The Huaneng Clean Energy Research Institute (HCERI) was formed from the China Huaneng Group’s Thermal Power Research Institute (TPRI) to focus on clean coal power generation and renewable generation technology. TPRI’s former development work on a two-stage gasifier transferred to HCERI, along with the Chinese GreenGen project (see below). HCERI and its forerunner TPRI have developed and patented gasification technology that is being used in numerous gasification facilities throughout China.
HCERI gasification technology is characterized as an entrained flow, dry feed, oxygen-blown, water wall-cooled, slagging gasifier system with quench. In the operation of this gasifier, 75-85% of the design feed rate of coal, along with steam and oxygen, are injected into the first stage. The resulting exothermic reactions raise the internal temperature to 1400-1500°C. The resulting heated mixed stream of solids and gases enters the second stage along with up to 25% of the design coal feed and steam, initiating an endothermic reaction that generates the mixed gas stream exiting the second reaction chamber. The temperature of the outlet syngas is decreased to 900°C due to the second stage's endothermic reaction - helping the slag particles to solidify, as well as improving the gasifier's thermal efficiency. The hot gas stream leaving the second stage passes into and through either a syngas cooler or a syngas quench system.
The advantages of the two-stage HCERI gasifier are reported to be as follows:
- High fuel flexibility – petcoke to lignite
- Low maintenance: Membrane wall – 20 years, Burners – 10 years
- Second stage fuel or quench reduces oxygen (O2) consumption
- Wide pressure range (0.5 – 4 MPa) provides operating flexibility
- Minimal gas recycle required for gas cooling
- Dry feed: low O2 consumption and high cold gas efficiency > 83%
- Carbon monoxide (CO)+hydrogen (H2) content of syngas > 90%
- Carbon conversion > 99%
The gasification technology can be applied to various feedstocks, such as petcoke, and low quality coals with high sulfur content. Commercially available sulfur capture equipment can effectively remove up to 99.9% of the sulfur from a gasification gas stream, ensuring the plant's environmental compliance.
Demonstration and Early Commercialization
Since the 1990s, TPRI and later HCERI had as a major focus the development of an entrained flow, dry feed, oxygen blown, slagging, two-stage, membrane wall gasifier. The technology evolved as follows:
- First Stage – Theoretical research and simulation (1993 ~ 1997)
- Second Stage – Bench-scale experiments, maximum feed capacity of 0.7 tons/day (1997 ~2001)
- Third Stage – Pilot-scale experiments in a system with throughput capacity of 36 tons/day (10Mwth) (2001 ~ 2005)
- Fourth Stage – Demonstration/commercial gasifier at feed capacity of 2000 tons/day (2005 – present)
The government of China's Ministry of Science and Technology (MOST) funded the latter large-scale trials, and supported China Huaneng Group and its industry partners in developing the GreenGen IGCC project, a 2,000 tons-per-day advanced coal power plant which began producing 250 MW of electricity to the Tianjin area of China in early 2012. The Shilin methanol plant in Inner Mongolia converts 300,000 tons-per-year (TPY) of coal to methanol. The plant began operations in early 2011.
In addition to these plants already in operation, HCERI gasifiers are currently being deployed into several commercial gasification plants that are in various stages of completion. The Manzhouli methanol project, in Inner Mongolia, will convert lignite to methanol (producing 600,000 TPY), and is expected to start-up in 2014. The Xinsheng methanol project, in Xia County, Shanxi, will have an annual production capacity of 300,000 TPY from bituminous coal conversion, and anticipates start-up in late 2014. The Huaneng Group synthetic natural gas (SNG) project, in Zhundong, Xinjiang, will produce 4 billion m3/y of SNG from bituminous coal by late 2014, using eight HCERI gasifiers each with 3300 tons/day coal capacity.
A projection suggests that HCERI gasifier-based projects will cumulatively be utilizing 37,600 tons of coal per day to produce 2,600 kt/y methanol, 400 kt/y olefins, 4.0 billion m3/y SNG and 250 MW IGCC power in China. Existing and planned gasification projects using HCERI gasifiers are tabulated in the China Gasification Database.
Some years ago, rights to HCERI gasification technology had been acquired by EmberClear, Inc. in the United States. The plan was for EmberClear’s 270 MW IGCC project located in Good Springs, Pennsylvania to utilize a 2000 tons/day HCERI gasifier. However, the IGCC project was dropped in May 2012, when the developer opted for developing a natural gas combined cycle plant instead.
- Peckham, Jack, "China Huaneng Gasification Technology Nabbing More Projects," Gasification News, Vol. 14, Issue 10, May 8, 2011.
- Lui, Ke; Song, Chunshan; Subramani, Velu; Hydrogen and Syngas Production and Purification Technologies, American Institute of Chemical Engineers, 2010, pg. 198-199.
- Zhimin Huang, Jiansheng Zhang, Guangxi Yue, “Status of domestic gasification technology in China,” Front. Energy Power Eng. China 2009, 3(3): 330–336
- Coal Gasification in China-A Study Report