Bio-oil and biochar production from halophyte biomass: effects of pre-treatment and temperature on Salicornia bigelovii pyrolysis

Abstract

Salicornia bigelovii (SB), a strategically important plant in many regions to its ability to grow in arid climates and saline water. This study evaluates the effects of halophyte biomass pre-treatment...

In-depth study of bio-oil and biochar production from macroalgae Sargassum sp. via slow pyrolysis

“…Meanwhile, the decrease in bio-oil yield as the pyrolysis temperature increased further to 600 °C was due to the further cracking of the products at a temperature above 500 °C, generating non-condensable gases, such as CH 4 , CO, and CO 2 , as reported in the previous study. 34,35 This was supported by the fact that the gas yield significantly increased with increasing the temperature from 400 °C to 600 °C. The enhancement of the gas yield might also be due to the high presence of alkali and alkaline earth metal species in the Sargassum sp.…”

“…46 The main component of N -aromatic compounds observed in this study was heterocyclic derivatives, such as pyrazine, pyridine, 3-hydroxy pyridine, 2-imidazolidinone, and 4-aminopyridine. The finding of this study follows the previous research by Iaccarino et al , 34 who reported that amino acids could undergo decarboxylation, cyclization, and dehydration to generate the N-heterocyclic derivatives during the pyrolysis of Salicornia bigelovii .…”

“…The selectivity of aliphatic hydrocarbons in the bio-oil increased with the temperature following the trend: 12.08% (400 °C) < 12.65% (500 °C) < 16.65% (600 °C). The aliphatic hydrocarbons could be generated from the ring-opening, cracking, and dehydration of cellulose, as reported by Iaccarino et al 34 Macroalga Sargassum sp. also produces a trace amount of amine/amide compounds, such as butylamine, acetamide, and pentanamide.…”

“…58 This could be attributed to the lower lignin content in macroalgal biomass than in terrestrial plant biomass. Having said that, the BET surface area from this study was comparable with the previous work of Iaccarino et al , 34 who observed that the surface area of biochar from Salicornia bigelovii was in the range 1.30–2.35 m 2 g −1 . Furthermore, it could be confirmed from this study that an increase in the pyrolysis temperature led to an increase in the BET surface area and total pore volume, which could be because more volatile matter and pore-blocking substances from the biomass matrix were released, resulting in more pores in the biochar.…”

“…The formation of propionic and acetic acids has been linked to the thermal decomposition of lipids. 34 Meanwhile, 5-HMF formation is derived from the decomposition of cellulose. 38 The formation of propionic acid decreased while the acetic acid content steadily increased when the temperature was increased from 400 C to 500 C. This could be due to the decomposition of lipids, or long-chain carboxylic acid-generating short-chain carboxylic acid, which was enhanced with the rise in the pyrolysis temperature.…”