Gang Wang

Oligomerization and Polymerization of Ethylene Initiated by a Novel Ni(II)-Based Acetyliminopyridine Complexes as Single-Site Catalysts

Abstract Novel Ni(II)-based acetyliminopyridine complexes 1b, 2b, 3b (1–3b), which are synthesized from ligands 1a, 2a, 3a (1-3a) and [NiCl2(DME)], are suitable precursors for the catalysts that are necessary for ethylene oligomerization and polymerization reactions, activated by methylaluminoxane (MAO). The MAO-treated 1–3b presents an active catalytic center, which may oligomerize and polymerize ethylene to produce linear α-olefins and polyethylene, respectively. The molecular weight distributions of oligomers that are obtained are in good agreement with the Schulz-Flory rules for oligomers>C4. The activity of 3b-MAO complex is 6.3 × 107 g/(molNi-h) at 50 °C. The activities and molecular weight distributions of oligomers show significant reliance on the structures of catalyst precursors.

Analysis on the Effect of External-Wall Insulation on Energy Consumption of Residential Building in Lanzhou

Based on the comparison of external wall with different insulation thicknesses and without insulation, residential buildings energy consumption was simulated by using hourly energy consumption simulation software DeST-h in Lanzhou.The effects of external wall insulation on building energy consumption were analyzed. The result shows that the total annual load can be reduced to 42% ~ 72% with the insulation thicknesses vary from 10mm to 80mm. But With the increase of the thickness of the insulation layer, the amount of fluctuation of building load reduce gradually.That is not to say the insulation layer is thicker the energy saving effect is more distinct and there is shoud be the thickness is the most economical thickness. So the economic insulation thickness is determined as 40mm by using a life-cycle cost analysis.

The Effect of CO Pretreatment on Fe/ADM Catalyst for Higher Alcohols Synthesis from Syngas

The catalyst of FeS modified K2CO3/MoS2 (ADM) (Fe/ADM) were prepared and tested for higher alcohols (C2+OH) synthesis (HAS) from synthesis gas(syngas, mixture of H2 and CO). The effects of CO pretreatment on Fe/ADM catalyst and the catalytic performance for HAS were investigated. The ability for C2+OH formation was enhanced and the hydrocarbon selectivity was lowered after CO pretreatment. The XPS spectra revealed that the iron carbide species appeared and the potassium enriched on the surface of CO pretreated Fe/ADM catalyst, which might be responsible for the high activity of higher alcohols and low hydrocarbons synthesis, respectively.

Fracture Analysis of Φ73mm N80 NU Tubing in Western China Oilfields

Combined with the accident of tubing fracture in flowing well of western China oilfields, this paper analysed well condition, investigated experimentally and compared comprehensively mechanical properties and materials microstructure between the fractured and the new tubing.Caused of fractured tubing is the brittleness break which resulted from the microstructure difference of the pipe body and fracture section.It is suggested that the tubing should carry out the overall length heat treatment.