Torrefaction: Process Parameters and Reactor Design

Torrefaction is a thermochemical process, where biomass is obtained in temperature range from from 200 to 300 °C, in inert atmosphere with the aim to increase carbon content of biomass. In this paper, emphasis is on biomass feedstock types, different effects on torrefaction success, and torrefaction reactors

Influence of Natural Zeolites on the Thermal Decomposition of Multi-layered Plastic Waste

The pyrolysis process drove scientific attention lately, as it represents the basis for the production of second generation of synthetic fuels and other chemicals. The process takes place in inert atmosphere, and liquids, gases, and small number of solid particles represent main reaction products. Pyrolysis can be thermal or catalytic. Thermal pyrolysis requires very high temperatures, and products do not have high quality, while addition of catalysts reduces the reaction time, there is a better conversion rate, and lower operation temperature. In this paper, multi-layered plastic waste is used as raw material for thermogravimetric analysis (TGA). The composition of used plastic waste was previously determined based on the analysis of a large number of samples from fraction of mechanically non-recyclable plastic waste collected from waste treatment facilities in Croatia. Two natural zeolites with the most promising catalysts properties were selected for the reaction. Thermogravimetric analysis was used to understand the pyrolysis process of multi-layered plastic waste and to determine the thermochemical behavior and kinetics. Kinetic analysis was performed using the isoconversional Kissinger-Akahira-Sunose method. The aim of this paper was to investigate how selected natural zeolite catalysts influence the kinetics of the pyrolysis process of multi-layered plastic waste

Matematičko modelovanje proizvodnje etanola u toku fermentacije medovine

Niz autora je dokazalo da se modifikovana Gompertz-ova jednačina možeprimijeniti za matematičko modelovanje kinetike fermentacije različitih supstrata.U ovom radu se po prvi put analizira primjenjivost modifikovane Gompertz-ovejednačine za opisivanje kinetike nastanka etanola prilikom procesa fermentacijemedovine u laboratorijskim uslovima. Optimalni kinetički parametri su dobijenifitovanjem eksperimentalnih podataka u modifikovani Gompertzov-model, teprimjenom nelinearne regresione analize i ocjenom regresionih koeficijenatametodom najmanjih kvadrata. Numerička optimizacija parametara i njihova statističkaanaliza je izvršena primjenom matematičkih alata Solver i Regression iz programskogpaketa Microsoft Excel. Dobijeni matematički model opisuje nastanak etanola tokomfermentacije medovine, predviđa maksimalnu koncentraciju etanola, maksimalnubrzinu fermentacije i lag vrijeme produkcije etanola

UTICAJ TEMPERATURE NA PIROLIZU OTPADNE PLASTIKE U REAKTORU SA FIKSNIM SLOJEM

Piroliza, kao jedna od tehnika hemijske reciklaže plastičnih materijala, danas izaziva sve veća intersovanja kao ekološki i ekonomski prihvaljiva opcija obrade otpadnih materijala. Istraživanja ovih procesa se provode pri različitim eksperimentalnim uslovima, u različitim vrstama reaktora i sa različitim sirovinama, što čini poređenje procesa i direktnu primjenu procesnih parametara dosta složenim. U ovom radu dati su rezultati istraživanja uticaja temperature, u intervalu od  450°C do 525°C, na prinos procesa pirolize smjese otpadne plastike u sastavu: polipropilen 40%, polietilen niske gustine 35% i polietilen visoke gustine 25%. Istraživanja su provedena u pilot reaktoru sa fiksnim slojem koji je razvijen za ovu namjenu. Rezultati provedenih istraživanja pokazuju da se pri temperaturi od 500°C  postiže potpuna konverzija sirovine u vremenu od 45 min, uz maksimalni prinos pirolitičkog ulja od 32,80%, prinos gasovitih produkata od 65,75% i čvrsti ostatak od 1,46%. Sa daljim porastom temperature raste prinos gasovitih produkata, na račun smanjenja prinosa pirolitičkog ulja. Dobijeno pirolitičko ulje ima visoku toplotnu moć (45,96 МЈ/kg), te u tom pogledu ima potencijal primjene kao alternativno gorivo

Pyrolysis as a key process in biomass combustion and thermochemical conversion

Biomass is a fuel with a highly volatile content and due to that, pyrolysis as a part of the combustion process, has a dominant role in the overall process development, as well as on final products and the process efficiency. It is of key importance to investigate the influence of the process parameters; as temperature, furnace/reactor environment, fuel properties, type, particle size, geometry, and the structure of the pyrolysis process has an influence regards the design of the combustion/pyrolysis equipment and the final products of the processes. This paper gives some results of the investigation’s related to this problem, mainly focussing on wooden biomass as the most important biomass type, as well as a comparison with relevant documented literature. Besides that, pyrolysis based technologies are one of the key directions in synthetic fuels production based on biomass. Biomass pyrolysis process parameters are crucial in reactor design as well as the quantity and quality of the final products. This paper provides discussion dedicated to this aspect with a focus on slow pyrolysis, targeting charcoal as the key product, and fast pyrolysis, targeting synthetic gas as the key product

RENEWABLE ENERGY SOURCES AND THEIR POTENTIAL ROLE IN MITIGATION OF CLIMATE CHANGES AND AS A SUSTAINABLE DEVELOPMENT DRIVER IN BOSNIA AND HERZEGOVINA

Bosnia and Herzegovina have significant physical potential regarding to renewable energy sources. Hydro, biomass, geothermal, wind, and solar potential can play important role in the whole state economy. Bosnia and Herzegovina is Non-Annex I country according to UNFCCC and according to that it is obligated to participate in the global efforts in order to reduce green house gases emission. This paper gives some analysis of the physical, technological, economic, and market potential of renewable energy sources in Bosnia and Herzegovina and their potential role in mitigation of climate changes. Paper also gives the analysis of the potential connections between renewable energy sources and sustainable development of the economy, taking in to consideration specific political structure of the state. Bosnia and Herzegovina is consisting from two entities: Republic of Srpska and Federation of Bosnia and Herzegovina, and Brcko District; energy sector and climate changes mitigation measures are under their jurisdiction. According to that some of this paper results can be useful for the improvement of entity and state strategies with the final aim to place renewable energy sources on the right position, as some of the major economy drivers, not only in Bosnia and Herzegovina, but in whole region