Thermodynamic analysis and optimization for steam methane reforming hydrogen production system using high temperature gas-cooled reactor pebble-bed module

2021 ◽  
pp. 1-14
Author(s):  
Yongle Zhang ◽  
Guang Hu ◽  
Huang Zhang ◽  
Qianfeng Liu ◽  
Junbo Zhou
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Thermodynamic Analysis ◽  
Production System ◽  
Methane Reforming ◽  
Pebble Bed ◽  
Steam Methane Reforming ◽  
Steam Methane ◽  
High Temperature Gas

Transport Mechanism of Steam Methane Reforming on Fixed Bed Catalyst Heated by High Temperature Helium for Hydrogen Production: A Computational Fluid Dynamics Investigation

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Feng Wang ◽  
Ziqiang Yang ◽  
Long Wang ◽  
Qiang Wen
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Temperature Difference ◽  
Fixed Bed ◽  
Inlet Temperature ◽  
Methane Reforming ◽  
Outlet Temperature ◽  
Inlet Velocity ◽  
Steam Methane Reforming ◽  
Steam Methane

In this study, we numerically evaluated the performance of a steam methane reforming (SMR) reactor heated using high-temperature helium for hydrogen production. The result showed that with an increase in the reactant gas inlet velocity, the temperature at the same reactor length position decreased. The maximum gas temperature difference at the gas collection chamber reached approximately 55 °C. The outlet temperature difference increased to 35 °C when the inlet temperature increased from 370 °C to 570 °C. A higher inlet temperature did not have a positive effect on the system's thermal efficiency. The methane conversion rate increased by 68%, and the hydrogen production rate increased by 55%, when the helium inlet velocity increased from 2 m/s to 22 m/s. When the helium inlet temperature increased by 200 °C, the highest temperature of the reactant gas increased by 132 °C. In the SMR for hydrogen production using a high-temperature gas-cooled reactor (HTGR), low reactant-gas inlet velocity, suitable inlet temperature, high inlet velocity, and a high HTGR outlet temperature of helium were preferable.

Conceptual Structure Design of High Temperature Isolation Valve for High Temperature Gas Cooled Reactor

2010 ◽  
Author(s):  
Shoji Takada ◽  
Kenji Abe ◽  
Yoshiyuki Inagaki
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Production System ◽  
Conceptual Structure ◽  
Structure Design ◽  
Radioactive Material ◽  
Normal Operation ◽  
Temperature History ◽  
Allowable Limit ◽  
High Temperature Gas

The high temperature isolation valve (HTIV) is a key component to assure the safety of a high temperature gas cooled reactor (HTGR) connected with a hydrogen production system, that is, protection of radioactive material release from the reactor to the hydrogen production system and combustible gas ingress to the reactor at the accident of fracture of an intermediate heat exchanger and the chemical reactor. The HTIV used in the helium condition over 900 °C, however, has not been made for practical use yet. The conceptual structure design of an angle type HTIV was carried out. A seat made of Hasteloy-XR is welded inside a valve box. Internal thermal insulation is employed around the seat and a liner because high temperature helium gas over 900 °C flows inside the valve. Inner diameter of the top of seat was set 445 mm based on fabrication experiences of valve makers. A draft overall structure was proposed based on the diameter of seat. The numerical analysis was carried out to estimate temperature distribution and stress of metallic components by using a three-dimensional finite element method code. Numerical results showed that the temperature of the seat was simply decreased from the top around 900 °C to the root, and the thermal stress locally increased at the root of the seat which was connected with the valve box. The stress was lowered below the allowable limit 120 MPa by decreasing thickness of the connecting part and increasing the temperature of valve box to around 350 °C. The stress also increased at the top of the seat. Creep analysis was also carried out to estimate a creep-fatigue damage based on the temperature history of the normal operation and the depressurization accident.

Comparative Analysis of Advanced H2/Air Cycle Power Plants Based on Different Hydrogen Production Systems From Fossil Fuels

2004 ◽  
Author(s):  
M. Gambini ◽  
M. Vellini
Keyword(s):  
Hydrogen Production ◽  
Power Plants ◽  
Fossil Fuels ◽  
Coal Gasification ◽  
Fossil Fuel ◽  
H2 Production ◽  
Combined Cycle ◽  
Methane Reforming ◽  
Steam Methane Reforming ◽  
Steam Methane

In this paper two options for H2 production by means of fossil fuels are presented, evaluating their performance when integrated with advanced H2/air cycles. The investigation has been developed with reference to two different schemes, representative both of consolidated technology (combined cycle power plants) and of innovative technology (a new advance mixed cycle, named AMC). The two methods, here considered, to produce H2 are: • coal gasification: it permits transformation of a solid fuel into a gaseous one, by means of partial combustion reactions; • steam-methane reforming: it is the simplest and potentially the most economic method for producing hydrogen in the foreseeable future. These hydrogen production plants require material and energy integrations with the power section, and the best connections must be investigated in order to obtain good overall performance. The main results of the performed investigation are quite variable among the different H2 production options here considered: for example the efficiency value is over 34% for power plants coupled with coal decarbonization system, while it is in a range of 45–48% for power plants coupled with natural gas decarbonization. These differences are similar to those attainable by advanced combined cycle power plants fuelled by natural gas (traditional CC) and coal (IGCC). In other words, the decarbonization of different fossil fuels involves the same efficiency penalty related to the use of different fossil fuel in advanced cycle power plants (from CC to IGCC for example). The CO2 specific emissions depend on the fossil fuel type and the overall efficiency: adopting a removal efficiency of 90% in the CO2 absorption systems, the CO2 emission reduction is 87% and 82% in the coal gasification and in the steam-methane reforming respectively.

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