Characterization of pore coking in catalyst for thermal down-hole upgrading of heavy oil
Characterization of pore coking in catalyst for thermal down-hole upgrading of heavy oil
复制标题
稠油井下热改质催化剂孔隙结焦表征
DOI：
10.1016/j.ces.2015.03.052
复制
发表时间：
2015
影响因子：
4.7
通讯作者：
Dim P
中科院分区：
文献类型：
--
作者：
Dim P
重油和沥青是传统轻质原油的潜在替代能源。然而，这些资源的回收会对环境产生重大影响。井下升级提供了提高采收率和减少环境影响的前景。然而，使用催化剂来增强井下改质受到限制，因为需要一种能够承受重油裂化产生的极端焦化条件的催化剂。在这项工作中，考虑了氢供体改善升级和延长催化剂寿命的潜力。为了提取反应过程中催化剂结构演变的详细信息，使用了新型并行吸附和热孔测定表征方法。该技术可以获得有关不同孔隙的空间并置、它们的相对连通性以及尺寸分布的详细信息。对于在所研究的条件下操作的催化剂，已经发现焦化发生在较小的孔中，该较小的孔从提供进入催化剂内部的较大孔分支出来。已经发现，虽然使用不同类型的氢供体后的焦化导致剩余可进入空隙空间的孔隙尺度描述符中相似的主要演化模式，但总体可进入体积确实出现差异。因此，氢供体似乎影响孔结构变化的位置而不是一般性质。然而，在二级审查中，不同氢供体的孔隙尺度演化也存在一些差异。确定的这些差异有助于理解不同氢供体和催化剂组合的性能变化。
Heavy oil and bitumen are a potential alternative energy source to conventional light crude. However, recovery of these resources can have substantial environmental impact. Downhole upgrading offers the prospect of both improving recovery, and decreasing environmental impact. However, use of catalysts to enhance downhole upgrading is limited by the need for one that can survive the extreme coking conditions arising from the cracking of heavy oil. In this work the potential of hydrogen donors to improve upgrading and enhance catalyst lifetime was considered. In order to extract detailed information on the catalyst structural evolution during reaction a novel parallel adsorption and thermoporometry characterization method was used. This technique allows detailed information to be obtained on the spatial juxtaposition of different pores, and their relative connectivity, as well as on size distributions. For catalyst operated at the conditions studied, it has been found that coking arises in smaller pores branching off the larger pores providing access to the catalyst interior. It has been found that while coking following use of different types of hydrogen donor leads to similar primary patterns of evolution in the pore-scale descriptors of the remaining accessible void-space, differences do arise in the overall accessible volume. Hence, it seems the hydrogen donor affects the location rather than general nature of the pore structure changes. However, at a secondary level of scrutiny, some differences in pore-scale evolution are also identified for different hydrogen donors. These differences identified helped the understanding of variations in the performance of different hydrogen donor and catalyst combinations.