Treatment Of Oil Polluted Water By Adsorption Process

Description

ABSTRACT

Produced water (formation and injected water containing production chemicals) represents the largest volume waste stream in oil and gas production operations on most offshore platforms. Produced water is a complex mixture of dissolved and particulate organic and inorganic chemicals in water that ranges from essentially freshwater to concentrated saline brine. The most abundant organic chemicals in most produced waters are water-soluble low molecular weight organic acids and monocyclic aromatic hydrocarbons. Concentrations of total PAH and higher molecular weight alkyl phenols, the main toxicants in produced water, typically range from about 0.040 to about 3 mg/L. The metals most frequently present in produced water at elevated concentrations, relative to those in seawater, include barium, iron, manganese, mercury, and zinc. Upon discharge to the ocean, produced water dilutes rapidly, often by 100-fold or more within 100 m of the discharge. The chemicals of greatest environmental concern in produced water, because their concentrations may be high enough to cause bioaccumulation and toxicity, include aromatic hydrocarbons, some alkylphenols, and a few metals. One commonly used technique for remediation of petroleum contaminated water is adsorption. The main objective of this study is to examine the removal of oil from oil–water emulsions by adsorption on bentonite, powdered activated carbon (PAC) and deposited carbon (DC). The results gave evidence of the ability of the adsorbents to adsorb oil and that the adsorptive property of the three adsorbents (bentonite, PAC, and DC) has been influenced by different factors. The effects of contact time, the weight of adsorbents and the concentration of adsorbate on the oil adsorption have been studied. Oil removal percentages increase with increasing contact time and the weight of adsorbents, and decrease with increasing the concentration of adsorbate. Equilibrium studies show that the Freunlich isotherm was the best fit isotherm for oil removal by bentonite, PAC, and DC. The data show higher adsorptive capacities by DC and bentonite compared to the PAC.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE STUDY
• PROBLEM STATEMENT
• RESEARCH AIM AND OBJECTIVE
• SIGNIFICANCEOFTHESTUDY
• LIMITATION OFSTUDY
• PROJECT ORGANISATION

CHAPTER TWO

LITERATURE REVIEW

• OVERVIEW OF THE STUDY
• OVERVIEW OF PRODUCED WATER
• PRODUCED WATER GENERATION
• IMPORTANCE OF PRODUCED WATER TO THE OIL AND GAS INDUSTRY
• REVIEW OF ADSORPTION
• PRODUCED WATER ADSORBENTS
• ADSORPTION PHENOMENON
• TYPES OF ADSORBENTS
• ADSORPTION AND ADSORBING MATERIALS
• REVIEW OF RELATED STUDIES

CHAPTER THREE

METHODOLOGY

• MATERIALS USED
• PREPARATION OF ADSORBENTS
• PREPARATION OF SAMPLES
• TREATMENT OF SAMPLES
• DETERMINATION OF OIL CONTENT

CHAPTER FOUR

4.1       RESULTS AND DISCUSSION

CHAPTER FIVE

• CONCLUSION
• REFERENCES

CHAPTER ONE

1.0                                                      INTRODUCTION

1.1                                         BACKGROUND OF THE STUDY

Produced water is a water phase contained in a hydrocarbon reservoir and its comes to the external through oil or gas extraction [Howard, 2012], these water has a variable complex organic and inorganic compounds depending on the geographical site of the field, natures of produced hydrocarbon, geological formation, extraction methods and the lifetime of a reservoir [Bande, 2008], according to the different source, the compositions of produced water are differenced by order and magnitude, and its considered a largest source for environmental pollution associated to oil production activities [Cumming, 2019].

The global generations of produced water to crude oil is about (3:1) and will increase in a near future with increasing lifetime of wells, that will boost the growth of the PW management techniques and marketing, to reused again in oil production field, or for further different purposes such as livestock watering, irrigation, municipal, aquifer storage and further industrial uses [Sharmani, 2012].

One of the harmful organic contaminants   contained in produced water is dispersed oil that is a blend of hydrocarbons such as toluene, benzene, ethylbenzene, xylenes         (BTEX), naphthalene, phenanthrene,  dibenzothiophene (NPD), polyaromatic hydrocarbons (PAHs) and phenols, which not dissolve in the water, should be removed before disposal or reused. Different available techniques were used to manage the produced water, such as micro- filtration and biological processes, variety of filters, ultrafiltration and nanofiltration membranes, membrane bioreactor, air flotation, electrocoagulation, adsorption [Frank, 2018]. The adsorption method is one of commonly applied technic to eliminate a dissolved organic material in water, which is a physical adhesion of the contaminating material on the surface of a solid. A wide range of a biosorbent materials for removal oil from produced water actually have been used in latest years, such as activated carbon, bentonite and deposited carbon, banana peel, Eggshell, rice husks ash carbonized rice husks anhydrous and hydrophobized vermiculite [Frank, 2015].

For the high cost of adsorbent material used for treating wastewater, many attempts have been done to satisfy the alternative material they are available easily throughout the world. Due to hazards of oil field effluents on environment, treatment is necessary before disposal. Treatment of these effluents may result in improved oil/water separation, improved water quality, oil recovery, water reuse, protection of downstream facilities and environmental permit compliance [ Bande et al, 2008].

Many techniques are available for the separation of oil–water emulsions, including a variety of filters, chemical dosing, reverse osmosis, gravity separation, ultra-filtration, micro-filtration, biological processes, air flotation, membrane bioreactor, chemical coagulation, electrocoagulation and electroflotation. One commonly used technique for removing organics dissolved in water is the process of adsorption; which involves the separation of substances from one phase to the surface of another. The adsorbing phase is the adsorbent, and the material concentrated or adsorbed at the surface of that phase is the adsorbate [Frank, 2015].

The objective of this work is to report a removal efficiency of crude oil produced water using adsorption method.

1.2                                 PROBLEM STATEMENT

Produced water is water trapped in underground formations that is brought to the surface during oil and gas exploration and production. In traditional oil and gas wells, produced water is brought to the surface along with oil or gas. The treatment of produced water is a significantly growing challenge for the oil and gas industry that requires serious attention. With adsorption being defined as the least expensive treatment method, the second part will introduce general adsorption principals.

1.3                                   AIM AND OBJECTIVE OF THE STUDY

The main aim of this study is to examine the removal of oil from oil–water emulsions by adsorption.

The main objective of this study is to investigate the oil removal efficiencies of different adsorbents such as PAC, bentonite, and DC from oil–water emulsion.

1.4                                         SIGNIFICANCE OF THE STUDY

This study will discuss adsorption method is a low-cost bio-sorbent for the elimination a crude oil from produced water. The study provides the basis for development of an eco-friendly and promising material for treatment of oil and hydrocarbon pollution from water bodies in environmental clean-up.

1.5                                           LIMITATION OF THE STUDY

As we all know that no human effort to achieve a set of goals goes without difficulties, certain constraints were encountered in the course of carrying out this project and they are as follows:-

1. Difficulty in information collection: I found it too difficult in laying hands of useful information regarding this work and this course me to visit different libraries and internet for solution.
2. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).

• Time Constraint: The researcher will simultaneously engage in this study with other academic work. This consequently will cut down on the time devoted for the research work.

1.6                                    PROJECT ORGANISATION

The work is organized as follows: chapter one discuses the introductory part of the work,   chapter two presents the literature review of the study,  chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.