Recent advances in hydrothermal carbonisation:from tailored carbon materials and biochemicals to applications and bioenergy

Introduced in the literature in 1913 by Bergius, who at the time was studying biomass coalification, hydrothermal carbonisation, as many other technologies based on renewables, was forgotten during the "industrial revolution". It was rediscovered back in 2005, on the one hand, to follow the trend set by Bergius of biomass to coal conversion for decentralised energy generation, and on the other hand as a novel green method to prepare advanced carbon materials and chemicals from biomass in water, at mild temperature, for energy storage and conversion and environmental protection. In this review, we will present an overview on the latest trends in hydrothermal carbonisation including biomass to bioenergy conversion, upgrading of hydrothermal carbons to fuels over heterogeneous catalysts, advanced carbon materials and their applications in batteries, electrocatalysis and heterogeneous catalysis and finally an analysis of the chemicals in the liquid phase as well as a new family of fluorescent nanomaterials formed at the interface between the liquid and solid phases, known as hydrothermal carbon nanodots

Carbon materials functionalized with sulphonic groups as acid catalyst

26 figures.-- Chapter 8Sulfonic carbons are very promising and sustainable acid catalysts prepared from renewable precursors. The properties of the final catalysts are customizable, including morphological (particle size and shape), textural (surface area and porosity), hydrophilic/hydrophobic, and acidic properties. In this chapter, we present a brief overview of the different carbon materials, with their properties and the methods for their modification, the procedures to introduce sulfonic groups and the available techniques for their characterization, as well as some examples of catalytic applications and the deactivation mechanisms detected for this kind of materials. This revision will serve as guideline for research in new directions for streamlining the application of this versatile acid catalyst.Introduction.-- Types of carbon materials functionalized with sulfonic groups.-- Modification of carbons.-- Methods to introduce sulfonic groups and their characterization.-- Acid-catalyzed reactions.-- Deactivation mechanisms.-- Concluding remarks.-- Reference

Oil extraction from sheanut (Vitellaria paradoxa Gaertn C.F.) kernels assisted by microwaves

Shea butter, is highly solicited in cosmetics, pharmaceuticals, chocolates and biodiesel formulations. Microwave assisted extraction (MAE) of butter from sheanut kernels was carried using the Doehlert’s experimental design. Factors studied were microwave heating time, temperature and solvent/solute ratio while the responses were the quantity of oil extracted and the acid number. Second order models were established to describe the influence of experimental parameters on the responses studied. Under optimum MAE conditions of heating time 23 min, temperature 75 °C and solvent/solute ratio 4:1 more than 88 % of the oil with a free fatty acid (FFA) value less than 2, was extracted compared to the 10 h and solvent/solute ratio of 10:1 required for soxhlet extraction. Scanning electron microscopy was used to elucidate the effect of microwave heating on the kernels’ microstructure. Substantial reduction in extraction time and volumes of solvent used and oil of suitable quality are the main benefits derived from the MAE process