Ricardo R. Soares

Tuning the surface properties of biochar by thermal treatment

In this work, the effect of controlled thermal treatment to tune biochar surface properties such as area/porosity, functionalities and reactivity was investigated. TG-MS, CHN, Raman, IR, BET, Zeta and SEM analyses suggested that thermal treatment led to the decomposition of an organic complex/amorphous phase to produce micropores based on graphene nanostructures and a strong increase on surface area from 3m2g-1 for biochar to 30, 408 and 590m2g-1, at 400, 600 and 800°C, respectively. The treatment also led to a gradual decrease on oxygen content from 27 to 14wt% at 800°C due to decomposition of surface functionalities changing surface properties such as zeta potential, adsorption of anionic and cationic species and an increase on the activity for sulfide oxidation which is discussed in terms of increase in surface area and the presence of surface redox quinone groups.

Rejeitos de Biomassas Oriundas da Cadeia de Biocombustíveis no Brasil: Produção de Bio-óleo e Sub-produtos

Neste trabalho e descrito o potencial de utilizacao da pirolise rapida como rota para a obtencao de diferentes produtos a partir de quatro rejeitos de biomassa oriundas das cadeias de biocombustiveis no Brasil, i.e. tortas de tucuma e mamona(biodiesel) e palha/bagaco de cana (producao de etanol).Atraves de dados de analise elementar, TG,CGEM,balancos de massa, analise imediata e poder calorifico, observou-se que as tortas de biodiesel produzem de 17-25% de um gas composto de CO x , H 2 e hidrocarbonetos C 1 -C 2 , 33-38% biocarvao e 42-45% de liquidos, composta de 18-23% de uma fracao aquosa altamente acida e elevada carga orgânica e 22-23% de uma fracao oleosa constituida de uma complexa mistura de compostos orgânicos. A pirolise rapida da palha e do bagaco de cana produziu 6% de gas composto basicamente de COx, 6-18% biocarvao e 25-75% de liquidos. Com base nasinformacoes obtidas, diferentes possibilidades de usos sao discutidas para as fracoes obtidas.

Ni/CeZrO2-based catalysts for H2 production

Abstract Ni/CeZrO 2 -based catalysts were investigated in autothermal methane reforming. The use of alumina propitiated a higher surface area for the samples, which favored the formation of smaller nickel oxide, and metallic nickel particles as observed by XRD and metal dispersion experiments. XRD analysis showed the formation of a ceria zirconia solid solution. In general, the catalytic performance of Ni/CeZrO 2 /Al 2 O 3 was better than the ones observed for the other samples, which may be correlated to the higher reducibility and better redox properties verified for this catalyst.