应曲面的拟合方程 

   2.3 试验方案优化

   2.4 最优解试验分析

3 结论