Turning promise into reality: ground-breaking needed soon1 January 2007
Annual report from the US Gasification Technologies Conference, which has enjoyed a remarkable boom in delegate numbers in recent years, as interest in the technology continues to grow dramatically. What is needed now are a few ground-breaking ceremonies to mark the start of real projects.
The 25th annual Gasification Technologies Conference, jointly organised by the Gasification Technologies Council and EPRI, came to Washington this year for the second time. If the attendance at this year’s conference, which took place on 1-4 October, is anything to go by then gasification is in very good shape. The 941 registered attendees represent a 38% growth on last year, according to GTC Executive Director Jim Childress, who reported that he had had to turn away people wanting to speak at the conference, despite extending the length of the conference to a full three days, from the two and a half day format of previous years. This success had its noticeable side-effects in that the distribution of the printed papers and presentations provided at previous conferences could not be handled in such large numbers - but the proceedings were posted on the internet in record time (www.gasification.org).
The drivers for this high level of interest were similar to those of 2005, but most have become more powerful. In October 2005 the US Energy Policy Act had only been passed some two months before the meeting. A year later the numbers of applications for tax credits under this act was known: 45 of the 49 projects submitted were for coal gasification based systems, representing a total investment of 52 billion dollars and a potential tax credit volume of 4.6 billion dollars. Of these projects 18 were IGCC power plants, while the rest were other kinds of gasification based project. Given that the act only authorised 1.15 billion dollars of tax credits, it is clear that not all the projects will receive what they have applied for, but the volume of non-tax credit investment proposed is a good indicator of the interest in the technology.
IGCC projects in the USA
Twelve months is not a long time in the development of a large capital project such as a 600 MWe IGCC power station. Nonetheless the progress made by the projects announced last year is impressive.
Front end engineering design (FEED) is in progress and air permit applications have been filed by AEP for their Great Bend (Ohio) and Mountaineer (West Virginia) projects. Both these projects are using GE gasification technology and GE 7FB gas turbines based on the GE–Bechtel reference plant configuration.
The Duke (formerly Cinergy) project in Edwardsport, Indiana, is also using the GE–Bechtel reference plant configuration and progress is similar to that of the AEP projects. Permit applications have been filed. Approvals are expected in the third quarter of 2007 with construction beginning in the fourth quarter.
The Excelsior Mesaba project in Minnesota is using ConocoPhillips E-Gas Technology and two Siemens SGT5-500F gas turbines to produce 606 MWe and is at a similar state of development. The plant has been designed for a broad range of fuels including bituminous and sub-bituminous coals as well as a petroleum coke blend. Air and water appropriation permit applications were submitted in June 2006. Permitting is expected to be completed late 2007 with financial close in the first quarter of 2008.
A fourth project in an advanced state of planning is Southern Company’s 285 MWe Stanton demonstration project in Orlando, Florida. This project uses KBR’s air-blown transport gasifier and a GE 7FA gas turbine. The proposed fuel is Powder River Basin sub-bituminous coal. While this is surprising in view of the distance the coal will have to be transported, the project’s use of this material will demonstrate the use of a low-rank coal in the IGCC environment. The other technologically interesting aspect of the project is the fact that it is air blown. The gasifier operates in a non-slagging mode and at these temperatures (about 1000°C), the efficiency penalty in the gasifier for using air as oxidant is not so high as with a slagging gasifier. Furthermore for non-slagging gasifiers much more moderator is required to keep the ash below its fusion temperature and (particularly in the power application) nitrogen from the air is cheaper that the alternative of steam. Permit applications have already been submitted and approvals are expected for the first quarter of 2007. FEED will also be completed at about the same time, and equipment procurement is scheduled to begin in April 2007.
A new entry into IGCC was presented by NRG, with three projects at sites in the North East USA (New York, Connecticut and Delaware). These projects represent an interesting and more realistic approach to repowering existing sites than was being discussed at the conference two years ago, when the natural gas price started going up. At that time the repowering focus was on converting “stranded” natural gas fired turbines to operate on syngas. NRG is planning on building its IGCC’s at existing coal fuelled sites. Permitting a coal plant – however clean – on a site that was originally permitted for natural gas is so much more difficult and time consuming than “cleaning up” an existing coal-permitted site with IGCC, so that the latter is proving to be the route of choice. Another interesting and important aspect of these projects is that CO2 capture is included in the initial IGCC design. Clearly this will add to the cost of the projects now, but in the North East location it may be a key feature required to get the projects through the permitting procedures.
The project plans for these plants indicate that site activities will be starting for at least some of them by the time of next year’s conference. There is however a note of caution needed. The cost of plant construction has been increasing rapidly over the last year and a half. Since this is a general trend and not IGCC-specific, it is unclear how it will affect IGCC’s competitive position. What is clear however is that it remains a threat to all of these projects until final financial sanction has been approved.
A full session was devoted to carbon capture and storage. Although not part of this session, the most important statement on this issue came from Texas railroad Commissioner, Mike Williams, in his keynote speech. He revealed that the State of Texas would assume the liabilities from CO2 storage associated with the FutureGen project, should a Texas site be selected. This highlighted the most important issue challenging the whole “CO2 capture and storage” (CSS) concept as a strategy for addressing global warming. While CO2 capture, particularly in the IGCC configuration, is essentially proven technology, which only has a cost hurdle to overcome, the storage part is still a minefield strewn with additional problems such permitting, monitoring and verification, legal issues and most importantly public acceptance, all of which still need to be resolved. The process described by Scott Tinker for the selection of the Texas candidate sites for FutureGen showed how public support was being sought long before any decisions or even applications were made.
FutureGen Alliance CEO, Mike Mudd, gave an overview of where this government supported project stands now. Technically the plant will be a 275 MWe IGCC incorporating CO2 capture. It will use processes which will incorporate moderate step outs from existing technology, but ones that will still provide minimum risk to the overall mission of capturing and sequestering at least 1 million tons and up to a maximum of 2.5 million of CO2 per year. This plant will provide a full-scale “backbone” to which smaller “sub-scale” research units can dock in, with slip streams extracted from and returned to the main facility. Site selection is underway and the number of sites has been reduced from an initial 12 to a short list of four. Final site selection is expected in mid 2007.
BP presented an overview of its 500 MWe Carson “decarbonised power” project. Although sharing many similarities with the FutureGen project, its technical approach will be more conventional, incorporating only those step outs that are necessary for the project, such as two hydrogen fired GE 7FB gas turbines. The storage part is likely to be offshore EOR, a solution which will offer least problems in the realm of public acceptance.
Coal to liquids and other industrial applications
Last year’s initial interest in coal-to-liquids (CtL or Fischer–Tropsch) technology to produce synthetic diesel has continued, bringing forth a number of concrete projects. Rentech has announced two projects, both located on the Mississippi. In the more advanced project, at East Dubuque, an existing ammonia plant will be converted from natural gas to coal feed, whereby the gas production unit will be sized initially to feed an 1800 bpd Fischer–Tropsch unit. In a second phase the Fischer–Tropsch unit will be expanded to 6800 bpd. Construction of the new gas production facilities is slated to begin in 2007. While the scale of this project places it firmly in the demonstration category, Rentech has other projects of commercial scale (10 000-30 000 bpd) in the scoping and feasibility stages including a second Mississippi plant at Natchez.
A commercial scale mine-mouth project for 15 000 bpd at Medicine Bow, Wyoming, was presented by DKRW with start of construction scheduled for 2008. This is approximately the scale of a single train of the Oryx GtL plant recently commissioned in Qatar.
CtL market leader Sasol also indicated that it is pursuing further GtL and CtL projects, but pointed out that with these highly capital intensive projects, particularly with coal feed, one needs some assurance of a floor price of oil during the capital repayment period and suggested that some form of government assistance may be required for this.
The first synthetic ammonia plants built by Haber and Bosch used coal gasification for generating the syngas and this remained the usual method until the advent of steam reforming.
Agrium’s existing ammonia plant at Kenai, Alaska, is facing a diminishing source of natural gas and is turning to coal to provide an alternative source of synthesis gas, thus bringing ammonia syngas generation back to its roots. Feasibility studies have shown that this “re-fuelling” project is feasible at a size of 2600 t/d anhydrous ammonia with cogeneration of 62 MWe of export power.
Refineries and oil sands
The last year has seen the commissioning of the fourth Italian refinery-residue-based IGCC, which is located in ENI’s Sannazzaro refinery. It uses gasification technology licensed from Shell.
The start up duration from first light off to commercial operation was just under six weeks, after a four month commissioning period. The intensive effort made during commissioning to test all the instrumentation and ESD system was reported to have made a major contribution to this result – an observation that corresponds very much with my own experience. An interesting feature of the Sannazzaro plant design is the incorporation of a carbonyl removal system. It may take some time to see the effect of this measure, so that a future report on its long term performance would be useful.
The Canadian oil sands projects continue, and are in their engineering and construction phases. The first to come on stream will be the OPTI upgrader project, also using Shell technology, with start up slated for 2007. Those present at the conference saw some impressive pictures of the site. Apart from the sheer size of the project – particularly when one is reminded that the long term plan is to quadruple the output from the phase I 72 000 bpd to an ultimate 288 000 bpd by 2015 – technically interesting is that OPTI has announced its intention to process the partial oxidation soot with the Zimpro Wet Air Oxidation (WAO) process. There has been a need for a new, more economically attractive soot management system in partial oxidation units and it will be interesting to see how this new technological direction works out.
Other bitumen-based oil sands gasification projects include the North West Upgrader (Lurgi technology) and the Northern Lights (GE technology) projects. In the conference breaks there was considerable discussion about similar projects based on petroleum coke, but these seem to be taking longer to get off the ground – no doubt because of the larger capital investment requirement.
Black liquor gasification
Biomass gasification tends to suffer economically from its inherently small scale (typically < 50 MWt). This is not the case with the black liquor gasification process presented by Chemrec for which plant sizes of up to 300 MWt are expected in large pulp mills. The cost of bringing such large quantities of biomass to a central location is already covered by the pulp, which hosts the gasifier. The black liquor, which contains that biomass not usable in the pulp product, is usually burnt in a Tomlinson boiler. The Chemrec process replaces the boiler with a gasifier, which produces syngas and green liquor to recycle to the pulp mill. The syngas can be used for power production in an IGCC configuration or for the manufacture of liquid fuels such as methanol or DME. Chemrec announced that they had taken their technology from an atmospheric air-blown operation referenced at 50 MWt to an oxygen-blown pressurised operation at their 3 MWt pilot unit in Sweden. Plans for a 45 MWt demo unit to produce motor fuels in Sweden from about 2008 were discussed.
A session on China
A new feature of the 2006 conference was the devotion of one session to China. Given the rapid, coal-based growth in China, this promised to be an interesting session. In fact it turned out to be rather disappointing. Mostly it consisted of the leading international technology suppliers talking about their recent marketing successes in China. The one really interesting presentation was of the Chinese home-grown Opposed Multi-burner (OMB) gasification technology developed by the Institute of Clean Coal Technology at the East China University of Science and Technology. The most surprising aspect was the degree of commercialisation already achieved. A 1150 t/d coal feed gasifier supplying a methanol and power plant was started up started up last year with an on-stream factor of about 70%. A second, smaller unit was started up in December 2004. Orders for four further gasifiers in three plants are in the design phase. The original design used a slurry feed, but the pilot plant has been converted to dry-feed operation with either nitrogen or carbon dioxide as carrier gas. A commercial dry-feed plant is now in the design phase.
Future Energy secured
This was the first GTC conference since the Siemens acquisition of Future Energy in June 2006. The focus of Future Energy’s marketing has previously been China, as was evidenced by their contribution to the China session. Siemens presentations included descriptions of the gasification technology, but it is clearly too early to see an integrated package of the kind that GE has developed since its acquisition of the ChevronTexaco technology. Siemens is obviously working on a similar concept. A modular reference combined cycle unit is already available from Siemens and I expect that in a year’s time the integration efforts with the newly acquired gasification technology will become far more visible.
The reference plant concept has now been adopted by all the industry leaders. GE Energy claims 90% completion of its reference design and anticipates reducing the investment gap between IGCC and PC combustion from about 20% to about half of that.
New technological developments
Of the new technological developments presented, one is likely to lose its predicate of “new” in the coming year. That is the Japanese Clean Coal Power consortium’s dry-feed, two stage air-blown gasifier (see Modern Power Systems, January 2006, pp 29-32). A 250 MWe demonstration plant has been under construction at the Nakoso power station for the last two years and is due to be started up in 2007. The plant uses a Mitsubishi 701D gas turbine. First start up reports can be expected at next year’s conference.
Cost breakthroughs are promised by two technologies that deserve the new in their title. Both draw on science already applied in other industries. Pratt & Whitney Rocketdyne (PWR) are drawing on their experience in rocket engine technologies to develop a dry-feed plug flow gasifier with water quench in a fraction of the volume of existing gasifiers. In fact a 90% reduction in the gasifier volume is claimed. Currently an 18 t/d coal feed pilot plant is under construction at the GTI Flex Fuel test facility in Chicago.
While PWR uses conventional gasifier chemistry in its reactor, Alchemix has drawn inspiration from the steel and non-ferrous metal industry for its HydroMax technology. The HydroMax reactor operates cyclically between hydrogen generation (while steam is used to oxidise molten iron) and CO generation (while coal or other carbonaceous feed is used to reduce the iron oxide from the first part of the cycle). A small pilot plant has been operated at CSIRO in Australia. Diversified Energy Inc, an Alchemix licensee, is developing a near-term commercial-scale pilot demonstration facility.
It will be interesting to watch the progress of both these processes in their attempt to provide a new cost baseline in gasification technologies.
Turning promise into reality
All in all it was an encouraging conference for all those in the gasification industry, but it will need one or two ground-breaking ceremonies in the next twelve months to turn a lot of promise into reality.
AEP’s Great Bend AEP’s Mountaineer projects Excelsior’s Mesaba project Stanton, with an image of the proposed IGCC superimposed on a photo of the existing power plant (source: Southern Company) OMB process