Evaluation of Engineered Biochar-Based Catalysts for Syngas Production in a Biomass Pyrolysis and Catalytic Reforming Process

Abstract

Biochar, originating from biomass pyrolysis, has been proven a promising catalyst for tar cracking/reforming with great coke resistance. This work aims to evaluate various engineered biochar-based catalysts on syngas production in a biomass pyrolysis and catalytic reforming process without feeding extra steam. The tested engineered biochar catalysts include physical-and chemical-activated, nitrogen-doped, and nickel-doped biochars. The results illustrated that the syngas yields were comparable when using biochar and activated biochar as catalysts. A relatively high specific surface area (SSA) and a hierarchical porous structure are beneficial for syngas and hydrogen production. A 2 h physical-activated biochar catalyst induced the syngas with the highest H 2 /CO ratio (1.5). The use of N-doped biochar decreased the syngas yield sharply due to the collapse of the pore structure but obtained syngas with the highest LHV gas (18.5MJ/Nm 3 ). The use of Ni-doped biochar facilitated high syngas and hydrogen yields (78.2 wt % and 26 mmol H 2 /g-biomass) and improved gas energy conversion efficiency (73%). Its stability and durability test showed a slight decrease in performance after a three-time repetitive use. A future experiment with a longer time is suggested to determine when the catalyst will finally deactivate and how to reduce the catalyst deterioration.

Influence of Pyrolysis Temperature and Time on Biochar Properties and Its Potential for Climate Change Mitigation

“…The first phase of the process is to expel moisture and volatile substances from the biomass structure; hence, more moisture is expelled from the DBC feedstock when the temperature rises (Table 2). Initially, the VM content and tarry vapors (such as CO, CO2, CxHy, CxHyOz, H2O, HCN, and NH3), which are associated with cellulose and hemicellulose contents [15,60,83], were excreted from feedstocks [23], which resulted in the majority of mass loss [45,88], inducing bond rupture and the generation of hydroperoxide, -COOH and -CO groups [13,35,40]. The results showed that increasing the pyrolysis for 20 min of holding time from 400 °C to 500 °C significantly decreased the MC and VM contents of DBC biochar from 2.18% to 1.66% and 28.72% to 19.23%, respectively.…”

“…According to the meta-analysis literature, biochar is recognized as a potential material for achieving environmental sustainability due to its unique properties and diverse applications, which include agricultural applications that can reduce greenhouse gas emissions [6][7][8] and achieve carbon capture and storage [9,10], in addition to achieving increases in soil fertility and enhancing crop productivity [11,12]. Moreover, biochar has the potential to be applied as a catalyst [13], an adsorbent [14], and for energy storage [15].…”

Advancements and applications of microwave-assisted deep eutectic solvent (MW-DES) lignin extraction: a comprehensive review

“…Biorefineries are also anticipated to decrease greenhouse gas emissions and ease the energy crisis, 5,6 while offering economic opportunities for agriculture and forestry industries, organic waste management, and production of liquid fuels, platform chemicals, and carbon-neutral energy. 7 Global annual production of LCB is estimated at 181.5 billion tons with potential supplies being provided by various sectors. 8,9 LCB is a heterogeneous organic matrix with a three-dimensional structure that is primarily composed of lignin, cellulose, and hemicellulose, as well as a few other minor components, such as minerals and extractives.…”

“…Biorefineries are also anticipated to decrease greenhouse gas emissions and ease the energy crisis, 5,6 while offering economic opportunities for agriculture and forestry industries, organic waste management, and production of liquid fuels, platform chemicals, and carbon-neutral energy. 7 Global annual production of LCB is estimated at 181.5 billion tons with potential supplies being provided by various sectors. 8,9…”

Oxygen-Vacancy-Rich Co–Ce/C for Highly Stable Catalytic Steam Reforming of Toluene at Low Temperature

“…Historically, the Ni-based catalysts have attracted much more attention. − Taking into account the endothermic nature of the steam reforming reaction, the catalysts usually exhibit excellent activity at high temperatures with tar completely converted and a high yield of syngas and H 2 produced. − However, Ni-based catalysts are prone to rapid deactivation due to sintering of active components and carbon deposition . Currently, the research focus in this field has gradually shifted to the design of catalysts with high activity and high stability to achieve complete conversion of biomass tar at lower catalytic temperatures. , …”