Process Plant Engineering Assignment 1

Curtin University

Curtin University

Tony Van

Tony Van

Process Plant Engineering CHEN3000/5017

Assignment 1 – PFD/P&ID & Process Evaluation

Process Plant Engineering CHEN3000/5017

Assignment 1 – PFD/P&ID & Process Evaluation

Table of Contents

1.0 Process Description 1

1.1 Heavy Hydrocarbon Removal 1

1.2 Why must Hydrogen Sulphide and Carbon Dioxide be removed? 2

1.2.1 Hydrogen Sulphide “Sweetening” 2

1.2.2 Removal of Carbon Dioxide 3

1.3 Water and Mercury Removal 4

1.3.1 Treatment of Water in Natural Gas 4

1.3.2 Presence of Mercury 5

2.0 Technology Survey, Advantages and Disadvantages 6

2.1 Heavy Hydrocarbon Separation 6

2.2 Sweetening Stage – Both H2S and CO2 6

2.3 Dehydration and Mercury Removal 7

2.3.1 Water 7

2.3.2 Mercury 7

3.0 Process Block Flow Diagram (BFD) 8

4.0 Process Flow Diagram (PFD) 9

References 11

Table of Figures

Figure 1: H2S & CO2 Removal by Absorption (Gas Sweetening, 2015). 2

Figure 2: Simple Glycol Dehydration Unit (Hy-Bon Blog, 2014). 4

Figure 3: Simple Block Flow Diagram of LNG Process (Van, 2015). 8

Figure 4: LNG Process Flow Diagram Part 1 (Van, 2015). 9

Figure 5: LNG Process Flow Diagram Part 2 (Van, 2015). 10

1.0 Process Description

The process of turning raw natural gas into usable natural gas can involve several complex processes. This is due to the fact that the raw natural gas may consist of many different substances, each with its own method of extraction and its uses in the real world. The composition of raw natural gas will vary from place of origin however the main components are methane, ethane, propane, butane, hydrogen sulphide, carbon dioxide, impurities and water, along with other heavier hydrocarbons (PetrolStrategies Inc. 2000).

Out of these components, it is only the methane that is required for purification and turned into liquefied natural gas (LNG) for export and use while the other components are used elsewhere in...