TY - JOUR

T1 - Thermo-oxidative aging of linear and branched alcohols as stability criterion for their use as e-fuels

AU - Lichtinger, Anne

AU - Poller, Maximilian J.

AU - Schröder, Olaf

AU - Türck, Julian

AU - Garbe, Thomas

AU - Krahl, Jürgen

AU - Jakob, Markus

AU - Albert, Jakob

N1 - Publisher Copyright: © 2024 The Royal Society of Chemistry.

PY - 2024/6/19

Y1 - 2024/6/19

N2 - The decarbonization of the energy supply is one of the biggest and most important challenges of the 21st century. This paper contributes to the solution of the energy crisis by investigating the stability of alcohols as e-fuels. The focus is on the investigation of the aging mechanism of the linear alcohols 1-hexanol and 1-octanol compared to the iso-alcohol 2-hexanol. It is analysed in detail how the time-dependent aging varies depending on the chain length and the position of the hydroxy-group, both in the liquid and in the gas phase. It is shown that a variety of aging products such as aldehydes, acids, short-chain alcohols and esters are formed during the aging of the n-alcohols by oxidation, decarboxylation, oxidative C-C bond cleavage and esterification. In contrast, the decomposition of the iso-alcohol is significantly lower. The results show that the total acid number is significantly higher for aged n-alcohols than for the aged iso-alcohos, while the kinematic viscosity decreases for all alcohols during aging. Carbon mass balancing shows that after accelerated aging for 120 hours, around 80% of the iso-alcohol is still present, compared to only around 57-63% for the n-alcohols. In addition, significantly fewer acids are formed with the iso-alcohol. In this study, iso-alcohols have a higher stability against thermo-oxidative aging compared to n-alcohols, showing their potential as e-fuels. Furthermore, the chain length of the alcohols has also an influence on aging, as more different aging products can be formed with increasing chain length.

AB - The decarbonization of the energy supply is one of the biggest and most important challenges of the 21st century. This paper contributes to the solution of the energy crisis by investigating the stability of alcohols as e-fuels. The focus is on the investigation of the aging mechanism of the linear alcohols 1-hexanol and 1-octanol compared to the iso-alcohol 2-hexanol. It is analysed in detail how the time-dependent aging varies depending on the chain length and the position of the hydroxy-group, both in the liquid and in the gas phase. It is shown that a variety of aging products such as aldehydes, acids, short-chain alcohols and esters are formed during the aging of the n-alcohols by oxidation, decarboxylation, oxidative C-C bond cleavage and esterification. In contrast, the decomposition of the iso-alcohol is significantly lower. The results show that the total acid number is significantly higher for aged n-alcohols than for the aged iso-alcohos, while the kinematic viscosity decreases for all alcohols during aging. Carbon mass balancing shows that after accelerated aging for 120 hours, around 80% of the iso-alcohol is still present, compared to only around 57-63% for the n-alcohols. In addition, significantly fewer acids are formed with the iso-alcohol. In this study, iso-alcohols have a higher stability against thermo-oxidative aging compared to n-alcohols, showing their potential as e-fuels. Furthermore, the chain length of the alcohols has also an influence on aging, as more different aging products can be formed with increasing chain length.

KW - Sustainability Governance

UR - http://www.scopus.com/inward/record.url?scp=85197926631&partnerID=8YFLogxK

U2 - 10.1039/d4se00400k

DO - 10.1039/d4se00400k

M3 - Journal articles

AN - SCOPUS:85197926631

JO - Sustainable Energy and Fuels

JF - Sustainable Energy and Fuels

SN - 2398-4902

ER -