Synergic EVA Copolymer Additives for Paraffin Crude Oil Pour Point Reduction
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Solution Overview
Problem
Current Pour Point Depressant additives for crude oils are inefficient in significantly lowering the gel point of paraffinic crude oils with high paraffin content, particularly those with a Pour Point above 10° C., due to limitations in co-crystallization with a wide range of paraffins and excessive crystal growth.
Innovation Solution
A synergic composition of ethylene-vinyl acetate (EVA) copolymers with different vinyl acetate comonomer contents, combined with a dispersing agent having a HLB>10, which co-crystallizes with paraffins and alters their crystalline structure, effectively lowering the Pour Point of paraffinic crude oils by widening the range of action and preventing crystal growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional single-grade EVA copolymers are used as Pour Point Depressants, then the additive can be dissolved in crude oil at suitable temperatures, but the gel point reduction is insufficient for crude oils with high paraffin content and PP above 10° C.
Solution Approach 1:
The invention divides the single EVA copolymer into multiple segments with different vinyl acetate contents (15-50% VA). Each segment (copolymer grade) targets specific paraffin crystal types, collectively providing comprehensive coverage across the entire paraffin spectrum, thereby resolving the insufficient gel point reduction for high paraffin content crude oils.
Solution Approach 2:
The invention creates a composite additive system by combining multiple EVA copolymer grades with different vinyl acetate contents and molecular weights. This composite approach synergistically interacts with various paraffin crystal structures, achieving superior gel point reduction compared to single-grade additives while maintaining solubility in crude oil.
2Quantity of substance
If additives are used at low concentrations to hinder paraffin crystallization, then economic costs are reduced, but the crystal growth is not sufficiently prevented for crude oils with high paraffin content
Solution Approach 1:
The invention optimizes the vinyl acetate content parameter across different copolymer grades (15-50% VA) to enhance interaction with paraffin crystals. This parameter variation allows the additive to effectively hinder crystal growth at low concentrations by improving the thermodynamic compatibility and interaction strength with paraffin structures.
Solution Approach 2:
Different EVA copolymer grades with specific vinyl acetate contents are selectively effective against specific paraffin crystal types. The local quality of each copolymer grade (its specific VA content and molecular weight) is optimized for targeting particular crystal structures, enabling effective crystal growth prevention at low overall additive concentrations.
3Ease of operation
If emulsions or suspensions containing dispersed polymers in aqueous/organic solvents are used, then the additives can be conveyed in crude oil, but the system complexity increases and additional solvents are required
Solution Approach 1:
The EVA copolymer additives are inherently soluble in crude oil without requiring external solvents or emulsifiers. The additive system serves itself by utilizing the crude oil medium directly for dissolution and transport, eliminating the need for complex emulsion or suspension formulations and reducing system 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
The synergic mixture of EVA copolymers with varying vinyl acetate contents and a surfactant achieves a significant reduction in the Pour Point of paraffinic crude oils, making them suitable for transportation and commercialization, with some achieving Pour Points below 0° C., even at low concentrations.
Implementation Method 1
The main action of these additives consists in co-crystallization with the paraffins present in the oil, altering/weakening their crystalline structure.
Implementation Method 2
a dispersing agent having a HLB>10, which co-crystallizes with paraffins and alters their crystalline structure
Data Source
AI summary
A polymeric composition suitable for lowering the Pour Point of paraffinic crude oils comprising a synergic mixture including at least two ethylene-vinyl acetate copolymers respectively having an average molecular weight Mw lower than 130,000 Dalton (measured via GPC), a content of vinyl acetate monomer ranging from 15 to 50% by weight, with the proviso that the content of vinyl acetate monomer in the respective copolymers differs from one copolymer to another, by over 5%, on a weight basis.