Universal correlation for gas hydrates suppression temperature of inhibited systems: II. Mixed salts and structure type

AIChE Journal ◽  
2018 ◽  
Vol 64 (6) ◽  
pp. 2240-2250 ◽  
Author(s):  
Yue Hu ◽  
Bo Ram Lee ◽  
Amadeu K. Sum
AIChE Journal ◽  
2017 ◽  
Vol 63 (11) ◽  
pp. 5111-5124 ◽  
Author(s):  
Yue Hu ◽  
Bo Ram Lee ◽  
Amadeu K. Sum

2013 ◽  
Vol 68 (7) ◽  
pp. 761-777 ◽  
Author(s):  
Anna J. Lehner ◽  
Caroline Röhr

In the course of the synthesis of mixed oxidosulfido molybdates and tungstates by passing H2S gas through solutions of the oxido metalates, several new salts containing the metalates [MOS3]2- besides further anions (halides X-, hydrosulfide SH- or thiosulfate S2O2-3) were obtained as well-formed crystals. Their crystal structures have been determined using single crystal X-ray data. The salts containing SH- as the additional anion crystallize with a new structure type (orthorhombic, space group Pmn21, M=Mo=W, TM =20=-125 °C: a=957.7(2)/954.15(2), b=636.2(2)/636.19(1), c=812.4(2)/809.88(2) pm, Z =2, R1=0.0319=0.0185). The mixed sulfidomolybdate/ chloride K3[MoO1.25S2.75]Cl (orthorhombic, space group Pca21, a=1246.3(1), b=623.20(4), c=1230.44(8) pm, Z =4, R1=0.0472) is isotypic with the sulfidotungstate K3[WOS3]Cl, but contains 25% of the disulfido molybdate. The structures of the SH- and the Cl- salts are closely related: In both cases, the trisulfido metalates are overall coordinated by cuboctahedra of 12 K+ ions, and the small additional anions are centered in K+ octahedra. In this regard, the structures are both derivatives of the cubic perovskite (and thus the Cu3Au) type. This crystallographic group-subgroup relation is discussed in detail. Yellow hexagonal columns of the double salt K6[WOS3]2(S2O3) were obtained by the methanothermal decomposition of the disulfidotungstate K2[WO2S2]. It crystallizes with a new structure type (hexagonal, space group P63mc, a=983.78(8), c=1227.3(1) pm, Z =2, R1=0.0175). Like in the other mixed salts, the two crystallographically different [WOS3]2- anions exhibit an overall cuboctahedral coordination by 12 potassium cations. The smaller S2O2-3 anions are surrounded by nine K+ ions arranged in the form of two flat facesharing octahedra. Again similar to the mixed halides and hydrosulfides, the two K polyhedra around the anions, here present in a 2 : 1 ratio, are arranged in a space-filling packing, in this case related to the ht- BaMnO3 (and thus the Ni3Ti) structure type. According to their ‘double salt’ character, the Mo/W-O and Mo/W-S distances and the intramolecular vibrational frequencies of the tetrahedral moieties of the title compounds are similar between them and those in the pure potassium trisulfido metalates. This further becomes apparent from the additive nature of their molar volumes, which correspond to the sum of the volumes of the simple salts KCl, KSH or K2(S2O3) and K2[MoOS3].


AIChE Journal ◽  
2018 ◽  
Vol 64 (11) ◽  
pp. 4097-4109 ◽  
Author(s):  
Yue Hu ◽  
Jeong-Hoon Sa ◽  
Bo Ram Lee ◽  
Amadeu K. Sum

2000 ◽  
Vol 626 ◽  
Author(s):  
Antje Mrotzek ◽  
Kyoung-Shin Choi ◽  
Duck-Young Chung ◽  
Melissa A. Lane ◽  
John R. Ireland ◽  
...  

ABSTRACTWe present the structure and thermoelectric properties of the new quaternary selenides K1+xM4–2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22. The compounds K1+xM4-2xBi7+xSe15 (M= Sn, Pb) crystallize isostructural to A1+xPb4-2xSb7+xSe15 with A = K, Rb, while K1-xSn5-xBi11+xSe22 reveals a new structure type. In both structure types fragments of the Bi2Te3-type and the NaCl-type are connected to a three-dimensional anionic framework with K+ ions filled tunnels. The two structures vary by the size of the NaCl-type rods and are closely related to β-K2Bi8Se13 and K2.5Bi8.5Se14. The thermoelectric properties of K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22 were explored on single crystal and ingot samples. These compounds are narrow gap semiconductors and show n-type behavior with moderate Seebeck coefficients. They have very low thermal conductivity due to an extensive disorder of the metal atoms and possible “rattling” K+ ions.


2018 ◽  
Vol 11 ◽  
pp. 77-91
Author(s):  
V.T. Gudzenko ◽  
◽  
A.A. Varenichev ◽  
M.P. Gromova ◽  
◽  
...  

Author(s):  
Bruna Drumond ◽  
Bonifácio Oliveira Fialho ◽  
José Adilson Castro ◽  
Adriana Teixeira ◽  
Bárbara Louise Lemos Drumond Silva
Keyword(s):  

Author(s):  
Gustavo Alonso Barrientos Sandoval ◽  
Rafhael Andrade ◽  
Edson Soares ◽  
Roney Thompson ◽  
Flavio Barboza Campos ◽  
...  
Keyword(s):  

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