The Gas to Liquids (GTL) technology is opening up new markets for natural gas as its products are tied to the high-value oil market.
This allows gas resources to enter into the existing transportation fuel market which is predicted to have a supply-demand deficit in the foreseeable future.
GTL is the perfect match in areas with a high degree of crude import and accessible gas resources, thereby facilitating increased security of supply.
Natural gas represents a global energy resource similar in size to that of crude oil. However, considerable volumes of natural gas are located in remote areas lacking pipelines or other infrastructure to transport them directly to the customer. Substantial amounts are also flared (burned off) as an unwanted by-product of oil production.
The challenge of exploiting remote gas has partly been overcome by chemically converting it to methanol or ammonia (for fertilizers), or cooling it to liquefied natural gas (LNG). All of these products can be readily transported on land and at sea. Another attractive option is to produce synthetic oil from natural gas, using a process known as gas-to-liquids or GTL.
Modern GTL conversion involves first the production of synthesis gas (CO + H2) and its conversion to synthetic fuel using the Fischer-Tropsch process (F-T).
The F-T technology is a catalytic process invented by two German scientists (of the same names) and has been known since the 1920’s; indeed, Germany produced petroleum from coal in this way to partly fuel its military machine during the Second World War. However, it is only in recent years that the process has been sufficiently advanced to produce hydrocarbon liquids economically from natural gas.
The primary upgraded products produced by the Fischer-Tropsch process are synthetic diesel, naphtha, lubricants and more specialized commodities. They are clean burning, almost odourless and biodegradable – qualities that make them environmentally attractive.
Gas to Liquids technology represents a mean of monetizing remote gas reserves by converting natural gas into hydrocarbon liquids, and is opening up new markets for natural gas.
Large gas reserves can in this way be tied to the oil market without the market challenges associated with natural gas. Though energy and capital intensive, the process offers the potential to convert gas to higher value, high purity, and synthetic liquids like diesel, naphtha and lubricant base oils which can be transported to consuming markets. At high oil prices the GTL process may create greater value than the main alternatives for gas monetisation.
GTL technology, initially developed by StatoilHydro’s research centre, is now further developed, scaled up and proven in the world’s biggest GTL demonstration facility in Mossel Bay in South Africa.
