化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2015年
5期
1912-1918
,共7页
吴水木%李英杰%孙荣岳%路春美
吳水木%李英傑%孫榮嶽%路春美
오수목%리영걸%손영악%로춘미
H2S吸收%CaO%碳酸化/煅烧%硫化%CO2捕集%制氢
H2S吸收%CaO%碳痠化/煅燒%硫化%CO2捕集%製氫
H2S흡수%CaO%탄산화/단소%류화%CO2포집%제경
H2S adsorption%CaO%carbonation/calcination%sulfidation%CO2 capture%hydrogen production
ZEC(zero emission coal)系统中,粗煤气进入碳酸化/重整炉前需先脱除H2S,提出利用经过多次碳酸化/煅烧捕集CO2循环的煅烧石灰石(CaO)脱除H2S,并研究循环碳酸化/煅烧次数、硫化温度、H2S浓度和微观结构对循环CaO硫化特性的影响。结果表明,多次循环碳酸化/煅烧捕集CO2后CaO仍具有较高H2S吸收性能。前20次循环,CaO硫化转化率随循环次数增加迅速降低;20次循环后,CaO硫化转化率缓慢下降。硫化120 min后,未循环CaO的硫化转化率接近100%,而经历1、20和100次循环后CaO的硫化转化率分别为94%、81%和74%。H2S浓度对循环CaO硫化性能影响较大。硫化温度(800~1000℃)对循环CaO的硫化性能影响较小,最佳硫化温度为900℃。随循环次数增加,CaO颗粒发生高温烧结,导致比表面积降低和20~150 nm内孔隙减少,而这是与H2S吸收密切相关的孔隙,导致CaO硫化转化率降低。
ZEC(zero emission coal)繫統中,粗煤氣進入碳痠化/重整爐前需先脫除H2S,提齣利用經過多次碳痠化/煅燒捕集CO2循環的煅燒石灰石(CaO)脫除H2S,併研究循環碳痠化/煅燒次數、硫化溫度、H2S濃度和微觀結構對循環CaO硫化特性的影響。結果錶明,多次循環碳痠化/煅燒捕集CO2後CaO仍具有較高H2S吸收性能。前20次循環,CaO硫化轉化率隨循環次數增加迅速降低;20次循環後,CaO硫化轉化率緩慢下降。硫化120 min後,未循環CaO的硫化轉化率接近100%,而經歷1、20和100次循環後CaO的硫化轉化率分彆為94%、81%和74%。H2S濃度對循環CaO硫化性能影響較大。硫化溫度(800~1000℃)對循環CaO的硫化性能影響較小,最佳硫化溫度為900℃。隨循環次數增加,CaO顆粒髮生高溫燒結,導緻比錶麵積降低和20~150 nm內孔隙減少,而這是與H2S吸收密切相關的孔隙,導緻CaO硫化轉化率降低。
ZEC(zero emission coal)계통중,조매기진입탄산화/중정로전수선탈제H2S,제출이용경과다차탄산화/단소포집CO2순배적단소석회석(CaO)탈제H2S,병연구순배탄산화/단소차수、류화온도、H2S농도화미관결구대순배CaO류화특성적영향。결과표명,다차순배탄산화/단소포집CO2후CaO잉구유교고H2S흡수성능。전20차순배,CaO류화전화솔수순배차수증가신속강저;20차순배후,CaO류화전화솔완만하강。류화120 min후,미순배CaO적류화전화솔접근100%,이경력1、20화100차순배후CaO적류화전화솔분별위94%、81%화74%。H2S농도대순배CaO류화성능영향교대。류화온도(800~1000℃)대순배CaO적류화성능영향교소,최가류화온도위900℃。수순배차수증가,CaO과립발생고온소결,도치비표면적강저화20~150 nm내공극감소,이저시여H2S흡수밀절상관적공극,도치CaO류화전화솔강저。
Zero emission coal (ZEC) process based on calcium looping in which CO2is captured through a cyclic carbonation/calcination process is a promising technology for hydrogen production. In this process, H2S should be removed before raw gas flows into the downstream carbonator/reformer. In this work, the cycled CaO derived from limestone after multiple carbonation/calcination cycles for CO2 capture was used to remove H2S from raw gas. Cyclic carbonation/calcination of CaO was performed in a dual fixed-bed reactor and then the cycled CaO was sent to a sulfidation reactor for H2S removal. The effects of carbonation/calcination cycle number, sulfidation temperature, H2S concentration and CaO microstructure on sulfidation performance of the cycled CaO from CO2 capture cycles were investigated. The cycled CaO after the long-term carbonation/calcination cycles for CO2 capture still had high H2S removal capacity. Sulfidation conversion of CaO derived from limestone decreased rapidly with increasing number of carbonation/calcination cycles in the first 20 cycles, and then decreased slowly with further increasing cycle number. After sulfidation for 120 min, sulfidation conversion of the CaO after 0 cycle was nearly 100%. And sulfidation conversions of the cycled CaO after 1, 20 and 100 cycles were 94%, 81% and 74%, respectively. H2S concentration showed a great effect on H2S removal of the cycled CaO. Sulfidation temperature in the range of 800—1000℃ had a little effect on H2S removal of the cycled CaO, and the optimum sulfidation temperature was 900℃. As the cycle number increased, specific surface area of the cycled CaO dropped due to sintering. The pores 20—150 nm in diameter of the cycled CaO which were closely related with H2S adsorption also decreased. Thus, H2S removal capacity of the cycled CaO decayed with the number of cycles.