Catalytic Pyrolysis Using a Nickel-Functionalized Chemically Activated Biochar Catalyst: Insight into Process Kinetics, Products, and Mechanism

Abstract

The present study highlighted the impact of biochar (BC)-based catalysts on catalytic pyrolysis of pine needle biomass. Thermogravimetric plots showed positive influence of catalysts by indicating reduction in the temperature requirement of the process. The same had also been stated through process kinetics by demonstrating reduction in the process’s activation energy (E a). E a had been reduced from 25.95 kJ/mol in noncatalytic pyrolysis to 20.79, 15.20, 10.52, 13.99, and 9.69 kJ/mol for BC, Ni/BC, Ni/BC-ZnCl2, Ni/BC-H3PO4, and Ni/BC-NaOH catalytic pyrolysis, respectively. Physicochemical characteristics of bio-oil indicated improvement in its high heating value and % deoxygenation achieved during the process. Catalyst incorporation in the process increased the production of phenols as well as aliphatic and aromatic hydrocarbons. The presence of surface acidic functionalities coupled with metallic sites in Ni/BC-ZnCl2, Ni/BC-H3PO4, and Ni/BC-NaOH increased the aromatics selectivity to 35.18, 36.47, and 35.64%, respectively. Similarly, aliphatics were also enhanced to 9.61, 10.12, and 11.68% using Ni/BC-ZnCl2, Ni/BC-H3PO4, and Ni/BC-NaOH, respectively. Also, chemically activated catalysts showed high stability toward deactivation. Thus, low-cost BC-based catalysts can be effectively employed in place of currently utilized high-cost catalysts in the catalytic pyrolysis process, which will help to make the process more integrated and closed-loop.

Environmental Footprints of the Catalytic Pyrolysis of Pine Needles through Integration of a Nickel-Decorated Chemically Modified Biochar Catalyst

“…The goal of the investigation is to determine the environmental footprints of the production of bio-oil through the biochar-based catalytic pyrolysis process and its postutilization through combustion, along with the identification of the major environmental hotspots in the process life cycle. A total of six different processes were considered: (1) noncatalytic pyrolysis, (2) biochar (BC) catalyzed pyrolysis, (3) nickel doped biochar (Ni/BC) catalyzed pyrolysis, (4) nickel doped ZnCl 2 activated biochar (Ni/BC-ZnCl 2 ) catalyzed pyrolysis, (5) nickel doped H 3 PO 4 activated biochar (Ni/BC-H 3 PO 4 ) catalyzed pyrolysis, and (6) nickel doped NaOH activated biochar (Ni/BC-NaOH) catalyzed pyrolysis . The process was modeled with GaBi software (10.5.1.124 version).…”

“…Biochar is a carbon-rich coproduct that has several potential applications as fuel, catalyst support material, soil amendment, etc. The noncondensable gases (NCGs) produced from catalytic/noncatalytic pyrolysis consist of CO 2 (46.12–52.46 mol %), CO (19.11–31.66 mol %), CH 4 (9.59–12.37 mol %), and H 2 (9.85–19.71 mol %). , The increment in CO 2 proportions in the evolved gases after catalyst addition elucidates the deoxygenation tendency of the employed biochar-based catalysts. The gases produced from the noncatalytic/catalytic process have a sufficient heating value (∼8.66–10.21 MJ/Nm 3 ).…”

One-Step Carbothermal Reduction Synthesis of Metal-Loaded Biochar Catalyst for In Situ Catalytic Upgrading of Plastic Pyrolysis Products

“…Metal loading is a widely used method for biochar activation. The presence of metallic sites improves the acidity of biochar . Sun et al revealed that biochar activated with ZnCl 2 showed a maximum selectivity of 47.6% for aromatics from plastic catalytic pyrolysis.…”

“…The presence of metallic sites improves the acidity of biochar. 16 Sun et al 17 revealed that biochar activated with ZnCl 2 showed a maximum selectivity of 47.6% for aromatics from plastic catalytic pyrolysis. The reduction process that uses a reducing agent at high temperatures is a widely adopted strategy for stimulating the activity of metallic sites on the catalyst support.…”

In Situ Catalytic Pyrolysis of Municipal Sewage Sludge under Calcined Copper Slag: Thermokinetic Analysis and Real-Time Monitoring of Evolved Gases

“…For the noncatalytic pyrolysis of SS, the evolution curve of CO 2 showed three peaks located at 300, 672, and 817 °C. The appearance of the peak at 300 °C was attributed to the decarboxylation and decarbonylation reactions of organic compounds in SS, 45 the peak at 672 °C was attributed to the decomposition of carbonates, 9 and the peak at 817 °C was probably due to the redox reactions of the carbon residue of SS pyrolysis with metal oxides in SS. 46 With the addition of Calcined CS, there was a certain increase in the peak located at 300 °C, which indicated that Calcined CS could promote decarboxylation and decarbonylation reactions of organic compounds.…”