Teco and Texaco remain cautiously optimistic16 November 2001
Although gasification technology is yet to make a major impact in the power generation sector, its proponents remain confident that it has bright future - albeit in niche markets.
Gasification's shift to commercial electricity generation is underway", claimed Richard Ludwig, president, Teco Power Services, at this year's Gasification Technologies Council (GTC) annual conference (San Francisco, 7-10 October). "Although three quarters of the installed gasification facilities today are for chemical and fuel production", he noted, "nearly seventy per cent of the planned capacity is earmarked for electrical power generation." Nevertheless he acknowledged that progress to date has been very slow, with "barely a handful" of gasification power plants built over the last ten years. "This is a pretty dismal result for all of our efforts, I am afraid to say. By most all accounts, you'd have to conclude that this program has been a failure."
He believes that to get the technology moving, efforts are needed, including government action, to make gasification projects more bankable in a competitive generation market. The technology itself needs to achieve more standardisation, lower and more predictable costs, shorter construction times and higher reliability. Low gas prices have not helped the gasification cause, but recent gas price volatility has prompted some increased interest. Gasification has a particular advantage in the face of volatile gas prices because it enables lower-cost fuels to be used for clean power generation at much more predictable prices. Richard Ludwig thinks we are going to see more volatility and sustained higher gas prices in the future as the effects of high demand on finite gas resources come to be felt.
His company, Teco Power Services, has been a long-time champion of gasification for power generation, collaborating with sister company Tampa Electric on the 250 MWe Polk coal-fuelled integrated gasification combined cycle (IGCC) plant in the early 1990s (using Texaco gasification technology). Teco is currently "working on over a half-dozen gasification projects", of which "I would expect several to be successful," Richard Ludwig said.
CITGO Lake Charles IGCC
One TECO project that does appear to be making progress is the 670 MW CITGO Lake Charles IGCC, although its planned commercial operation date is not until January 2005. A separate TECO paper at the GTC conference (by R King) gave a project update.
The CITGO Lake Charles IGCC is being developed under a partnership between TECO Power Services (TPS) and gasification technology supplier Texaco Power and Gasification (TP&G).
The polygeneration plant is to be sited adjacent to CITGO's Lake Charles, Lousiana, complex, the sixth largest refinery in the USA. It will take petroleum coke (5000 t/d) and fuel gas (300-1400 MMBtu/h) from the refinery. Outputs will include 570 MW of electricity to power marketers and/or municipal utilities (via the Entergy grid), together with steam and hydrogen to CITGO Lake Charles and the adjoining CIT-CON petrochemical facility in the following quantities: HP steam equivalent to 96 MW; 1.9-2.4 million lb/h of 250/400 psig process steam; and 50-60 million standard cubic ft/d of hydrogen.
Gasification block ownership will be split 50:50 between TP&G and TPS, while power block ownership will be 43 per cent TP&G, 43 per cent TPS and 14 per cent CITGO. Project financing is permanent non-recourse.
The proposed CITGO Lake Charles IGCC plant will use three Texaco quench gasifiers, three GE7FA gas turbines, three heat recovery steam generators and two steam turbines.
The preliminary engineering is due to start in February 2002, with Bechtel and Fluor contracted for early engineering work. CITGO, TPS and TP&G are currently working on value improvement practices.
The project received a favourable review from the Louisiana Public Service Commission in March 2001 and the air permit application was filed in September.
Texaco re-energises its gasification efforts
CITGO Lake Charles is one of a number of gasification projects that Texaco is currently looking at in the USA and Canada, but the company is realistic about the fact that gasification is a niche technology and that only a percentage of these projects will come to fruition.
Nevertheless, Texaco remains bullish about the prospects for gasification, particularly in two areas which it sees as growth markets: refinery-based poly-generation; and clean coal-based stand-alone power, in which there has been a resurgence of interest.
According to a presentation at the GTC conference by Texaco's William E Preston, the company has "aggressively re-energised its pursuit of deploying gasification in the coal-fed power market in selected areas." Texaco is also undergoing a transition from mainly a process licensor to mainly a developer/owner/operator of gasification and power projects, and is "now actively seeking opportunities to be an equity partner in many gasification projects around the world."
William Preston reported that, in terms of capacity additions per decade, the gasification business has been growing geometrically and "much of the growth is attributable to the application of Texaco gasification for power generation." However, the number of plants is relatively modest and part of the reason for the surprisingly rapid increase is the fact that power plant gasification projects tend to be bigger than petrochemical ones.
In the last 18 months, some thirteen projects using Texaco gasification technology have started up, five of them cogenerating electricity and steam.
Three of these power projects, API Energia, ISAB and SARAS, are in Italy, enabling refiners to use their high sulphur petroleum streams and benefiting from Italian price incentives for IPPs using indigenous fuels. The ISAB project achieved final acceptance in January 2001, API Energia in April 2001 and SARAS in July 2001.
The fourth power project, which also went commercial in July 2001, is in Singapore at an ExxonMobil refinery. Steam cracker tar is used to produce syngas, which powers a large on-site cogen plant.
The fifth power project is the Motiva Delaware City plant which is to gasify 2300 t/d of pet coke to produce 160 MWe and up to 1 million lb/h of steam. Syngas has been produced and transferred to its two GE MS-6001FA combustion turbines, but, according to William Preston, the "unit has been plagued by nagging startup problems and their resolution has been delayed by unrelated refinery problems that have diverted attention away from this plant." These issues are, however, expected to be dealt with soon.
While North America currently seems to be leading the field in terms of potential gasification power projects, there are still possibilities in Europe. For example feasibility studies for a refinery-based IGCC project at Gonfreville, Normandy, have been underway since 1998 under an agreement between TotalFinaElf, EDF and Texaco. The first phase of this project, the building of a gas fired cogen unit producing 260 MWe and 375 t/h of steam, is underway with operation due in 2003. However the feasibility of the next phase, the gasification part of the project, is still under study.
Meanwhile in Spain, there are plans to build an 800 MW IGCC adjacent to the Petronor refinery in Bilbao. This project, under development by PIEMSA, an affiliate of Petronor (one of the Repsol YPF group), would process refinery heavy stocks to produce electricity and hydrogen for refinery use. If built it would be the biggest project of its type so far. Feasibility studies of the project, as discussed at the Gasification Technologies Council conference in a paper by L Bressan of Foster Wheeler Italiana and L O'Keefe of Texaco Power and Gasification, have demonstrated its benefits. One advantage, relative to the gas turbine combined cycle (GTCC) option, is that investment costs account for a large percentage of electricity costs (see diagram, above right) while GTCC generation costs are very sensitive to volatility in fuel gas prices: "once the IGCC is built," say Bressan and O'Keefe, "considering that the heavy residues cost is approaching zero value, the investment cost for an IGCC is less exposed during its life to unpredictable events than a GTCC that always is subject to natural gas price variations."
It remains to be seen whether such arguments prove powerful enough for the PIEMSA IGCC project to get final approval to go ahead.