Process Mass Spectrometry Provides Fast, Accurate Analysis of Fuel Gas

The United States has access to significant shale resources. In the Annual Energy Outlook 2014, the U.S. Energy Information Administration (EIA) estimated that the United States is currently the fourth highest global producer of shale natural gas, with approximately 610  trillion cubic feet (Tcf)  of technically recoverable shale natural gas resources.

According to National Geographic, natural gas is a fossil fuel and is characterized in two different way: conventional and non-conventional:

Natural gas that is economical to extract and easily accessible is considered “conventional.” Conventional gas is trapped in permeable material beneath impermeable rock.

Natural gas found in other geological settings is not always so easy or practical to extract. This gas is called “unconventional.” …

Shale gas is [a] type of unconventional deposit. Shale is a fine-grained, sedimentary rock that does not disintegrate in water. Some scientists say shale is so impermeable that marble is considered “spongy” in comparison. Thick sheets of this impermeable rock can “sandwich” a layer of natural gas between them.

When it comes to exploration, field-portable x-ray fluorescence instruments can be used as important enabling tools in exploration operations because they provide valuable information about the mineral composition of the rock and whether or not it has properties favorable to oil and gas production. Although these instruments cannot analyze hydrocarbons, they can be used to characterize reservoir properties that influence porosity (cements), permeability (clays, cement type), fracture population (Si content), and productivity (e.g. Si, Mg content).

Natural gas is a common fuel gas. Furnace or power plant fuel gases which have variable composition pose particular challenges for process engineers who need to achieve optimum efficiency and product yield. As the gas composition changes, the heating (calorific) value changes and the burner temperature can therefore change. So too can the amount of air that is required for combustion. Unless these properties are monitored and compensated for, the furnace or power plant will not be properly controlled, causing significant inefficiency, wastage and even burner damage.

Normally furnaces are operated at constant temperature; to achieve this, a gas-fired furnace would ideally burn a gas of constant composition, delivered at a constant rate and using a constant intake of air at the correct rate for complete combustion. In practice, the gas supply is of varying composition, especially on a petrochemical complex or integrated iron and steel works, where fuel gases from a variety of processes are utilized. Thus in order to maintain a constant temperature, either the rate of the gas supply needs to be varied or, in the case of a mixing station mixing various gas streams, the relative flow rates of the different gases need to be varied. Also, the air supply rate needs to be varied, since there will be energy wasted if either too little air or too much air is used. If there is too little air, some of the fuel gas will be unburned and wasted. If too much air is added then heat will be wasted. In metallurgy processes, excess air can also cause surface defects on metal surfaces due to oxidation, and poor temperature control can have an adverse effect on product quality.

Typical components of fuel gases include hydrogen, methane, carbon monoxide, ethylene, propane, butane, and many others. The wide range of energy values means that relatively low concentrations of some components can have a significant impact on the energy value of the gas stream. It is therefore imperative to provide a comprehensive analysis of the gas stream, not just measure the major components. Process mass spectrometry is becoming widely adopted as the ideal technique for determining the properties of fuel gases, by virtue of its speed and accuracy.

Read Fast On-Line Monitoring of Fuel Gases with the Thermo Scientific Prima PRO Process Mass Spectrometer to see results of on-line analysis of a wide range of fuel gases, especially on petrochemical & chemical complexes and integrated iron and steel works. These measurements include calorific value, density, specific gravity, Wobbe Index, stoichiometric air requirement and CARI as well as complete compositional analysis.