Integrated Hydroconversion and Deasphalting for Residue Conversion
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Solution Overview
Problem
Existing processes for converting heavy hydrocarbon residues with high sulfur and nitrogen content, such as vacuum residues, are limited in conversion efficiency due to the catalytic system and stability of products, typically achieving less than 80% conversion, and require multiple equipment stages and high operating costs.
Innovation Solution
A process integrating hydroconversion and deasphalting stages within the same reaction section, using boiling bed technology with recycling of the deasphalted hydrocarbon fraction (DAO) to enhance thermal integration and achieve greater than 85% net conversion of residual fractions, while reducing equipment needs and operating expenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional boiling bed hydroconversion is used, then catalytic activity can be maintained constant, but net conversion of residual fraction is limited to less than 80%
Solution Approach 1:
The process is divided into two distinct stages: hydroconversion stage followed by deasphalting stage. This segmentation allows each stage to perform its specific function optimally - hydroconversion breaks down heavy molecules while deasphalting removes asphaltene deposits that would otherwise deactivate the catalyst, enabling net conversion to exceed 80% while maintaining catalyst stability.
Solution Approach 2:
Asphaltene deposits that form during hydroconversion are removed through the deasphalting stage using a solvent extraction unit. The deasphalted oil is then recycled back to the hydroconversion stage, while the asphalt is discarded. This recovery and removal cycle prevents catalyst deactivation and maintains high conversion efficiency.
2Adaptability or versatility
If multiple separate equipment stages are used for hydroconversion and deasphalting, then process functionality is complete, but initial investment and operating expenses increase
Solution Approach 1:
The hydroconversion reactor and deasphalting extraction unit are integrated into a single reaction section where the effluent from hydroconversion is directly fed to the deasphalting unit without intermediate separation equipment. This merging reduces the number of equipment pieces and thermal integration requirements while maintaining complete process functionality.
Solution Approach 2:
The deasphalted oil is recycled back to the hydroconversion stage as a feedback loop. This internal recycling eliminates the need for external processing units and reduces overall equipment complexity while ensuring continuous removal of asphaltenes and maintenance of catalyst activity.
3Productivity
If deasphalted oil is recycled to hydroconversion stage, then net conversion exceeds 85%, but process complexity increases
Solution Approach 1:
The recycling of deasphalted oil is integrated directly into the hydroconversion reaction section without requiring separate storage or handling equipment. The deasphalted oil from the extraction unit is fed back to the reactor inlet, merging the recycling function with the existing process flow and minimizing additional complexity.
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
This integrated process achieves a net conversion of residual fractions greater than 85%, improves product quality, and reduces the need for fluxing agents, enhancing the yield and quality of gasoline and middle distillates while minimizing equipment and operational costs.
Implementation Method 1
hydroconversion of at least one portion of the feedstock in the presence of hydrogen in at least one three-phase reactor, whereby the reactor contains at least one hydroconversion catalyst and operates in a boiling bed
Implementation Method 2
convert these residues by breaking the heavy molecules of residues for producing smaller molecules by cracking
Implementation Method 3
operates in a boiling bed, with an upward flow of liquid and gas
Implementation Method 4
deasphalting of at least one portion of the heavy liquid fraction that boils at a temperature that is greater than 300° C.
Implementation Method 5
recycling of at least one portion of the deasphalted hydrocarbon fraction (DAO) that is obtained from stage c) and mixing with the feedstock upstream from the hydroconversion stage a)
Data Source
AI summary
For conversion of crude oil or a heavy hydrocarbon fraction having an initial boiling point of at least 300° C., conducting a catalytic hydroconversion in a three-phase reactor operating in a boiling bed with an upward flow of liquid and gas, separating resultant effluent into a light liquid fraction boiling at less than 300° C. and a heavy liquid fraction boiling above 300° C., deasphalting the heavy liquid fraction to obtain a deasphalted hydrocarbon fraction and residual asphalt, and recycling at least one portion of the deasphalted hydrocarbon fraction upstream of the hydroconversion stage.