Assessing performances of Equations of State for CO2 mixtures to reduce the uncertainties in the CCS measurement chain

为了继续支持全球公司为财政应用实现高精度的测量，同时也为了在2050年前实现净零目标，我们需要提高整个CCS(碳捕获和封存)价值链上的二氧化碳测量的准确性。为了减少二氧化碳测量中的不确定性，并达到财政标准，我们需要克服与状态方程(EOSS)相关的挑战。确定和使用适合于CO2混合物的正确的EOSS将有助于高精度地确定压力和温度相包络/边界，-选择最合适的技术，-预测两相流体流动问题。评估EOSS的性能还将有助于根据组成计算准确的密度，并将体积流量转换为高精度的质量流量，以实现财政测量。改进用于二氧化碳的EOS将有助于减少CCS测量链中的不确定性，并实现对CCS经济和排放管理重要的财政不确定性水平。例如：如果我们考虑一个每年600万吨的CCS运输设施，假设二氧化碳质量流量有5%的不确定性，这600万吨每年有5%的不确定性导致30万吨二氧化碳，如果我们假设每吨二氧化碳的价格为85美元，这将导致每年2550万美元，这意味着每天大约有7万美元的未计算在内的测量。这突出表明，5%而不是2.5%的不确定性将导致对二氧化碳捕获量的高估或低估，从而歪曲了二氧化碳捕获量和未排放的量。这种不确定性是不可接受的，因为我们需要对排放进行准确的监测，以确保我们在2050年达到净零排放。由于使用了正确的状态方程，这种不确定性必须得到改善，这就是该项目的目的。

To continue to support worldwide companies in achieving high accuracy measurements for fiscal applications but also to achieve the net zero target by 2050, we need to improve the accuracy of the CO2 measurement across the CCS (Carbon Capture and Storage) value chain. To reduce the uncertainties in the CO2 measurement, and achieve fiscal standards, we need to overcome the challenges related to Equations of State (EoSs).Determining and using the correct EoSs adapted for CO2 mixtures will help to- determine pressure and temperature phase envelopes/boundaries with high accuracy,- select the most suitable technologies,- anticipate two phase fluid flow issues.Evaluating the performances of EoSs will also help to calculate accurate density from composition and convert volumetric flowrate to a mass flowrate with high accuracy to achieve fiscal measurement. Improving the EoS used for CO2 will help in reducing the uncertainties in the CCS measurement chain and to achieve fiscal levels of uncertainties which is important for the CCS economy and for the management of the emissions. For example: if we consider a CCS transportation facility of 6 million tons per year, let's assume a 5% uncertainty on the CO2 mass flowrate, 5% of these 6 million tons per year is leading to 300,000tons, if we assume a price of $85 per ton of CO2 this is leading to $25,500,000 per year, which means that there is around $70,000 of unaccounted measurement per day. This is highlighting that an uncertainty of 5% instead of 2.5% would lead to an over estimation or underestimation of the amount of CO2 captured, thus misrepresenting the quantity of CO2 that is captured and not emitted. Such an uncertainty is not acceptable as we need to have an accurate monitoring of the emissions to ensure that we reach the net zero by 2050\. This uncertainty has to be improved thanks to the use of correct Equation of States and this is the purpose of the project.