In this paper, we examine the advantages of integrating greenhouse gas and emission calculations and forecasting into natural gas hydraulic pipeline simulation. Today, more than any other time before, the public is acutely aware of the significance of climate change and its impact on the world around us. In the United States, the Environmental Protection Agency has as recently as November 2021, proposed new requirements for states to reduce emissions, expand and strengthen emission reduction requirements, and further encourage emission detection technologies. For this reason, having a better understanding of the potential impacts of pipeline designs and pipeline operations on greenhouse gas and pollutant emissions, and improving our reporting of it, will become critical for all engineers in the natural gas industry.
Emission calculations are usually done separately from hydraulic simulation, and estimating pollutant and greenhouse gas emissions for pipeline or compressor station designs, as well as operational studies to estimate normal daily or annual emissions, can be quite tedious.
By incorporating greenhouse gas and pollutant emissions calculations directly into everyday steady state and transient hydraulic pipeline simulations, the effort required to produce emissions estimates and reports can be significantly reduced, and the accuracy of these emission estimates improved.
In this case study, CO2 emissions and pollutant emissions such as NOx, SO2, CO, VOCs, and others from fuel combustion and flaring, are automatically calculated during simulation runs, and estimated methane emissions from direct venting, line purges, and leaks, are available to be incorporated into the models. Emissions and potential carbon taxes are stored in the simulation model, with warnings issued if violations occur, and CO2 equivalent Greenhouse Gas (GHG) emissions using Global Warming Potential factors are also automatically calculated.
Reports are generated summarizing local, regional, and systemwide pollutant emissions, CO2 equivalent Greenhouse Gas emissions, as well as potential Carbon Taxes if carbon tax rates are applicable and entered into the simulation model.