Heavy Oil Premixing Additives for Low-Fouling Slurry Hydroconversion
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Solution Overview
Problem
Existing slurry hydroconversion processes face fouling issues in equipment upstream of the hydroconversion reactor, particularly in preheating devices, due to metal and carbon build-up, which limits equipment operability and is not adequately addressed by current slurry catalysts.
Innovation Solution
A process involving the pre-mixing of a heavy oil feedstock with an organic additive containing carboxylic acid, ester, or acid anhydride functions, followed by the addition of a catalyst precursor, forming a colloidal or molecular catalyst in situ, which reduces fouling and enhances catalyst dispersion, thereby improving the hydroconversion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heavy oil feedstock is directly introduced into the hydroconversion reactor, then the conversion process can proceed, but fouling occurs in equipment upstream particularly in preheating devices
Solution Approach 1:
The patent applies preliminary action by pre-mixing the heavy oil feedstock with an organic additive containing carboxylic acid or ester functions before introducing it to the hydroconversion reactor. This preliminary treatment modifies the feedstock properties to prevent fouling during subsequent processing, particularly in preheating equipment, thereby maintaining continuous operation without shutdowns for cleaning.
Solution Approach 2:
The organic additive acts as an intermediary substance between the heavy oil feedstock and the equipment. By introducing this intermediate compound, the patent prevents direct harmful interactions between the feedstock and equipment surfaces, reducing fouling and allowing the conversion process to proceed continuously.
2Device complexity
If conventional hydroconversion is used without organic additive, then the process is simpler, but asphaltenes are not fully processed leading to coke precursor and sediment formation
Solution Approach 1:
The patent changes the chemical parameters of the feedstock by adding organic compounds with carboxylic acid or ester functions. This parameter modification enables complete processing of asphaltenes, preventing coke precursor and sediment formation that would otherwise compromise equipment operability and require complex maintenance procedures.
3Productivity
If heavy oil feedstock with high asphaltene content is processed, then the throughput is maintained, but coke precursors and sediments form affecting equipment efficiency
Solution Approach 1:
The patent converts the harmful effect of high asphaltene content into a beneficial outcome. By adding the organic additive, the asphaltenes that would normally form coke precursors and sediments are instead fully processed and converted into desirable products. This allows high throughput of challenging feedstocks to be maintained while eliminating the harmful effects.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process effectively minimizes equipment fouling, increases conversion levels, reduces coke precursor and sediment formation, and allows for higher temperature operation, extending equipment life and increasing throughput.
Implementation Method 1
an organic additive containing carboxylic acid or ester functions to reduce fouling
Implementation Method 2
pre-mixed with an organic additive containing carboxylic acid or ester functions
Implementation Method 3
a dispersed catalyst or catalyst precursor is injected on a continuous basis within the heavy oil feedstock in the slurry reactor, promoting hydrogenation of radicals formed by thermal cracking reactions, and limiting coke formation
Implementation Method 4
promoting hydrogenation of radicals formed by thermal cracking reactions
Implementation Method 5
the heavy oil is heated to a temperature at which the high boiling fractions of the heavy oil feedstock typically having a high molecular weight and/or low hydrogen/carbon ratio, an example of which is a class of complex compounds collectively referred to as 'asphaltenes', tend to undergo thermal cracking to form free radicals
Implementation Method 6
the catalyst and liquid heavy oil feedstock act like one homogeneous phase
Implementation Method 7
The catalyst of very small size, dispersed within the feedstock, is entrained out of the reactor with the effluents
Data Source
AI summary
The present invention relates to a slurry hydroconversion process of a heavy oil feedstock comprising: (a) preparing a first conditioned feedstock (103) by blending said heavy oil feedstock (101) with an organic chemical compound (102) comprising at least one carboxylic acid function and/or at least one ester function and/or an acid anhydride function; (b) preparing a second conditioned feedstock (105) by mixing a catalyst precursor composition (104) with said first conditioned feedstock so that a colloidal or molecular catalyst is formed when it reacts with sulfur; (c) heating the second conditioned feedstock in at least one preheating device; (d) introducing the heated second conditioned feedstock (106) into at least one slurry bed reactor and operating said slurry bed reactor in the presence of hydrogen and at hydroconversion conditions to produce an upgraded material (107), the colloidal or molecular catalyst being formed during step (c) and/or (d).