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Numerical simulation of NO production in a pulverized coal fired furnace

Straka R., Makovička J., Beneš M.

Environment Protection Engineering

2011

Vol. 37, nr 2

13-22

Behaviour of air-coal mixture has been described using the Navier-Stokes equations for the mixture of air and coal particles, accompanied by the turbulence model. The undergoing chemical reactions are described by the Arrhenius kinetics (reaction rate proportional to exp(-E/RT) ). Heat transfer via conduction and radiation has also been considered. The system of partial difference equations is discretized using the finite volume method and the advection upstream splitting method as the Riemann solver. The resulting ordinary differential equations are solved using the 4th order Runge-Kutta method. Results of simulation for typical power production level are presented together with the air staging impact on NO production.

Geochemistry and age of groundwater in a hydrochemically diversified aquifer (Permo-Carboniferous, the Intra-Sudetic Synclinorium, SWPoland) derived from geochemical modelling and isotopic studies

Dobrzyński D.

Acta Geologica Polonica

2009

Vol. 59, no. 3

371-411

Comprehensive investigations of groundwater were performed in a sedimentary aquifer of Permo-Carboniferous, Intra-Sudetic Synclinorium, in SWPoland. The investigation included aqueous chemical and isotopic composition, chemistry of mineral phases, geochemical modelling, and tritium and radiocarbon groundwater dating. Chemical diversity in the groundwater system is created by the mixing of modern fresh water and older sulphate water with higher dissolved solids. The system is treated as a system of flows of two end-member water types. Geochemical modelling is used for: (1) explaining the origin of the chemistry of both water components, (2) quantifying the groundwater mixing, (3) correcting the radiocarbon age of the groundwater for the effects of chemical water-rock interactions, and (4) calculating reaction rates. Study of stable (C, S, O, H) and unstable ([^3H], [^14]C) isotopes allowed the inverse mass balance geochemical models to be verified and specified, and the groundwater to be dated. The chemistry of the modern, tritium-bearing, fresh water is a result of dissolution of limestones, dolomites and gypsum. The mean tritium-age of this water, based on the lumped-parameter approach, varies between 10 and 200 years. The sulphate mineral water owes its chemistry to the process of dedolomitization driven by gypsum dissolution. Its radiocarbon age is about 5.9 ka BP, i.e., during theMid-Holocene Climatic Optimum. Rates of chemical reactions responsible for the formation of sulphate type water are estimated to be: dissolution of gypsum (2.85 [mi]mol/L/year) and dolomite (0.21 [mi]mol/L/year), calcite precipitation (0.20 [mi]mol/L/year), organic matter decomposition (0.08 [mi]mol/L/year).