| As biological diesel has the advantages of green and renewable,the process of producing biodiesel lead to its by-product glycerol is mostly wasted.Reforming of glycerol for hydrogen production is an effective way for the use of glycerol.In order to improve the utilization rate of glycerol and the yield of hydrogen,the research of glycerol reforming and strengthening means has become a hotspot in recent years.Fluidized bed reactor has a promising prospect because of its better fluidity?heat transfer and mass transfer ability.Therefore,the thermodynamic and hydrodynamic simulation of the glycerol reforming process and its strengthening means in the fluidized bed were carried out in this paper.In order to reduce the energy input,the heat release from the oxidation reaction is used to achieve the autothermal state,and the glycerol autothermal steam reforming system is constructed.The reforming system under different operating conditions has been analyzed.The results show that the autothermal reforming can effectively reduce the energy input,but the hydrogen production is significantly reduced.Considering the addition of the absorbent in the system,the reaction is carried out by balancing the reaction and promoting the reaction.At the same time,the system can reach the autothermal state by the exothermicity of absorbing reaction.The thermodynamic simulation results of the glycerol reforming system show that the addition of calcium oxide increases the hydrogen production and the operating temperature corresponding to the maximum hydrogen production is reduced.Due to the decomposition of calcium carbonate and other factors,the reactor temperature should not be controlled above 850 K,calcium oxide-glycerol feed ratio between 3 to 4 is more suitable for the reforming system.Considering that the semipermeable membrane can effectively separate the hydrogen inside the reaction system,the reaction equilibrium will move and the hydrogenation process of glycerol reforming will be strengthened.The thermodynamic simulation results of the glycerol autothermal reforming system show that the hydrogen removal by the membrane reactor can increase the hydrogen yield and counteract the negative effects of the introduction of oxygen,and the greater the separation coefficient of hydrogen,the more obvious the effect.But the hydrogen separation will promote the methanation reaction in the reforming system,increase the carbon deposition.In order to explore the feasibility of crude glycerol reforming,the reaction system introduced ethanol impurities.The results show that the introduction of ethanol will have a negative impact on the hydrogen production,and this negative effect will increase with the increase of hydrogen separation coefficient.The gas-solid multiphase fluid model established in this paper was used to simulate the hydrogen production process of glycerol water vapor in fluidized bed reactor.The results show that the particles in the fluidized bed show a significant fluidization.There are obvious dilute and dense areas in the bed,accompanied by particle agglomeration and bubble generation and motion phenomena,and there is a phenomenon of particle reflow inside the reactor.The temperature of the particles in the reactor shows a decreasing trend with the gradual increase of the particle concentration.It is found that within the fluidized bed reactor,glycerol and water vapor are used as reactants to rapidly decompose at the bottom of the reactor to produce a series of gaseous gases,in which hydrogen is the main component of glycerol reforming Product.The results show that the addition of calcium oxide in the system to absorb carbon dioxide as a means of absorption and strengthening can not only improve the reaction system,but also can effectively improve the conversion rate of glycerol.And the yield of hydrogen.After adsorption strengthening,the hydrogen content at the reactor port increased from 47% to 55%,and the share of carbon monoxide and methane was relatively reduced. |
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