ENGINEERING A NEW MATERIAL FOR HOT GAS CLEANUP

Wheelock, T.D. ; Doraiswamy, L.K. ; Constant, K.

National Energy Technology Laboratory (U.S.)

关键词: Limestone;    Thickness;    01 Coal, Lignite, And Peat;    Regeneration;    Pelletizing;   

DOI  :  10.2172/803200
RP-ID  :  FG26-99FT40587--02
RP-ID  :  FG26-99FT40587
RP-ID  :  803200

美国|英语

来源: UNT Digital Library

【 摘 要 】

The overall objective of this project is the engineering development of a reusable calcium-based sorbent for desulfurizing hot coal gas. A two-step pelletization method has been employed to produce relatively strong, ''core-in-shell,'' spherical pellets. Each pellet consists of a highly reactive core surrounded by a strong, inert, porous shell. A suitable core is composed largely of CaO which reacts with H{sub 2}S to form CaS. Pellet cores have been prepared by pelletizing either pulverized limestone or plaster of Paris, and shells have been made of various materials. The most suitable shell material has been formed from a mixture of alumina and limestone particles. The core-in-shell pellets require treatment at high temperature to convert the core material to CaO and to partially sinter the shell material. Pellet cores derived from plaster of Paris have proved superior to those derived from limestone because they react more rapidly with H{sub 2}S and their reactivity does not seem to decline with repeated loading and regeneration. The rate of reaction of H{sub 2}S with CaO derived from either material is directly proportional to H{sub 2}S concentration. The rate of reaction does not appear to be affected significantly by temperature in the range of 1113 K (840 C) to 1193 K (920 C) but decreases markedly at 1233 K (960 C). The rate is not affected by shell thickness within the range tested, which also provides adequate compressive strength.