We report here kinetic and isotopic evidence for the elementary steps involved in dimethyl ether (DME) homologation and for their role in the preferential synthesis of 2,2,3-trimethylbutane (triptane) and isobutane. Rates of methylation of alkenes and of hydrogen transfer, isomerization and b-scission reactions of the corresponding alkoxides formed along the homologation path to triptane were m...

A self quenching streamer (SQS), or limited streamer mode has been studied in single wire chambers with cross-sections 12·12 mm and wire diameters 15, 25 and 50 μm. Chambers were filled with either pure dimethyl ether (DME) or isobutane gases and irradiated with Gd alpha and Fe x-ray sources. Clear transitions from a proportional to 100% SQS mode were observed on all three diameter wires with b...

The research presented here describes the numerical optimization of a multi-step ignition model to predict the auto-ignition of dimethyl ether (DME) in a rapid compression machine. The multi-step modeling concept is aimed at capturing the ignition behavior of new oxygenated fuel blends, where detailed or reducedmechanisms are not available. Experimental data for the ignition ofDME/O2/N2mixtures...

Due to its excellent conductivity, good thermal stability and large specific surface area, carbon nano-tubes (CNTs) were selected as support to prepare a Re-based catalyst for dimethyl ether (DME) direct oxidation to polyoxymethylene dimethyl ethers (DMMx). The catalyst performance was tested in a continuous flow type fixed-bed reactor. H3PW12O40 (PW12) was used to modify Re/CNTs to improve its...

Being reactive and spontaneously combustible, dried Victorian brown coals can not be exported, and have to be used in mine-mouth power stations which also suffer from low efficiency and high CO2 emission. Synthesis of dimethyl ether (DME) is an option for the production of liquid fuel, a transportable product for power generation and transportation. This paper presents a steady-state process mo...

Dehydration of methanol to dimethyl ether (DME) over a commercial Al2O3 catalyst was studied in an isothermal integral fixed bed reactor. The experiments were performed on the temperature interval 513-613 K, liquid hourly space velocity (LHSV) of 0.9-2.1h, pressures between 0.1 and 1.0 MPa. The effect of different operation conditions on the dehydration of methanol was investigated in a laborat...

The production of dimethyl ether (DME) as compared to methanol from synthesis gas allows for increased conversions in a single pass. A challenge this process is the combination and dehydration functionalities catalyst without mutual negative interference their performances. Here, we studied use hydrated niobium pentoxide (Nb2O5·nH2O) phosphate (NbOPO4) with copper-based direct DME, while gamma-...