Ex Situ Catalytic Pyrolysis of Invasive Pennisetum purpureum Grass with Activated Carbon for Upgrading Bio-Oil

Abstract

Energy demands keep increasing in this modern world as the world population increases, which leads to a reduction in fossil fuels. To resolve these challenges, Pennisetum purpureum, an invasive grass in Brunei Darussalam, was examined as the feedstock for renewable energy through a catalytic pyrolysis process. The activated carbon was applied as the catalyst for a simple and economical solution. The catalytic pyrolysis was executed at 500 °C (the temperature for the highest biofuel yield) for both reactors to produce the highest amount of upgraded biofuels. The biochar produced from the non-catalytic and catalytic pyrolysis processes showed a consistent yield due to stable operating conditions, from which the activated carbon was generated and used as the catalyst in this work. A significant amount of improvement was found in the production of biofuels, especially bio-oil. It was found that for catalysts, the number of phenolic, alcohol, furans, and ketones was increased by reducing the amount of acidic, aldehyde, miscellaneous oxygenated, and nitrogenous composites in bio-oils. The highest amount of phenolic compounds was produced due to a number of functional groups (-C=O and -OH) in activated carbon. The regenerated activated carbons also showed promising outcomes as catalysts for upgrading the bio-oils. The overall performance of synthesized and regenerated activated carbon as a catalyst in catalytic pyrolysis was highly promising for improving the quality and stability of bio-oil.

Synthesis and Characterization of Biochars and Activated Carbons Derived from Various Biomass for CO₂ Adsorption

“…For some samples, (i.e sample OPW6), the activated carbon was prepared from the bichar/hydrochar of dried okara through physiochemical activation processes. The biochar, produced at a 600 •C pyrolysis temperature, or hydrochar produced at 200 o C hydrothermal treatment was used for further treatment, to produce a high porosity product with less tars impurity [34]. The biochar/hydrochar was mixed with KOH and water with a mass ratio of biochar: KOH: water being 1:4:5.…”

Advanced Applications of Carbonaceous Materials in Sustainable Water Treatment, Energy Storage, and CO2 Capture: A Comprehensive Review

“…Biochar is a potential carbon source ma terial for activated carbons due to its high reactivity and other distinct properties [60] Biochar made from biomass has the potential to be used as an alternative precursor fo activated carbon production due to its advantages. As a result, the number of technologies for water treatment, energy conservation, and CO2 reduction has grown significantly [61] Sometimes, the activated carbons derived from biochar perform equally well or even bet ter than commercially available activated carbons [62].…”

Influence of Catalyst on the Yield and Quality of Bio-Oil for the Catalytic Pyrolysis of Biomass: A Comprehensive Review

“…In comparison to the non-catalytic process, the production of bio-oil reduced from 36.70 to 34.72% in the ex situ catalytic pyrolysis of invasive Pennisetum purpureum grass with activated carbon, whereas the output of syngas increased from 35.90 to 37.52%. This was because of the catalytic effect of the catalytic and pyrolytic vapors [26].…”

“…Due to its strong structure and surface area, it can be used to adsorb gas and further crack the components into smaller components. Both physical and chemical-activation processes can be used to transform the biochar product, which is produced during the pyrolysis of biomass, into activated carbon [26]. Activated carbon is a substance that contains a high amount of carbon and can be used as a catalyst to crack the bigger components into smaller components [210].…”

“…The kind of catalyst employed, the structure of the biomass, and operational parameters like temperature, catalyst-to-biomass ratio, reactor type, particle size, heating rate, and residence time, affect the yield and quality of the bio-oil generated during catalytic pyrolysis [24,25]. Normally, the yield of bio-oil produced by catalytic pyrolysis is somewhat lower than that of non-catalytic pyrolysis [26]. According to earlier research, different catalysts have distinct potentialities in the catalytic pyrolysis process [27].…”