Search results for "etanoli"
showing 10 items of 14 documents
Exploring CO2 hydrogenation to methanol at a CuZn–ZrO2 interface via DFT calculations
2023
Multi-component heterogeneous catalysts are among the top candidates for converting greenhouse gases into valuable compounds. Combinations of Cu, Zn, and ZrO2 (CZZ) have emerged as promisingly efficient catalysts for CO2 hydrogenation to methanol. To explore the catalytic mechanism, density functional theory (DFT) calculations and the energetic span model (ESM) were used to study CO2 conversion routes to methanol on CuZn–ZrO2 interfaces with a varying Zn content. Our results demonstrate that the presence of Zn sites at the interface improves CO2 binding. However, the adsorption and activation energies are insensitive to Zn concentration. The calculations also show that the hydrogenation of …
Microwave-Assisted Esterification of Tall Oil Fatty Acids with Methanol Using Lignin-Based Solid Catalyst
2016
During alkaline pulping significant amounts of lignin, carbohydrates (mostly hemicelluloses), and extractives (tall oil soap and turpentine) are removed from wood feedstock. In this study, the catalytic esterification of fatty acids in tall oil with methanol to produce fatty acid methyl esters under microwave irradiation was performed at 100 °C for 10–60 min. A novel heterogeneous acid catalyst tested for this purpose was synthesized from the hardwood alkali lignin that was precipitated by acidification from the black liquor from soda-AQ pulping. The comparative reaction data were obtained by using other solid catalysts, Amberlyst 15, and p-toluenesulfonic acid. The results showed the highe…
TNT:n ja RDX:n määrittäminen HPLC:lla ja menetelmän validointi
2009
Methylophilaceae and Hyphomicrobium as target taxonomic groups in monitoring the function of methanol-fed denitrification biofilters in municipal was…
2017
Abstract Molecular monitoring of bacterial communities can explain and predict the stability of bioprocesses in varying physicochemical conditions. To study methanol-fed denitrification biofilters of municipal wastewater treatment plants, bacterial communities of two full-scale biofilters were compared through fingerprinting and sequencing of the 16S rRNA genes. Additionally, 16S rRNA gene fingerprinting was used for 10-week temporal monitoring of the bacterial community in one of the biofilters. Combining the data with previous study results, the family Methylophilaceae and genus Hyphomicrobium were determined as suitable target groups for monitoring. An increase in the relative abundance …
Improvement of xylose fermentation of Saccharomyces cerevisiae
2012
The increasing need of oil and the negative impacts of fossil fuels on climate change have motivated the research towards environmental friendly alternatives to diminish the use of fossil resources. Until today, bioethanol production and use has increased worldwide. The raw materials used today compete with food industry and conquently, the ethanol production from lignocellulose has been developed intensively. However, to make the processes economically competitive, also pentoses in lignocellulose should be fermented at high rate. Saccharomyces cerevisiae, alias baker’s yeast has an excellent ethanol production capacity but it can not naturally utilize xylose. Several xylose-utilizing S. ce…
Kuusen pihkan etanoliuuton optimointi
2018
Kuusessa on muutakin hyödynnettävää kuin paperin ja kartongin valmistukseen tarvittava raaka-aine. Mielenkiinto on kohdistunut etenkin puun sisältämiin yhdisteisiin, joilla on havaittu olevan suotuisia terveydellisiä vaikutuksia. Tällainen on kuusen pihka, joka on useamman yhdisteen seos. Kuusen eri osien sisältämien yhdisteiden tutkimus on yhä ajankohtaisempaa. Esimerkiksi niin kuusesta kuin männystä saatavia antibiootteja tutkitaan Itä-Suomen yliopistossa. Repolar Pharmaceuticals Oy perustettiin vuonna 2006 pihkavalmisteiden tuotannon aloittamiseksi. Idea saatiin kotitekoisesta pihkasalvasta, jota yleisesti käytettiin Lapissa haavojen hoitoon. Repolar Pharmaceuticalsin tilaaman työn aihee…
Lignoselluloosan happamassa esikäsittelyssä poistuvat hiilihydraatit
2017
Tämän lisensiaattitutkielman kirjallisessa osassa esitettiin kuvaus biomassoista, (ligno- selluloosamateriaalit) ja niihin pohjautuvien jalostettujen polttoaineiden tuotannon haasteista ja kustannuksta sekä tarkasteltiin biomassaraaka-aineiden esikäsittelymene- telmiä. Tarkastelun pohjana oli Suomen kasvuoloissa yleisimpien lingoselluloosa- materiaalien, havu- ja lehtipuun sekä ruokohelpin, soveltuminen bioetanolituotantoon niin integroituna perinteisen sellutehtaan yhteyteen kuin myös omana erillisenä tuo- tantonaan. Tutkielman kokeellisessa osassa analysoitiin eri esikäsittelymenetelmien, laimean ja väkevän rikkihappokäsittelyn sekä vesikäsittelyn vaikutusta tuotetun hydrolysaatin koostum…
Enrichment of Bacterioplankton Able to Utilize One-Carbon and Methylated Compounds in the Coastal Pacific Ocean
2018
International audience; Understanding the temporal variations and succession of bacterial communities involved in the turnover of one-carbon and methylated compounds is necessary to better predict bacterial impacts on the marine carbon cycle and air-sea carbon fluxes. The ability of the local bacterioplankton community to exploit one-carbon and methylated compounds as main source of bioavailable carbon during a productive and less productive period was assessed through enrichment experiments. Surface seawater was amended with methanol and trimethylamine-N-oxide (TMAO), and bacterial abundance, production, oxygen consumption, as well as methanol turnover and growth rates of putative methylot…
Hiilihydraateista bioteknisesti valmistettavat merkittävät teollisuuskemikaalit
2010
Effect of atomic layer deposited zinc promoter on the activity of copper-on-zirconia catalysts in the hydrogenation of carbon dioxide to methanol
2023
Funding Information: The work at Aalto University has been financially supported by the Academy of Finland (COOLCAT consortium, decision no. 329977 and 329978 ; ALDI consortium, decision no. 331082 ). This work made use of Aalto University Bioeconomy, OtaNano and RawMatters infrastructure. Hannu Revitzer (Aalto University) is thanked for the ICP-OES analysis, Aalto workshop people (especially Seppo Jääskeläinen) for working on the reactor modifications. The DFT calculations were made possible by computational resources provided by the CSC — IT Center for Science, Espoo, Finland ( https://www.csc.fi/en/ ) and computer capacity from the Finnish Grid and Cloud Infrastructure (urn:nbn:fi:resear…