One‐Pot Process for Hydrodeoxygenation of Lignin to Alkanes Using Ru‐Based Bimetallic and Bifunctional Catalysts Supported on Zeolite Y

Abstract

The synthesis of high-efficiency and low-cost catalysts for hydrodeoxygenation (HDO) of waste lignin to advanced biofuels is crucial for enhancing current biorefinery processes. Inexpensive transition metals, including Fe, Ni, Cu, and Zn, were severally co-loaded with Ru on HY zeolite to form bimetallic and bifunctional catalysts. These catalysts were subsequently tested for HDO conversion of softwood lignin and several lignin model compounds. Results indicated that the inexpensive earth-abundant metals could modulate the hydrogenolysis activity of Ru and decrease the yield of low-molecular-weight gaseous products. Among these catalysts, Ru-Cu/HY showed the best HDO performance, affording the highest selectivity to hydrocarbon products. The improved catalytic performance of Ru-Cu/HY was probably a result of the following three factors: (1) high total and strong acid sites, (2) good dispersion of metal species and limited segregation, and (3) high adsorption capacity for polar fractions, including hydroxyl groups and ether bonds. Moreover, all bifunctional catalysts proved to be superior over the combination catalysts of Ru/Al O and HY zeolite.

High Catalytic Efficiency of Lignin Depolymerization over Low Pd-Zeolite Y Loading at Mild Temperature

“…After that, the oven was heated up to 300°C at the rate of 10°C/min and held for 5 min. Eluting compounds were determined using a MS (Agilent Technologies 5975C) inter XL EI/CI MSD with a triple axis detector and matched to NIST GC-MS libraries (Wang et al, 2017). Scanning electron microscopy (SEM) analysis was performed using a field emission SEM instrument (Hitachi S-4800), operating at an accelerating voltage of 10 kV.…”

“…Nevertheless, state-of-the-art lignin utilization technologies still face tremendous challenges, including depolymerization and upgradation, especially the catalytic depolymerization process (Alonso et al, 2010;Xu et al, 2014;Li et al, 2015;Yang et al, 2015). Among various catalysts for lignin depolymerization, zeolites are widely accepted due to their low-cost, high surface area, and outstanding acid sites catalytic performance (Taarning et al, 2011;Ben and Ragauskas, 2012;Wang et al, 2017). External Brønsted acidity in meso-/microporous zeolites was reported to effectively affect the selectivity of de-alkylation and de-etherification reactions in parallel during lignin conversion (Taarning et al, 2011;Singh and Ekhe, 2014;Deepa and Dhepe, 2015).…”

Development of Bifunctional Hydrodeoxygenation Catalyst Rh‐HY for the Generation of Biomass‐Derived High‐Energy‐Density Fuels

“…Most noble metal‐containing zeolite catalysts have been designed to reduce catalyst deactivation and to improve the conversion and selectivity toward deoxygenated products from lignin‐derived compounds. Several researchers have studied the activity and selectivity of HDO reactions using bifunctional catalysts containing the most commonly used hydrogenation catalysts, such as Pt, Pd, Rh, and Ru, supported on acidic zeolites such as Y and beta . These noble metals were selected due to their superior hydrogenation performance at relatively mild reaction conditions.…”

Techno‐economic analysis of jet‐fuel production from biorefinery waste lignin

“…The former include phenolic resins, epoxies, adhesives, polyolefins, carbon fiber, and PHAs . The latter consists of syringol, guaiacol, BTX (benzene, toluene, and xylene), vanillin, lipids, and jet fuel . Some current and future market and product opportunities are presented in Fig.…”

“…Data are being collected for three more technologies, including ATJ‐SKA, developed by Byogy (Byogy Renewables, Inc., San Jose, USA), Swed Biofuels (Swedish Biofuels AB, Stockholm, Sweden), and the IH demonstration scale by Shell (Royal Dutch Shell, UK), which acquired the technology from the Gas Technology Institute (GTI) (Des Plaines, USA) in 2009. Indeed, there are many more technologies in exploratory discussions, such as Vertimas: one‐step catalytic conversion of ethanol to jet, petrol, diesel fuel, and chemicals, which was originally invented at Oak Ridge National Laboratory; SBI Bioenergy: a continuous catalytic process that converts fat, oil or grease into renewable gasoline, diesel, and jet fuel with proprietary process intensification and continuous flow through processing technologies (PICFTR); Joule: CO 2 ‐derived fuels ‘Sunflow‐J’ jet fuel from specially engineered photosynthetic bacteria, waste carbon dioxide, sunlight and water; Global Bioenergies: biological production of isobutene and process to jet fuel; Eni: hydrogenated vegetable oil (HVO); Enerkem: municipal waste gasification and catalytic conversion to ethanol followed conversions to biofuels and chemicals; and Washington State University (WSU): lignin‐to‐jet‐fuel (LJ‐D&HDO) through one‐step proprietary catalytic upgrading of lignin waste to jet fuel …”