Offshore Effluent Treatment via Oxidative Emulsion Destabilization

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Solution Overview

Problem

Current methods for treating effluents from oil production units, especially in offshore environments, fail to effectively remove oil and soluble toxic contaminants like sulphides, benzenes, toluenes, and polyaromatic hydrocarbons due to the stability of oil-in-water emulsions caused by colloidal ferrous sulphide, leading to environmental concerns and operational challenges.

Innovation Solution

A process that changes the equilibrium thermodynamic conditions of oil-in-water emulsions using oxidizing agents like hydrogen peroxide or sodium hypochlorite, destabilizing the emulsions and oxidizing toxic contaminants, allowing for their separation with the oil phase, thereby reducing toxicity and facilitating treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional treatment methods (mechanical agitation, flocculation, flotation) are used, then dispersed oil and solids can be removed, but soluble toxic contaminants remain in the effluent

Engineering Contradiction:
Improveoil removal efficiencyVSAvoidtoxic contaminant concentration
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The invention changes the chemical parameters of the effluent by adjusting pH to specific ranges (acidic pH 2-4 or basic pH 9-11) and introducing oxidizing agents, transforming the treatment mechanism from physical separation to chemical oxidation that can degrade soluble toxic contaminants

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs strong oxidizing agents (ozone, hydrogen peroxide, sodium hypochlorite, or Fenton's reagent) to chemically oxidize and degrade soluble toxic contaminants such as sulphides, benzenes, toluenes, xylenes and polyaromatic hydrocarbons, converting them into less harmful substances

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

2Object-generated harmful factors

If oxidizing agents are added to change equilibrium thermodynamic conditions, then toxic contaminants are oxidized and separated with oil phase, but additional chemical treatment steps are required

Engineering Contradiction:
Improvetoxic contaminant concentrationVSAvoidtreatment process steps
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The invention combines multiple treatment functions into a unified process: pH adjustment, oxidation of toxic contaminants, emulsion destabilization, and phase separation all occur in an integrated sequence that reduces the need for separate treatment units

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The oxidizing agents serve multiple functions simultaneously: they oxidize soluble toxic contaminants, destabilize the oil-in-water emulsion by attacking emulsion stabilizers, and facilitate phase separation, making the treatment process more efficient with fewer steps

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 efficiently reduces the concentration of oil and toxic contaminants in effluents, making it suitable for safe discharge or reuse, minimizing environmental impact and operational costs while maintaining the injectability of fluids into reservoirs.

Implementation Method 1

The change in the equilibrium thermodynamic conditions of the emulsion is brought about by one or more redox reaction(s) by adding specific oxidizing agents (hydrogen peroxide (H2O2) or sodium hypochlorite (NaClO), for example). Together with the change in the equilibrium thermodynamic conditions, the soluble toxic contaminants derived from the oil are also oxidized

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

The change in the equilibrium thermodynamic conditions of the emulsion is brought about by one or more redox reaction(s) by adding specific oxidizing agents

Methodology Applied
Scientific EffectRedox reactions: Redox Reactions

Implementation Method 3

separating the treated effluent by means of the separating device into at least two, preferably, distinct, phases: a first phase containing predominantly water and a second phase containing oil and the soluble toxic contaminants

Methodology Applied
Scientific EffectPhase separation: Phase Change

Data Source

PatentEP2058040B1Process for treating effluents from the oil industry for discharge or reutilization
Publication Date: 2014.04.16 PETROLEO BRASILEIRO SA PETROBRAS
  • EP2058040B1 patent drawingFigure 1

AI summary

A process is described for treating effluents from oil production units for discharge or reutilization, to remove oil and other soluble toxic contaminants such as sulphides, benzenes, toluenes, xylenes and polyaromatic hydrocarbons, before discharging or reusing this effluent, especially in an offshore environment. This process for effluent treatment includes a step of changing the equilibrium thermodynamic conditions of an oil-in-water emulsion, followed by a step of separating the oil and the water, to be carried out in an offshore oil production unit.