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Abstract Atacama Large Millimeter/submillimeter Array (ALMA) data toward QSO J1851+0035 (l= 33.°498,b= +0.°194) were used to study absorption lines by Galactic molecular gas. We detected 17 species (CO,13CO, C18O, HCO+, H13CO+, HCO, H2CO, C2H,c-C3H,c-C3H2, CN, HCN, HNC, CS, SO, SiO, and C) and set upper limits to 18 species as reference values for chemical models. About 20 independent velocity components at 4.7–10.9 kpc from the Galactic center were identified. Their column density and excitation temperature estimated from the absorption study, as well as the CO intensity distributions obtained from the FUGIN survey, indicate that the components withτ≲1 correspond to diffuse clouds or cloud outer edges. Simultaneous multiple-Gaussian fitting of COJ= 1–0 andJ= 2–1 absorption lines shows that these are composed of narrow- and broad-line components. The kinetic temperature empirically expected from the high HCN/HNC isomer ratio (≳4) reaches ≳40 K and the corresponding thermal width accounts for the line widths of the narrow-line components. CN-bearing molecules and hydrocarbons have tight and linear correlations within the groups. The CO/HCO+abundance ratio showed a dispersion as large as 3 orders of magnitude with a smaller ratio in a smallerN(HCO+) (or lowerAV) range. Some of the velocity components are detected in single-dish CO emission and ALMA HCO+absorption but without corresponding ALMA CO absorption. This may be explained by the mixture of clumpy CO emitters not resolved with the ∼1 pc single-dish beam surrounded by extended components with a very low CO/HCO+abundance ratio (i.e., CO-poor gas).
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Plasma‐catalytic synthesis of acrylonitrile from methane and nitrogen
Abstract In this work, we demonstrate plasma‐catalytic synthesis of hydrogen and acrylonitrile (AN) from CH4and N2. The process involves two steps: (1) plasma synthesis of C2H2and HCN in a nominally 1:1 stoichiometric ratio with high yield up to 90% and (2) downstream thermocatalytic reaction of these intermediates to make AN. The effect of process parameters on product distributions and specific energy requirements are reported. If the catalytic conversion of C2H2and HCN in the downstream thermocatalytic step to AN were perfect, which will require further improvements in the thermocatalytic reactor, then at the maximum output of our 1 kW radiofrequency 13.56 MHz transformer, a specific energy requirement of 73 kWh kgAN−1was determined. The expectation is that scaling up the process to higher throughputs would result in decreases in specific energy requirement into the predicted economically viable range less than 10 kWh kgAN−1.
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- PAR ID:
- 10516001
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- AIChE Journal
- Volume:
- 70
- Issue:
- 1
- ISSN:
- 0001-1541
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/aic.18261
