A Novel Method of Removal of Nitrogen and Sulfur by Use of Nanoparticles Containing Composites Produced from Inexpensive Raw Materials

利用廉价原材料生产的含纳米颗粒的复合材料去除氮和硫的新方法

• 批准号: 11218202
• 负责人: OHTSUKA Yasuo
• 金额: $ 20.22万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11218202/
• 关键词: Nanoparticles; Carbon composites; Nitrogen removal; Sulfur removal; Hot gas cleanup; ナノ微粒子複合体; 石炭

This project has been performed to develop a novel method of removing nitrogen and sulfur by using nanoparticles containing composites, which are produced from inexpensive raw materials, from a viewpoint of hot gas cleanup for an integrated gasification combined cycle process. The main achievements are summarized as follows :(1) Nanoscale Fe particles on coal chars, prepared by carbonizing brown coals with externally added Fe ions, show higher activity in the catalytic decomposition of NH_3 to N_2 than Fe catalyst loaded on a commercial activated carbon, when 2000 ppm NH_3 diluted with He is fed at a high space velocity of 45000 1/h.(2) The TEM, XRD and TPD measurements strongly suggest that the highly dispersed Fe particles play the crucial role in NH_3 decomposition and catalyze this reaction through a cycle mechanism involving α-Fe and the nitride species(3) Some chars, prepared by simply pyrolyzing low rank coals with significant amounts of Fe and Ca cations naturally present as minerals, also work efficiently as the catalysts, and there is a strong correlation between NH_3 conversion and Fe content in char.(4) The char with the largest content (2 wt%) of inherent Fe provides the stable conversion of 80% during 25 h reaction at 750℃ and achieves complete decomposition of NH_3 at 850℃.(5) When NH_3 decomposition is carried out in the presence of 2000 ppm H_2S, CaO in the char is completely deactivated to form CaS, but Fe particles in it are still active, showing that the char can realize the removal of sulfur compounds and the catalytic decomposition of NH_3 simultaneously.(6) The coexistence of syngas, a mixture of CO and H_2 with the molar ratio of 2 : 1, lowers the activity of the Fe catalyst, whereas the addition of C0_2 to syngas restores the performance to the original state without syngas, which suggests that some chars can be utilized in an actual hot gas cleanup process.

本课题从整体气化联合循环工艺的热气净化的观点出发，开发了使用廉价原料制造的含有纳米粒子的复合材料的氮、硫的去除新方法。（1）在空速为45000 l/h的条件下，以褐煤为原料，外加Fe离子制备的纳米Fe/煤焦催化剂，在2000 ppm的NH_3和He稀释液中催化分解NH_3制N_2的反应中，表现出比活性炭负载Fe催化剂更高的活性。(2)TEM、XRD和TPD研究表明，高分散的Fe颗粒在NH_3分解中起着关键作用，并通过α-Fe和氮化物物种的循环机制催化NH_3分解。（3）由低煤阶煤热解制备的一些煤焦也可以作为有效的催化剂，其中含有大量的Fe和Ca阳离子。NH_3转化率与半焦中Fe含量之间存在较强的相关性。(4)在750℃下反应25 h，固有铁含量最高（2wt%）的半焦转化率稳定在80%以上，850℃时NH3完全分解。(5)在2000 ppm H2S存在下进行NH3分解时，半焦中的CaO完全失活生成CaS，但其中的Fe颗粒仍具有活性，表明半焦可以同时实现脱除硫化合物和催化分解NH3的作用。(6)CO和H_2摩尔比为2：1的合成气的共存降低了Fe催化剂的活性，而向合成气中加入CO_2则使催化剂的性能恢复到没有合成气时的原始状态，这表明某些半焦可以用于实际的热气体净化过程。

项目成果

Y.Ohtsuka, C.Xu, D.Kong, N.Tsubouchi: "Decomposition of ammonia with iron and calcium catalysts supported on coal chars"Fuel. 82(In press). (2003)

Y.Ohtsuka、C.Xu、D.Kong、N.Tsubouchi：“用煤焦负载的铁和钙催化剂分解氨”燃料。

多賀谷英幸, 進藤隆世志, 大塚康夫, 玉井康文, 門川淳一: "有機資源化学"朝倉書店. 150 (2002)

Hideyuki Tagaya、Takayoshi Shindo、Yasuo Otsuka、Yasufumi Tamai、Junichi Kadokawa：《有机资源化学》朝仓书店 150 (2002)。

Y.Ohtsuka: "High temperature decomposition of ammonia with low rank coal chars"Amer. Chem. Soc. Div. Fuel Chem.. 47(2)(To be presented). (2002)

Y.Ohtsuka：“氨与低阶煤焦的高温分解”Amer。

Y.Ohtsuka, C.Xw, D.Kong, N.Tsubouchi: "Catalytic decomposition of ammonia with iron nanoparticles supported on carbons"Amer. Chem. Soc. Div. Fuel Chem.. 46・1. 151-153 (2001)

Y.大冢，C.

Y.Ohtsuka: "High catalytic performances of low rank coal chars in ammonia decomposition at high temperatures"Amer.Chem.Soc.Div. Fuel Chem.. 48(In press). (2003)

Y.Ohtsuka：“低阶煤焦在高温氨分解中的高催化性能”Amer.Chem.Soc.Div。