0000000000136436
AUTHOR
Kari Eränen
Ionic liquids versus amine solutions in biogas upgrading: the level of volatile organic compounds
Background: This article provides information related to the occurrence of volatile organic compounds before and after biogas purification, by means of both aqueous amine solutions and ionic liquids. Results & discussion: Encouraging results were obtained. Under the experimental conditions, 1-butyl-3-methylimidazolium acetate ionic liquid appeared to perform at least two-times better than aqueous amines solutions, since it captured 65 wt% of the identified volatile organic compounds, while aqueous amine solutions retained around 35 wt% only. However, in the case of octamethylcyclotetrasiloxane and dichlorobenzene, aqueous amine solutions rendered better purification performance and diminish…
Isomerization of α-pinene oxide over ZSM-5 based micro-mesoporous materials
Abstract Few types of ZSM-5 based micro-mesoporous materials obtained via a dual template method, steam-assisted conversion and dual-functional templating were evaluated in α-pinene oxide isomerization. Complete conversion and the highest selectivity towards trans-carveol (ca. 40–43%) were achieved over X-ray amorphous micro-mesoporous aluminosilicates as well as mesoporous molecular sieves AlSi-SBA-15. In addition, X-ray amorphous samples containing the secondary building units of ZSM-5 zeolite demonstrated the highest rate of α-pinene oxide isomerization. The yield of the most desired product trans-carveol to a large extent depends on the accessibility of acid sites to the reagents molecu…
Oxidative dehydrogenation of alcohols on gold : An experimental and computational study on the role of water and the alcohol chain length
The oxidative dehydrogenation of primary alcohols promoted by gold nanoparticles was investigated from an experimental and computational viewpoint to derive a plausible reaction mechanism and to understand the role of water and alcohol chain length in the elementary steps. The influence of water in reaction kinetics and product distribution was determined in a laboratory-scale microreactor adding water to the reaction mixture in different amounts. DFT calculations revealed that the presence of water on the catalyst surface is beneficial to assist the key step in alcohol oxidation i.e., oxygen activation by protonation. The calculations were performed for primary alcohols ranging from methan…
From a fixed bed Ag–alumina catalyst to a modified reactor design: how to enhance the crucial heterogeneous–homogeneous reactions in HC-SCR
Abstract A highly active Ag/alumina catalyst for continuous reduction of NO to nitrogen with n-octane under lean conditions was prepared. It was observed in the reactor set-up experiments for optimization of the converter, that surface generated gas phase species are crucial for obtaining high conversion. EPR and matrix isolated FTIR studies at low temperature (10–18 K) were performed for identification of the radicals. Experimental data, observed at steady state conditions in the temperature range 300–550 °C, was used to produce an artificial neural network model of the catalytic converter with four catalyst beds.
HC-SCR of NOx over Ag/alumina: a combination of heterogeneous and homogeneous radical reactions?
Matrix isolation combined with EPR and FT-IR technique at low temperature has been used to study the gas phase species involved in HC-SCR over a highly active Ag/alumina catalyst. A combination of heterogeneous and homogeneous (radical) reactions is proposed to take place over a Ag/alumina catalyst during HC-SCR. Radicals of low molecular weight were trapped in a growing argon matrix behind the Ag/alumina catalyst. In the same matrix, cyanogen isocyanate was detected and is suggested to be a key intermediate for the formation of amines and ammonia via the hydrolysis of isocyanate species.
CO2 capture from biogas: Absorbent selection
The development of proper biogas upgrading technology offers a viable means to utilize biogas in conventional power systems. In this paper, various molecular and ionic solvent systems were evaluated for CO2 removal from biogas in a loop reactor system. The performance of amine solutions, ionic liquids and their mixtures, amino acid salts and solutions blended with piperazine was compared in terms of their CO2 loading capacity. The experimental results revealed that addition of small amounts of piperazine can increase on average by 30 vol% the efficiency of above-mentioned solutions. The CO2 capturing capacity achieved for the most promising solvents was in the range of 50–60 L CO2/L absorbe…