Maximizing biofuel production in a thermochemical biorefinery by adding electrolytic hydrogen and by integrating torrefaction with entrained flow gasification

Abstract

Document Version Peer reviewed version Link back to DTU Orbit Citation (APA):Clausen, L. R. (2015). Maximizing biofuel production in a thermochemical biorefinery by adding electrolytic hydrogen and by integrating torrefaction with entrained flow gasification. Energy, 85, 94-101. DOI: 10.1016/j.energy.2015 Maximizing biofuel production in a thermochemical biorefinery by adding electrolytic hydrogen and by integrating torrefaction with entrained flow gasification AbstractIn a "conventional" thermochemical biorefinery, carbon is emitted from the plant in the form of CO2 to make the synthesis gas from the gasifier suitable for fuel production. The alternative to this carbon removal is to add hydrogen to the plant. By adding hydrogen, it is possible to more than double the biofuel production per biomass input by converting almost all of the carbon in the biomass feed to carbon stored in the biofuel product. Water or steam electrolysis can supply the hydrogen to the biorefinery and also the oxygen for the gasifier. This paper presents the design and thermodynamic analysis of two biorefineries integrating water electrolysis for the production of methanol. In both plants, torrefied woody biomass is supplied to an entrained flow gasifier, but in one of the plants, the torrefaction process occurs on-site, as it is integrated with the entrained flow gasification process. The analysis shows that the biorefinery with integrated torrefaction has a higher biomass to methanol energy ratio (136% vs. 101%) as well as higher total energy efficiency (62% vs. 56%). By comparing with two identical biorefineries without electrolysis, it is concluded that the biorefinery with integrated torrefaction benefits most from the integration of electrolysis.

Energy efficient thermochemical conversion of very wet biomass to biofuels by integration of steam drying, steam electrolysis and gasification

“…Previous work within this field of integrating gasification and electrolysis for synthesis of fuels or chemicals include [1][2][3][4][5][6][7][8]. The biofuels produced in these references are: methanol [1,[4][5][6][7], Fischer-Tropsch fuels [2], synthetic natural gas (SNG) [3], and dimethyl ether (DME) [8]. Liquid water electrolysis is used in these studies, except for [2,8], in which steam electrolysis is used instead.…”

Biomass gasification for bioenergy

“…If a liquid fuel is produced, CO2 removal would most likely be used in both Fig. 12a and b to lower the synthesis reactor size and reduce the syngas loss by the synthesis loop purge (Clausen, 2015). Most of the operating modes shown in Fig.…”

“…Pressurization of both gasifier and SOC could be highly feasible for large-scale systems, and would reduce the syngas and would reduce the consumption of power for syngas compression. Pressurized gasification is typically assumed for large-scale systems (Clausen, 2015;Larson et al, 2009) and is commercially used by coal gasifiers, but pressurized SOC operation is rarely assumed, and only few pressurized SOC experiments have been performed (Jensen et al, , 2017.…”

Optimization of a flexible multi-generation system based on wood chip gasification and methanol production

“…The hypothesis is that the present FMG is advantageous in an energy system with large shares of intermittent renewable power generation as it may absorb additional power in periods with excess generation (low power prices) and convert it to methanol by boosting product gas from the gasifier with hydrogen from the SOEC [29]. Similarly, it may reduce power consumption in periods with high power prices by reducing SOEC load and thereby methanol production.…”

“…In the present work, a surrogate model of the biorefinery was developed based on the models presented by Clausen et al [28] [29]. The gasifier was assumed fed by imported wood chips.…”