In the series study, rice husk and corn stalk have been pyrolyzed in an auger pyrolysis reactor at various pyrolysis temperatures of 350, 400, 450, 500, 550 and 600 °C in order to investigate the effect of the pyrolysis temperature on the pyrolysis performance of the reactor and physicochemical properties of pyrolysis products (this part focus on the char and gas, the next part focus on the pyrolysis liquid). The results have shown that the pyrolysis temperature significantly affects the mass yields and properties of the pyrolysis products. The mass yields of pyrolysis liquid and char are comparable to

Two nickel-based catalysts were prepared and investigated in relation to their influence over aromatic compounds contained in tar from the pyrolysis−gasification of refuse derived fuel (RDF), using a two-stage reaction system. The results were compared with those obtained in experiments carried out using a bed of sand, both with steam and without steam. The condensed tar was analyzed for its polycyclic aromatic hydrocarbon (PAH) content using gas chromatography−mass spectrometry (GC-MS), size exclusion chromatography (SEC), and Fourier transform infrared spectroscopy (FTIR) techniques. It was found that, in the presence of Ni/α-Al 2 O 3 catalysts, some of the PAHs from three to four rings were eliminated; however, some single-ring and two-ring compounds such as styrene and indene were identified. This was also inferred from the molecular mass data (SEC). The identified PAHs consisted mainly of naphthalene, biphenyl, acenaphthylene, fluorene, and phenanthrene, but other PAHs also were identified for example: methylnaphthalenes. The influence of catalyst type on the gas composition showed that, using a 10 wt % Ni/α-Al 2 O 3 catalyst, ∼45 vol % of hydrogen was achieved, while the CH 4 and C 2 −C 4 concentrations were markedly reduced, compared with the 5 wt % Ni/α-Al 2 O 3 catalyst, which gave similar results to those obtained with the sand bed under the same conditions. The presence of oxygenated compounds in the tar samples was compared at different gasification temperatures. The results showed the presence of oxygenated compounds such as catechols and alcohols at 600 °C, these compounds were reduced as the gasification temperature increased, while the concentration of aromatic compounds increased.

Abstract:A Ni-Mg-Al-Ca catalyst was prepared by a co-precipitation method for hydrogen production from polymeric materials. The prepared catalyst was designed for both the steam cracking of hydrocarbons and for the in situ absorption of CO 2 via enhancement of the water-gas shift reaction. The influence of Ca content in the catalyst and catalyst calcination temperature in relation to the pyrolysis-gasification of a wood sawdust /polypropylene mixture was investigated.The highest hydrogen yield of 39.6 mol H 2 /g Ni with H 2 /CO ratio of 1.90 was obtained in the presence of the Ca containing catalyst of molar ratio Ni:Mg:Al:Ca = 1:1:1:4, calcined at 500 °C.In addition, thermogravimetric and morphology analyses of the reacted catalysts revealed that Ca introduction into the Ni-Mg-Al catalyst prevented the deposition of filamentous carbon on the catalyst surface. Furthermore, all metals were well dispersed in the catalyst after the pyrolysisgasification process with 20-30 nm of NiO sized particles observed after the gasification without significant aggregation.

A series of Ni/SiO 2 catalysts have been prepared and investigated for their suitability for hydrogen production and tar reduction in a two-stage pyrolysis-reforming system, using refuse derived fuel (RDF) as the raw material. Experiments were conducted at a pyrolysis temperature of 600 ºC, and a reforming temperature of 800 ºC. The product gases were analysed by gas chromatography (GC) and the condensed fraction was collected and quantified using gas chromatography-mass spectrometry (GC-MS). The effects of the catalyst preparation method, nickel content and the addition of metal promoters (Ce, Mg, Al), were investigated. Catalysts were characterised using BET surface area analysis, temperature programmed oxidation (TPO), and scanning electron microscopy (SEM). The TPO and SEM analysis of the reacted catalysts showed that amorphous type carbons tended to be deposited over the Ni/SiO 2 catalysts prepared by impregnation, while filamentous type carbons were favoured with the sol-gel prepared catalysts. The influence of catalyst promoters (Ce, Mg, Al) added to the Ni/SiO 2 catalyst prepared by the sol-gel method was found not to be significant, as the H 2 production was not increased and the tar formation was not reduced with the metaladded catalyst. The highest H 2 concentration of 57.9 vol.% and lower tar amount produced of 0.24 mg tar /g RDF ; were obtained using the 20 wt.% Ni/SiO 2 catalyst prepared by sol-gel. On the other hand a low catalytic activity for H 2 production and higher tar produced were found for the impregnated series of catalysts, which might be due to the smaller surface area, pore size and due to the formation of amorphous carbons on the catalyst surface. Alkenes and alcohol functional groups were mainly found in the analysed tar samples, with major concentrations of styrene, phenol, indene, cresols, naphthalene, fluorene, and phenanthrene.

Ultrasound‐assisted extraction of anthocyanins and total phenolic compounds from the dried cob of purple waxy corn was investigated using response surface methodology, where the process variables were ultrasound amplitude levels (25, 50, 100%) and different solvents (pure water, water–ethanol ratio 1:1, pure ethanol), using a sample–solvent ratio of 1:20, and extraction temperature of 65 °C for 30 min. Central composite face‐centered design was used to determine optimum process conditions. The results showed that the overall optimal condition for simultaneous extraction of anthocyanins and phenolic compounds was obtained by using 50% water in water–ethanol mixed solvent as solvent and amplitude level of 50%. The optimal yields of anthocyanins and phenolic compounds were 240.161 μg cyanidin‐3‐glucoside/g dry sample and 27.662 mg gallic acid/g dry sample, respectively. The result for the antioxidant activity of the extract obtained from this optimal extraction condition to decrease the initial DPPH• concentration by 50% was approximately 4.64 mg/ml. Practical applications This article has practical application to study extraction of total anthocyanins and total phenolic compounds from dried cob of purple waxy corn using ultrasound‐assisted extraction. The response surface method using central composite face‐centered design was successfully employed to predict the effect of two independent variables on the ultrasound assisted extraction of total anthocyanins and total phenolic compounds. Moreover, the methodology and results presented in this study could be beneficial for future efforts to increase the recovery of potentially bioactive compounds from fruits, vegetables, plants and agricultural residues.