| 1. |
- Davidsson, K.O., et al.
(författare)
-
Countermeasures against alkali-related problems during combustion of biomass in a circulating fluidized bed boiler
- 2008
-
Ingår i: Chemical Engineering Science. - : Elsevier. - 0009-2509 .- 1873-4405. ; 63:21, s. 5314-5329
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this work was to study different ways to mitigate alkali-related problems during combustion of biomass in circulating fluidized beds. Wood chips and wood pellets were fired together with straw pellets, while the tendency to agglomerate and form deposits was monitored. In addition to a reference case, a number of countermeasures were applied in related tests. Those were addition of elemental sulphur, ammonium sulphate and kaolin to a bed of silica sand, as well as use of olivine sand and blast-furnace slag as alternative bed materials. The agglomeration temperature, composition and structure of bed-ash samples were examined. The flue-gas composition, including gaseous alkali chlorides, was measured in the hot flue gases and in the stack. Particles in the flue gas were collected and analysed for size distribution and composition. Deposits were collected on a probe in hot flue gases and their amount and composition were analysed. Addition of kaolin was found to be the best method to counteract the agglomeration problem. The deposition problem is effectively counteracted with addition of ammonium sulphate, while kaolin is too expensive to be used commercially against deposits, and sulphur is less effective than ammonium sulphate.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Tyumentsev, Mikhail S, 1988, et al.
(författare)
-
Coordination of Trivalent Lanthanides with Bismalonamide Ligands: Implications for Liquid-Liquid Extraction
- 2017
-
Ingår i: European Journal of Inorganic Chemistry. - : Wiley. - 1434-1948 .- 1099-0682. ; 2017:37, s. 4285-4298
-
Tidskriftsartikel (refereegranskat)abstract
- The complexation of the bismalonamide ligand 2,2'[1,2-phenylenebis(methylene)] bis(N, N, N', N'-tetraethylmalonamide) (L), bearing two C-alkylated N, N, N', N'-tetraethylmalonamide groups, onto an ortho-xylylene [C6H4(CH2)(2)] platform with trivalent lanthanides was investigated, both in solid and solution states. The crystal structures [Nd-2(NO3)(6)L-2]center dot(CH3CN)(3) (2), [Nd-2(NO3)(4)L-2]center dot[Nd(NO3)(5)]center dot(CH3CN) 1.5 (3), Ce(NO3)(3)L-2 (4), and [NdL2]center dot(ClO4)(3)center dot C2H5OH (5) were analyzed by single-crystal X-ray diffraction. The ortho-bismalonamide (L) is tetradentate in structures 2, 3, and 5 and bidentate in 4 only. It was found that structures 2 and 3 are composed of dimeric species. According to electrospray-ionization mass spectrometry, the dimers are prevailing in acetonitrile solutions. The polydentate coordination of the ortho-bismalonamide (L) with trivalent lanthanides suggests that an entropy effect favors liquid-liquid extraction of metal ions with this type of ligand.
|
|
