Mathaba Machodi
Institute for Catalysis and Energy Solutions, University of South Africa, Pioneer Ave, Florida Park, Roodepoort, 1709, South Africa.
Sci Rep. 2024 Sep 27;14(1):22153. doi: 10.1038/s41598-024-73553-y.
Ammonia co-firing with coal seems to be the preferred approach to reduce unburnt carbon in existing pulverized coal-fired power plants. However, some operational conditions such as combustion temperature need to be carefully considered. As such, this study investigated the effect of combustion temperature on the unburnt carbon during ammonia co-firing with pulverized coal. Horizontal tube furnace with ammonia injection was employed and operating at different combustion temperature (800 to 1200 C). Proximate analysis results showed that the raw coal sample contained 64.2 wt% fixed carbon. Additionally, based on the several analyses employed to assess the effect of combustion temperature efficacy on the unburnt carbon reduction, an effective combustion efficiency was achieved with ammonia co-firing with coal. X-ray fluorescence results revealed that SiO for the co-firing experiment decreased from 56.7476 wt% (800 C) to 45.9423 wt% (1200 C) while carbon decreased from 20.06 to 18.32 wt%, at the same combustion temperature respectively. X-ray diffraction also revealed a well-defined peak at 2θ = 25, a graphite characteristic, which decreased significantly with increasing temperature, signifying unburnt carbon reduction. Thus, it can be confirmed that ammonia co-firing with coal can be used to improve the combustion efficiency coal fired power plants.
氨与煤混烧似乎是降低现有煤粉发电厂未燃尽碳的首选方法。然而，一些运行条件，如燃烧温度，需要仔细考虑。因此，本研究调查了燃烧温度对氨与煤粉混烧过程中未燃尽碳的影响。采用了带氨注入的卧式管式炉，并在不同燃烧温度（800至1200℃）下运行。工业分析结果表明，原煤样品含有64.2 wt%的固定碳。此外，基于用于评估燃烧温度对未燃尽碳减少效果的多项分析，氨与煤混烧实现了有效的燃烧效率。X射线荧光结果显示，在相同燃烧温度下，混烧实验中SiO从56.7476 wt%（800℃）降至45.9423 wt%（1200℃），而碳从20.06 wt%降至18.32 wt%。X射线衍射还显示在2θ = 25处有一个明确的峰，这是石墨的特征峰，随着温度升高该峰显著降低，表明未燃尽碳减少。因此，可以确认氨与煤混烧可用于提高燃煤发电厂的燃烧效率。
