Costs, CO2 emissions, and energy balances of applying Nordic slash recovery methods in British Columbia

This study evaluated the costs, CO2 emissions, and energy balances associated with three potential systems for recovering roadside slash in British Columbia, Canada, in which the biomass is transported as slash, hog fuel, or bundles. Costs, CO2 emissions, and energy balances of all three systems showed strong dependence on transportation distance and considerably weaker dependence on slash amounts at landing (cutting block size). The results indicated that the hog fuel system is the cheapest, per unit of delivered biomass, whereas the bundle system is the most expensive system when transportation distances are short (<100 km), and the slash system is the most expensive when transportation distances exceed 100 km. However, the viability of the systems is strongly dependent on payload assumptions

Class 1 bluetooth power amplifier with 24dBm output power and 48% PAE at 2.4GHz in 0.25um CMOS

Abstract In this paper, we report an RF power amplifier design in digital CMOS technology for the Class 1 power level specification ( 20 dBm) in the Bluetooth Communications standard. We have also investigated hot carrier effects under large signal RF operation of the power amplifier. The two stage circuit, designed in 0. 25 f1m CMOS technology, utilizes a high-density ring capacitor structure for interstage matching. In a chip-on-board configuration tested at 2. 4 GHz, this CMOS power amplifier delivers an output power of 24 dBm with 48% PAE at a supply voltage of2. 5

Particulate matter emissions from combustion of wood in district heating applications

The utilization of wood biomass to generate district heat and power in communities that have access to this energy source is increasing. In this paper the effect of wood fuel properties, combustion condition, and flue gas cleaning system on variation in the amount and formation of particles in the flue gas of typical district heating wood boilers are discussed based on the literature survey. Direct measurements of particulate matter (PM) emissions from wood boilers with district heating applications are reviewed and presented. Finally, recommendations are given regarding the selection of wood fuel, combustion system condition, and flue gas cleaning system in district heating systems in order to meet stringent air quality standards. It is concluded that utilization of high quality wood fuel, such as wood pellets produced from natural, uncontaminated stem wood, would generate the least PM emissions compared to other wood fuel types. Particulate matter emissions from grate burners equipped with electrostatic precipitators when using wood pellets can be well below stringent regulatory emission limit such as particulate emission limit of Metro Vancouver, Canada.Wood biomass Particulate matter emissions Dioxin and furan District energy systems Biomass combustion systems Flue gas cleaning systems

Assessing the integration of torrefaction into wood pellet production

Abstract not availableMahdi Mobini, Jörn-Christian Meyer, Frederik Trippe, Taraneh Sowlati , Magnus Fröhling, Frank Schultman

Economic sensitivity of wood biomass utilization for greenhouse heating application

This paper presents an analysis of the impacts of technical and market changes on the economic feasibility of using wood biomass to produce heat for an average-sized greenhouse in British Columbia. A previous techno-economic analysis determined that the installation of a wood pellet or a wood residue boiler to generate 40% of the greenhouse heat demand is more economical than using a natural gas boiler alone to generate all the heat [1]. As the techno-economic analysis contained forecasted parameters, a thorough sensitivity analysis is needed for sound decision making. This paper extends the previous techno-economic study by assessing the effect of fuel price, wood biomass energy contribution, and greenhouse size changes on the net present value (NPV) when using a wood pellet or wood residue boiler with or without an electrostatic precipitator (ESP). The results indicate that the attractiveness of using wood biomass will increase if the price of fossil fuels increases more than 3% per year or carbon taxes and regulations are applied. Increasing the biomass energy contribution by 20% (to provide 60% of the total heat demand) would still be economical. The installation of a wood pellet boiler or a wood residue boiler is economical for average (7.5 ha) or large (15 ha) greenhouses.Sensitivity analysis Economic evaluation Greenhouses Wood pellets Wood residue Wood biomass boiler

Lewis acid behavior of SF4: synthesis, characterization, and computational study of adducts of SF4 with pyridine and pyridine derivatives

Accepted author manuscriptSulfur tetrafluoride was shown to act as a Lewis acid towards organic nitrogen-bases, such as pyridine, 2,6-dimethylpyridine, 4-methylpyridine, and 4-dimethylaminopyridine. The SF4·NC5H5, SF4·2,6-NC5H3(CH3)2, SF4·4-NC5H4(CH3), and SF4·4-NC5H4N(CH3)2 adducts can be isolated as solids that are stable below –45 °C. The Lewis acid-base adducts were characterized by low temperature Raman spectroscopy and the vibrational bands were fully assigned with the aid of density-functional-theory (DFT) calculations. The electronic structures obtained from the DFT calculations were analyzed by the quantum theory of atoms in molecules (QTAIM). The crystal structures of SF4·NC5H5, SF4·4-NC5H4(CH3), and SF4·4-NC5H4N(CH3)2 revealed weak S---N dative bonds with nitrogen coordinating in the equatorial position of SF4. Based on the QTAIM analysis, the non-bonded valence shell charge concentration on sulfur, which represents the lone pair, is only slightly distorted by the weak dative S---N bond. No evidence for adducts between quinoline or isoquinoline with SF4 was found by low-temperature Raman spectroscopy.Ye