Enhancing the performance of Co-hydrothermal liquefaction for mixed algae strains by the Maillard reaction

Abstract

It is important to tailor the ratio between protein and carbohydrate to enhance the HTL performance for microalgae.

High‐Performance Plasma‐Enabled Biorefining of Microalgae to Value‐Added Products

“…Phenols and indoles are usually products of the dehydration of glucose and Maillard reactions between ammonia (from protein degradation) and reducing sugars . Hydrocarbons with variable lengths (alkanes and alkenes) could be produced by fatty acid decarboxylation or decarboxylation and deamination . The largest hydrocarbon fraction obtained in the OH − ‐derived product suggests that base catalysis may be more effective in biofuel production from microalgae under the PCL conditions used in this study.…”

“…Since biomass liquefaction can be considered to be a typical liquid–solid heterogeneous thermochemical reaction, the reaction efficiency is largely dependent on the biomass/solvent ratio, which directly affects heat and mass transfer between the biomass and the solvent . The effect of ethylene glycol (EG)/microalgae mass ratio on the conversion process is shown in Figure d. The higher the solvent/solid mass ratio, the greater the conversion for both H + and OH − treatments.…”

“…As the lipid content of the C. pyrenoidosa used is up to 22 wt %, it is expected that the amount of free fatty acids and alcohols (mainly glycerol) released from the bound fatty acids would also be large. Phenols and indoles are usually products of the dehydration of glucose and Maillard reactions between ammonia (from protein degradation) and reducing sugars . Hydrocarbons with variable lengths (alkanes and alkenes) could be produced by fatty acid decarboxylation or decarboxylation and deamination .…”

“…This surface charge then acts as a barrier that prevents negatively charged OH − ions from reaching the biomass surface and at the same time attracts more positively charged H + ions . Therefore, the degradation pathway for plasma catalytic conversion of biomass mainly involves generation of electrons and free radicals, acceleration of electrons, radicals, and ions (H + or OH − ), heat accumulation and thermal degradation or oxidation of biomass through both free‐radical reactions, which mainly include dehydration, decarboxylation, deamination and other bond‐scission reactions, and ionic pathways, similar to high‐temperature solvolysis (general conversion pathways of the PCL of C. pyrenoidosa are also detailed in Figure c) …”

“…The Fourier‐transform (FT)IR spectrum of C. pyrenoidosa algae indicates that the composition of raw algae biomass includes higher amino‐containing (e.g., proteins) and hydroxyl‐containing (e.g., polysaccharides) compounds (a broad and strong peak from 3100 to 3600 cm −1 ; Figure S4) . The adsorption at 1700 cm −1 , which is usually ascribed to the stretching of C=O bonds, indicates the presence of carbonyl compounds, mainly from lipids and/or proteins.…”