Alternative biofuels:PVTx measurements for DME + propane

This study presents the experimental results for the dimethyl ether (DME) ? propane system obtained using the Burnett method. The apparatus was calibrated using helium. PVTx measurements were taken for four isotherms (344, 354, 364, and 375 K), performing 16 Burnett expansions in pressures ranging from about 3,000 to 70 kPa. The second and third virial coefficients were derived from experimental results. The experimental uncertainty in the second and third virial coefficients was estimated to be within ±5 cm 3/mol and ±1,000 cm6/mol2,respectively

PVT properties of an alternative biofuel: dimethyl ether

Dimethyl ether is an important chemical material and it has many engineering applications. It is a clean and economical alternative fuel and an ozone-friendly refrigerant. In this work, its PVT properties have been object of study. In particular, the experimental work was performed both in the two-phase region and in the superheated vapor region phase by means of the isochoric method. The isochoric measurements were carried out at temperatures from 219 K to 363 K and at pressures from 22 kPa up to 1,740 kPa. A total of 159 points, both in the two phase (71 points) and in the superheated vapor region (88 points) were obtained. The present experimental PVT data contribute to the deeper knowledge of the behaviour of the fluid both in the superheated vapour and in the saturation pressure region and to the development of a new equation of state

Direct Conversion of Dimethyl Ether in High Temperature Polymer Electrolyte Fuel Cells under Stationary and Dynamic Conditions

The behavior of a polybenzimidazole-based high-temperature polymer electrolyte membrane fuel cell using dimethyl ether (DME) as fuel was investigated under stationary and dynamic load conditions. The power density was enhanced significantly with an increase of both operating temperature and anodic water stoichiometry. Likewise, the power density decreased with increasing DME stoichiometry. The characterization of the dynamic operation showed a strong qualitative similarity to low-temperature direct methanol fuel cells. The development of the cell voltage after a spontaneous change of cell current density could be assigned to the electrochemical oxidation of an intermediate species

Potassium(I) Amidotrihydroborate: Structure and Hydrogen Release

Potassium(I) amidotrihydroborate (KNH(2)BH(3)) is a newly developed potential hydrogen storage material representing a completely different structural motif within the alkali metal amidotrihydroborate group. Evolution of 6.5 wt % hydrogen starting at temperatures as low as 80 degrees C is observed and shows a significant change in the hydrogen release profile, as compared to the corresponding lithium and sodium compounds. Here we describe the synthesis, structure, and hydrogen release characteristics of KNH(2)BH(3)

Multiscale Characterization of Lignocellulosic Biomass Variability and Its Implications to Preprocessing and Conversion: A Case Study for Corn Stover

Feedstock variability that originates from biomass production and field conditions propagates through the value chain, posing a significant challenge to the emerging biorefinery industry. Variability in feedstock properties impacts feeding, handling, equipment operations, and conversion performance. Feedstock quality attributes, and their variations, are often overlooked in assessing feedstock value and utilization for conversion to fuels, chemicals, and products. This study developed and employed a multiscale analytical characterization approach coupled with data analytic methods to better understand the sources and distribution of feedstock quality variability through evaluation of 24 corn stover bales collected in 4 counties of Iowa. In total, 216 core samples were generated by sampling nine positions on each bale using a reliable bale coring process. The samples were characterized for a broad suite of physicochemical properties ranging across field and bale, macro, micro, and molecular scales. Results demonstrated that feedstock quality attributes can vary at all spatial scales and that multiple sources of variability must be considered in order to establish and manage biomass quality for conversion processes

Multiscale Characterization of Lignocellulosic Biomass Variability and Its Implications to Preprocessing and Conversion: A Case Study for Corn Stover

Feedstock variability that originates from biomass production and field conditions propagates through the value chain, posing a significant challenge to the emerging biorefinery industry. Variability in feedstock properties impacts feeding, handling, equipment operations, and conversion performance. Feedstock quality attributes, and their variations, are often overlooked in assessing feedstock value and utilization for conversion to fuels, chemicals, and products. This study developed and employed a multiscale analytical characterization approach coupled with data analytic methods to better understand the sources and distribution of feedstock quality variability through evaluation of 24 corn stover bales collected in 4 counties of Iowa. In total, 216 core samples were generated by sampling nine positions on each bale using a reliable bale coring process. The samples were characterized for a broad suite of physicochemical properties ranging across field and bale, macro, micro, and molecular scales. Results demonstrated that feedstock quality attributes can vary at all spatial scales and that multiple sources of variability must be considered in order to establish and manage biomass quality for conversion processes