We present energy and carbon balances and cost estimates based on detailed Aspen Plus process simulations for five plant designs to co-produce dimethyl ether (DME) and electricity from coal. Four of the designs include capture of CO2 for long-term underground storage. We also illustrate the potential DME offers for reducing emissions by facilitating a shift to more energy-efficient vehicles.

There is concern over the decline of aspen and the lack of successful regeneration due to excessive browsing of aspen suckers by cattle and other wild and domestic ungulates. We conducted a 2-yr study on Lassen National Forest, California, to aid development of cattle grazing strategies to enhance aspen regeneration. We evaluated seasonal biomass, nutritional quality, and utilization by cattle ...

Snow ablation modelling at the stand scale must account for the variability in snow cover and the large variations of components of energy transfer at the forest ̄oor. Our previous work successfully predicted snow ablation in a mature jack pine stand by using a one-dimensional snow process model and models predicting radiation below forest canopies. This work represents a second test of our bas...

HYSYS process modeling software was used to analyze the effect of reflux ratio and number of trays on the purity of ethylene in a vapor recompression distillation column and also in an ordinary distillation column. Analysis of data showed that with increased pressure a higher reflux ratio is needed to obtain a purity of 99.9% for both towers. In addition number of trays was varied to see its ef...

Quaking aspen (Populus tremuloides) is commonly believed to be declining throughout western North America. Using a historical vegetation map and Landsat TM5 imagery, this study detects changes in regional aspen cover over two different time periods of 85 and 18 years and examines aspen change patterns with biophysical variables in the Targhee National Forest of eastern Idaho, USA. A subpixel cl...

A retarding field energy analyzer (RFEA) has been designed and developed to measure ion energy distribution function (IEDF) in helicon plasma. To design RFEA, determination of shape, size of the analyzer orifice, choice of grid and their separations are discussed. The four grid energy analyzer assembly provides easy access of all internal mechanical components and electrical connections. Fundam...

Forest structural heterogeneity due to species composition, spatial relationships and tree size are widely studied patterns in forest systems, but their impacts on tree function are not as well documented. The objective of this study was to examine how stand composition, tree proximity relationships and tree size influence the leaf functional traits of aspen, an early successional species, and ...

Trembling aspen (Populus tremuloides Michx.) generally grows as clones in which stems, ranging from many thousands to only a few, are interconnected by a common root system. When clones are very large, in one recorded case involving about 47␣ 000 stems joined together over a 43 ha area, aspen becomes a candidate for earth’s most massive and oldest organism. Recent analyses suggest that aspen cl...

A new simulation model for Hydrogen production is developed on the Aspen Plus platform. Designing, Analysis and Optimization of the Metal Chloride based cyclic process is done thereby calculating the energy, exergy and overall efficiency of the same using the simulation software. Kinetic and thermodynamic analysis of chemical reactions occurring in each equipment of the proposed model is done. ...

1 Corresponding author: [email protected]; 715-346-4098 2 [email protected]; 541-737-3056 ABSTRACT: Aspen (Populus tremuloides) stands inside and outside Yellowstone National Park (YNP), Wyoming, USA, were compared to test whether the lack of overstory aspen recruitment observed in YNP extended to winter ranges of elk (Cervus elaphus) in adjacent national forests. Remote sensing and fi...