Fueling the Future: Small & Mid-Scale FLNG Solutions For Stranded Gas Opportunities

By: Tariq Siddiqui

LNG & ENERGY SECURITY

The war in Europe has put energy security in the fore-front.  LNG supplies from US have played a crucial role in augmenting energy security. The prioritization of energy security however, does not undermine decarbonization, and LNG value chain offers substantial opportunity to minimize lifecycle emissions with various technologies.  In this article, we explore trends in small and mid-scale FLNG

SMALL & MID SCALE FLNG

There is no strict definition of small /mid-scale F/LNG; however, a liquefaction capacity between 1.0 - 3.0 mtpa is generally considered the small/mid-scale. As of April 2023, there were 5 operational FLNG units with total liquefaction capacity of 12.1 mtpa. Of this, 5.1 mtpa are characterized as small to mid-scale FLNG (1.0 – 3.0 mtpa).

1. PFLNG-1 (1.2 mtpa) - Malaysia

2. PFLNG-2 (1.5 mtpa) - Malaysia

3. Cameron GoFLNG (2.4) - Cameron

4. Coral Sul (3.4 mtpa) - Mozambique

5. Prelude (3.6 mtpa) - Australia

FLNG SOLUTION FOR STRANDED OFFSHORE & OFFSHORE GAS

Floating LNG (FLNG) solutions help monetize the stranded gas at offshore and near-shore locations. The existing trends of projects in pipeline (under construction & Pre-FID) indicate a growing demand for small to mid-scale LNG trains from 2023 – 2030.

The New Development

There have been considerable developments in FLNG that has checkered history. The development has moved from large, complex and expensive first-generation customized designs (Prelude) to smaller standardized and less complex and affordable second-generation FLNG (Petronas, Satu).

Small & Mid-Size Concept/Design

There are several concepts in floater design that have been tried.  They are broadly classified in three categories (cost ~ $/tonne)

1. Barge mounted   (< 0.5 mtpa)   ~ $375/tonne

   1. Caribbean FLNG (By Wison Offshore & Marine - Shanghai

2. Floater (New Builds vs. Converted)

   1. New Build ~ $750/tonne

      1. Petronas ZLNG (By Samsang Heavy Industries & JGC)

   2. Converted MOSS LNG Tanker ~$550/tonne

      1. Example: Cosmos Energy’s GIMI FLNG (Mk II) at Greater Tortue field (By Golar)

3. Platform Structure

Small & Mid-Size FLNG - The Benchmark

Petronas PFLNG-Satu (New Build) at 1.5 mtpa capacity is the industry benchmark for small & Mid-Scale FLNG. It took six (6) years; from contract award in Dec, 2010 to production start-up on Dec, 2016, and its relocation in March, 2019.

Liquefaction Technologies

Small / Mid-scale FLNG require relatively simple and less complex liquefaction technologies then their larger counterparts for safety reasons and space limitations in floating unit:

1. Air Products (AP) with 68% of total market share in operational capacity dominates the market in liquefaction technology.

2. ConocoPhillips Optimized Cascade Process has growing share currently at 22%.

3. Air Products AP-N technology and Black & Veatch’s PRICO processes have been successfully used in Petronas PFLNG-1 (Satu) and Cameroon FLNG respectively.

Reducing Carbon Emissions

There are three main sources of carbon emissions on a liquefaction facility:

1. CO2 emissions vented during pre-treatment of acid gas removal

2. CO2 released in flue-gas from gas turbine driving the liquefaction train

3. CO2 released in flue-gas from gas turbine driving the power-generation units

The emissions can be reduced by

1. Carbon Capture & Sequestration (underground):

2. Capturing CO2 from Natural Gas processing plant

3. Capturing CO2 from Post-combustion flue gases

4. Using all-electric facility to drive liquefaction and power-generation turbines.

5. Using renewable energy to drive liquefaction trains and power-generation.