Fischer-Tropsch based technology present viable route in producing non-crude oil based high quality fuels and specialty products to meet the growing market demand. GTL opens new markets to natural gas producers as the estimated natural gas reserves have continuously increased over the past decade.
Three main steps to produce GTL
GTL is capable to produce products that have less pollutants (low in sulphur and aromatics), higher cetane number and it is technically feasible to synthesise almost any hydrocarbon from any other. Over the past five decades several processes have been developed to synthesise liquid hydrocarbons from natural gas.
Fischer-Tropsch based technology present viable route in producing non-crude oil based high quality fuels and specialty products to meet the growing market demand. GTL opens new markets to natural gas producers as the estimated natural gas reserves have continuously increased over the past decade. GTL is capable to produce products that have less pollutants.
A risky business
Gas-to-liquid (GTL) seems to be a highly risky business. The technology is here, thanks to the past few decades of technical advances, studies and demonstration facilities, like those of BP Alaska (2002), ConocoPhillips Oklahoma (2002), Syntroleum/Marathon, Oklahoma (2003) and Eni Sannazzaro Italy (2001). There are four commercial GTL plants in operation; two Sasol plants Mossel Bay in South Africa and Oryx in Qatar and two Royal Dutch Shell plants in Bintulu Malaysia and Pearl Qatar. The commercial and political aspects puts GTL technology to a position where it’s more a matter of will and risk taking to invest in this highly capital intensive way of meeting the growing demand of high quality fuels. Some governments have implemented GTL as a part of the long-term strategies, like Qatar.
Current market prices boosting GTL
Shell and Sasol are both considering GTL projects in Lousiana US, and Sasol is exploring opportunities in Canada and Uzbekistan. Sasol announced 2012 company plans to invest between $16 and $21 billion in an integrated GTL and ethane cracker complex in Westlake. The front end engineering and design (FEED) is currently on-going for this project. Cheap natural gas combined with the high market price of distillates makes GTL projects attractive at current market conditions. However, since developing and constructing a large scale GTL plant takes years, including the very common project delays, there’s significant market timing risks involved. What will be the price of natural gas feedstock and the distillate product prices at the time when the production starts?
Some say that thinking smaller is the answer for the high risk involved with GTL. WorldGTL and CompactGTL with Petrobras are developing small scale modular systems for offshore platforms. Along with LNG, could GTL be the answer in reducing wastes from natural gas venting and flaring in stranded areas? Velocys, Houston Texas based company is developing in collaboration with Ventech and Haldor Topsoe the modular GTL designs. “Compared to traditional field construction methods, where all materials are delivered to the project site and then built on location, modularization is providing to be an effective solution for achieving fast-track project schedules, and for building refining and gas processing facilities in remote locations. Modularized GTL plants enable otherwise wasted gas to be converted into additional revenue. In the larger economic picture, a modular GTL capability can be the key factor that enables the construction of upstream projects that would otherwise be cancelled because of poor results derived from economic models. These projects can be enhanced by converting the gas to higher-value clean fuels produced in the GTL process.” explains Kenneth Roberts from Velocys in his article published at PTQ Q1 2013.
Proven valve technologies
Besides proven technological steps in catalysts, reactor designs and ancillary units, automation and valves do have a role to play in successful GTL project completion and safe plant operations. It is a combination of fit for purpose valve type and material selection and sizing for many different applications from air separation, syngas production and Fischer-Tropsch synthesis to final product upgrading compiled with experience in large GTL project management and execution capabilities to ensure scheduled commissioning and start-ups. Companies designing, building and operating GTL-plants will benefit further from valve suppliers who are committed to technological developments, such as noise reduction capabilities in gas applications.
Proven reliability in extreme GTL conditions. Neles ball valve with noise reduction trim.
GTL technology involves conversion of methane to high molecular weight hydrocarbons from LPG to waxy paraffins. The process itself consists of mainly 3 steps, syngas production through steam reforming or partial oxidation, liquid production through Fischer-Tropsch (F-T) reactions with cobalt or iron-based catalyst followed by product updgrading through mild hydrocracking to convert high molecular weight waxes to LPG, naphta and diesel.