Oryx, a joint venture between Qatar Petroleum (51%) and Sasol of South Africa (49%) has constructed a second-generation gas-to-liquids (GTL) complex in the Ras Laffan industrial city complex in Qatar.

Construction of the new facility began in late 2003 and was complete by December 2005 with operations started officially in late June 2006, following a stringent commissioning and validation process.

At the opening ceremony Sasol CE Patrick Davies said: “Oryx GTL is a vital cog in our strategy to create a substantial GTL business in the next decade, along with a number of international business partners.

Decades of continuous research and development, as well as proven design and operating experience in this field, have set us apart as leaders in the commercialisation of GTL. We are confident that Sasol will play an important role in the energy mix of the future.”

The investment for the project, jointly owned by Qatar Petroleum and Sasol, was a little over $900m. The facility is supplied with 330,000ft³/d of lean methane-rich gas from the Qatar North gas field and is able to produce 34,000bpd of liquids (24,000 barrels of diesel, 9,000 barrels of naphtha and 1,000 barrels of liquefied petroleum gas). The Qatar North gas field has proven reserves of over 900 trillion cubic feet.

EXPANSION ALREADY IN THE ‘PIPELINE’

In March 2004 Qatar Petroleum and Sasol, in conjunction with Chevron, announced a plan to evaluate the expansion of the Oryx GTL complex in Ras Laffan to produce 100,000 barrels of liquids per day. This is requiring the construction of a three-train, 65,000bpd facility with an expected start-up date of 2009 for the first train and 2011 for the subsequent trains.

In addition, plans were put forward by Qatar Petroleum, Sasol and Chevron to build a 130,000bpd upstream / downstream integrated GTL facility based upon the Sasol slurry phase distillate process, which would also exploit the reserves of the Qatar North gas field. This will involve the construction of a six-train facility, with a tentative start-up date of 2010.

The expansion of GTL technology in Qatar to build a further two plants over and above the original foundation plant will take the total investment to $6bn. The Oryx GTL expansion project is now underway. Sasol and Qatar Petroleum hope to be producing 450,000bpd of liquids by 2015 with several new facilities planned.

GTL TECHNOLOGY FOR THE FUTURE OF GAS

GTL technology has been known to be problematic in the past. However, second-generation GTL has now been well developed by most major oil companies, and in particular Sasol of South Africa, who have a great deal of experience in this technology.

“The GTL plant also offers the chance of producing higher value feed stocks for other petrochemical industries.”

Since the process is only about 60% thermal energy efficient, it is a question of economics as to whether gas-rich countries such as Qatar use their gas feed stocks in GTL plants, export the gas as liquefied natural gas via tanker or pipeline, or just export the natural gas to domestic markets.

GTL products can be stored and transported using existing conventional tankers and storage facility infrastructure, whereas LNG transportation requires liquefaction facilities, specially designed tankers and then regasification facilities at the other end.

The GTL plant also offers the chance of producing higher value feed stocks for other petrochemical industries in Qatar such as polymers, fertilizers and paints/dyes.

Rising crude oil / natural gas prices can dictate the direction of the resource (gas can be channelled into whichever process will give the best return) and by construction of new GTL facilities Qatar has an additional option for what to do with its surplus of natural gas.

GAS-TO-LIQUIDS COMPLEX CONTRACTORS AND CONSTRUCTION

The front-end engineering and design of the Oryx phase one GTL complex was carried out by Foster Wheeler Energy, UK. The engineering, procurement and construction contract was awarded to Technip-Coflexip of Italy. The EPC contract included the responsibility for the validation, commissioning, start-up and initial operation of the plant right up to a performance-testing phase.

The design of the plant incorporates the Sasol Slurry Phase Distillation (SPD) process, which uses specially developed catalysts to convert natural gas into premium petrochemicals and environmentally friendly fuels.

GAS-TO-LIQUIDS COMPLEX PROCESS AND TECHNOLOGY

The SPD process combines three commercial technologies: autothermal reforming for the production of synthesis gas from natural gas; slurry-phase Fischer-Tropsch synthesis over a catalyst for the conversion of the syngas to a waxy syncrude, and isocracking technology with mild hydrocracking / hydrotreating to upgrade the syncrude into liquid fuels.

The incoming gas is also scrubbed with an amine scrubber since any sulphur-containing gases passing into the process are detrimental to the life of the catalyst. The facility can be thought of as a gas processing and syngas preparation facility at the front end, which leads to several air separation plants, then a large-scale chemical conversion facility (Fischer-Tropsch), and finally a refinery on the back end to separate and process the petrochemical feed stocks produced.

“The plant incorporates the Sasol Slurry Phase Distillation (SPD) process.”

Other facilities in the plant include a hydrogen plant to provide hydrogen for hydrocracking and large-scale steam and electrical facilities, and finally a wastewater treatment facility.

The waste heat generated from the plant is captured and channelled into electrical power generation to save on the process running costs.

FINANCE FOR THE GAS-TO-LIQUIDS COMPLEX PROJECT

The commercial close for the project was finalised in December 2002. Arrangers for the deal included Abbey National Treasury Services, Arab Banking Corporation, Apicorp (joint regional book runner), Gulf International Bank (joint regional book runner), Bank of Tokyo-Mitsubishi, BNP Paribas (documentation and facility agent), Credit Lyonnaise, Credit Agricole Indosuez (international book runner), HSBC Investment Bank (security trustee), Hypo Vereinsbank, KBC Ireland (pre financial close technical), Mizuho Financial Group (pre financial close insurance), Qatar National Bank, RBS and Sumitomo-Mitsui Banking Corporation.