ENERGY EFFICIENT USAGE OF NATURAL GAS CRITERIAS

Abstract

The article suggests that Wobbe Index is one of the main criteria when determining quality of natural gas for natural gas Interchangeability from different sources ДСТУ ISO:13686:2016. For effective natural gas combustion the Wobbe Index Ws gas of should not differ form Ws of gas G20 by more than 2 percent. Especially in cases where equipment designed precisely to work with G20 gas. In that case it is necessary to adjust gas pressure or substitute machine design for different gas usage. Methane number that is corrected by Wobbe Index could be another criteria of quality of gas determination. Authors suggest minimal methane number of MN=65 defined by EN 16726:2015 is not sufficient. It is proven that even in case of higher combustion energy output for gas with Wobbe Index significantly lower of G20 gas test values the overall efficiency of using this gas in particular burner system is much lower. Flame flow for natural gas in streams M166 and M208 is closer to wrinkles due to chemical mixture of gas and natural gas in M1204 stream creates "yellow tipping" due to incomplete combustion, sulfur content similar to G21 test gas. With mediocre combustion energy output same burners consume more natural gas to provide same amount of energy. Natural gas from stream M404 has almost ideal mixture of components. Its Wobbe Index is 50,41 MJ/Nm3 but hydrocarbon dew point of 15.3 °C at P=3.92 MPa. That indicates relative humidity of 100%. Specific humidity of gas in stream is 0.44 grams per cubic meter that is dangerous for creating natural gas hydrates, solid clathrate compounds that may damage machinery or obstruct pipeline flow. Authors suggest to provide certain set of actions to process natural gas into so called clean “pipeline quality dry gas” at wells or gas-processing plants to improve gas parameters to be closer to European Union standards. As for government policies they have to be reworked from using “energy saving” term to “energy efficiency” term and start improving on efficient usage of natural gas by approving and applying newest energy efficient technologies and machinery into gas transport\consumer network.