A Comparative Study of Gas Condensate Stabilization Techniques using Aspen HYSYS

Abstract

In this report, we perform a comparison of two gas condensate stabilization techniques: fractional distillation and multi-flash vaporization. Our prime objective is to compare relevant parameters .e.g. Reid vapor pressure (RVP) and associated costs in order to determine the more effective method for the stabilization of our gas condensate feed. The Aspen Plus software application suite was extensively used for the process design and simulation as well as the economic analysis for this project. It should be noted that both proposed designs yield stabilized condensates with RVP below the required threshold value of 10psia. Despite the lower RVP obtained using fractional distillation, the multi-flash vaporization method was selected as the preferred technique for stabilizing the condensate due to its much lower equipment and utilities costs. With recent discoveries of gas condensate reserves along the Nigerian coastline, we believe the results of our analysis will be of relevance in future years.

Table of Contents

Abstract ...................................................................................................................................... i Acknowledgments..................................................................................................................... ii

List of Tables ........................................................................................................................... iii

List of Figures ............................................................................................................................ v

1. Introduction to Natural Gas Condensates ........................................................................... 1

1.1. Definition and Properties ............................................................................................ 1

1.2. Applications and Markets............................................................................................ 2

1.3. Overview of the project ............................................................................................... 3

2. Literature Review ............................................................................................................... 5

2.1. By–Products of the Process ......................................................................................... 5

2.2. Methods of Gas Condensate Stabilization .................................................................. 6

3. Methodology ....................................................................................................................... 7

4. Process Description ............................................................................................................ 9

4.1. Proposed Design for the Fractional Distillation Method .......................................... 10

4.2. Proposed Design for the Multi-Flash Vaporization Method ..................................... 12

5. Equipment Specification and Design ............................................................................... 15

5.1. Fractional Distillation Method .................................................................................. 15

5.2. Multi-Flash Vaporization Method:............................................................................ 16

6. Economic Analysis ........................................................................................................... 18

7. Limitations of Proposed Designs ...................................................................................... 20

8. Discussion and Comparison of the Designs: .................................................................... 21

9. Conclusions & Recommendations .................................................................................... 25

10. Works Cited .................................................................................................................. 26

Appendix A: HYSYS Worksheets for Proposed Design for Fractional Distillation Method . 28

Appendix B: HYSYS Worksheets for Proposed Design for Multi-Flash Vaporization Method................................................................................................................................................. 31

Appendix C: Equipment Sizing for the Fractional Distillation Method .................................. 35

Appendix D: Equipment Sizing for Multi-Flash Vaporization Method .................................. 38

Appendix E: Energy Balances ................................................................................................. 41

Glossary .................................................................................................................................. 42