Thermodynamic study of the supercritical water reforming of glycerol

Supercritical Water Gasification of Biomass: A Literature and Technology Overview

“…The superscripts − and + refer to the flows leaving the system and flows entering the system, respectively. Gutié rrez Ortiz et al [133] performed process simulations using AspenPlus TM for gasification of glycerol in supercritical water. They investigated the effect of process conditions on the hydrogen yield.…”

The BioSCWG Project: Understanding the Trade-Offs in the Process and Thermal Design of Hydrogen and Synthetic Natural Gas Production

“…The advantage of empirical EOS in general compared to their activity coefficient counterparts is the ability to predict phase equilibria at elevated pressures where infinite dilution in a single phase is experienced [41]. Some of the EOS adapted in literature are the Peng-Robinson (PR) [24,26,28,31,32,35], Soave Redlich Kwong (SRK) [36,38], Duan [27,40], Statistical Association Fluids Theory (SAFT) [25], Virial EOS [30] and the original ideal package [33]. Some authors employed Energies 2016, 9, 838 5 of 27 hybrid approaches to account for inaccuracy of some models, Gassner et al [40] employed a hybrid Duan-Lee Kesler modelling approach for their BioSNG production case.…”

“…Withag et al [36] attempted to compare a list of 6 PR and SRK based EOS combinations with non-quadratic mixing rules, and reported a bandwidth of deviation for molar hydrogen prediction below 3.5% for all. However, Ortiz et al [38] examined the accuracy of the predictive SRK EOS for enthalpy prediction, and reported a slight deviation for organic-H 2 O mixtures, which would be amplified with a high water throughput in SCWR. Valderrama [41] in his review of different cubic EOS reiterated that a hybrid approach, that considers integrated excess Gibbs energy models (a non-quadratic mixing rule) within empirical EOS parameters remains necessary to offer more reliable equilibria data for non-ideal mixtures with a supercritical component.…”

“…Notes: 1 Different EOS property methods for supercritical processing were assessed, and PR-BM was selected for the reactor model based on reported higher accuracy; 2 Stoichiometric conversion of glucose model compound was the basis for reactor modelling, under the assumption of complete conversion of organics to syngas (H 2 -CH 4 -CO 2 ) and complete precipitation of inorganics; 3 Fiori et al [35] did not report the EOS used in simulation, however in the groups' earlier work [29], in which the reported conceptual design was based, the authors used the PR-VdW EOS; 4 Examined seven combinations of PR and SRK based EOS with different mixing rules; the authors reported only a 3% variation in the upper limit of H 2 yield predictions; 5 The simulation model used the PSRK EOS while no mixing rule was reported, the Holderbaum-Gemehling mixing rule for supercritical mixtures was reported in the group's earlier work [38]; 6 Equilibrium conditions for SCWG were based on previous experimental results with a ruthenium catalyst, however the modelling approach was not specifically reported; 7 Algal conversion and yield data for the model were based on experimental findings reported in one of the publications [43]. It is accepted that through the fine-tuning of the reactive conditions and subsequent unit configurations, the SCWG process could be either designed for BioSNG production under catalytic, low temperature and higher solid content conditions [21,36,40,[42][43][44] or for hydrogen under high temperature, lower solid content and longer residence times [15,20,25,27,34,35,[37][38][39]45]. Another critical design question, aside from maximizing conversion to the desired product within the reactor system, is the development of a thermal recovery system to minimize the higher thermodynamic quality heat and power demand of the core conversion step taking place under supercritical conditions.…”

“…The reported work of Galera et al [37] and Ortiz et al [38] developed detailed heat exchanger networks for a synthesized glycerol to power and/or H 2 gas plant as part of an ongoing effort to establish new valorization means for the glycerol byproduct from existing biodiesel industry. Two heat recovery options were considered; the combustion of a produced syngas split or a partially oxidized reactor configuration.…”