Pyrolysis of lignocellulosic and algal biomasses in a fixed‐bed reactor: A comparative study on the composition and application potential of bioproducts

Abstract

The pyrolysis of six biomass samples consists of Rice husk (RH), Coconut shell (CS), and Walnut shell (WS) as lignocellulosic biomasses and Cladophora glomerata (CG), Gracilaria gracilis (GG), and Azolla filiculoides (AF) as algal biomasses were investigated at a constant operating condition in a fixed-bed reactor. The effect of biomass biochemical structure on the yields and composition of pyrolysis products and their potential for future applications were discussed. CS, AF, and CG showed respectively the highest yield of bio-oil (50.25 wt%), biogas (33.70 wt%), and biochar (40.21 wt%). WS, AF, and RHderived gas products had a medium level of LHV (10-13 MJ/Nm 3 ), and CG and GG algae samples had a very suitable H 2 /CO ratio close tow. Characterization of bio-oils showed that CS, WS had a high content of hydrocarbon components (23.5%, 17.6%, and 17%, respectively), and phenols (35.3% and 35.6%, respectively). Furthermore, useful nitrogen-containing components such as pyridine, nitrile, indole, and derivatives were detected in algae bio-oils. Biochar characterization showed the highest surface area and total pore volume for AF. Also, CG's biochar with a high concentration of carboxylic and carbonyl groups in their structure may be suitable for absorbing water and soil contaminants.

Production of high‐quality bio‐product by pyrolysis of acid/metal modified chickpea husk

“…At the following temperature range (380°C‐450°C), the methoxy groups fragment in the ortho site of the hydroxyl groups, and the aromatic rings lose their ‐CH 3 and ‐OH groups at temperatures between 450°C and 800°C 40 . In the range of 580°C‐900°C, the slow decomposition of fixed carbon was assigned to the final stage, and the weight of the residual material was used to calculate the ash content of biomass 3 …”

“…Additionally, it can be used to generate hydrogen and syngas through gasification or steam reforming. Other liquid fuels, including jet fuel, diesel, and ethanol, can also be produced through secondary refinery processes 3 …”

“…One of the most useful oxygenated molecules in bio‐oil made from the breakdown of hemicellulose's xylose ring is furan components, particularly furfural and its derivatives. Furfural has a wide range of uses, including the production of polymers, paints, pharmaceuticals, adhesives, resins, and so on 3 …”

“…Also, to supply the worldwide fuel needs, they are widely and easily available. Hence, the production of biofuels from lignocellulosic biomass such as agricultural residues flourished through thermochemical conversion 3 …”

“…Hence, the production of biofuels from lignocellulosic biomass such as agricultural residues flourished through thermochemical conversion. 3 Pyrolysis is one of the most advantageous methods of converting biomass to biofuels that have been considered in recent years. This method can directly convert biomass into solid (biochar), gaseous (biogas), and liquid (bio-oil) fuels in the absence of oxygen by thermal decomposition.…”