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Chemical engineering is mostly taught using traditional classroom teaching and laboratory experiments when possible. Being a wide discipline encompassing topics such as analytical chemistry, process design, and microbiology, it may be argued that brewing of beer has many relations to chemical engineering topic-wise. This work illustrates how brewing of beer on a pilot scale system may actually cover 81% of the ECTS of the bachelor degree in Chemical Engineering and Biotechnology taught at Aalborg University, which emphasizes project organized problem based learning. This large degree of coverage, exemplified for both classroom topics and student projects leads, to the conclusion that brewing may be regarded as a comprehensive learning platform in chemical engineering.

Kraft lignin depolymerisation using hydrothermal liquefaction suffers from the formation of char, resulting in a decreased product yield as well as causing operational problems. While this may be mitigated by the addition of capping agents such as phenol and isopropanol, other reaction parameters, for example reaction time and temperature, are also important for the product yields. In this work, the effect of short reaction times on the hydrothermal liquefaction of kraft lignin in an alkaline water and isopropanol mixture was investigated at 1–12 min and 290 °C. The results show that there were swift initial reactions: the major ether bonds in the lignin were broken within the first minute of reaction, and the molecular weight of all product fractions was halved at the very least. Longer reaction times, however, do not cause as pronounced structural changes as the initial reaction, indicating that a recalcitrant carbon-carbon skeleton remained in the products. Nevertheless, the yields of both char and monomers increased slowly with increasing reaction time. The swift initial depolymerising reactions were therefore followed by slower repolymerisation as well as a slow formation of monomers and dimers, which calls for careful tuning of the reaction time. [ABSTRACT FROM AUTHOR]

Supercritical carbon dioxide extraction was utilized for the fractionation of a pinewood derived hydrothermal liquefaction bio-crude. The experiments were performed at temperature 120 °C and at pressure levels that correspond to CO2 density of 500, 615 and 730 kg/m³. Extraction yields of 34 to 49% were achieved, which increased with increasing solvent density. Density was reduced for all extracts (2-10%) while the H/C ratio increased when compared to the bio-crude. Low boiling point components such as ketones, 1-ring aromatic hydrocarbons and low molecular weight fatty acids were extracted preferentially (K-values up to 11). 1-ring phenols and benzenediols were enriched in the extracts as well (K-values 1-3). Heavy hydrocarbons and long chain fatty acids were extracted at the later stages of extraction when the lighter components were depleted. [ABSTRACT FROM AUTHOR]

The performance of natural gas dehydration using triethylene glycol (TEG) strongly depends on the purity level of TEG in the regeneration unit. Coldfinger is a TEG regeneration technology reported to be capable of increasing TEG purity to levels above 99.8 wt.%, but conceptual models of this equipment appear to be lacking. This work presents a methodology for modeling Coldfinger, where the equipment is represented as two theoretical equilibrium stages operating at different temperatures in the presence of internal vapor recirculation. The key parameters governing the functioning of the equipment are discussed on the basis of a series of simulations carried out for different top temperatures and internal recirculation ratios. The results demonstrate that a regeneration of TEG up to approximately 99.9 wt.% is achievable by injecting smalls amounts of dry gas, considerably lower than conventional enhanced TEG regeneration by gas stripping. [ABSTRACT FROM AUTHOR]

Triazine is one of the most commonly used scavengers for removal of hydrogen sulphide in the offshore oil and gas industry, but the kinetics of the scavenging reactions are still poorly understood. In this work the feasibility of Raman spectroscopy for on-line monitoring of the aqueous phase reaction between 1,3,5-tri-(2- hydroxyethyl)- hexahydro-s-triazine (HET) and HS- was studied. It was found that the development of specific peaks in the Raman spectra reveals clear patterns related to the changes of concentration of HET and HS- with time. On this basis, a qualitative evaluation of the dependence of the reaction kinetics on temperature and pH was carried out. No change in Raman peaks was observed at 40 °C for reaction time of 30 minutes, but a reaction was observed at 50 °C. Furthermore, a decrease in the reaction rate as the initial pH increases was observed in the pH range 8.5 to 10.3. No change in peaks was observed at pH 10.3 within 30 minutes. [ABSTRACT FROM AUTHOR]