ABSTRACT

This study presents ASPEN Base Case Simulation (ABCS), preliminary process design with filtration integration, techno-economics and uncertainty analysis of bioclarified water production from petroleum wastewater. ABCS, scale-up design and economics were performed using inherent design and costing algorithms in ASPEN Batch Process Developer (ABPD) V10. The process profitability indices such as Net Present Value (NPV), Internal Rate of Return (IRR), Return on Investment (ROI) and Payback Time (PBT) were evaluated in a user-defined developed Microsoft-excel version 2018. Predictive models for predicting and optimizing techno-economic parameters: return on investment (ROI), payback time (PBT) and production rate (PR) were achieved in RSM via Box-Behnken Design (BBD) technique of Design Expert V13. The regression models gave R² values of 0.9984, 0.9920 and 0.8867 for return on investment, payback time and production rate respectively. Monte Carlo Simulation in Crystal Ball Oracle software was used to perform the profitability sensitivity and uncertainty analyses. The annual production target (600,000litres/year) scale-up simulation results gave batch size 406litre/batch, annual number of batches produced 1469batches/year.  Base case capacity results showed that the total capital investment, NPV, IRR, ROI and PBT are $631485, $68932.18, 9%, 15.8% and 6.33yrs respectively.  Sensitivity analysis shows that selling price has the highest contribution for both the NPV and the IRR respectively. The certainty of the base case model after 30000trials was 99.98% for NPV, 90.89% for IRR and 61.23% for production rate. This study showed that petroleum wastewater BFS scale-up design is feasible.

TABLE OF CONTENTS

Cover page

Title page                                                                                                                    i

Declaration                                                                                                                  ii

Certification                                                                                                                iii

Dedication                                                                                                                  iv

Acknowledgements                                                                                                    v

Table of contents                                                                                                        vi

List of tables                                                                                                               viii

List of figures                                                                                                             ix

Abbreviations/Nomenclature                                                                                      xi

Abstract                                                                                                                      xiii

CHAPTER 1

INTRODUCTION

1.1       Background of study                                                                                      1

1.2       Statement of problem                                                                                     6

1.3       Aim of study                                                                                                   7

1.4       Objectives                                                                                                       7

1.5       Significance of the study                                                                                8

1.6       Scope of the study                                                                                          8

CHAPTER 2

LITERATURE REVIEW

2.1       Petroleum wastewater                                                                                     9

2.2       Petroleum wastewater characteristics                                                             10

2.3       Petroleum wastewater treatment technologies                                               11

2.3.1    Physical treatment                                                                                           12

2.3.2    Membrane                                                                                                       12

2.3.3    Coagulation/flocculation                                                                                 15

2.3.4.   Electro-coagulation                                                                                         17

2.3.5.   Adsorption                                                                                                      18

2.3.6.   Physical-chemical treatment                                                                           19

2.3.7    Chemical treatment                                                                                         19

2.3.8    Biological treatment                                                                                        20

2.3.8.1 Aerobic biological processes                                                                           21

2.3.8.2 Anaerobic biological process                                                                          21

2.3.9    Aerated lagoons                                                                                              22

2.3.10 Activated sludge process                                                                                22

2.3.11 Biofilm-based reactor                                                                                     22

2.4       Filtration process integration                                                                          23

2.5       Techno-Economic Analysis                                                                            24

2.5.1    Techno-economic analysis of bioclarified water production                          24

2.5.2    Process modelling and simulation                                                                   25

2.5.3    Response Surface Methodology (RSM)                                                         26

2.5.4    Process economics, sensitivity and uncertainty analyses                                27

2.6       Review of related works                                                                                 29

2.7       Research gap                                                                                                   30

CHAPTER 3

MATERIALS AND METHOD

3.1       Aspen batch base case process simulation environment                                 31

3.2       Simulation procedures using aspen batch process developer                          32

3.2.1   Mixing                                                                                                              33

3.2.2   Coagulation stage                                                                                            33

3.2.3   Flocculation stage                                                                                            33

3.2.4    Settling stage                                                                                                  34

3.2.5    Filtration stage                                                                                                34

3.3       Base case process description and scale-up process design                            34

3.4       Process economics and profitability evaluation                                              36

3.5       Techno‑economic modelling and optimization study                                     38

3.5.1    Optimization study methodology                                                                   42

3.6       Monte Carlo simulation uncertainty and sensitivity analyses                         42

CHAPTER 4

RESULTS AND DISCUSSION

4.1       Process base case scale-up simulation and annual production design results 44

4.2       Process economics results                                                                               48

4.2.1    One-factor at a time (OFAT) profitability sensitivity analysis                       50

4.2.2    Effect of discounted rate cumulative cash flow diagram                               53

4.3       RSM techno‑economic model fitting                                                             54

4.3.1:   Effect of the cost factors on PBT                                                                   58

4.3.2:   Effect of the cost factors on ROI                                                                   62

4.3.3:   Effect of the cost factors on production rate                                                 66

4.4:      Bioclarified water production optimization studies                                       70

4.5:      Profitability uncertainty and sensitivity results                                              73

CHAPTER 5

CONCLUSION AND RECOMMENDATIONS

5.1       Conclusion                                                                                                      79

5.2       Research recommendations                                                                            80

5.3       Contributions to knowledge                                                                           80                                                                                           

REFERENCES                                                                                                        81

APPENDIX                                                                                                               95

LIST OF TABLES

Table                                                              Title                                                    Page

3.1:      Properties of independent variable selected for BBD method                       30

3.2:      The BBD experimental design                                                                        30

4.1:      Stream balance of bio-clarified water production from petroleum wastewater46

4.2:      Batch process design throughput parameters of bio-clarified water production47

4.3:      Process base-case economic parameters of bioclarified water production

from PPW                                                                                                       50

4.4:      The BBD experimental design matrix                                                            56

4.5:      Fit summary for the production of bioclarified water from petroleum

wastewater                                                                                                      57

4.6:      ANOVA Results for PBT                                                                              60

4.7:      ANOVA Results for ROI                                                                              64

4.8:      ANOVA Results for Production rate                                                             68

4.9:      Optimization criteria for bioclarified water production                                  71

LIST OF FIGURES

Figure                                                             Title                                                    Page

3.1:      Process flowsheet for bio-clarified water reclamation from PPW                  26

4.1:      Distribution of ASPEN-installed cost factors for total capital investment    49

4.2a:    variation of the project total capital investment with profitability indices     52

4.2b:    variation of the project annual production cost with profitability indices      52

4.2c:    Effect of discount rate on PBT, NPV, ROI and IRR                                                53

4.3:      Profitability evaluation of bio-clarified water production using cumulative cash

flow diagram                                                                                                   54

4.4:      Design expert plot, predicted vs. actual plot for (a) PBT (b) ROI

(c) Production rate                                                                                          57

4.5:      Design expert plot; response surface 3D plot for PBT with: (a) AB (b) AC

(c) AD (d) AE (e) BC (f) BD (g) BE (h) CD (i) CE  (j) DE                          62

4.6:      Design expert plot; response surface 3D plot for ROI with: (a) AB (b) AC

(c) AD (d) AE (e) BC (f) BD (g) BE (h) CD (i) CE (j) DE                           66

4.7:      Design expert plot; response surface 3D plot for Production rate with: (a) AB

(b) AC (c) AD (d) AE (e) BC (f) BD (g) BE (h) CD (i) CE (j) DE               70

4.8:       Optimization results ramp for bioclarified water production.            72

4.9a:    Contribution of input variable variation on NPV                                           74

4.9b:    Contribution of input variable variation on IRR                                            74

4.9c:    Contribution of input variable variation on production rate                           75

4.10a: Uncertainty level (NPV) for bioclarified water production from PPW         77

4.10b: Uncertainty level (IRR) for bioclarified water production from PPW           78

4.10c: Uncertainty level (production rate) for bioclarified water production from PPW 78

NOMENCLATURE OF ABBREVIATIONS

ABPD                         -           Aspen Batch Process Developer

ASDM                        -           activated sludge digestion model

BAF                            -           biological aerated filter

BBD                            -           Box-Behnken Design

BFS                             -           Biocoagulation-Flocculation-Sedimentation

BOD                           -           Biochemical oxygen demand

BTEX                          -           chemicals (benzene, toluene, ethylbenzene and xylene)

CAPD                         -           Computer-Aided Process Design

CCFD                         -           Cumulative Cash Flow Diagram

CF                               -           Coagulation-Flocculation

CF–MBR                    -           cross-flow membrane bioreactor

CFS                             -           Coagulation-Flocculation-Sedimentation

COD                           -           Carbon Oxygen Demand

COD                           -           Chemical Oxygen Demand

DPC                            -           Direct Production Cost

FCI                              -           Fixed Capital Investment

HF-MBR                     -           hollow-fiber membrane bioreactor

HRT                            -           hydraulic retention times

IPC                              -           Indirect Production Cost

IRR                             -           Internal Rate of Return

IRR                             -           internal rates of return

MAD                           -           Mean Absolute Deviation

MAPE                         -           Mean Absolute Percentage Error

MBR                           -           membrane bioreactor

MF                              -           microfiltration

MSE                            -           Mean Square Error

NA                              -           naphthenic acids

NF                               -           Nanofiltration

NPV                            -           Net Present Value

NPV                            -           net present values

NTU                            -           Nephelometric Turbidity unit

OCB                            -           Oracle Crystal Ball

PAH                            -           Poly-Aromatic, Phenol and Hydrocarbons

PBT                             -           Payback Time

PBT                             -           payback time

PC                               -           Production Cost,

PPW                            -           Petroleum Produced Water

PW                              -           Produced Water

RMSE                         -           Root Mean Square Error

RO                              -           Reverse Osmosis

ROI                             -           return on investment

RSM                            -           Response Surface Methodology

SS                                -           Suspended Solids

TCI                              -           Total Capital Investment

TCI                              -           Total Capital Investment

TDP                             -           Total Dissolved particles

TEA                            -           Techno-economic analysis

TMP                            -           Trans-membrane pressure

TPDC                          -           Total Plant Direct Cost

TPIC                           -           Total Plant Indirect Cost

TSS                             -           Total Suspended Solids

UF                               -           Ultrafiltration

WC                              -           Working Capital

LIST OF APPENDIX

APPENDIX I:           Optimization solutions for bioclarified water production

APPENDIX II:          Definition of terms