Elżbieta Szczepaniec-Cięciak

Analysis of odorous compounds at municipal landfill sites.

The aim of this investigation was to determine odorous compounds in the air over the landfill sites in France and Poland. Air samples were collected by passive and dynamic methods of preconcentration analytes and analysed by GC-MS and GC-FID. The coupling µTD-µGC-MS was also used for on-site analysis of odorous compounds. The achieved results indicated that the concentrations of odorants in the air varied and strongly depended on the sampling site. The highest concentrations were observed at the points situated near biogas wells and above the fresh waste layer. The concentrations were influenced by landfill activities such as failures of the landfill gas collection system, heavy truck traffic, machinery operations and compacting fresh waste.

Operational and Meteorological Influence on the Utilized Biogas Composition at the Barycz Landfill Site in Cracow, Poland

The aim of the present investigation was to determine time variation of biogas composition at the gas collection network on the ‘Barycz’ landfill site in Cracow, Poland, as well as the influence of operational and meteorological conditions on the biogas composition. The study of biogas composition at selected gas wells and gas collectors was conducted using a portable IR landfill gas analyser. The methane concentration in biogas on the part of the landfill site currently in operation varied in the range 59-63% vol. and on the reclaimed part of the landfill, in the range 42-62% vol. It was found that biogas composition is significantly affected by operational conditions and meteorological parameters. For example, methane concentrations were more constant when the pressure in the installation was above the ambient atmosphere than when it was below, where fluctuations of 15% vol. were seen. Low air temperature, high precipitation and high atmospheric pressure, which lower the permeability of the outer layer of the landfill, result in higher quality of the biogas getting to the gas collection system.

Solubility of Solid 2-Methyl-1,3-butadiene (Isoprene) in Liquid Argon and Nitrogen at the Standard Boiling Points of the Solvents

The solubility of solid 2-methyl-1,3-butadiene (isoprene) in liquid argon at a temperature of 87.3 K and in liquid nitrogen at 77.4 K has been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. GC–MS was used to identify impurities in the solute. The experimental value of the mole fraction solubility of solid isoprene in liquid argon at 87.3 K is (1.41 ± 0.27) × 10−6 and (1.56 ± 0.36) × 10−7 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbon in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters l12 were also calculated. At 90.0 K liquid argon is a better solvent for isoprene than is liquid nitrogen. The experimental values of the solubilities of isoprene in liquid argon and nitrogen were compared with results obtained for selected unsaturated and aromatic hydrocarbons.

Solubility of solid 1-hexene and 2-methylpentane in liquid argon and nitrogen at the standard boiling points of the solvents

The solubilities of solid 1-hexene and 2-methylpentane in liquid argon at a temperature of 87.3 K and in liquid nitrogen at 77.4 K have been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. The experimental value of the mole fraction solubility of solid 1-hexene in liquid argon at 87.3 K is (3.87 ± 0.74) × 10−7 and (7.94 ± 2.47) × 10−9 in liquid nitrogen at 77.4 K. The experimental value of the mole fraction solubility of solid 2-methylpentane in liquid argon at 87.3 K is (1.45 ± 0.36) × 10−5 and (6.80 ± 2.16) × 10−8 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbons in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters 112 were also calculated. At 90.0 K, liquid argon is a better solvent for solid 1-hexene and 2-methylpentane than is liquid nitrogen.

Solubility of 1-Pentene Ice in Liquid Nitrogen and Argon at the Standard Boiling Points of the Solvents

The solubilities of 1-pentene ice in liquid nitrogen at a temperature of 77.4 K and in liquid argon at 87.3 K have been measured by the filtration method. The 1-pentene content in solution was determined using gas chromatography. The experimental value of the mole fraction solubility of 1-pentene ice in liquid nitrogen at 77.4 K is: (1.28±0.25)×10−7 and (4.11±0.44)×10−7 in liquid argon at 87.3 K. The Preston–Prausnitz method was used for calculation of the solubilities of 1-pentene ice in liquid nitrogen in the temperature range 64.0–90.0 K and in liquid argon in the temperature range 84.0–90.0 K. The parameters l12 were also calculated. At 90.0 K liquid argon is the better solvent for 1-pentene ice than is liquid nitrogen.

Solubility of hex-1-ene, hexane and cyclohexane in liquid nitrogen

The solubilities of hex-1-ene, hexane and cyclohexane have been measured in liquid nitrogen at a temperature of 77.4 K by the filtration method. The solubilities of the C6 hydrocarbons in LN2 at 77.4 K vary from 0.5 × 10–8 mole fraction for cyclohexane, to 0.7 × 10–8 mole fraction for hexane and 0.16 × 10–6 mole fraction for hex-1-ene. The results are compared with the solubilities calculated on the basis of the Scatchard–Hildebrand equation of regular solution theory. Correlation between the solubilities of alkanes, alkenes and cyclic hydrocarbons in liquid nitrogen, and some properties of solutes {normal boiling point (Tb), critical point (Tc), heat of vaporization at normal boiling point (ΔHb), the mean of the heat of vaporization and the enthalpy of melting [(ΔHb+ΔHm)/2] and Lennard–Jones force constant (Iµ/kB} are presented.

Solubility of solid 2,3-dimethylbutane and cyclopentane in liquid argon and nitrogen at the standard boiling points of the solvents

The solubilities of solid 2,3-dimethylbutane and cyclopentene in liquid argon at a temperature of 87.3 K and in liquid nitrogen at 77.4 K have been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. GC–MS was used to identify impurities in solutes. The experimental value of the mole fraction solubility of solid 2,3-dimethyl-butane in liquid argon at 87.3 K is (8.26 ± 1.60) × 10−6 and (2.77 ± 0.94) × 10−8 in liquid nitrogen at 77.4 K. The experimental value of the mole fraction solubility of solid cyclopentene in liquid argon at 87.3 K is (5.11 ± 0.44) × 10−6 and (4.60 ± 0.76) × 10−8 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbons in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters l12 were also calculated. At 90.0 K liquid argon is a better solvent for investigated solid hydrocarbons than is liquid nitrogen.

Solubility of Solid 1-Hexyne in Liquid Argon and Nitrogen at the Standard Boiling Points of the Solvents

The solubilities of solid 1-hexyne in liquid argon at 87.3 and in liquid nitrogen at 77.4 K have been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. GC–MS was used to identify impurities in 1-hexyne. The experimental value of the mole fraction solubility of solid 1-hexyne in liquid argon at 87.3 K is (0.85 ± 0.19) × 10−7 and (1.25 ± 0.08) × 10−8 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbon in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters l12 were also calculated. At 90.0 K liquid argon is a better solvent for solid 1-hexyne than is liquid nitrogen.

Solubility of Solid Hexane and Cyclohexane in Liquid Argon at 87.3 K

The solubilities of solid hexane and cyclohexane in liquid argon at 87.3 K have been measured by the filtration method. The hexane and cyclohexane content in solution was determined using gas chromatography. The solubilities of the C6 hydrocarbons in liquid argon at 87.3 K are (0.56 ± 0.11) × 10-7 mole fraction for hexane and (1.04 ± 0.30) × 10-7 mole fraction for cyclohexane. The Preston–Prausnitz method was used for calculation of the solubilities of solid hexane and cyclohexane in liquid argon in the temperature range 84–110 K. The values of the solvent–solute interaction constant l12 were also calculated.

Solubility of solid pentane, 2-methylbutane, and cyclopentane in liquid argon at 87.3 K

The solubilities of solid pentane, 2-methylbutane (isopentane), and cyclopentane in liquid argon at 87.3 K have been measured by the filtration method. The C5 hydrocarbon content in solution was determined using gas chromatography. The solubilities of the C5 hydrocarbons in liquid argon at 87.3K vary from 0.61 × 10−7 mole fraction for cyclopentane, to 1.37 × 10−7 mole fraction for pentane, and 8.83 × 10−6 mole fraction for 2-methylbutane. The Preston–Prausnitz method was used for calculation of the solubilities of solid C5 hydrocarbons in liquid argon in the temperature range 84–110 K and in liquid nitrogen in the range 64–90K. The values of the solvent–solute interaction constant l12 were also calculated.