Monday, August 25, 2008

GTL (Gas to Liquid Technology)

A piece of fact that is gonna amaze you terribly: Click here.
(...if captured and converted, it's like finding another Saudi Arabia)

Stranded natural gas is being flared, releasing tonnes of CO2.

What is Gas To Liquid (GTL) technology?

In General, it is a technology that converts natural gas to liquid fuel. It is totally different from LNG (liquefied Natural Gas).

Scientifically, it's a catalyzed chemical reaction in which the synthesis gas (syngas) is converted into longer chain hydrocarbon, which is in liquid form.

(Syngas is a gas mixture essentially comprises of Hydrogen and Carbon Monoxide. Syngas is produced via gasification of carboneous compounds such as methane, CH4. It can either be burnt and used a fuel source or being used as an intermediate in the industrial synthesis of hydrogen and ammonia.)

GTL technology review:

Activation energy is energy barrier or the minimum energy that must be overcome so that the reaction can take place.

Direct conversion is not economically attractive. Thus it is not practiced in industry. Indirect conversion, on the other hand, is commonly used in the industry, whereby the F-T process is a more specific term of GTL that converts natural gas to liquid fuel.

The figure shows the process flow of F-T process. There are 2 principal processes involved: the gasification of methane to produce syngas and the other one is the F-T process to produce GTL fuel or products.

GTL fuel:

1. Higher Cetane Number, thus permitting a superior performance of engine design.

Cetane Number indicates how quickly the fuel wil auto-ignite, and how evely it will combust. A higher Cetane Number implies a lower flame temperature providing a reduction in the formation of Nitrogen Oxide. Typical fuel has a miminum Cetane Number of around 45-50 while GTL diesel has Cetane Number in excess of 70, allowing more complete combustion.

2. Cleaner fuel--> low sulfur content

GTL releases less particulate matter, which is composed of unburnt carbon and aromatics, and compounds of sulfur. Fine particulates can cause respiratory problems while some aromatics are carcinogenic.

Low sulfur content reduces the particulate generation significantly, whereas the low aromatic content reduces the toxicity of particulate matter.

GTL is thought to be able to effective curb acid rain which is principally caused by presence of NOx and SOx in excess.

GTL products:

3 major products of F-T process are Naptha, Paraffin and Lubricant based oil.

GTL Naptha-->highly paraffinic, ideal for being the feedstock for ethylene and propylene manufacture, results in higher yield compared to petroleum-based naptha feedstock.

Paraffin-->it's thought to be the future LAB feedstock of choice, which can significantly save cost for LAB producers.

Lubricant based oil--> Advances in engine design and the need to improve emission and fuel economy lead to significant increase in demand for it. GTL Base Oils will bring a step change in the ability to meet the future lubricant requirement.

In a nutshell

GTL has made the natural gas much more valuable than ever. It surpass way ahead the LNG (Liquefied Natural Gas). It can converts natural gas into liquid fuel with energy density better than the conventional diesel. It can also be blended with crude oil and results in unproportional output.

Having added so much value to natural gas, by all means, GTL unlocks the its natural gas potential. In fact, natural gas is the cleanest fossil fuel and it is so abundant that it can last until 22nd century.

Shell is one of the pioneers in GTL as it has improvised the F-T process by the name Shell Middle Distillate Synthesis (SMDS). Shell has even operated the first ever commercial scale GTL plant in Bintulu, Malaysia, with a capacity of 14,700bbl/day.

The GTL technology is still evolving! So, it's inevitable that the days of GTL will most certainly come!

More on GTL, click here

Technology breakthrough as of August 2008, click here

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