Catalytic Hydropyrolysis of Biomass Using Molybdenum Sulfide Based Catalyst. Effect of Promoters

Abstract

11 Catalytic hydropyrolysis of beech wood was conducted in a fluid bed reactor at 450°C and a total pressure 12 of 26 bar. The differences in hydrodeoxygenation activity, selectivity and the resulting product composition 13 between sulfided Mo/MgAl 2 O 4 , CoMo/MgAl 2 O 4 or NiMo/MgAl 2 O 4 catalysts have been investigated. The 14 acidity and molybdate species in the oxide catalyst precursors were characterized with ammonia 15 temperature programmed desorption (NH 3-TPD) and Raman spectroscopy. The spent sulfided catalysts 16 were also extensively characterized by scanning electron microscopy (SEM) and by scanning transmission 17 electron microscopy (STEM) coupled with energy dispersive X-ray spectroscopy (EDS). The catalytic 18 hydropyrolysis of beech wood produced four kinds of products: Liquid organic and aqueous phases, solid 19 char and gases. The solid char and aqueous phase yields were not affected by the type of catalyst. The sum 20 of condensed organics and C 4+ gas yield varied between 24.3 and 26.4 wt.% on dry, ash free basis (daf) and 21 was highest for the Mo catalyst and lowest for the NiMo catalyst. The NiMo catalyst had the highest 22 hydrogenation, cracking, and de-carbonylation activity. The oxygen content in the condensed organic phase 23 was between 9.0 and 12 wt.% on dry basis (db) and was lowest for the CoMo catalyst and highest for the

New insights into the effect of pressure on catalytic hydropyrolysis of biomass

“…These two catalysts were chosen due to their well-known activity in HDO reactions [21][22][23][24][25][26][27][28][29][30], where the NiMo catalyst mainly promotes the removal of oxygen from phenols after it has saturated the aromatics (HDO pathway), while the CoMo to a larger extent promotes the direct removal of oxygen from phenol (DDO pathway) [27,[31][32][33][34]. At the applied temperatures in the fluid bed reactor the hydrogenation/deoxygenation of phenols are controlled by the thermodynamic equilibrium [20], thus it has been shown that the CoMo catalyst is the best choice for the fluid bed reactor [35]. In addition a catalyst with MgAl2O4 as support material was chosen for the fluid bed reactor because of its relatively high mechanical strength, which decreases the catalyst loss due to attrition.…”

The Influence of Active Phase Loading on the Hydrodeoxygenation (HDO) of Ethylene Glycol over Promoted MoS2/MgAl2O4 Catalysts

“…Catalytic hydropyrolysis is an efficient process for the direct production of diesel and gasoline type fuels from solid lignocellulosic biomass such as wood and agricultural residues [1][2][3][4][5]. Such fuels are necessary to reach the goal of becoming independent of fossil fuels, especially in the heavy duty and aviation sector, which are not immediately moving towards electrification.…”

Hydrodeoxygenation (HDO) of Aliphatic Oxygenates and Phenol over NiMo/MgAl2O4: Reactivity, Inhibition, and Catalyst Reactivation

“…More advanced techniques than one-step bio-oil upgrading are more promising. One option is to perform the HDO step in situ during fast pyrolysis as catalytic fast hydropyrolysis in a fluid bed reactor [4,16,[45][46][47][48][49]. In this way, reactive oxygenates can be upgraded immediately once they are formed, and more stable compounds such as phenols, can be deoxygenated downstream.…”