The public at large has been hearing more and more about the Gas to Liquids (GTL) process, which takes natural gas and turns it into a range of high quality liquid products. But what are those products and what are they used for? ‘Shell in the Middle East’ visits the offices of the Pearl GTL project in Doha, in Qatar, to learn about these unique products, including the properties and applications they will offer consumers in markets around the world...

The Pearl GTL project, launched in July 2006 by Qatar Petroleum (QP) and Shell, is now well into the construction phase. When completed, the plant will be the largest GTL facility in the world and will deliver high quality and sulphur- free liquid GTL products to markets around the globe.

As Andy Brown, Shell Qatar Country Chairman and Managing Director for the Pearl GTL Project, said recently, “This is where we aspire to be. Pearl GTL fits Shell’s strategy of more upstream and profitable downstream, it fits our commitment to be a technology leader, and it fits our strong position in the downstream with fuels that are different.”

When completed around the end of the decade the Pearl GTL integrated development project will produce some 140,000 barrels per day (bpd) of GTL fuels and products and 120,000 bpd of LPG (Liquefied Petroleum Gas), condensate and ethane.

Louis van Eijk, General Manager for Marketing, Logistics and the Supply of GTL Products for the Pearl GTL Project, says, “Pearl GTL will use wet well head gas from Qatar’s North Field. This gas will be processed to strip out the associated liquids and gases [ethane, LPG and condensate], which account for around 120,000 bpd of the total production volumes.

“Removing the associated natural gas liquids from the natural gas does not involve new or specialised technology. Indeed, with the exception of ethane extraction, other gas plants in Qatar go through the same process before they convert the gas into LNG (Liquefied Natural Gas) for example.

“However in Pearl’s case the resulting clean, dry methane gas will feed the technologically advanced GTL complex and will produce around 140,000 bpd of high quality GTL fuels and products,” he says.

So what is the practical value of the ‘upstream products’?

Louis explains, “The first product is ethane [C2H6]. Ethane will be extracted and fed into the Ras Laffan Industrial City ethane pipeline network as soon as required by Qatar to feed local petrochemical manufacturing plants.

“The second product is LPG, consisting of propane [C3H8] and butane [C4H10]. These products are familiar to many of us living in the Middle East, where the gas is bottled and used for cooking. LPG is also an important feedstock for the chemical industry and has many other uses, for example, as fuel for lighting and heating, as well as for auto gas and power generation.

“The third product is condensate [C5+], which is a valuable feedstock for refineries and chemical cracking units.

“Both LPG and condensate will be stored in a common, or shared, tank farm before being sold by Tasweeq into global markets. Tasweeq is a new wholly-owned Qatar Government entity responsible for exporting all regulated products, including LPG and condensate.”

Moving on to talk about GTL products, Louis says, “The clean, dry methane gas is converted into five key GTL products using Shell’s unique proprietary SMDS [Shell Middle Distillate Synthesis] process in combination with highly advanced and patented Shell catalyst technology.

“This technology has been in use since 1993 in Shell’s Bintulu plant in Malaysia, which is today producing some 14,700 bpd of GTL products. However, the difference between the Bintulu plant and the Pearl GTL plant in Qatar is that Pearl has ten times more capacity, uses newer technology and has a baseoil manufacturing component.”

John Hesse, Manager for Logistics and the Supply of GTL Products for Pearl GTL, elaborates, “The five key products produced during the GTL process are GTL Naphtha, GTL Normal Paraffin, GTL Kerosene, GTL Gasoil and GTL Baseoils.

“GTL Naphtha is a premium quality feedstock for petrochemical plants to make ethylene and propylene. These are the basic building blocks for the production of poly-ethylene and poly-propylene, which in turn are used to make a wide range of products for everyday household and industrial use.

“GTL Naphtha has a paraffin content of over 90 per cent, which is considerably higher than standard naphtha. The high paraffin content gives petrochemical manufacturers a higher yield in terms of production of ethylene and propylene as well as high-value co-products, such as gasoline components.

“GTL Normal Paraffin is used for the production of LAB [otherwise known as linear alkyl-benzene], which is a feedstock used to manufacture household detergents, soaps and washing powders.

“Usually manufacturing plants making detergents would need to have a Molex unit to extract paraffin from their kerosene feedstock,” says John. “However, the construction of a Molex unit is expensive. In addition, the process of extracting paraffin from kerosene has a yield of around 20 per cent, leaving the manufacturer with the problem of disposing of the surplus kerosene. This usually means that detergent manufacturers have to be located in close proximity to a refinery. “By using GTL Normal Paraffin, detergent manufacturers can save on the capital investment required for a Molex plant and do not need to be located near a refinery. So these are major benefits.”

GTL Normal Paraffin has been tested extensively and is found to be equal or better in every aspect than kerosene-derived normal paraffin. John goes on to say, “GTL Kerosene is another liquid which can be used for a number of applications, which include heating fuel, lamp oil and cooking oil. When used in any of these applications GTL Kerosene burns with a clear flame and produces less soot and smoke and very little smell. This offers considerable benefits for developing countries where kerosene is used mostly indoors for lighting and cooking.” An area which is currently being examined with great interest is the potential use of GTL Kerosene as an aviation jet fuel. In November of last year at the Dubai Airshow, Qatar Petroleum, Qatar Fuel Company (WOQOD), Qatar Airways, the Qatar Science and Technology Park, Airbus, Rolls Royce and Shell launched a unique R&D effort to look closely at the benefits of this product in aviation fuel.

In parallel, last February a super jumbo Airbus A380, powered by Rolls Royce Trent 900 engines, and using Shell GTL Jet Fuel in one engine, completed a successful test flight between Bristol in the UK and Toulouse in France.

“The results so far have been encouraging and show that GTL Kerosene can deliver a number of benefits, including lower emissions, less pollution and some efficiency gains,” says John. “This means that with the same fuel load aircraft could carry more freight over the same distance or go further carrying the same weight.

He goes on to say, “Then there is GTL Gasoil, which will be one of the main GTL products coming from the Pearl GTL plant. GTL Gasoil has a very high cetane number, is clear and odourless and gives lower local air emissions than standard gas oil. It can be used as a fuel in a large number of applications but the ones we are primarily developing are automotive diesel and marine diesel for use in ecologically sensitive areas, such as large cities with high local pollution levels.

“GTL Gasoil is also used to produce a speciality niche product called SBM [synthetic-based mud], which is a drilling fluid used in the oil and gas exploration industry. As SBM is fully biodegradable, it offers significant advantages over conventional drilling muds. GTL Gasoil is so clear that GTL Gasoil from Bintulu has even been used for dry-cleaning purposes.”

GTL Baseoils are the fifth product which will be produced by Pearl GTL. John says, “OEMs [Original Equipment Manufacturers] and regulatory bodies are driving finished lubricant manufacturers and marketers hard to raise the quality standards of automotive and industrial lubricants in order to reduce pollution, improve energy savings and reduce the overall consumption of lubricants.

“Since baseoils are the carrier fluid of finished lubricants, the demand for higher standards of baseoils is also rising all the time.

“GTL Baseoils from the Pearl GTL plant will be amongst the highest quality baseoils available and will represent a significant portion of the total global production for high quality baseoils.

“So that is the GTL product range in a nutshell and these products will start to flow into world markets around the end of the decade,” says John.

Louis concludes, “The production of GTL products will bring economic and reputational benefits to Qatar, offering the country an economically viable alternative use for its enormous natural gas resources and fulfilling its goal to become ‘the GTL capital of the world’.

“The Pearl GTL plant will bring benefits to Shell in terms of a robust return on investment and reinforcement of Shell’s technical leadership position. But, quite significantly, for the world it will bring a whole new range of high performance and more environmentally friendly products.”