Sevgi Şensöz

Slow pyrolysis of wood barks from Pinus brutia Ten. and product compositions

Biomass in the form of pine bark (Pinus brutia Ten.) was pyrolysed in an externally heated fixed-bed reactor. The effects of temperature and heating rate on the yields and compositions of the products were investigated. Pyrolysis runs were performed using reactor temperatures between 300 and 500 degrees C with heating rates of 7 and 40 degrees Cmin(-1). The product yields were significantly influenced by the process conditions. The bio-oil obtained at 450 degrees C, at which the liquid product yield was maximum, was analysed. It was characterized by Fourier transform infrared spectroscopy. In addition, the solid and liquid products were analysed to determine their elemental composition and calorific value. Chemical fractionation of bio-oil showed that only low quantities of hydrocarbons were present, while oxygenated and polar fractions dominated. The empirical formula of the bio-oil with heating value of 31.03 MJkg(-1) was established as CH(1.43)O(0.332)N(0.0013).

The effects of different catalysts on the pyrolysis of industrial wastes (olive and hazelnut bagasse).

Pyrolysis of olive and hazelnut bagasse biomass samples with two selected catalysts, namely activated alumina and sodium feldspar, have been conducted in a fixed-bed reactor. Experiments were carried out under certain pyrolysis conditions in a fixed-bed Heinze reactor. The catalyst was mixed with feedstock in different percentages. The effects of catalysts and their ratio (10%, 20%, 30% and 40% w/w) on the pyrolysis product yields were investigated and the results were compared with the results of experiments performed without catalyst under the same conditions. The maximum bio-oil yields for the bio-oils obtained from pyrolysis of olive bagasse were found as 37.07% and 36.67% on using activated alumina and sodium feldspar as catalysts, respectively, while these values were 27.64% and 31.68%, respectively, for the bio-oils from hazelnut bagasse. The oxygen contents of the bio-oils were also markedly reduced while the yield of bio-oil was reduced by the use of catalysts. The pyrolysis oils were examined using some spectroscopic and chromatographic analysis techniques. The results were compared with the petroleum fractions and the possibility of being a potential source of bio-oils was investigated.

PRODUCTION OF BIOFUEL FROM SOFT SHELL OF PISTACHIO (PISTACIA VERA L.)

Soft shell of pistachio (Pistacia vera L.) pyrolysis experiments were performed in a fixed-bed reactor to produce bio-oil. The effects of temperature, heating rate, and sweep gas (N2) flow rates on the yields and compositions of products were investigated. Pyrolysis runs were performed using reactor temperatures between 350° and 500°C with heating rates of 15° and 50°C/min. Nitrogen flow rates varied between 50 and 200 cm3/min and mean particle size was 0.8 mm. The maximum bio-oil yield of 33.18% was obtained in a nitrogen atmosphere with nitrogen flow rate of 150 cm3/min and at 450°C pyrolysis temperature with a heating rate of 50°C/min.The elemental analysis and gross heating value of the bio-oil were determined, and then the chemical composition of the bio-oil was investigated using chromatographic and spectroscopic techniques. The chemical characterization has shown that the bio-oil obtained from soft shell of pistachio can be used as a renewable fuel and chemical feedstock.

Pyrolysis of hornbeam (Carpinus betulus L.) sawdust: Characterization of bio-oil and bio-char.

Slow pyrolysis of hornbeam (Carpinus betulus L.) sawdust was performed to produce bio-oil and bio-char. The operational variables were as follows: pyrolysis temperature (400-600°C), heating rate (10-50°Cmin-1) and nitrogen flow rate (50-150cm3min-1). Physicochemical and thermogravimetric characterizations of hornbeam sawdust were performed. The characteristics of bio-oil and bio-char were analyzed on the basis of various spectroscopic and chromatographic techniques such as FTIR, GC-MS, 1H NMR, SEM, BET. Higher heating value, density and kinematic viscosity of the bio-oil with maximum yield of 35.28% were 23.22MJkg-1, 1289kgm-3 and 0.6mm2s-1, respectively. The bio-oil with relatively high fuel potential can be obtained from the pyrolysis of the hornbeam sawdust and the bio-char with a calorific value of 32.88MJkg-1 is a promising candidate for solid fuel applications that also contributes to the preservation of the environment.

Effect of pyrolysis temperature on chemical and surface properties of biochar of rapeseed (Brassica napus L.).

The biochar is an important carbon-rich product that is generated from biomass sources through pyrolysis. Biochar (charcoal) can be both used directly as a potential source of solid biofuels and as soil amendments for barren lands. The aim of this study was investigate influence of pyrolysis temperature on the physicochemical properties and structure of biochar. The biochars were produced by pyrolysis of rapeseed (Brassica napus L.) using a fixed-bed reactor at different pyrolysis temperatures (400–700°C). The produced biochars were characterized by proximate and elemental analysis, Brunauer–Emmett–Teller (BET) surface area, particle size distributions, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy. The results showed that both chemical and surface properties of the biochars were significantly affected by the pyrolysis temperature. Aromatic hydrocarbons, hydroxyl and carbonyl compounds were the majority components of the biochar. The biochar obtained at 700°C had a high fixed carbon content (66.16%) as well as a high heating value, and therefore it could be used as solid fuel, precursor in the activated carbons manufacture (specific surface area until 25.38 m2 g−1), or to obtain category-A briquettes.