New build: recession will sort the sound from the merely marginal

1 January 2009

This year’s Gasification Technologies Conference was held in Washington, DC, 5 – 8 October. Chris Higman, who also visited the PCC, reports.

This year’s Gasification Technologies Conference, which took place in Washington, DC, USA, 5-8 October, was held against the background of dramatically deteriorating conditions in financial markets and an unprecedented drop in the price of oil. Nonetheless the mood among the 1000 or so attendees remained confident, although the euphoria of the previous year or two has certainly been replaced by a degree of realism.

Gasification projects tend to be capital intensive and a lack of available finance is bound to affect some of them – particularly those that might have been doubtful anyway. But many of the more serious projects have made good progress during the last year.

Against the background of a significantly expanded exhibition area, Ross Fava of Shell, this year’s GTC Chairman, commented that the conference had had a greater international response then ever before.

Availability improvements

Although plant availability was not the focus of any of the individual sessions, it was interesting to observe how often the topic was raised – in almost all cases as a matter of achievement in improving plant on-stream time. For some time low availabilities have been regarded as an Achilles heel of IGCC technology. At the GTC in 2005, this correspondent reported the results of a study into actual availability of operating IGCCs. The report pointed out the extent to which outages were attributable to the power block and also noted that many outages in other parts of the plant were due to poor execution rather than a cause fundamental to the technology.

One of the most remarkable achievements in this area has been reflected in the start up of the Clean Coal Power 250 MWe Nakoso IGCC in Japan (Figure 1), which uses Mitsubishi Heavy Industries’ dry feed air-blown gasification technology and an MHI 701DA gas turbine. The gasifier was started for the first time in October 2007. After a number of part load tests, the first full load operation of the power plant with a load rejection test was made in March 2008. A long term continuous operation test of 2039 hours was completed between June and September 2008. A 5000 hour durability test is planned for 2009.

Saras reported an extremely impressive set of numbers showing the sustained reliability of its refinery-residue-fired 500 MWe IGCC in Italy. The plant has achieved an availability of 90% and higher over each of the last five years.

GE showed data from seven Chinese plants started up two to three years ago. The average availability was about 93%. The best performance was by a plant achieving a reliability of 98%. Shell also displayed data from two plant with reliabilities in the 90% plus region.

In discussions outside the formal presentations, your correspondent learned that Nuon had this year operated its Shell designed Buggenum plant in The Netherlands for over 4000 hours without interruption.

Clearly in the matter of reliability, availability and maintenance, the feedback of lessons learned from the 1990s generation of IGCC is having the positive effects predicted. Nonetheless securing such performance remains a matter of attention to detail throughout the life cycle of the plant, and recording improvements cannot be taken as a signal to relax.

Power generation projects

Duke Energy’s 630 MWe Edwardsport, IN power project (Figure 2) continues to lead US IGCC developments. While the design of the plant is based on the GE-Bechtel Alliance reference plant, the project execution plan has departed significantly from the “total wrap” concept originally developed by the Alliance to meet power industry demands. The total wrap concept has proved to be simply too expensive. The revised contracting strategy is a blend of cost reimbursable, target cost and lump sum pricing, with Duke Energy Indiana managing the project and holding the escalation and warranty risk. Duke is also managing all outside battery limits (OSBL) facilities itself. For a large utility accustomed to buying natural gas combined cycle units and managing the balance of plant with its own resources, this makes more sense than a total wrap around the whole facility. The major aspect likely to be unfamiliar – gas production and treatment – are still included in a single wrap with a scope typical of what many medium size EPC contractors provide regularly into the chemical industry.

The project execution is progressing well with much of the key equipment already on order. Permitting is essentially completed, though studies on retrofitting CO2 capture and storage have been required and are ongoing. Detail engineering progress to end of September was 18%. Overall site grading is ongoing with the piling contract due for award at the end of October. Projected commercial operation is due for summer 2012.

Excelsior’s Mesaba project in Minnesota continues its over five year path through the permitting process. Initial work on this project began in 2004. The final decision by the Public Utilities Commission is anticipated in the second quarter of 2009 and draft permits will be issued for public comment shortly thereafter. In the meantime, like Duke Mesaba is having to address its response to the CO2 sequestration issue.

CO2 capture and storage

As mentioned above new projects such as Edwardsport and Mesaba are being required to demonstrate a CO2 capture and storage plan. These are not the only projects addressing the issue. Although there is no obligation at this point in time to do so, Saras also reported on a recent study it had performed to retrofit its 500 MWe IGCC with CCS. It investigated two cases: one capturing the CO2 in the syngas only and a second case with two-stage shift, enabling 85% capture. While the first case did not appear attractive, the second case could be viable depending on the price of CO2. At present this study would appear to be a precautionary measure, pending the outcome of current deliberations on EU climate policy for the post-Kyoto period.

Meanwhile EPRI, co-sponsors of the conference, announced that it was seeking three projects to capture and sequester CO2 in IGCC plants. The first project to capture 10-20% of the CO2 from syngas at an existing IGCC is scheduled to complete engineering by mid-2010 with implementation and demonstration thereafter. The second and third projects are looking for 40-70% (natural gas equivalency) and 80-90% (full capture) respectively, probably at new plants. The engineering on these projects is planned to extend into 2013. These projects are part of a wider initiative including demonstrations in such fields as “smart grids”, solar power and other clean coal technologies. The purpose of these demonstrations is to reduce risk and advance understanding of the issues surrounding an integrated IGCC-CCS operation. It is also envisioned that these projects will help accelerate the development of design guidelines for capture, transport and storage of CO2.

Another ‘real life’ CCS project was presented by Australia’s ZeroGen. This project, which is owned by the Queensland government, is planned in two stages. The first stage, scheduled to go on stream in 2012 is a 120 MWe power plant based on Shell gasification technology and a GE Frame 6F gas turbine. About 75% of the CO2 emissions will be captured with partial sequestration at a location approximately 140 miles from the plant. The learnings from stage one of the project will then flow into the second stage, which is planned as a ~450 MWe plant with up to 90% capture. The on-stream date is slated as 2017.

Gasification in China

Gasification continues to flourish in China, although one should always remember that with the rate of development in that country, gasification still represents only a small portion of a very large market. ECUST-ICCT reports a total of 13 projects and 33 gasifiers with their OMB technology, mostly for ammonia or methanol plants. Interestingly this now includes one dry-feed membrane wall reactor, due to come on stream in 2010. Further they have developed a radiant boiler for use in an IGCC downstream of a 2200 t/d gasifier. the first plant with this configuration is also due to start up in 2010. With this impressive commercialisation after the start of the first demonstration unit in 2005, it can only be a matter of time before the technology starts appearing in other parts of the world.

Other technologies are also showing success in the Chinese market. The first two 500 MWt Siemens gasifiers were shipped in May and have now arrived at the Shenhua Ningxia site (Figure 3). Another two are to follow before the end of the year. At another Shenhua site, at Erdos, Inner Mongolia, the two Shell gasifiers providing the hydrogen for the direct coal liquefaction plant have been taken into service successfully (Figure 4). Four 500 t/d GE gasifiers were also started up by Shanghai Coking, doubling the size of their Huayi facility.

Coal-to liquids

An interesting development in the coal-to-liquids area was the change in product slate announced by DKRW for their Medicine Bow, WY, project. When this project was originally presented at the 2006 conference, it was one of a number of US projects planning to use Fischer-Tropsch technology to produce a sulphur-free diesel. This choice of product for a US location had always seemed odd, given the fact that the US is a major exporter of diesel to Europe, and imports European naphtha in return. During the course of the last two years, the project has developed considerably and in doing so the product has changed to gasoline, to be sold into the Denver market. The technology to be used is ExxonMobil’s methanol-to-gasoline (MTG) process. A 14500 bbl/d commercial facility has been commercially operated in New Zealand and another plant is under construction in Shanxi, China.

Product development and new technologies

The established gasification technology vendors continue to develop their market offerings. GE announced its 1800 ft³ 1000 psig (2700 t/d, 70 bar) quench gasifier for chemical applications. It was however left unclear, whether this product will be made available in the power market, where the 1800 ft³ gasifier with radiant cooling and quench is currently offered as the standard or reference configuration. It would be a pity if the 1800 ft³ quench unit were not available for power applications, since it is like to prove particularly attractive for carbon capture applications. In another GE paper a dry feed capability based on the use of the Stamet pump was announced. This will be developed at a new gasification research facility to be built at the University of Wyoming.

With GE’s acquisition of Stamet, the potential benefits of using a “solids pump” for reducing the costs of dry feeding appeared to be lost to other technology suppliers. This increased the importance of Pratt & Witney Rocketdyne’s development of a similar piece of equipment. This work is taking place at the Energy and Environmental Research Center (EERC) in North Dakota and is partly being funded by ExxonMobil. Engineering tests were started in 2008 and testing of a 400 t/d pump is expected to begin in 2010.

Uhde followed up on their surprise announcement earlier in the year that Prenflo was to be marketed separately from its Shell cousin. Uhde and Shell had been marketing the two technologies jointly under the Shell banner, but the need to develop a quench version as a response to CCS requirements has led to very different approaches. Shell’s partial quench, reported on last year, takes a conservative line in retaining as much of the original concept as possible. Uhde have been much more radical

in developing their Prenflo Direct Quench (PDQ) process. The existing dry feed burner/membrane wall configuration has been retained, but the burners have now been located at the top of the gasifier. The syngas flow is downwards into a quench bath. The result looks much like a side-fired Siemens gasifier. It will certainly require much more capital than the original upflow design used at Puertollano, Spain, and Uhde claims already to have sold fifteen 1000 MWt units.

This year the Pittsburgh Coal Conference was held the week before the GTC conference, so that your correspondent took the opportunity to visit both. There were a number of interesting papers including one from MHI revealing some of the details of their Nakoso project. In particular MHI has developed its own process for COS hydrolysis using a proprietary monolithic catalyst. This catalyst is insensitive to halide poisoning and so can be placed upstream of the water wash. The result is a minor saving on steam consumption, one small contribution to efficiency improvements.

Sorting the sound from the marginal

The difficulties currently being experienced in the financial world will no doubt have the effect of sorting out the sound and robust projects from those that were in any case only marginal. However financing difficulties do not appear to be having an impact on the good projects, so that we can expect more development over the next year.

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