Development of a wide range-operable, rich-lean low-NOx combustor for NH 3 fuel gas-turbine power generation

Osamu Kurata, Norihiko Iki, Takahiro Inoue, Takayuki Matsunuma, Taku Tsujimura, Hirohide Furutani, Masato Kawano, Keisuke Arai, Ekenechukwu Chijioke Okafor, Akihiro Hayakawa, Hideaki Kobayashi

Research output: Contribution to journalArticlepeer-review

145 Citations (Scopus)


Low-NOx NH 3 -air combustion power generation technology was developed by using a 50-kWe class micro gas-turbine system at the National Institute of Advanced Industrial Science and Technology (AIST), Japan, for the first time. Based on the global demand for carbon-free power generation as well as recent advances involving gas-turbine technologies, such as heat-regenerative cycles, rapid fuel mixing using strong swirling flows, and two-stage combustion with equivalence ratio control, we developed a low-NOx NH 3 -air non-premixed combustor for the gas-turbine system. Considering a previously performed numerical analysis, which proved that the NO reduction level depends on the equivalence ratio of the primary combustion zone in a NH 3 -air swirl burner, an experimental study using a combustor test rig was carried out. Results showed that eliminating air flow through primary dilution holes moves the point of the lowest NO emissions to the lesser fuel flow rate. Based on findings derived by using a test rig, a rich-lean low NOx combustor was newly manufactured for actual gas-turbine operations. As a result, the NH 3 single fueled low-NOx combustion gas-turbine power generation using the rich-lean combustion concept succeeded over a wide range of power and rotational speeds, i.e., below 10-40 kWe and 75,000-80,000rpm, respectively. The NO emissions were reduced to 337ppm (16% O 2 ), which was about one-third of that of the base system. Simultaneously, unburnt NH 3 was reduced significantly, especially at the low electrical power output, which was indicative of the wider operating range with high combustion efficiency. In addition, N 2 O emissions, which have a large Global Warming Potential (GWP) of 298, were reduced significantly, thus demonstrating the potential of NH 3 gas-turbine power generation with low environmental impacts.

Original languageEnglish
Pages (from-to)4587-4595
Number of pages9
JournalProceedings of the Combustion Institute
Issue number4
Publication statusPublished - 2019


  • Carbon-free power generation
  • Low NOx combustion
  • NH -air gas turbine


Dive into the research topics of 'Development of a wide range-operable, rich-lean low-NOx combustor for NH 3 fuel gas-turbine power generation'. Together they form a unique fingerprint.

Cite this