Integrated Solvent Deasphalting and Hydrotreating for Crude Oil Pyrolysis
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Solution Overview
Problem
Conventional steam pyrolysis processes face limitations due to coke formation and differences in yields and distributions of olefins and aromatics when using heavy hydrocarbons as feedstocks, necessitating the exploration of alternative feedstocks like crude oil to enhance petrochemical production efficiency.
Innovation Solution
An integrated solvent deasphalting, hydrotreating, and steam pyrolysis process that involves charging crude oil to a solvent deasphalting zone, followed by hydroprocessing with hydrogen, and then thermally cracking the effluent in the presence of steam to produce olefins and aromatics, while recycling hydrogen and recovering pyrolysis fuel oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heavy hydrocarbons are used as feedstock for steam pyrolysis, then petrochemical production capacity is increased, but coke formation increases causing reactor clogging and operational failures
Solution Approach 1:
The patent applies preliminary action by implementing solvent deasphalting and hydrotreating processes before steam pyrolysis. These pre-treatment steps remove asphaltenes, resins, and other coke precursors from the heavy hydrocarbon feedstock, preventing coke formation in the pyrolysis reactor while maintaining high petrochemical production capacity
Solution Approach 2:
The patent segments the conventional single-step pyrolysis process into multiple distinct stages: solvent deasphalting, hydrotreating, and steam pyrolysis. Each stage performs a specific function to progressively prepare the feedstock, with the deasphalting unit removing problematic components and the hydrotreating unit saturating aromatics to reduce coke propensity
2Quantity of substance
If heavy hydrocarbons are used as feedstock, then feedstock availability is improved, but the yield and distribution of desired olefins and aromatics deteriorates compared to light hydrocarbon feedstocks
Solution Approach 1:
The patent applies parameter changes by systematically adjusting process conditions across multiple units: solvent composition and ratio in deasphalting, temperature and pressure in hydrotreating, and steam-to-hydrocarbon ratio in pyrolysis. These parameter optimizations ensure high olefin yields from heavy feedstocks, matching or exceeding light hydrocarbon performance
Solution Approach 2:
The patent introduces intermediate processing steps with intermediary units (solvent deasphalting and hydrotreating) that transform heavy hydrocarbons into a feedstock suitable for pyrolysis. These intermediary processes modify the molecular structure of heavy hydrocarbons, converting them into a form that produces desired olefin and aromatic yields comparable to light hydrocarbons
3Device complexity
If crude oil is directly processed without pre-treatment, then process complexity is reduced, but coke formation and contaminant content in products increase
Solution Approach 1:
The patent merges solvent deasphalting, hydrotreating, and steam pyrolysis into an integrated process train that efficiently processes crude oil. By combining these functions in sequence, the process achieves effective contaminant removal and coke prevention while maintaining operational simplicity and product quality
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 process reduces coke formation, increases paraffinicity, and improves the yield of desired petrochemicals, allowing for direct processing of crude oil to produce olefins and aromatics with reduced contaminants and increased API gravity, thus addressing the limitations of conventional steam pyrolysis.
Implementation Method 1
charging the crude oil to a solvent deasphalting zone with an effective amount of solvent for producing a deasphalted and demetalized oil stream
Implementation Method 2
producing a deasphalted and demetalized oil stream and a bottom asphalt phase
Implementation Method 3
charging the deasphalted and demetalized oil stream and hydrogen to a hydroprocessing zone operating under conditions effective to produce a hydroprocessed effluent having an increased paraffinicity, reduced Bureau of Mines Correlation Index
Implementation Method 4
producing a hydroprocessed effluent having a reduced content of contaminants
Implementation Method 5
thermally cracking the hydroprocessed effluent in the presence of steam to produce a mixed product stream
Implementation Method 6
thermally cracking the hydroprocessed effluent in the presence of steam
Data Source
AI summary
A system is provided integrating a steam pyrolysis zone integrated with a solvent deasphalting zone and a hydrotreating zone to permit direct processing of crude oil feedstocks to produce petrochemicals including olefins and aromatics.