Chapter 2
LITERATURE SURVEY
2.1. Characteristics of Hydrogen Sulphide
2.1.1. Physical and Chemical Properties
H2S is a colourless gas characterised by a rotten gas odour which is highly toxic. It is soluble in different liquids including water and alcohols. It is typically formed under deficit oxygen conditions in the presence of organic matter and sulphate compounds (WHO, 2003). Hydrogen Sulphide is also present in the atmosphere in the range of 0.0001-0.0002 ppm though it may vary with places and therefore goes unnoticed (WHO, 1981). The table gives description of physical and chemical properties of H2S:
Table 2.1: Properties of Hydrogen Sulphide (AIHA, 1991):
Description Hydrogen Sulphide
Molecular formula H2S
Molar mass 34.08g/mol
Boiling point -60.4 0C
Melting point -85.5 0C
Critical temperature 100.50C
Density 1.43g/m3
Short Term Exposure Limit(STEL) 5 ppm (15 min)
Immediate Damage to Life or Health (IDLH) 100 ppm
Vapour pressure 18.266 bar at 210C
Conversion factor 1ppm= 1.5 mg/m3
2.1.2. Health Effects
Hydrogen sulphide is an asphyxiant and irritant gas. Concentrations above a limit of 20 ppm might irritate the eyes and the respiratory tract, above 50-100 ppm have neurotoxic effects and concentrations above 100 ppm are considered of immediate life danger (WHO, 2003). H2S is a dense …show more content…
At this temperature, the water vapour condenses to form water and releases latent heat in the parcel. Due to this the cooling rate of the parcel slows down. This rate is called the wet adiabatic lapse rate. The wet adiabatic lapse rate is always less than the dry adiabatic lapse rate because the air parcel cools slower when heat is released. The wet adiabatic lapse is not constant and changes with temperature and pressure (Hanna,S.R.,et.al.,1982). However, the average value in the middle troposphere is taken approximately as -6 to -70C /
LITERATURE SURVEY
2.1. Characteristics of Hydrogen Sulphide
2.1.1. Physical and Chemical Properties
H2S is a colourless gas characterised by a rotten gas odour which is highly toxic. It is soluble in different liquids including water and alcohols. It is typically formed under deficit oxygen conditions in the presence of organic matter and sulphate compounds (WHO, 2003). Hydrogen Sulphide is also present in the atmosphere in the range of 0.0001-0.0002 ppm though it may vary with places and therefore goes unnoticed (WHO, 1981). The table gives description of physical and chemical properties of H2S:
Table 2.1: Properties of Hydrogen Sulphide (AIHA, 1991):
Description Hydrogen Sulphide
Molecular formula H2S
Molar mass 34.08g/mol
Boiling point -60.4 0C
Melting point -85.5 0C
Critical temperature 100.50C
Density 1.43g/m3
Short Term Exposure Limit(STEL) 5 ppm (15 min)
Immediate Damage to Life or Health (IDLH) 100 ppm
Vapour pressure 18.266 bar at 210C
Conversion factor 1ppm= 1.5 mg/m3
2.1.2. Health Effects
Hydrogen sulphide is an asphyxiant and irritant gas. Concentrations above a limit of 20 ppm might irritate the eyes and the respiratory tract, above 50-100 ppm have neurotoxic effects and concentrations above 100 ppm are considered of immediate life danger (WHO, 2003). H2S is a dense …show more content…
At this temperature, the water vapour condenses to form water and releases latent heat in the parcel. Due to this the cooling rate of the parcel slows down. This rate is called the wet adiabatic lapse rate. The wet adiabatic lapse rate is always less than the dry adiabatic lapse rate because the air parcel cools slower when heat is released. The wet adiabatic lapse is not constant and changes with temperature and pressure (Hanna,S.R.,et.al.,1982). However, the average value in the middle troposphere is taken approximately as -6 to -70C /