RESUMEN
This article studies the release of phenolic compounds during cocoa heating under vacuum, N2, and air atmospheres, and proposes fast heating (60 °C ⢠s-1) as a methodology that allows the release of polyphenols from fermented cocoa powder. We aim to demonstrate that gas phase transport is not the only mechanism to extract compounds of interest and that convective-type mechanisms can facilitate the process by reducing their degradation. The oxidation and transport phenomena were evaluated both in the extracted fluid and in the solid sample during the heating process. Polyphenols transport phenomena were assessed based on the fluid (chemical condensate compounds) that was collected cold with an organic solvent (methanol) in a hot plate reactor. Out of all the polyphenolic compounds present in cocoa powder, we assessed specifically the release of catechin and epicatechin. We found that high heating rates combined with vacuum or N2 favor the ejection of liquids; then, it is possible to extract compounds such as catechin-which is dissolved/entrained and transported in the ejected liquids-and avoid degradation phenomena.
Asunto(s)
Catequina , Chocolate , Calefacción , Fenoles , PolifenolesRESUMEN
The primary sludge produced by the wastewater treatment plant of a pulp and paper mill has high physicochemical heterogeneity, which limits the efficiency of thermochemical methodologies for the final disposal of this residue. As a solution, co-pelletization of the Primary Sludge (PS) with two other principal Industrial Solid Residues (ISRs) of the plant, Coal Boiler Ashes (CBA) and Wood Waste chips (WW), was proposed as a way to valorize the PS for energy use, while reducing dewatering costs. The energy potential was evaluated through a series of thermal co-processing tests of disaggregated and pelletized mixtures. Due to their differing fixed-carbon-to-volatile-material ratios, combining the ISRs resulted in a reduction of up to 45% of the mass of the ISR generated, improving the disposal conditions and achieving a minimum thermal power of 5.0â¯MJ/Nm3 through gasification. Finally, the environmental implications of the thermal co-processing of the wastes were assessed, finding very low impacts due to pollutant emissions, in accordance with the legal environmental regulations in force in Colombia.
Asunto(s)
Residuos Industriales , Residuos Sólidos , Ceniza del Carbón , Colombia , Aguas del AlcantarilladoRESUMEN
Three kinds of waste resulting from woods from the Colombian industry were selected (PinusPátula, Tectona Grandis and Acacia Mangium) in order to assess their energy potential. Several techniques of physicochemical characterization were used to predict the most appropriate energy exploitation process in each case; which was validated at laboratory scale by carrying out the torrefaction, gasification and combustion process. Results allowed us to the identification of the high energy potential of such wood waste as well as their feasibility to generate torrefied products and synthesis gas as products with greater added values. As a special case, the species Tectona Grandis displayed the greatest conversion and synthesis gas quality on the basis of the gasification process, due to its physicochemical characteristics. These samples can be torrefacted in order to get a new product with higher energy potential than the original sample. Experimental study carried out, allowed us to demonstrate that there is a relationship between biomass chemical composition, yield, and process products. In addition, applying an additivity law of individual effects of the component, it is not possible to predict the process performances.
Asunto(s)
Residuos Industriales , Madera , Biomasa , Fenómenos FísicosRESUMEN
The present study aims to evaluate the operating costs of biodiesel production using palm oil in a pilot-scale plant with a capacity of 20,000 L/day (850 L/batch). The production plant uses crude palm oil as a feedstock, and methanol in a molar ratio of 1:10. The process incorporated acid esterification, basic transesterification, and dry washing with absorbent powder. Production costs considered in the analysis were feedstock, supplies, labor, electricity, quality and maintenance; amounting to $3.75/gal ($0.99/L) for 2013. Feedstocks required for biodiesel production were among the highest costs, namely 72.6% of total production cost. Process efficiency to convert fatty acids to biodiesel was over 99% and generated a profit of $1.08/gal (i.e., >22% of the total income). According to sensitivity analyses, it is more economically viable for biodiesel production processes to use crude palm oil as a feedstock and take advantage of the byproducts such as glycerine and fertilizers.