Engineering topics
Li, Shiguang
Publications and source records attributed to Li, Shiguang.
Roles of interaction between components in CZZA/HZSM-5 catalyst for dimethyl ether synthesis via CO 2 hydrogenation
The roles of interaction between two catalyst components in CuO–ZnO–ZrO 2 –Al 2 O 3 (CZZA)/HZSM-5 bifunctional catalyst for dimethyl ether (DME) synthesis via carbon dioxide hydrogenation were investigated. It was found that CZZA catalyst showed excellent stability during methanol (MeOH) synthesis for 100 h, while there was a severe loss of catalytic activity in the bifunctional catalyst for DME synthesis. So, the effects of different degrees of intimacy of two catalyst components were studied for DME synthesis, including mixed and separated modes. For the mixed mode, the particle size of catalysts and the amount of reaction intermediates were proven to influence the catalyst deactivation. For the separated mode, the catalysts showed rapid deactivation within a short time. Various characterizations indicated that the remarkable deactivation of separated mode was mainly caused by the decrease of copper active centers (e.g., sintering and oxidation) and blockage of acid sites via increased coke deposition on HZSM-5.
Devices and methods for hydrogen generation via ammonia decomposition
Systems and methods for hydrogen generation via ammonia decomposition that utilize a fixed bed reactor configured to receive inflows of NH 3 and oxidant and to produce an outflow of high purity H 2 . The fixed bed reactor contains a fixed bed of a NH 3 decomposition catalyst wherewith the NH 3 decomposes to form N 2 and H 2 ; a plurality of ceramic hollows fibers with a high surface to volume ratio disposed in the fixed bed, the hollow fibers having an H 2 selective membrane disposed thereon for extracting H 2 from N 2 and to form a permeate of the high purity H 2 and a retentate of primarily N 2 ; and a catalytic H 2 burner also disposed in the fixed bed, the catalytic H 2 burner for burning a portion of the H 2 with the oxidant to provide thermal energy for the NH3 decomposition.