高温固体氧化物电解水制氢效率与经济性

Efficiency and Economy of Hydrogen Production from High Temperature Solid Oxide Electrolysis of Water

电解水制氢因工艺简单、氢气纯度高等优点成为了科研及产业领域的热点问题。本文分析研究了高温固体氧化物电解池(SOEC)制氢过程的能量利用效率,并与碱性电解和质子交换膜(PEM)电解进行对比,进而以1000Nm^(3)/h电解水制氢装置为例,分析了当前高温SOEC电解制氢的成本,研究了电价与固定投资对成本的影响,并预测了其未来应用的经济性。结果表明:在高温SOEC电解所需能耗与水蒸气等预热均采用电能的条件下,其电解效率高于碱性和PEM电解。考虑利用火电厂电力和高温蒸汽进行电解水制氢整个过程,碱性电解能量利用效率仅为21.42%~26.04%,PEM电解为31.08%~33.18%,高温SOEC电解在三种工作模式下分别为38.22%、42.79%和48.98%,能量利用效率大幅提升。对于碱性电解和PEM电解,制氢总成本取决于电耗;对于高温SOEC电解,制氢总成本由电费和固定投资共同决定,降低固定投资是未来降低总成本的主要方向之一。从长期来说,碱性电解和PEM电解制氢成本将有望降至2.23元/Nm^(3)和1.78元/Nm^(3)。高温SOEC制氢成本可降至1.58元/Nm^(3),有望成为市场主流技术之一。

Hydrogen production by electrolysis of water has become a hot issue in scientific research and industry due to its simple process and high hydrogen purity.In this paper,the energy utilization efficiency of hydrogen production process by high temperature solid oxide electrolytic cell(SOEC)is analyzed and studied,and compared with alkaline electrolysis and proton exchange membrane(PEM)electrolysis.Then,taking 1000 Nm^(3)/h water electrolysis hydrogen production device as an example,the current cost of hydrogen production by high temperature SOEC is analyzed,and the effects of electricity price and fixed investment on cost are studied,The economy of its future application is predicted.The results show that the electrolysis efficiency is higher than that of alkaline and PEM electrolysis under the condition that both the energy consumption and water vapor preheating required for high-temperature SOEC electrolysis use electric energy.Considering the use of power from thermal power plants and high temperature steam to electrolyze water for hydrogen production,the energy utilization efficiency of alkaline electrolysis is only 21.42%~26.04%,PEM electrolysis is 31.08%~33.18%,high-temperature SOEC electrolysis is respectively 38.22%,42.79% and 48.98% in the three working modes,and the energy utilization efficiency is greatly improved.For alkaline electrolysis and PEM electrolysis,the total cost of hydrogen production depends on power consumption;for high temperature SOEC electrolysis,the total cost of hydrogen production is determined by the electricity bill and fixed investment.Reducing fixed investment is one of the main directions for reducing the total cost in the future.In the long run,the cost of hydrogen production by alkaline electrolysis and PEM electrolysis is expected to drop to 2.23 yuan/Nm^(3) and 1.78 yuan/Nm^(3).The cost of high temperature SOEC hydrogen production can be reduced to 1.58 yuan/Nm^(3),which is expected to become one of the mainstream technologies in the market.