Search results for "Biomassa"
showing 10 items of 99 documents
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…
Modeling biomass char gasification kinetics for improving prediction of carbon conversion in a fluidized bed gasifier
2014
Gasification of biomass in a fluidized bed (FB) was modeled based on kinetic data obtained from previously conducted thermo- gravimetic analysis. The thermogravimetric analysis experiments were designed to closely resemble conditions in a real FB gasifier by using high sample heating rates, in situ devolatilization and gas atmospheres of H 2 O / H 2 and CO 2 / CO mixtures. Several char kinetic models were evaluated based on their ability to predict char conversion based on the thermogravimetric data. A modified version of the random pore model was shown to provide good fitting of the char reactivity and suitability for use in a reactor model. An updated FB reactor model which incorporates t…
Advanced Biorefinery Concepts Integrated to Chemical Pulping
2017
Simultaneous production of furfural and levulinic acid from pine sawdust via acid-catalysed mechanical depolymerization and microwave irradiation
2019
Abstract In this work pine sawdust was converted into levulinic acid (LA) and furfural. Sawdust was first pre-treated with sulfuric acid-catalysed mechanical depolymerization. The conversion reactions were then performed with microwave heating at 180 °C. To enhance the furfural yield and the efficient separation of furfural and LA, a biphasic water-toluene reaction system was used. The effect of an additional catalyst, AlCl3, on the yield of LA and furfural was also studied. According to the results the pre-treatment method enhanced the yields of LA. In addition, due to the microwave heating the reaction times were short. Additional AlCl3 catalyst enhanced the LA yield, however excellent fu…
Assessment of microalgae species, biomass, and distribution from spectral images using a convolution neural network
2022
AbstractEffective monitoring of microalgae growth is crucial for environmental observation, while the applications of this monitoring could also be expanded to commercial and research-focused microalgae cultivation. Currently, the distinctive optical properties of different microalgae groups are targeted for monitoring. Since different microalgae can grow together, their spectral signals are mixed with ambient properties, making estimations of species biomasses a challenging task. In this study, we cultured five different microalgae and monitored their growth with a mobile spectral imager in three separate experiments. We trained and validated a one-dimensional convolution neural network by…
Microwave-assisted conversion of novel biomass materials into levulinic acid
2018
Levulinic acid is considered one of the most important platform chemicals. It is currently produced mainly from lignocellulosic biomasses. However, there are also other abundant biomass materials, which could be used as raw materials for levulinic acid production. In this work, levulinic acid was produced from two novel biomasses in the presence of Brønsted (H2SO4) and Lewis acid (CrCl3·6H2O or AlCl3·6H2O) catalysts. The studied materials were carbohydrate-rich potato peel waste and sporocarps of the fungus Cortinarius armillatus. Reaction conditions, i.e., time, temperature, H2SO4, and Lewis acid concentrations, were studied by utilizing full 24-factorial experimental designs. Microwave ir…
Nuovi Catalizzatori Sol-Gel per la Chimica Fine e la Valorizzazione della Biomassa
2014
Tiellä kohti uusien energiateknologioiden kaupallistumista : eri toimijoiden näkemyksiä puubiomassaa polttoaineenaan käyttävien pien- ja mikro-kokolu…
2011
Tässä laadullisessa tutkimuksessa selvitettiin puubiomassaa polttoaineenaan käyttävien pien- ja mikro-kokoluokan CHP-teknologioiden innovaatioprosessiin, erityisesti kaupallistamiseen ja markkinoilla yleistymiseen, liittyviä edistämistekijöitä ja esteitä. Tutkimusaineisto koottiin haastattelemalla 10 eri toimijaa, jotka edustivat kattila- ja laitevalmistajia, korkeakouluja, tutkimuslaitoksia, julkisia rahoittajia sekä kehitysyhtiöitä. Haastateltavilta kysyttiin heidän näkemyksiään tarkasteltavien energiateknologioiden innovaatioprosessiin vaikuttavista edistämistekijöistä ja esteistä viidestä eri näkökulmasta: poliittisesta, taloudellisesta, sosiaalisesta, teknologisesta ja ympäristötekijöi…
Comparison of the Properties of Activated Carbons Produced in One-Stage and Two-Stage Processes
2018
Activated carbons (ACs) can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later activating the bio-chars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in one-stage and two-stage processes are considered. Activated carbons were produced by physical activation of two types of starting materials: bio chars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific …
Protein recovery as a resource from waste specifically via membrane technology : from waste to wonder
2021
Economic growth and the rapid increase in the world population has led to a greater need for natural resources, which in turn, has put pressure on said resources along with the environment. Water, food, and energy, among other resources, pose a huge challenge. Numerous essential resources, including organic substances and valuable nutrients, can be found in wastewater, and these could be recovered with efficient technologies. Protein recovery from waste streams can provide an alternative resource that could be utilized as animal feed. Membrane separation, adsorption, and microbe-assisted protein recovery have been proposed as technologies that could be used for the aforementioned protein re…