Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Entire DC Network
A Radiant Flow Reactor For High-Temperature Reactivity Studies Of Pulverized Solids, John C. Chen, Stephen Niksa
A Radiant Flow Reactor For High-Temperature Reactivity Studies Of Pulverized Solids, John C. Chen, Stephen Niksa
Mechanical Engineering
Our radiant two‐phase flow reactor presents several new possibilities for high‐temperature reactivity studies. Most importantly, the thermal histories of the suspension and entrainment gas can be independently regulated over wide ranges. At low suspension loadings, outlet temperatures can differ by hundreds of degrees and gas temperatures are low enough to inhibit hydrocarbon cracking chemistry, so primary products are quenched as soon as they are expelled. With coal suspensions, tars were generated with the highest H/C ratio and lowest proton aromaticity ever reported. Alternatively, particles and gas can be heated at similar rates to promote secondary chemistry by increasing particle loading. …
Suppressed Nitrogen Evolution From Coal-Derived Soot And Low-Volatility Coal Chars, John C. Chen, Stephen Niksa
Suppressed Nitrogen Evolution From Coal-Derived Soot And Low-Volatility Coal Chars, John C. Chen, Stephen Niksa
Mechanical Engineering
This laboratory study uses a novel furnace to resolve nitrogen evolution during the three stages of pulverized coal combustion: primary devolatilization, secondary pyrolysis, and combustion. The behavior of six coals depicts continuous rank variations, as well as suppressed nitrogen evolution from low volatility coals. During primary devolatilization of any coal, aromatic compounds in tar and oils are virtually the only shuttles for nitrogen out of the coal matrix. The small amounts of HCN observed while primary devolatilization winds down probably come from the char, because char particles are significantly hotter than tar in these experiments. Secondary pyrolysis promotes additional HCN …