IN THE NAME OF GOD

Sara Madani Shima Dabaghi

PRICO PROCESS SIMULATION-OPTIMIZEITION

Introduction

The main liquefaction process

Prico process

Optimization

Simulation

Content

T h e L N G P r o c e s s

Introduction: What is LNG?

When natural gas is cooled to a temperature of approximate (–160 C) at atmospheric pressure it condenses to a liquid ,called (LNG).

Introduction:THE LNG PROCESS

• The liquefaction process reduces the original volume of the natural gas(≈1/600).

• The density of LNG is less than half that of water, (≈ 45% ).

• Odorless.

• Colorless.

• non-corrosive.

• non-toxic.

• When vaporized, it burns only in concentrations of 5% to 15%.

Introduction: The LNG Process

LNG is a safe and efficient way to transport gas .across long distances

Composition :Introduction

1917 First commercial natural gas liquefaction plant built in West Virginia.

1959 The world's first LNG tanker, safely carries LNG from Lake Charles, LA., to Canvey Island, United Kingdom, initiating commercial LNG shipping.

1964 The British Gas Council begins importing LNG from Algeria, making the United Kingdom the world's first LNG importer and Algeria as its first exporter.

1969 United States exports LNG to Asia for the first time: from Alaska to Japan.

A Brief History of LNG & NGL Production

The LNG Process

The LNG process removes the oxygen, carbon dioxide, sulfur compounds, and water.

The LNG Process chain

APCI propane precooled mixed refrigerant process

Phillips optimized cascade process

Black & veatch prico process

Statoil / Linde mixed fluid cascade process (MFCP)

Axens Liquefin process

Poly Refrigerant Integrated Cycle Operation)) Prico Process

Black & Veatch developed a single mixed refrigerant loop .called the PRICO Process.

The PRICO process is the only LNG process with proven installations in a wide capacity range.

The capacity of the PRICO process is limited to about 1/3 of the APCI or Phillips process units presently being constructed.

Why Prico Process?

Simplicity & Operation Reliability

Operating Flexibility

Rapid Startup

Prico process

This refrigerant is a mixture of nitrogen hydrocarbons ,ranging from methane to isopentane.

Utilization of SMR greatly simplifies the piping, controls, and equipment arrangements

The use of a single refrigeration system is the key aspect of a simple and reliable LNG plant.

The use of a single exchanger for the LNG production is another key to process simplicity.

Fluctuations of feed gas composition ,pressure and changes in ambient conditions have minor impact on the system.

The Prico Process

a main heat exchanger

a compressor

a condenser

two Joule-Thomson (JT)

valves

Equipment:

The process cools the natural gas feed

from ambient conditions to gas liquefaction

temperatures and then further cools the gas

to minimize vaporization when sending the

LNG to atmospheric storage tanks.

The Prico Process

Process Discribtion

• The refrigerant is partially condensed in the condenser and is fed to the NG HX and is cooled together with the natural gas stream.

• The refrigerant is a sub-cooled liquid at the outlet of NG

HX and is expanded to the low pressure (Pl). The resulting two-phase mixture provides the cooling in NG HX by vaporization.

• The outlet from the heat exchanger (NG HX) is slightly

super-heated, partly to avoid damage to the compressor.

Prico process optimization

The Prico process was selected for optimization :

First, it is a simple LNG process with 7 independent variable.

Second, it is possible to verify the results by investigating the resulting hot and cold Composite Curves (CCs).

The most important variables for the Prico process:

 

• the flow rate and

composition of the refrigerant

• the compressor suction pressure (low pressure)

• the condenser pressure (high pressure).

Prico process optimization:

The two most important unit operations in an LNG process:

Compressors

Heat exchangers

Degeneration of energy:

Parameters and variables in Prico process:

Composite curves for the initial solution:

Composite curves for case 1:

Composite curves for case 2:

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optimization–simulation Of

Prico process

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Enjoy small things, for one day

you may come back and see

they were big things.