Determination of Hydrocarbon Dew Point Hdp of Natural Gas – Experimental and Theoretical

Hydrocarbon dew point (HDP) temperature is defined as the temperature at which the first hydrocarbon liquid begins to condense in a natural gas cooled at constant pressure, which is an important qualitative parameter for pipeline operators. Hydrocarbon liquid drops-out along the gas pipeline will decrease the effective cross-sectional area of the pipes causing increased pressure drop, reduced line capacity as well as system shutdowns. It is therefore imperative that the gas pipelines be operated above the hydrocarbon dew point (HDP) temperature to ensure a trouble free line; this of course requires the knowledge of the HDP for the pipeline. In this work, onsite measurement of the HDP of 5 different natural gases from different flow stations and gas processing plants in the Niger-Delta region was done using an automatic optical condensation dew point meter. Subsequently, each of the gases was collected in stainless steel Proserv bottles and taken to the laboratory for compositional analysis using gas chromatographic technique with reference to GPA 2286. In addition, the Peng Robinson (PR) and Soave Redlich Kwong (SRK) Equations of state (EOS) were used to predict the hydrocarbon dew point temperature of the gases at the flow line pressures. The Average Absolute Error (AAE) for EOS PR was 9.33% while that for EOS SRK was 14.68%. Obviously, it showed that PR EOS gave better predictions than SRK EOS. The result of this work also showed that even a 50% variation in molar contributions of the non-hydrocarbon components had negligible effects on the predicted hydrocarbon dew point temperatures for all the gas samples tested.

RF-ICP Thermal Plasma for Thermoplastic Waste Pyrolysis Process with High Conversion Yield and Tar Elimination

This paper demonstrates an RF thermal plasma pyrolysis reaction apparatus that achieves 89 wt.% reaction conversion yield with no tar content. The demonstrated experimental apparatus consists of a 1100 W RFVII Inc. (104 Church St, Newfield, NJ 08344, United States) @ 13.56 MHz RF thermal plasma generator, a Navio matching network, intelligent feedback controller, and an 8-turn copper RF-ICP torch embedded in a 12 L thermochemical reactor. The intelligent feedback controller optimizes the thermal performance based on feedback signals from three online gas analyzers: CO, CO2 and NOx. The feedback controller output signal controls the RF thermal plasma torch current that provides real-time temperature control. The proposed reaction system achieves precise temperature profiles for both pyrolysis and gasification as well as increases end-product yield and eliminates undesired products such as tar and char. The identified hydrocarbon liquid mixture is 90 wt.% gasoline and 10 wt.%. diesel. The 8-turn RF-ICP thermal plasma torch has an average heating rate of +35 °C/min and a maximum operating temperature of 2000 °C and is able to sustain stable flame for more than 30 min. The reaction operating parameters are (550–990 °C τ = 30 min for pyrolysis and (1300 °C τ = 1 sec) for the gasification process. The identified hydrocarbon liquid products are 90 wt.% of a n-butyl-benzene (C6H5C4H9) and oluene (C7H8) mixture with less than 10 wt.% decane diesel fuel (C10 H22). Comsol simulation is used to assess the RF-ICP thermal plasma torch’s thermal performance.