China has abundant coal and extensive experience with coal gasification, going back over many years, predominantly for production of chemicals. Indeed coal gasification can be seen as a key part of the Chinese chemicals industry and crucial to its future growth. A very wide range of gasifier types are employed, both indigenously-developed and imported.*
There are already a few gas turbines running on syngas, for example, at coal-from-chemicals facilities operated by the Yankuang Corp (Yulin) and the Cathy Coal Chemicals Co (Guotai) (both employing indigenously developed ICCT OMB gasifiers), and at the Fujian oil refinery (Shell gasifier technology). But coal based IGCC and polygeneration, as elsewhere in the world, have yet to take off in a big way in China.
Several IGCC and polygeneration facilities were scheduled to be constructed during China’s 11th Five Year Plan period (2006-2010) and there were indications that further such facilities might feature in the 12th Five Year Plan (2011-2016), currently under preparation.
At one time there were thought to be around a dozen IGCC/polygeneration projects at various stage of planning, but few seem to have survived, with key people in the Chinese government believing the technology not to be cost effective compared with large supercritical PC plants, which the Chinese can build very quickly and relatively cheaply.
The China Power Investment Corp has been reported to have ambitious plans in the arena of coal fuelled IGCC, including a 2 x 400 MW project at Langfang, Hebei, and a 4 x 400 MW project reportedly proposed for the Binhai Port Area of Yangcheng City, Jiangsu.
In Guangdong, at Dongguan, the first phase of relatively small coal fuelled IGCC is understood to be under construction, in the form of a repowering project. This first phase, due to be commissioned in February 2011, consists of converting two oil fired 60 MW turbines to run on syngas from a gasifier. The gasifier design in this case is not Chinese, but uses Transport Integrated Gasification (TRIG) technology developed by KBR and Southern Company, with DoE support, in the USA. In September 2009 KBR announced it had been awarded a contract by Beijing Guoneng Yinghui Clean Energy Engineering Co, Ltd. to provide licensing, engineering services and proprietary equipment for the project, which is the first commercial implementation of TRIG. The project, known as the Dongguan IGCC power plant, is, according to the KBR press release of September 2009, envisaged as the first phase of what will eventually be a 920 MW IGCC, to be called the Sun State IGCC power plant, to be developed by Beijing Guoneng.
Pratt & Whitney Rocketdyne (PWR) also has hopes that China might host another first of kind project involving novel gasifier technology originating in the USA, namely the first full scale demonstration of the PWR compact gasification concept, under a joint venture agreement between ZEEP (Zero Emission Energy Plants Ltd), an entrepreneurial US based clean energy facility developer, and China’s ENN Research & Development Co, Ltd. The plan, says ZEEP, is to build a 400 t/d demo gasifier at an existing ENN facility in Zaozhuang City, Shandong, followed by a commercial scale 1500 t/d plant.
A coal-fuelled IGCC, of 200 MWe installed capacity, was planned for Huadian’s Banshan site, Hanghzhou, Zhejiang, but this project has been cancelled. This facility was to have employed a 2000t/d dry-feed gasifier of the OMB (opposed multi-burner) design, also developed in China, by ICCT (Institute of Clean Coal Technology) / ECUST (East China University of Science and Technology), with a gasification temperature of 1310°C and a pressure of 4 MPa.
In fact, the only large scale IGCC currently under construction in China is GreenGen Phase 1, near Tianjin – and even the schedule for this project has been put back by two years. Nevertheless construction is now underway, with an inauguration event in mid 2009, and commercial operation scheduled for late 2011/early 2012.
The idea is that GreenGen, a joint venture led by Huaneng (51% holding), with seven other shareholders (Datang, Huadian, Guodian, China Power Investment Corp, Shenhua, SDIC, China Coal, each with 7%), will eventually incorporate carbon capture and storage. But the first phase of the project, which has Asian Development Bank funding, consists of a ‘conventional’ bituminous coal fuelled 250 MW IGCC plant, employing a Siemens E-class (V94.2) gas turbine. The plan is to subsequently upgrade to produce hydrogen and to run a fuel cell facility as well as a hydrogen fired turbine, with an eventual installed capacity of 400 MW, with CCS also incorporated.
The 2000 t/d dry-feed gasifier is of an air-blown two-stage type developed in China by TPRI (Thermal Power Research Institute), which is owned by Huaneng (52%), plus Huadian, China Power Investment Corp, Datang and Guodian (12% each). It operates at a pressure of 3-3.5 MPa, with a syngas flow rate of 165000Nm3/h.
Intriguingly, there has also been a proposal to use the same technology in a 270 MW anthracite fuelled IGCC plant proposed in the USA – the Good Spring project.
Towards a standardised IGCC plant?
Meanwhile, on the vendor side, GE remains optimistic that, in the longer term, its IGCC offering could eventually play a role in China, building on the success of its gasification technology (which was acquired from ChevronTexaco six years ago) in the Chinese chemicals-from-coal sector, with some 44 facilities now licensed there.
In April GE and CPECC (China Power Engineering Consulting Group Corporation) signed agreements with the US Trade and Development Agency (USTDA) under which USTDA will fund a feasibility study on commercial scale IGCC plants for the Chinese market based on GE technology. In the initial study phase, GE and CPECC will evaluate cost and performance of an IGCC design, one aim being to determine the appropriate configuration and block size for China. This may help to establish an “IGCC template for China”, says Monte Atwell, general manager, gasification, GE Power and Water. He points out that this has been the process followed by China for other technologies, notably pulverised coal power stations. A template is established, initially a 300 MW plant size in the case of pulverised coal, and then widely adopted throughout the country.
The April agreements follow the memorandum of understanding signed between CPECC and USTDA in November 2009 as part of the US-China Clean Energy Announcements made by President Obama and President Hu. At the same time an MoU was also signed by GE and Shenhua, the world’s biggest coal company (which has extensive experience in building and operating gasification facilities and coal-fired power plants), with the aim of establishing a gasification joint venture. Key aims of the JV include improving the economics of gasification and IGCC, as well as deploying commercial scale IGCC plants with carbon capture.
An important reference for GE’s technology is Duke Energy’s IGCC plant currently under construction at Edwardsport, Indiana. One of the plant’s largest components, the radiant syngas cooler, which sits below the gasifier, was shipped to site last year from Belleli in Italy (which also supplied the RSC to the Polk IGCC plant 15 years ago), while shipments of the two 7F syngas gas turbines were announced in April 2010.
At 618 MW the Edwardsport dual train 60 Hz plant will be the world’s largest IGCC facility when it comes online in 2012. It is also designed to be “capture ready”, retrofittable with what GE calls its Carbon Island.
Of particular interest to the Chinese, with their 50 Hz grid, would be the 50 Hz 400 MW IGCC design, employing a 9F syngas turbine, being developed by a consortium of GE and Stanwell for the proposed Wandoan project in the Surat Basin, Queensland, Australia, with a target commercial operation date of 2015. This is a candidate for funding under the Australian government’s CCS Flagship Program.
What is now GE’s IGCC technology was also used in two other milestone projects, the Coolwater pilot IGCC plant in Barstow, California, and Tampa Electric’s 250 MW Polk station, which has been operating since 1996.
Gasification is well established in the chemicals sector, but GE’s key motivation for purchasing the Texaco gasification technology back in 2004 was the potential it saw for IGCC as a pathway to future clean coal power generation, not the chemicals side of the business. The latter has nevertheless proved to be robust, with a healthy number of GE licensees (another five licensing agreements being announced at the end of May 2010). This revenue stream has enabled the concept of gasification to maintain momentum, even though the number of IGCC plants in operation around the world remains stubbornly small, key issues being cost, reliability and complexity.
GE saw its purchase of the ChevronTexaco gasfication technology as an opportunity to really get to grips with improving the integration of the G part of IGCC with the CC part, resulting in a fully optimised power plant design with better buildability, performance, operability, and economics.
Recent GE developments aimed at reducing overall project costs include a larger scale quench gasifier and higher gasifier pressures.
Building on experience at Polk the radiant syngas cooler configuration and materials have been improved, resulting in 30% more steam from a smaller package, with internal quench. Other improvements include: use of Mark VIe control system; feed injector modifications to increase performance and extend life; better refractory performance through analysis of damage mechanisms and better understanding of slag effects; and enhancements to the 7F and 9F syngas turbines.
CCS: the new driver
GE also sees the growing emphasis on carbon capture and storage as a major new driver for IGCC, both in China and elsewhere, and regards IGCC as “carbon ‘capture ready’ today.”
GE estimates that about 17% of the carbon dioxide in the syngas can be removed by enhancing the acid gas removal system (typically Selexol based), without a shift reactor. “Natural gas equivalency” – 50-65% removal – can be achieved by adding a single stage shift with CO2 separation, while 90% removal is achievable with dual (or more) shift stages plus CO2 separation.
GE’s Carbon Island is a package designed to be fitted in an allocated plot space on the IGCC site, with a shift reactor integrated with the existing low temperature gas cooling system, upgraded acid gas removal system, and carbon dioxide enrichment and compression. For a two train 800 MW 50 Hz IGCC plant, with 65% carbon capture, output drops to around 700-740 MW and efficiency drops from about 38-40% to 30-35%, but it gives a coal fuelled plant a carbon footprint similar to natural gas.
In the words of Jason Crew, product line leader, gasification and IGCC, GE Energy, China, IGCC is potentially “the new face of coal.” Whether China wants to take a leadership in this area, which it certainly could, remains to be seen.
