噴流型粉粒流動層半乾式脱硫装置の脱硫率に及ぼす諸操作条件の影響 [in Japanese] The Effect of Operating Conditions on SO_2 Removal in Semidry Desulfurization Process by Powder-Particle Spouted Bed [in Japanese]
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本研究では噴流型粉粒流動層を用い, 水処理を必要としない新しいタイプの半乾式脱硫装置を開発した.ベンチスケール規模の噴流型粉粒流動層脱硫装置へ, 脱硫剤微粒子のスラリーを連続供給し, 乾燥しながらSO<SUB>2</SUB>と反応させ, 飛び出された反応済み脱硫剤の微粒子を捕集した.使用した脱硫剤は消石灰と消白雲石の微粒子のスラリーである.<BR>本研究では脱硫率に及ぼす静止層高, 空塔基準ガス速度, ガス中のSO<SUB>2</SUB>に対する脱硫剤の化学量論比, 層内ガス温度と対応する飽和状態の温度 (湿球温度) との差即ち飽和接近温度, 媒体粒子の粒子径などの影響を調べた.<BR>諸因子のうち, 脱硫率はガス中のSO<SUB>2</SUB>モル流量に対する供給した脱硫剤のモル流量との比, つまり化学量論比<I>Ca/S</I>と飽和接近度に大きく影響をうけた.すなわち飽和接近度の値を小さくすると脱硫率を著しく向上させた.脱硫率は<I>Ca/S</I>の値が12以上, 飽和接近度の値が13K以下であれば, 脱流率は95%以上となった.<BR>本装置では脱硫率は媒体粒子の層高が高いほどまた空塔基準ガス速度が小さいほど大きくなった.すなわち, 層内でのガスの平均滞留時間が大きいほど大きくなった.<BR>また, 本流動層における媒体粒子は流動化が正常であれば, そのサイズが脱硫反応へ影響を及ぼさないことを確認した.
A new type of semidry flue gas desulfurization (FGD) process without waste water treatment was developed with a powder-particle spouted bed reactor.<BR>Fine sorbent powder slurries were continuously fed to a bench scale experimental spouted bed in which coarse particles were fluidized. These slurries were fluidized and dried. SO<SUB>2</SUB> sorbent was reacted with SO<SUB>2</SUB> gas and entrained from the bed and collected by bag filters. Slaked lime and slaked dolomite were used as SO<SUB>2</SUB> sorbent.<BR>In this study the effects of static bed height, superficial gas velocity, stoichiometric ratio of SO<SUB>2</SUB> in simulated gas to feeding sorbent, difference between temperature of bed gas and wet bulb temperature of gas, that is, approach to saturation temperature and medium particle size on SO<SUB>2</SUB> removal, are investigated.<BR>Among these factors, the stoichiometric ratio <I>Ca/S</I> and the approach to saturation temperature are the most important factors. SO<SUB>2</SUB> removal is significantly improved by reducing the approach to saturation temperature. When the <I>Ca/S</I> ratio is greater than 1.2 and the approach to saturation temperature is less than 13 K, more than 95% SO<SUB>2</SUB> removal is realized.<BR>In this experiment, the removal of SO<SUB>2</SUB> increased with static bed height or decreased with superficial gas velocity. This is due to the longer apparent residence time of gas in the dense bed of particles. When coarse particles were normally fluidized in the spouted bed, the effect of the size of medium coarse particles in the bed on SO<SUB>2</SUB> removal was not observed.
- Chemical engineering
Chemical engineering 24(2), 279-284, 1998-03-10
The Society of Chemical Engineers, Japan