Abstract

The objective of the first part of the investigation was to use Aspen Plus software and the Redlich-Kwong-Soave equation of state in order to simulate an adiabatic methanation reactor for the production of synthetic natural methane (SNG) using 1 kg/hr of carbon dioxide. In this paper, we define the Synthetic Natural Gas Combined Cycle (SNGCC) as a combined cycle power plant where the fuel is synthetic natural gas (SNG) produced by a methanation reactor. The feed of the methanation reactor is the recycled stream of carbon dioxide of a CO2 capture unit treating the flue gas of the SNGCC power plant. The objective of the second part of the investigation is the utilization of Aspen plus software with SRK equation of state for the simulation of the SNGCC power plant. The metallurgical limitation of the gas turbine was fixed at 1300°C in this investigation. For effective absorption by amine solutions, the molar percentage of CO2 in the flue gas should be higher than 10%. Moreover, in order to reduce technical problems linked to oxidative degradation of amine in the CO2 capture plant, the percentage of O2 in the flue gas should also be lower than 5%. To reach this goal, the primary air for combustion has 10% excess air (compared to stoichiometric air) and 37% of the flue gas leaving the SNGCC is recirculated as the secondary air for cooling the turbine. As a result, the concentration of CO2 and O2 of the flue gas entering the CO2 capture unit were respectively equal to 10.2% and 2.01%. The simulation results of the SNGCC power plant indicate that 6.6 MJ of electricity are produced for each kg of carbon dioxide recycled from the CO2 capture unit of the power plant. In other terms, the production of the 24.88 kg/hr of synthetic natural gas (SNG) consumes 62.36 kg/hr of recycled carbon dioxide and 16.4 kg/hr of hydrogen. The SNG produced by the methanation reactor of the power plant generates 114 kW of electricity. It is assumed in this paper that the hydrogen needed for the methanation of carbon dioxide is a product of a catalytic reforming plant that produces gasoline from heavy naphta fraction of an atmospheric distillation unit of crude oil.

Highlights

  • Even with the visible consequences of global warming, fossil fuels will still be the main energy sources leading to an ever-increasing amount of carbon dioxide released into the atmosphere

  • The simulation results of the Synthetic Natural Gas Combined Cycle (SNGCC) power plant indicate that 6.6 MJ of electricity are produced for each kg of carbon dioxide recycled from the CO2 capture unit of the power plant

  • It is assumed in this paper that the hydrogen needed for the methanation of carbon dioxide is a product of a catalytic reforming plant that produces gasoline from heavy naphta fraction of an atmospheric distillation unit of crude oil

Read more

Summary

Introduction

Even with the visible consequences of global warming, fossil fuels will still be the main energy sources leading to an ever-increasing amount of carbon dioxide released into the atmosphere. The use of renewable energies and Carbon capture and storage (CCS) technologies are already being utilized as ways to reduce greenhouse gas emissions. In addition to these known technologies, various techniques are under investigation to slow down global warming by converting carbon dioxide emissions into more useful products. CO2 methanation was found to be one such vital reaction of converting CO2 to useful fuel, like methane, using different catalysts. In the United States and China, huge efforts have been made to increase SNG production [1]. The produced SNG can be distributed in the natural gas network, but can be stored

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call