Can “Electric Flare Stacks” Reduce CO₂ Emissions? A Case Study with Nonthermal Plasma

Gas flare stacks are the current benchmark technology for industrial pollution control. However, their impact on human health and the environment is not negligible. If net zero CO2 emissions are to be achieved, their current significant CO2 impact (400 Mt y–1 globally, 2022) should be reduced. Herein, a model nonthermal plasma “electric flare stack” consuming 6.6% less energy than an equivalent steam aided methane flare, with significant CO2 emission reductions (between 2.0× and 11.4× lower), when removing isobutylene is demonstrated. Isobutylene streams in air (1.3% v/v) are completely and rapidly consumed (>99% at flow rates up to 125 mL min–1, 1 atm, RT) by the electrically generated nonthermal plasma in a linear flow reactor. At low powers (≤50 J L–1 specific input energy), the major degradation products (>95%) are a complex mixture of low-molecular-weight oxygenates, including acetone, isobutylene oxide, and isobutyraldehyde. Only small amounts of CO/CO2 (<5% selectivity) are generated (at 50 J L–1). Complete oxidation of isobutylene to CO2 (>99% selectivity) results when the plasma oxidation is coupled to a heterogeneous catalyst bed. For the optimal V2O5 catalyst, synergistic interactions between the plasma and V2O5 are evident, as positioning the catalyst after the plasma provides optimal reactor performance (two-stage vs single-stage oxidation). Placement of shorter catalyst beds close to the plasma discharge region gives optimal reactor performance

Correction to Size and Density of Fibers in Fibrin and Other Filamentous Networks from Turbidimetry: Beyond a Revisited Carr–Hermans Method, Accounting for Fractality and Porosity

Correction to Size and Density of Fibers in Fibrin and Other Filamentous Networks from Turbidimetry: Beyond a Revisited Carr–Hermans Method, Accounting for Fractality and Porosit

A Comprehensive Mechanism of Fibrin Network Formation Involving Early Branching and Delayed Single- to Double-Strand Transition from Coupled Time-Resolved X‑ray/Light-Scattering Detection

The formation of a fibrin network following fibrinogen enzymatic activation is the central event in blood coagulation and has important biomedical and biotechnological implications. A non-covalent polymerization reaction between macromolecular monomers, it consists basically of two complementary processes: elongation/branching generates an interconnected 3D scaffold of relatively thin fibrils, and cooperative lateral aggregation thickens them more than 10-fold. We have studied the early stages up to the gel point by fast fibrinogen:enzyme mixing experiments using simultaneous small-angle X-ray scattering and wide-angle, multi-angle light scattering detection. The coupled evolutions of the average molecular weight, size, and cross section of the solutes during the fibrils growth phase were thus recovered. They reveal that extended structures, thinner than those predicted by the classic half-staggered, double-stranded mechanism, must quickly form. Following extensive modeling, an initial phase is proposed in which single-bonded “Y-ladder” polymers rapidly elongate before undergoing a delayed transition to the double-stranded fibrils. Consistent with the data, this alternative mechanism can intrinsically generate frequent, random branching points in each growing fibril. The model predicts that, as a consequence, some branches in these expanding “lumps” eventually interconnect, forming the pervasive 3D network. While still growing, other branches will then undergo a Ca2+/length-dependent cooperative collapse on the resulting network scaffolding filaments, explaining their sudden thickening, low final density, and basic mechanical properties