Search results for "Biomassa"
showing 10 items of 99 documents
Puuperäisiä biomassoja ja mikroturbiinitekniikkaa hyödyntävän pienen kokoluokan CHP-laitoksen mallintaminen osaksi aluelämpöverkkomallia
2015
Tässä tutkielmassa mallinnettiin MATLAB:lla pienen kokoluokan (< 1MW) yhdistetty lämmön- ja sähköntuotantoyksikkö (CHP), joka hyödyntää puuperäisiä biomassoja polttoaineena ja mikroturbiiniteknologiaa sähkön tuottamiseen. Mallinnustyö jakaantui tarkastelemaan puuhakkeen ja pellettien palamisessa muodostuvia savukaasuja, Turbec T100- mikroturbiinijärjestelmän sähköntuotantoa, vastavirta lämmönvaihtimien toimintaa sekä koko yksikön liittämistä osaksi VTT:n rakentamaa aluelämpöverkkomallia. In this thesis, a MATLAB based model was constructed of a small scale (< 1MW)combined heat- and power production (CHP) unit which utilizes woody biomasses as fuel and microturbine technology in the producti…
Potential applications of nanotechnology in bioenergy
2011
Nanotechnology has an increasingly large impact on a wide range of industries, but its current use in the production of electricity and heat from biomass is limited. This thesis examined the potential impact of nanotechnology on bioenergy production through a literature review and interviews with industry members. Current technologies and methods in use were reviewed, with a focus on fuel handling and combustion systems. Areas in which problems existed were identified and nanotechnologies with properties relevant to those problems examined. The major nanotechnology areas which were reviewed are nanostructured coatings (wear resistant, corrosion resistant, low friction and anti-icing), nanom…
Effect of Tire-Char Ash on the Extent of Synergy during CO2 Cogasification with Hydrochar from Potassium-Rich Coconut Fiber
2020
The influence of inherent tire char ash during co-gasification with coconut hydrochar prepared at different intensities was investigated by thermogravimetric analysis to ascertain the extent to which synergistic interaction, reactivity, and activation energy reduction were altered. High-ash tire tread (TT) and low-ash sidewall (SW) both exhibited enhanced synergy, reactivity, and activation reduction upon co-gasification with hydrochars; however, the extent of promotion was more pronounced in SW-hydrochar blends. This difference was caused by the inhibiting nature of TT inherent ash, particularly the role of Si-containing compounds. Inhibition in TT-hydrochar blends was mainly due to the pr…
Facile synthesis of sustainable activated biochars with different pore structures as efficient additive-carbon-free anodes for lithium- and sodium-io…
2022
The present work elucidates facile one-pot synthesis from biomass forestry waste (Norway spruce bark) and its chemical activation yielding high specific surface area (SBET) biochars as efficient lithium- and sodium-ion storage anodes. The chemically activated biochar using ZnCl2 (Biochar-1) produced a highly mesoporous carbon containing 96.1% mesopores in its structure as compared to only 56.1% mesoporosity from KOH-activated biochars (Biochar-2). The latter exhibited a lower degree of graphitization with disordered and defective carbon structures, while the former presented more formation of ordered graphite sheets in its structure as analyzed from Raman spectra. In addition, both biochars…
Biogas production from energy crops and crop residues
2006
Energiantuotantoa varten viljellyt energiakasvit ja erilaiset kasvintuotannon sivutuotteet ja jätteet eli peltobiomassat tarjoavat puhtaan ja kotimaisen uusiutuvan energialähteen. Kasvibiomassa voidaan hyödyntää energiana useilla eri tavoilla, joista yksi on biokaasun tuotanto. Biokaasua voidaan hyödyntää lämmön- ja sähköntuotannossa tai liikenteen polttoaineena fossiilisten polttoaineiden sijasta.Annimari Lehtomäki tutki mahdollisuuksia hyödyntää energiakasveja ja kasvijätteitä biokaasun tuotannossa pohjoisissa oloissa. Tutkimuksessa kartoitettiin Suomen oloissa menestyviä, biokaasun tuotantoon mahdollisesti soveltuvia kasvilajeja, sekä määritettiin niiden kemiallinen koostumus ja biokaasu…
Comparison of epifluorescence microscopy and flow cytometry in counting freshwater picophytoplankton
2021
The smaller the phytoplankton, the greater effort is required to distinguish individual cells by optics-based methods. Flow cytometry is widely applied in marine picophytoplankton research, but in freshwater research its role has remained minor. We compared epifluorescence microscopy and flow cytometry in assessing the composition, abundance and cell sizes of autofluorescent picophytoplankton in epilimnia of 46 Finnish lakes. Phycocyaninrich picocyanobacteria were the most dominant. The two methods yielded comparable total picophytoplankton abundances, but the determination of cell sizes, and thus total biomasses, were on average an order of magnitude higher in the microscopy results. Howev…
Vertical stratification of bacteria and archaea in sediments of a small boreal humic lake
2019
Bioindicatori della qualità del suolo
2012
La qualità del suolo è un aspetto fondamentale della gestione sostenibile dell’agrosistema, al pari della qualità dell’acqua e dell’aria. Studiare la qualità del suolo significa valutare quanto bene esso svolga le proprie funzioni e come esse possano essere migliorate o salvaguardate per il futuro. Poiché la definizione di qualità del suolo è oggettiva, essa non può essere valutata utilizzando fattori di opportuna convenienza, ma attraverso l’uso di indicatori. Le proprietà biochimiche possono essere utilizzate come “indicatori precoci” delle perturbazioni che degradano il suolo in quanto risultano maggiormente sensibili alle variazioni indotte dall’attività antropica e dall’ambiente rispet…
Regressiomenetelmiä viljapellon biomassan estimointiin ortokuvista ja digitaalisesta korkeusmallista
2012
Tutkielmassa esitellään käyttötarkoitus biomassan estimoinnille ja vertaillaan kolmea regressiomenetelmää, lineaarista regressiota, k:n lähimmän naapurin menetelmää sekä tukivektoriregressiota. Tutkielmassa esitellään myös aineisto ja aineistoon suoritetut muunnokset.
Carbons from second generation biomass as sustainable supports for catalytic systems
2018
Abstract In this study activated carbons were produced from the wood of three different wood species (pine, birch, spruce). The resulting activated carbons were characterized in bulk for ash content, carbon content (elemental analyses), specific surface area, and pore size distribution, and at the surface by measuring the autogenerated pH and studying their structure by XPS. All the samples presented high surface areas and appeared to be mesoporous materials (mesopores >80%). The carbons were then used as support for AuPt nanoparticles and tested in the liquid phase oxidation of glycerol (GLY) and in the hydrogenation of levulinic acid (LA), two important chemicals from cellulose-based biom…