Development of activated biochar supported Ni catalyst for enhancing toluene steam reforming

Abstract

Catalytic steam reforming of tar is considered to be an attractive pathway for tar removal and H 2 production in the modern world. In this study, activation of biochar (B) from pine wood pyrolysis was performed to boost its specific surface area and pore structure. The activated biochar (AB) was used as a catalyst support with the aim to enhance the catalytic activity. The catalytic reforming performance of toluene over Ni/AB catalyst was investigated, and the catalytic behavior of Ni/AB catalysts was compared with Ni/Al 2 O 3 and Ni/B. The effect of potassium hydroxide (KOH) to biochar ratio, Ni loading, reforming temperature, weight hourly space velocity and steam to carbon ratio(S/C) on the performance of Ni/AB catalysts were studied. The results showed that Ni/AB catalysts exhibited a superior catalytic activity for carbon conversion and H 2 production to Ni/B and Ni/Al 2 O 3 catalysts. In addition, high carbon conversion (86.2%) and H 2 production (64.3%) can be achieved with Ni/AB catalyst under the optimal operating conditions. Furthermore, in order to improve the stability of the Ni/AB catalyst, Ce was introduced to Ni/AB catalyst. According to stability tests, the H 2 concentration of Ni-Ce/AB catalysts was still higher than 2.24 mmol/min even after 20 hours reaction.

Stability and activity maintenance of Ni catalysts supported on La‐, Ce‐, and Mg‐promoted Al 2 O 3 and ZrO 2 for H 2 production from steam reforming of glycerol

“…12,[35][36][37][38] Carbon-based supports developed recently exhibited excellent activity for SR reaction at lower temperatures but their property and activity stabilities still need improvement. 41,42 Further modifications including adding promoters or optimizing the preparation method for Ni/Al 2 O 3 and Ni/ZrO 2 catalysts have been widely carried out for SR reactions. Kamonsuangkasem et al 18 24,26,45,46 For catalyst preparation, besides the most used impregnation method, sol-gel, 18 co-precipitation, 27 and more complex solvothermal method 11 have been investigated.…”

“…Therefore, considerable research has focused on screening suitable supports and promoters for Ni or modifying the catalyst preparation method, trying to overcome these obstacles. Studied carriers for active Ni mainly include single metal oxide such as Al 2 O 3, 6‐11 ZrO 2, 4,8,12 La 2 O 3, 13 CeO 2, 10,14,15 MgO, 8 CaO, 16 SiO 2, 8,10,17 composite oxides such as CeO 2 ‐Al 2 O 3, 18‐23 La 2 O 3 ‐Al 2 O 3, 6,24‐26 MgO‐Al 2 O 3, 27‐31 CaO‐Al 2 O 3, 32 La 2 O 3 ‐ZrO 2, 33,34 CeO 2 ‐ZrO 2, 35‐38 CeO 2 ‐La 2 O 3 ‐Al 2 O 3, 39 and carbon material such as CNT, 30,40,41 activated biochar, 42 and graphene oxide 43,44 . Al 2 O 3 ‐supported Ni catalysts have received the most extensive study as stated above because the porous γ‐Al 2 O 3 with high surface area is very beneficial to form highly dispersed Ni crystals over the catalyst surface, thus achieving a high level of activity for SR reaction 8,10 .…”

“…ZrO 2 ‐supported Ni and its promoted catalysts (Ni/CeO 2 ‐ZrO 2 ) also attracted much attention for their excellent stability and activity for SR reactions 12,35‐38 . Carbon‐based supports developed recently exhibited excellent activity for SR reaction at lower temperatures but their property and activity stabilities still need improvement 41,42 …”

Wheat-Straw-Derived Activated Biochar as a Renewable Support of Ni-CeO2 Catalysts for CO2 Methanation

“…For the BCCe30 material, the hydrogen consumption at 500 • C was mainly due to partial CeO 2 reduction at the surface, which was somewhat unexpected at such a low temperature [16]. This finding can probably be ascribed to the reductive properties of the carbon support [48]. On the other hand, hydrogen consumption in the range of 450-550 • C was observed for the BCN75 catalyst, although the mass spectrometer detected the presence of ammonia and the absence of water in the outlet stream.…”

Kinetic features of ethanol steam reforming and decomposition using a biochar-supported Ni catalyst

“…Due to its low cost and high porosity, it has garnered significant attention recently as a catalyst or metal catalyst support for various reactions, including reforming, (trans)esterification and hydrolysis [25]. The study of catalytic cracking and steam reforming of tar and its model compounds using biochar-based catalysts has been a major literature focus [26], demonstrating the high reforming and tar destruction activity of biochar-based catalysts [27][28][29][30]. In addition, the energy value of the spent biochar can be recovered by combustion or gasification further reducing energy loss and disposal cost [31][32][33].…”