Patent Application
20240409403
Hydrogen is a promising fuel for people to decarbonize combustion. There are numerous problems with the production, transportation, and combustion of hydrogen. The cost to generate hydrogen limits it's availability. Any improvement to the energy consumption of energy greatly improves the economics. Conventional carbon steel pipe is unable to transport significant amounts of hydrogen without detrimental effects to the grain boundaries of the material. Combustion of hydrogen is higher than traditional temperatures of methane combustion, and must be blended with methane to accommodate many turbines in service.
Plasma pyrolysis is a technology that exists today. This process uses various types of plasma, various types of catalysts, and various designs of reactors. The current designs are limited by the energy required to decompose methane into hydrogen and carbon. Most designs today use a static radio frequency to achieve plasma, ignoring the absorption spectra of methane. There is one application, JP2019/017116, Kyohei, that uses a target frequency of the gas to achieve a lower energy consumption. This process works, but is limited due to the variable composition of the inlet gas feed and the variable composition of the gas in the reactor. Natural gas feeding a turbine can vary in composition by percentages (Methane, Ethane, CO2). This changes the optimum frequency of the system. After initiation, the decomposition of methane results in CH3, CH2, and other excited stated of methane, further changing the optimum frequency and voltage of the system.
The improvement claimed in this application is an active control system that tunes the frequency of the plasma to a minimum power by measuring power leakage and power consumption. By monitoring the energy of the plasma leaving the process, the control system is able to minimize the energy used in the process. Specifically, this process tunes the frequency increasing and decreasing to monitor for leakage. This ensures the process occurs in a dwell of energy consumption. To avoid a false minimum, the algorithm will periodically scan the spectrum to map energy losses.
To achieve a realistic distribution of hydrogen throughout the world, methane is a likely carrier. By utilizing end devices capable of converting hydrocarbons to carbon and hydrogen, existing infrastructure can be utilized without degrading effects to the current materials.
This invention relates to the production of hydrogen and carbon from the plasma driven decomposition of a hydrocarbon stream. Hydrogen produced from this system is intended for use as a fuel source. The carbon produced from this system has numerous commercial, agricultural, and industrial applications. This patent specifically relates to the use of molecular vibrations and/or resonant structures of hydrocarbons to lower the overall required power for the decomposition of the hydrocarbons. This frequency is obtained by the use of an active control system to minimize the energy leakage. Once a minimum voltage is obtained, voltage may be adjusted to increase the conversion rate, or to accommodate higher pressures.
Plasma pyrolysis reactors are well documented in various forms. This patent specifically improves the process, by implementing a control system that will improve the economics of the process. This control system controls the frequency and voltage applied to the reactor, by starting the system at a frequency based on theoretical optimums, then drifting the frequencies to a minimum power leakage.
To optimize the energy consumption of plasma decomposition, frequency is the largest driver of efficiency. The optimum frequency changes based on numerous factors including; composition of the inlet feed, composition of the degraded reactants, pressure, catalyst state, electrode spacing, and flow rate. The combination of these variables can be modelled for an estimated starting state for the reactor, but quickly become non optimized. This is where leakage detection and power monitoring are critical to the success of low cost hydrogen.
RF energy into the system is either absorbed into the hydrocarbon stream, into the materials of the reactor (Structure or Catalyst), or is released from the system. By placing an antenna around the system, losses can be measured and optimized. A second point of measurement is by measuring the current and voltage into the system. By measuring both parts of the system, general losses can be minimized.
After the system is online, the control system will periodically scan for optimum points. This is defined by a system range of frequencies based on the reactor design, pressure, and composition. The system can scan linearly increasing and decreasing, while mapping the optimum points, or can utilize more modern optimization algorithms. Once the optimum points are defined, the system will operate near the optimum frequency, constantly fluctuating the frequency to maintain minimum energy consumption.
