Sulphur anion chemistry in hydrocarbon flames with H2S, OCS, and SO2 additives

1986 ◽  
Vol 64 (4) ◽  
pp. 689-694 ◽  
Author(s):  
John M. Goodings ◽  
Diethard K. Bohme ◽  
Kamal Elguindi ◽  
Arnold Fox
Keyword(s):  
Rate Constants ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Negative Ions ◽  
Ion Concentration ◽  
Concentration Profiles ◽  
Hydrocarbon Flame ◽  
Flowing Afterglow ◽  
Hydrocarbon Flames ◽  
Oxygen Flame

A premixed, fuel-rich, methane–oxygen flame at atmospheric pressure was doped separately with 0.2 mol% of H2S, OCS, and SO2 to probe the behaviour of fuel sulphur during combustion. These three additives represent compounds occurring early, intermediate, and late in the oxidation sequence of fuel sulphur. They are chemically ionized in the reaction zone of a hydrocarbon flame to give large signals of sulphurous negative ions. Those detected include S−, SH−, SO− (uncertain), SO2− (S2−), SO3−, HSO3−, CH3O−•SO2, SO4− (S2O2−, S3−), and HSO4−. Ion concentration profiles of these ions were measured along the conical flame axis by sampling the flame into a mass spectrometer. The shapes of the profiles are insensitive to the nature of the additive, but their relative magnitudes are indicative of the additive's position in the sulphur oxidation sequence. For each additive, the very large HSO4− signal has analytical implications as an indicator for total fuel sulphur. The sulphurous anion chemistry is discussed for each additive in terms of roughly twenty ion (electron)-molecule reactions of six basic types, whose rate constants were known previously, or were measured at room temperature using the York flowing afterglow apparatus.

Ion chemistry of second-row transition metals in hydrocarbon flames: cations and anions of Y, Zr, Nb, and Mo

1995 ◽  
Vol 73 (12) ◽  
pp. 2263-2271 ◽  
Author(s):  
Christine C.Y. Chow ◽  
John M. Goodings
Keyword(s):  
Transition Metals ◽  
Gas Phase ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Negative Ions ◽  
Ion Concentration ◽  
Oxidation States ◽  
Metallic Ions ◽  
Ion Chemistry ◽  
Hydrocarbon Flames

A pair of laminar, premixed, CH4–O2 flames above 2000 K at atmospheric pressure, one fuel-rich (FR) and the other fuel-lean (FL), were doped with ~10−6 mol fraction of the second-row transition metals Y, Zr, Nb, and Mo. Since these hydrocarbon flames contain natural ionization, metallic ions were produced in the flames by the chemical ionization (CI) of metallic neutral species, primarily by H3O+ and OH− as CI sources. Both positive and negative ions of the metals were observed as profiles of ion concentration versus distance along the flame axis by sampling the flames through a nozzle into a mass spectrometer. For yttrium, the observed ions include the YO+•nH2O (n = 0–3) series, and Y(OH)4−. With zirconium, they include the ZrO(OH)+•nH2O (n = 0–2) series, and ZrO(OH)3−. Those observed with niobium were the cations Nb(OH)3+ and Nb(OH)4+, and the single anion NbO2(OH)2−. For molybdenum, they include the cations MoO(OH)2+ and MoO(OH)3+, and the anions MoO3− and MoO3(OH)−. Not every ion was observed in each flame; the FL flame tended to favour the ions in higher oxidation states. Also, flame ions in higher oxidation states were emphasized for these second-row transition metals compared with their first-row counterparts. Some ions written as members of hydrate series may have structures different from those of simple hydrates; e.g., YO+•H2O = Y(OH)2+ and ZrO(OH)+•H2O = Zr(OH)3+, etc. The ion chemistry for the production of these ions by CI in flames is discussed in detail. Keywords: transition metals, ions, flame, gas phase, negative ions.

An experimental study of the reactivity of the hydroxide anion in the gas phase at room temperature, and its perturbation by hydration

1981 ◽  
Vol 59 (11) ◽  
pp. 1615-1621 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme
Keyword(s):  
Experimental Study ◽  
Proton Transfer ◽  
Gas Phase ◽  
Rate Constants ◽  
Room Temperature ◽  
Gas Phase Reactions ◽  
Flowing Afterglow ◽  
Hydroxide Anion

Flowing afterglow measurements are reported which provide rate constants and product identifications at 298 ± 2 K for the gas-phase reactions of OH− with CH3OH, C2H5OH, CH3OCH3, CH2O, CH3CHO, CH3COCH3, CH2CO, HCOOH, HCOOCH3, CH2=C=CH2, CH3—C≡CH, and C6H5CH3. The main channels observed were proton transfer and solvation of the OH−. Hydration with one molecule of H2O was observed either to reduce the rate slightly and lead to products which are the hydrated analogues of the "nude" reaction, or to stop the reaction completely, k ≤ 10−12 cm3 molecule−1 s−1. The reaction of OH−•H2O with CH3—C≡CH showed an uncertain intermediate behaviour.

Comparative sulphur cation chemistry in a hydrocarbon flame with H2S, OCS, and SO2 additives

1986 ◽  
Vol 64 (12) ◽  
pp. 2412-2417 ◽  
Author(s):  
Nicholas S. Karellas ◽  
John M. Goodings
Keyword(s):  
Reaction Zone ◽  
Atmospheric Pressure ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Negative Ions ◽  
Mass Range ◽  
Total Ionization ◽  
Ion Recombination ◽  
Diffusion Mass ◽  
Oxygen Flame

A fuel-rich, conical, premixed, methane–oxygen flame at atmospheric pressure was doped separately with 0.2 mol% of H2S, OCS, and SO2 to probe the chemistry of sulphur at its source during combustion. These three additives represent a broad range of fuel-sulphur contaminants since they occur early, intermediate, and late in the sulphur oxidation sequence. A wide variety of sulphurous cations, formed by chemical ionization reactions, is observed for each additive by sampling the flame into a mass spectrometer. The total ionization profile measured along the flame axis is enhanced in the reaction zone when a sulphur additive is present; the mechanism involves the formation of sulphurous negative ions which reduces the rates of cation loss by electron–ion recombination and ambipolar diffusion. Mass spectra measured in the mass range 10–110 u at fixed points on the flame axis are very similar for all three additives, and are not helpful in the identification of the additive. However, the general presence of sulphur is evident from large signals measured near the reaction zone at five principal mass numbers; namely, 45 u (CHS+), 47 u (CH3S+), 58 u (C2H2S+), 59 u (C2H3S+), and 69 u (C3HS+) related to CS, thioformaldehyde, thioketene, and C3S.

Flame-ion probe of the reaction zone in a CH4–O2–Ar flame with added HCN, NH3 and NO

1981 ◽  
Vol 59 (12) ◽  
pp. 1810-1818 ◽  
Author(s):  
John M. Goodings ◽  
Gary B. De Brou ◽  
Diethard K. Bohme
Keyword(s):  
Reaction Zone ◽  
Atmospheric Pressure ◽  
Protonated Form ◽  
Good Evidence ◽  
Ion Concentration ◽  
Bimolecular Reactions ◽  
Hydrocarbon Flames ◽  
Ion Probe ◽  
Increased Sensitivity ◽  
N Compounds

The addition of 0.3% of the fuel-nitrogen (fuel-N) compounds HCN, NH3, or NO to a premixed, fuel-rich, CH4–O2–Ar flame burning at atmospheric pressure demonstrated the rapid interconversion of nitrogenous intermediates in the reaction zone. The nitrogenous species (HCN/CN, HNCO/NCO, NH3, NH2, NH, NO, NO2) were observed as ions (CN−, H2CN+, NCO−, H2NCO+, NH4+, NH3+, NH2+, NO+, NO2−, and hydrate ions) formed in chemical ionization processes discussed previously (1). The ions were sampled directly into a flame-ion mass spectrometer which had sufficient spatial resolution for the measurement of ion concentration profiles through the reaction zone. The study bears on Fenimore's suggestion for the formation of "prompt NO" in fuel-rich hydrocarbon flames. These additive results were compared with previous results involving nitrogenous species present in a similar CH4–O2 flame doped with 10% N2. The increased sensitivity of the additive approach confirmed many of the mass assignments and mechanisms involved in the N2 study. Reasonably good evidence was obtained for the elusive intermediate HNCO (and possibly isomeric HCNO as well) in protonated form, and also formamide, NH2CHO, which had not been detected previously. Similarities in profile peak positions and magnitudes observed for many ions, irrespective of the nature of the fuel-N additive, indicated that the nitrogenous species were linked by a network of fast bimolecular reactions, many of which appeared to be balanced in the reaction zone.

Sulphurous negative ions in a fuel-rich, CH4–O2 flame with OCS additive

1983 ◽  
Vol 61 (8) ◽  
pp. 1703-1711 ◽  
Author(s):  
John M. Goodings ◽  
Kamal Elguindi ◽  
Diethard K. Bohme
Keyword(s):  
Reaction Zone ◽  
Atmospheric Pressure ◽  
Negative Ions ◽  
Ion Concentration ◽  
Quadrupole Mass ◽  
Ion Chemistry ◽  
Naturally Occurring ◽  
Pressure Profiles ◽  
Ion Profiles ◽  
Carbonyl Sulphide

Sulphurous negative ions S • SH • SO • SO2/S2• SO3• HSO3• SO4• and HSO4 were observed when 0.2% of carbonyl sulphide (OCS) was added to a conical, laminar, premixed. fuel-rich (equivalence ratio [Formula: see text]) CH4–O2 flame burning at atmospheric pressure. Profiles were obtained of ion concentration vs. distance along the flame axis by sampling the flame through a pinhole into a quadrupole mass spectrometer. Some of the ion signals observed in the flame reaction zone are very large, particularly that for HSO4. None of the sulphurous ions detected contain carbon. Of those listed above, only S−,•SH, • SO • and SO2 persist downstream through the burnt gas. The sulphurous ions are formed by chemical ionization processes of neutral sulphurous intermediates reacting with the naturally-occurring ions present in any hydrocarbon flame. The ion chemistry is discussed, as is the underlying neutral chemistry of sulphur relevant to the flame environment. The ion profiles show the rapidity with which OCS is oxidized through SH and SO to SO2 even within the reaction zone of this fuel-rich flame. No evidence was obtained for the presence of sulphuric or sulphurous acids, and the presence of S2: was not confirmed.

A room-temperature study of the kinetics of protonation of formaldehyde

1979 ◽  
Vol 57 (18) ◽  
pp. 2350-2354 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme
Keyword(s):  
Rate Constants ◽  
Room Temperature ◽  
Stable Isomer ◽  
Flowing Afterglow ◽  
Temperature Study ◽  
Kinetics Of

Rate constants measured with the flowing afterglow technique at 297 ± 2 K are reported for the protonation of CH2O by H3+, N2H+, CH5+, HCO+, C2H5+, H3O+, H3S+, and HCNH+ and for the subsequent deprotonation by NH3. The rate constants are compared with predictions of various theories for ion–molecule collisions. The protonation was observed to proceed in the absence of competing channels and further decomposition and is discussed in terms of the energetics of the two sites of protonation and the energetics and mechanism of H2 elimination. The rate measurements provide evidence for the room-temperature conversion of the adduct C2H3+•H2 to the more stable isomer derived from the direct protonation of C2H4.

Sulphur cation chemistry in a fuel-rich, CH4–O2 flame with OCS additive

1986 ◽  
Vol 64 (9) ◽  
pp. 1733-1742 ◽  
Author(s):  
Nicholas S. Karellas ◽  
John M. Goodings
Keyword(s):  
Reaction Zone ◽  
Atmospheric Pressure ◽  
Mass Spectra ◽  
Mass Range ◽  
Major Product ◽  
Premixed Flame ◽  
Ion Concentration ◽  
Concentration Profiles ◽  
Ion Chemistry ◽  
Ion Molecule Reactions

A fuel-rich, methane–oxygen, premixed flame at atmospheric pressure was doped with 0.2 mol% of OCS. More than 40 different sulphurous cations were observed in the mass range < 100 u by sampling the flame into a flame-ion mass spectrometer. Ion concentration profiles along the flame axis are presented, together with mass spectra at fixed points in the flame. In the reaction zone, primary sulphur ions CHxS+ (x = 1, 3, 5) undergo extensive ion–molecule reactions (association and condensation) with CH4/CH3, C2H2, and OCS to form a considerable variety of secondary sulphurous cations. Just downstream of the reaction zone, the ion chemistry is somewhat different; it appears to be dominated by reactions of primary sulphur ions including HxS+ (x = 0–3) with C2H2 present as an intermediate. A few ions (HxS+, OS+, S2+) persist throughout the burnt gas region in equilibrium with the natural flame ions CHO+ and H3O+. These sulphurous cation signals show the evolution of the sulphur chemistry, both ionic and neutral, through the flame reaction zone into the burnt gas downstream where H2S, not SO2, is the major product in fuel-rich combustion.

scholarly journals Cat-CrNP as new material with catalytic properties for 2-chloro-2-propen-1-ol and ethylene oligomerizations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jacek Malinowski ◽  
Dagmara Jacewicz ◽  
Artur Sikorski ◽  
Mariusz Urbaniak ◽  
Przemysław Rybiński ◽  
...  
Keyword(s):  
Complex Compound ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Organometallic Compounds ◽  
Ethylene Oligomerization ◽  
High Catalytic Activity ◽  
New Material ◽  
Activity Requirement ◽  
Olefin Oligomerization ◽  
Xrd Method

AbstractThe contemporary search for new catalysts for olefin oligomerization and polymerization is based on the study of coordinating compounds and/or organometallic compounds as post-metallocene catalysts. However known catalysts are suffered by many flaws, among others unsatisfactory activity, requirement of high pressure or instability at high temperatures. In this paper, we present a new catalyst i.e. the crystalline complex compound possesing high catalytic activity in the oligomerization of olefins, such as 2-chloro-2-propen-1-ol and ethylene under very mild conditions (room temperature, 0.12 bar for ethylene oligomerization, atmospheric pressure for 2-chloro-2-propen-1-ol oligomerization). New material—Cat-CrNP ([nitrilotriacetato-1,10-phenanthroline]chromium(III) tetrahydrate) has been obtained as crystalline form of the nitrilotriacetate complex compound of chromium(III) with 1,10-phenanthroline and characterized in terms of its crystal structure by the XRD method and by multi-analytical investigations towards its physicochemical propeties The yield of catalytic oligomerization over Cat-CrNP reached to 213.92 g · mmol−1 · h−1· bar−1 and 3232 g · mmol−1 · h−1 · bar−1 for the 2-chloro-2-propen-1-ol and ethylene, respectively. Furthemore, the synthesis of Cat-CrNP is cheap, easy to perform and solvents used during preparation are environmentally friendly.

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