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This work investigates the influence of temperature on the performance of hydrothermal carbonization of corn Stover between 175 and 250 °C, 240 min, 2.0 °C/min, and biomass-to-water ratio of 1:10. The performance analyzed for yields, energy densification and recovery. Aqueous phase analyzed for pH, acetic acid equivalent (HAc), HPLC, and GC, solid phase for dry and organic matter, ash, and elemental analysis. Solid yield (62.92–35.82%) increases with temperature, showing an inflection region between 200 and 225 °C, while that of liquid (35.43–54.59%) decreases in a similar behavior, and gas yield (1.49–9.59%) increases exponentially. GC identified alcohols, carboxylic acids, and furans. The concentration of furfural and Hidroxymethylfurfural (HMF) decreases exponentially and as a sigmoid with temperature, being not detectable at 250 °C. Carbon content increases, while oxygen and hydrogen decreases with temperature. The high heating values (HHV) increase, and the energy efficiency decreases with temperature. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Process simulation of deacidification of OLP by multistage gas extraction using CO 2 as solvent with Aspen-Hysis. • Best condition obtained at 333 K, 140 bar, S/F = 17 shows a yield of 36.65% with 96.95% hydrocarbons and 3.05% (wt.) oxygenates. • The oxygenates of OLP decrease from 10% (wt.), with 2.63% (wt.) FFA, to 3.05% (wt.) oxygenates, with 0.52% (wt.) FFA. • The results of simulations show that SC-CO 2 was able to deacidify OLP and to obtain fractions with lower olefins content. Abstract Fractionation of liquid phase products (OLP), obtained by thermal catalytic cracking of palm oil, simulated in multistage countercurrent absorber/stripping columns using SC-CO 2 as solvent with Aspen-Hysys, at 333 K, 140 and 180 bar, and (S/F) = 12, 15, 17, 25, 30, 38. RK-Aspen EOS applied to correlate equilibrium data of binary systems (OLP)-i/CO 2. Composition of OLP used to predict thermophysical properties and acentric factor of OLP compounds by group-contribution methods. The effect of pressure and (S/F) on process performance evaluated by computing the yield and recoveries of hydrocarbons, olefins, oxygenates, carboxylic acids. The regressions show that RK-Aspen EOS describe well phase equilibrium data, showing AAD between 0.8% and 1.25% and 0.01%– 0.66% for the liquid and gaseous phases. The best deacidifying conditions obtained at 333 K, 140 bar, and (S/F) = 17. Simulations show that SC-CO 2 was able to deacidify OLP and to obtain fractions with lower olefins content. [ABSTRACT FROM AUTHOR]

In this study, the influence of catalyst content on the physical–chemical properties, yield, and chemical composition of organic liquid products (OLP) obtained by thermal catalytic cracking of palm oil (Elaeis guineensis, Jacq.) was studied at a pilot scale. The experiments were carried out in a reactor of 143 L, running in batch mode at 450 °C and 1 atm, using 5%, 10%, 15%, and 20% (w/w) Na 2 CO 3 as the catalyst. Physical–chemical characterization of OLP was conducted for acid value, saponification value, specific gravity, refractive index, kinematic viscosity, copper strip corrosion, and flash point. The chemical composition of OLP was determined by gas chromatography–mass spectrometry (GC–MS). As the catalyst content increased, the kinematic viscosity of OLP decreased from 6.59 to 3.63 mm 2 s −1 and the acid value from 51.56 to 1.26 mg KOH/g. The GC–MS analysis showed that OLP comprise hydrocarbons (normal paraffin, olefin, and naphthenic) and oxygenated compounds (carboxylic acids, alcohols, ketones, and esters), with a high dependency on the catalyst level. As the catalyst content increased, the concentration of hydrocarbons increased, whereas the concentration of oxygenates decreased. The optimal sodium carbonate catalyst level was found to be 15% (w/w). This gave the highest rate of conversion into biofuel, of which around 60% was OLP, and produced biofuels with the lowest acid values. The physical–chemical properties were within the limits fixed by ANP No. 65 (Diesel S10 specification) due to their high hydrocarbon content (92.84%) and low oxygenate content (7.16%). The hydrocarbons produced had characteristics similar to those of petroleum diesel, offering the potential to replace petroleum fuels without requiring deacidification or deoxygenation pretreatment. [ABSTRACT FROM AUTHOR]