金属碳纤维催化重整制备合成气的实验研究

论文总字数：29559字

摘 要

以氢气和一氧化碳为主要成分的合成气是化工行业中重要的原料气体，人们用它可制备诸如甲醇、二甲醚、乙二醇等化学品。然而现阶段的合成气制备工艺还是停留在以天然气或煤为制备原料的阶段，这些工艺不利于化石能源的节约，不具备可持续发展的特性。为了实现绿色化工的理念，生物质作为一种绿色环保、成本低、储量大的能源，将在合成气制备领域被广泛地研究和关注。

在本次研究中，利用钢瓶气来模拟气态生物质原料气，制备金属/碳纤维催化剂来重整制备合成气。采用金属镍作为催化剂的活性组分，碳纤维作为催化剂的载体。对于催化剂的制备，首先碳纤维主要是通过静电纺丝的方法得到，再通过浸渍的方法将硝酸镍附着到碳纤维载体上，最后通过焙烧和通氢气还原得到附着在碳纤维载体上的金属镍单质。本实验主要研究的是利用生物质制备合成气中的甲烷与二氧化碳的重整反应。通过改变反应温度、反应物的进气流量、空速等实验条件，来研究不同的实验条件对该反应的影响。并且观察随着实验时间的增加，催化剂活性的变化对产物生成的影响。并且在得到相关的实验数据之后，建立了宏观反应动力学模型，对整个反应体系进行了分析。

本次研究得到的主要成果如下：在800℃以上，随着温度的升高，甲烷与二氧化碳重整反应速率加快。当其他条件一定时，甲烷流量升高，更有利于重整反应的进行，且产物中氢气与一氧化碳的量均有增加，尤其是当甲烷进气流量高于二氧化碳时，氢气的产量有着较为明显的提升。当其他实验条件不变时，仅改变二氧化碳含量时，可以发现二氧化碳流量的增加更有利于一氧化碳的生成而且会抑制氢气的生成。对于催化剂的寿命而言，随着实验时间的增加，反应产物中一氧化碳和氢气的量逐渐减少，说明催化剂的催化效果在下降。从空速对实验结果的影响来看，制备合成气的反应需要较长的反应物停留时间，在其他条件不变的情况下，延长反应物停留时间能够使得催化重整反应进行的更加充分。而空速与停留时间成反比，故对于本实验中的反应而言，空速越大，反应的效果越不佳。基于实验所收集到的数据建立了宏观反应动力学模型，得到此反应体系的表观活化能E=57.071kJ/mol，表观指前因子k₀=15280，进一步从反应动力学的角度描述了催化重整反应的反应体系。

关键词：合成气；甲烷；二氧化碳；金属/碳纤维催化剂

EXPERIMENTAL STUDY ON SYNTHESIS GAS BY CATALYTIC REFORMING OF METAL / CARBON FIBER

Abstract

Synthesis gas, which mainly contains hydrogen and carbon monoxide, is one of the important raw materials in chemical industry. It can be used for the preparation of chemicals such as methanol, two methyl ether, ethylene glycol and so on. However, at the present stage, the synthesis process of synthesis gas is still in the stage of using natural gas or coal as raw material, which is not conducive to the conservation of fossil energy, and does not have the characteristics of sustainable development. In order to realize the idea of green chemical industry, biomass is a kind of energy which is environment protection, low cost and large reserved, will be widely studied and concerned in the field of synthesis gas preparation.

In this study, cylinder gas is used to simulate gaseous biomass raw materials for the preparation of synthesis gas, metal / carbon fiber as the catalyst used in the experiment. Metal nickel is used as the active part of the catalyst, and the carbon fiber is used as the carrier of the catalyst. As for the preparation of catalyst, first carbon fiber is obtained by the method of the electrostatic spinning, then by impregnation method will nickel nitrate attached to the carbon fiber as a carrier, finally, metal nickel element are obtained by roasting and hydrogen reduction method. The main research of this paper is to study the reforming reaction of methane and carbon dioxide in the process of using biomass to synthesize the synthesis gas. The influence of different experimental conditions on the reaction is studied by changing the reaction temperature, the reactant inlet flow and space velocity. And with the increase of the experimental time, the effect of catalyst activity on the product formation is observed. And the reaction system is also analyzed from the point of view of reaction kinetics after getting the relevant experimental data.

The main results of this study are as follows: in the 800 degree above, with the increase of temperature, the reaction rate of methane and carbon dioxide reforming is accelerated. When the other conditions remain unchanged, methane flow rate increased is in favor of the reforming reaction and generation of hydrogen and carbon monoxide increased, especially when the inlet flow rate of methane is higher than carbon dioxide, hydrogen production has a more obvious improvement. When other conditions are unchanged, only the amount of carbon dioxide can be changed, it can be found that the increase in the flow of carbon dioxide is more conducive to the formation of carbon monoxide and will inhibit the formation of hydrogen. For the life of the catalyst, the amount of carbon monoxide and hydrogen decreased with the increase of experimental time, which showed that the catalytic effect of the catalyst decreased. From the point of view of effects of space velocity on the experimental results, the preparation of synthesis gas reactant reaction requires a longer residence time. Under certain conditions, the reaction time can be extended to make the catalytic reforming reaction more fully. The space velocity and the residence time is inversely proportional, so large space velocity is not beneficial to the reforming reaction. Through the macro reaction kinetics on the brief analysis of the experimental data can be obtained this reaction apparent activation energy E=57.071kJ/mol, form outlook refers to the factor k0=15280, further from the angle of the reaction kinetics of describing the catalytic reforming reaction of the reaction system.

Key words: Synthetic gas; methane; carbon dioxide; metal / carbon fiber catalyst

目 录

摘 要 I

Abstract II

目 录 IV

第一章 绪 论 1

1.1 研究背景及意义 1

1.1.1 合成气在化工行业中的运用及其制备原料获取 1

1.1.2 生物质能特点 1

1.2 文献综述 2

1.2.1 合成气制备研究现状 2

1.2.2 催化剂的研究现状 6

1.3 研究内容和技术路线 8

第二章生物质燃气催化重整实验设计 10

2.1 实验材料及实验仪器 10

2.1.1 实验材料 10

2.1.2 实验仪器 10

2.2 催化重整的实验方案 13

2.2.1 实验假设条件 13

2.2.2 实验步骤及条件 13

第三章 生物质燃气重整催化剂的制备 15

3.1 催化剂载体的制备 15

3.1.1 高压静电纺丝制备碳纤维 15

3.1.2 碳纤维的预氧化与碳化 15

3.2 金属/碳纤维催化剂制备 16

第四章 生物质燃气催化重整实验研究 17

4.1反应温度对生物质燃气重整的影响 17

4.2 反应物流量对生物质燃气重整的影响 18

4.2.1 甲烷进气流量影响 18

4.2.2二氧化碳进气流量影响 19

4.3 催化剂的寿命评价 20

4.4 空速对生物质燃气重整的影响 21

第五章 生物质燃气催化重整宏观反应动力学研究 22

5.1 宏观反应动力学的相关分析方法 22

5.2 相关分析 23

第六章 总结与展望 25

6.1 全文总结 25

6.2 不足与展望 26

致 谢 27

剩余内容已隐藏，请支付后下载全文，论文总字数：29559字