Energy: Coal. 石炭熱分解の解明

統合された石炭ガス化複合サイクル(IGCC)は、従来の石炭火力発電システムよりも高い熱効率のため注目を集めています。IGCCシステムの熱効率を向上させるため、高度なIGCCや高度ガス化燃料電池複合発電システムが提案されました。
それはダウナー熱分解装置、バブリング流動層チャーガス化装置や上昇未反応チャー燃焼器からなる新規の3つを組み合わせた複合循環流動層(TBCFB)です。

Fig. 1

しかしながら、TBCFBでの熱分解の詳細な特徴はまだわかっていません。ダウナー熱分解装置内での石炭熱分解の振る舞いの詳細な知識は、TBCFB反応器の設計や操作において大切です。

当学科では、流動層予熱器を用いて約1173Kで予熱された熱運搬粒子(ケイ砂)と接触した石炭粒子を直接持ってくることが出来る新しい並列ダウナー熱分解装置が開発されました。これは石炭と砂の粒子を別々に供給する新しいダウナー熱分解装置です。砂の供給速度の増加は炭素表面堆積物の量およびCO2とCOの収率が増加しました。

この研究は環境エネルギー技術に役立ちます。

詳しくはFuel Processing Technologyをご覧ください。[文責:大学院1年MI]

PYROLYSIS OF LOW-RANK COAL WITH HEAT-CARRYING PARTICLES IN A DOWNER REACTOR

The integrated coal gasification combined cycle (IGCC) has received much attention because of its higher thermal efficiency than conventional coal-fired power generation systems .To increase thermal efficiency of the IGCC systems, advanced IGCC and advanced integrated gasification fuel cell combined cycle systems have been proposed.This is a novel triple-bed combined circulating fluidized bed (TBCFB) gasifier, consisting of a downer pyrolyzer, a bubbling fluidized bed char gasifier and a riser unreacted char combustor . However, detailed characteristics of pyrolysis in the TBCFB remain unknown.Detailed knowledge of coal pyrolysis behavior in a downer pyrolyzer is important for the design and operation of TBCFB reactors, to sufficiently reduce tar emission from the pyrolyzer and the following gasifier. Fushimi research group developed a novel concurrent downer pyrolyzer that can directly bring coal particles into contact with heat-carrying particles (silica sand) pre-heated at approximately 1173 K using a fluidized bed preheater . In the present study, we developed a novel concurrent downer pyrolyzer that can directly bring coal particles into contact with heat-carrying particles (silica sand) pre-heated at approximately 1173 K using a fluidized bed preheater. This is a novel downer pyrolyzer that feeds coal and sand particles separately. Increase in sand feed rate increased the amount of carbon surface deposits and the yields of CO2 and CO.

This research is useful for the “green” energy technologies.

For further reading:Fuel Processing Technology