Solvent Deasphalting with Solid Adsorbent for Heavy Hydrocarbon Contaminant Removal
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Solution Overview
Problem
Current solvent deasphalting processes fail to effectively remove nitrogen, sulfur, and metal compounds from heavy hydrocarbon oils, leading to poor performance in refinery units and catalyst deactivation, which affects product yields and operational costs.
Innovation Solution
The process involves solvent deasphalting of heavy hydrocarbon feedstocks in the presence of a solid adsorbent, such as clay or zeolitic catalysts, which adsorbs contaminants, allowing for solvent recovery and recycling, and subsequent washing with aromatic or polar solvents to clean the adsorbent, thereby improving the quality of deasphalted oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional solvent deasphalting is used, then asphaltenes are removed from heavy hydrocarbon feedstocks, but nitrogen, sulfur, and metal compounds remain in the deasphalted oil causing catalyst deactivation
Solution Approach 1:
A solid adsorbent is introduced as an intermediary substance between the solvent deasphalting process and the downstream refinery units. The adsorbent captures nitrogen, sulfur, and metal compounds that conventional deasphalting misses, preventing catalyst deactivation without interfering with the primary asphaltene removal function
Solution Approach 2:
The treatment process applies different quality requirements to different components: asphaltenes are removed by conventional solvent deasphalting, while nitrogen, sulfur, and metal compounds are selectively removed by the solid adsorbent. This localized quality improvement targets specifically the harmful contaminants that cause catalyst deactivation
2Object-affected harmful factors
If solid adsorbent is added to solvent deasphalting, then nitrogen, sulfur, and metal compounds are removed, but process complexity increases
Solution Approach 1:
The solid adsorbent treatment is merged with the existing solvent deasphalting process. The adsorbent is added to the deasphalting unit or immediately downstream, combining two contamination removal mechanisms (solvent precipitation and adsorption) into a single integrated process flow, thereby reducing overall process complexity compared to separate treatment units
Solution Approach 2:
The spent adsorbent loaded with nitrogen, sulfur, and metal compounds is periodically discarded and replaced with fresh adsorbent. This simple discard-and-replace strategy avoids the complexity of adsorbent regeneration systems while maintaining continuous removal of harmful contaminants
3Manufacturing precision
If multiple separation steps are used to remove contaminants, then product purity improves, but processing time and operational costs increase
Solution Approach 1:
The solid adsorbent is introduced early in the process, either during the solvent deasphalting step or immediately afterward, to pre-remove nitrogen, sulfur, and metal compounds before the deasphalted oil enters downstream refinery units. This preliminary contamination removal prevents catalyst deactivation and eliminates the need for additional complex treatment steps later in the process
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 approach significantly reduces nitrogen, sulfur, and metal content in deasphalted oils, enhancing the efficiency of refinery units and enabling the recycling of solvents and adsorbents, providing economic and environmental benefits.
Implementation Method 1
solvent deasphalting of heavy hydrocarbon feedstocks in the presence of solid adsorbents... which adsorbs contaminants
Implementation Method 2
washing with aromatic or polar solvents to clean the adsorbent
Data Source
AI summary
A solvent deasphalting of crude oil or petroleum heavy fractions and residues is carried out in the presence of a solid adsorbent, such as clay, silica, alumina and activated carbon, which adsorbs the contaminants and permits the solvent and oil fraction to be removed as a separate stream from which the solvent is recovered for recycling; the adsorbent with contaminants and the asphalt bottoms is mixed with aromatic and/or polar solvents to desorb the contaminants and washed as necessary, e.g., with benzene, toluene, xylenes and tetrahydrofuran, to clean adsorbant which is recovered and recycled; the solvent-asphalt mixture is sent to a fractionator for recovery and recycling of the aromatic or polar solvent. The bottoms from the fractionator include the concentrated PNA and contaminants and are further processes as appropriate.