Biocrude Oil Production through the Maillard Reaction between Leucine and Glucose during Hydrothermal Liquefaction

Abstract

In this work, leucine and glucose were used as model molecules to investigate the Maillard reaction between proteins and carbohydrates during hydrothermal liquefaction (HTL) of microalgae. The main pathway of the Maillard reaction between leucine and glucose via HTL was related to the reaction of deaminated leucine with cyclic oxygenated compounds from degraded glucose to produce pyrazine derivatives. Gas chromatography–mass spectrometry results revealed that N and O heterocyclic compounds, organic acids, and carbonyls/imine/amine were the main components of both the biocrude oil and aqueous fraction. The optimal reaction temperature, reaction time, leucine/glucose weight ratio, and solid concentration for biocrude oil production are 320 °C, 60 min, 2:5, and 20 wt %, respectively. The obtained biocrude oil (higher heating value of 38.07 MJ/kg), presenting a large amount of pyrazine derivatives (84.2% peak area), yielded 47.6 wt % of leucine and glucose feedstock.

Advance in Hydrothermal Bio-Oil Preparation from Lignocellulose: Effect of Raw Materials and Their Tissue Structures

“…In mixtures with carbohydrates, the measured bio-oil yields exceeded those obtained from the conversion of the single substances (10-39 wt.%). Some similar researches could also be found in the published literature [69][70][71].…”

Synergistic Effect of Nitrogen Doping and Ultra-Microporosity on the Performance of Biomass and Microalgae-Derived Activated Carbons for CO2 Capture

“…Interestingly, for 14 h long HTC reactions, the temperature had an insignificant impact on the nitrogen content of the hydrochars (Figure B). These observations might be attributed to the occurrence of the Maillard complex reaction cascades between the amino groups of the SP microalgae and the existing carbonyl functional groups in the structure of biomass . This reaction depends on the temperature at low and high reaction times, as evident by the integration of a larger amount of nitrogen into the carbon matrix of the biomass in the experiments performed at the lowest (4 h) and highest (24 h) of reaction time points.…”

“…These observations might be attributed to the occurrence of the Maillard complex reaction cascades 42 between the amino groups of the SP microalgae and the existing carbonyl functional groups in the structure of biomass. 43 This reaction depends on the temperature at low and high reaction times, as evident by the integration of a larger amount of nitrogen into the carbon matrix of the biomass in the experiments performed at the lowest (4 h) and highest (24 h) of reaction time points. However, this temperature dependence does not operate on the global reaction time space as suggested by low F (2.05) and high P (0.1717) values in the temperature and nitrogen content relation (Figure 2B, Table S1).…”

Hydrothermal Liquefaction of Food Waste: Effect of Process Parameters on Product Yields and Chemistry

“…The highest nitrogen recovery was obtained in HTL-char for low temperatures and short reaction times (Figure 1D). Typically, the presence of glucose in lignocellulosic biomass inhibits nitrogen transfer to the bio-crude oil and aqueous phases (Qiu et al, 2019). Char with high nitrogen content used as an organic fertilizer can increase the amount of available nitrogen and phosphorous, increase crop yields, and reduce greenhouse gas emissions (Al-Wabel et al, 2018;Islam et al, 2021).…”