The social, economic, and environmental impacts of climate change have been shown to affect poorer populations throughout the world disproportionally, and the COVID-19 pandemic of 2020–2021 has only exacerbated the use of less sustainable energy, fuel, and chemical sources. The period of economic and social recovery following the pandemic presents an unprecedented opportunity to invest in biorefineries based on the pyrolysis of agricultural residues. These produce a plethora of sustainable resources while also contributing to the economic valorization of first-sector local economies. However, biomass-derived pyrolysis liquid is highly oxygenated, which hinders its long-term stability and usability. Catalytic hydrogenation is a proposed upgrading method to reduce this hindrance, while recent studies on the use of nickel and niobium as low-cost catalysts, both abundant in Brazil, reinforce the potential synergy between different economic sectors within the country. This review gathers state-of-the-art applications of these technologies with the intent to guide the scientific community and lawmakers alike on yet another alternative for energy and commodities production within an environmentally sustainable paradigm.

Recebido em 3/7/12; aceito em 19/12/12; publicado na web em 21/3/13 COMPARATIVE STUDY OF ESCHKA, INFRARED, THERMAL CONDUCTIVITY (TCD) AND ULTRAVIOLET METHODS OF TOTAL SULPHUR DETERMINATION IN SOLID FUELS. The oxidation of sulphur compounds upon burning emits large quantities of SOx into the atmosphere. Therefore, there is growing interest in fast and accurate methods for analyzing sulphur content in fuels. The objective of this work was to compare four different methods of total sulphur determination in solid fuels. The methods used in this work were Eschka, Infrared, Thermal Conductivity Detection (TCD) and Ultraviolet Fluorescence Detection (UV). The preliminary results showed that TCD and UV methods (nonstandard methods for solid fuels) have similar precision to the infrared method (standard method) for high-sulphur coal samples.

Resumo: A padronização dos testes garante que a metodologia utilizada tenha uma reprodutibilidade do experimento e uma confiabilidade do resultado. No entanto, para realizar alguns testes em escala de laboratório, é necessária uma adaptação para ajustar a uma quantidade de amostra ou a um parâmetro não operacional. O objetivo deste trabalho foi validar e comparar dois testes diferentes de densidade aparente para biomassa, seguindo as normas ASTM E873 e DIN EN 17828, mas com alterações (escala laboratorial) no volume a ser medido da amostra e do recipiente. recipiente foi feito com dimensões reduzidas proporcionalmente. O procedimento foi realizado por 6 operadores (3 DIN e 3 ASTM) com seis materiais (biomassas) de diferentes características físicas. Os resultados mostraram que os procedimentos de ambos os padrões resultam em valores aproximados em relação à densidade aparente dos materiais. Também foi observado que a heterogeneidade do material e os procedimentos manuais (sugeridos pela norma) contribuíram para algumas divergências nos resultados. Por fim, concluiu-se que uma repetição maior é recomendada para reduzir o erro devido à variação dos resultados entre as medidas. The standardization of the tests ensures that the methodology used guarantees a reproducibility of the experiment and a reliability of the result. However, to perform some tests on a laboratory scale, an adaptation is necessary to adjust to a quantity of sample or to a non-operational parameter. The objective of this work was to validate and compare two different tests of apparent density for biomass, following the standards ASTM E873 and DIN EN 17828, but with changes (laboratory scale) in the volume to be measured of the sample and the container. The container was made with reduced dimensions proportionately. The procedure was performed by 6 operators (3 DIN and 3 ASTM) with six materials (biomass) of different physical characteristics. The results showed that the procedures of both standards result in approximate values in relation to the bulk density of the materials. It was also observed that the heterogeneity of the material and the manual procedures (suggested by the standard) contributed to some divergences in the results. Finally, it was concluded that a greater repetition is recommended to reduce the error due to variation of results between as measurements.