Pyrolysis

About: Pyrolysis is a research topic. Over the lifetime, 34918 publications have been published within this topic receiving 833524 citations.

New organic aerogels based upon a phenolic-furfural reaction☆

Abstract: The aqueous polycondensation of (1) resorcinol with formaldehyde and (2) melamine with formaldehyde are two proven synthetic routes for the formation of organic aerogels. A new type of organic aerogel based upon a phenolic-furfural (PF) reaction was recently discovered. This solgel polymerization has a major advantage over past approaches since it can be conducted in alcohol (e.g., 1-propanol), thereby eliminating the need for a solvent exchange step prior to supercritical drying from carbon dioxide. The resultant aerogels are dark brown in color and can be converted to a carbonized version upon pyrolysis in an inert atmosphere. Brunauer-Emmett-Teller (BET) surface areas of 350–600 m2/g have been measured, and transmission electron microscopy reveals an interconnected structure of irregularly shaped particles or platelets with ∼ 10 nm dimensions. Thermal conductivities as low as 0.015 W/m K have been recorded for PF aerogels under ambient conditions. Chemistry and structure-property relationships of these new materials are described.

Formation of charcoal from biomass in a sealed reactor

Abstract: In this paper, samples o cellulose, hemicellulose, lignin, and nine species of whole biomass are pyrolyzed in sealed reactors. Very high charcoal yields (e.g., 40% from cellulose, 48% from Eucalyptus gummifera) were obtained. Higher sample loading (sample mass per unit reactor volume) increased charcoal yield and the associated exothermic heat release and lowered the reaction onset temperature. These effects were induced by the vapor-phase concentrations of the volatile products, and not the system pressure. Addition of water catalyzed the reaction and increased the char yield. These observations suggest that charcoal formation is autocatalyzed by water, an initial pyrolysis product. When whole biomass was used as a feedstock, higher charcoal yields were obtained from species with high lignin and/or low hemicellulose content.

Application of biochar to soil and N2O emissions: potential effects of blending fast-pyrolysis biochar with anaerobically digested slurry

Abstract: Soil applications of recalcitrant biochar offer the possibility of mitigating climate change effects through long-term carbon sequestration and potentially also by reducing emissions of the potent greenhouse gas nitrous oxide (N 2 O). This laboratory study examined the effect of combining a fast-pyrolysis biochar at small (1% by mass) and large (3%) concentrations with anaerobically digested slurry on soil N 2 O and carbon dioxide (CO 2 ) emissions over a period of 55 days. The results showed that fast-pyrolysis biochar applied on its own increased N 2 O emissions from soil. However, when biochar was applied together with slurry, the larger biochar concentration decreased N 2 O emissions by 47%, relative to those from the slurry treatment with the smaller biochar concentration. Reduced N 2 O emissions coincided with enhanced soil microbial activity and immobilization of nitrogen. A combined application of biochar and anaerobic digested slurry could therefore be beneficial for cropping systems in terms of soil nitrogen retention while concurrently mitigating N 2 O fluxes and sequestering carbon in soil.