Abstract：
The reliability of renewable hydrogen supply for off-take applications is critical to the future sustainable energy economy. Integrated water electrolysis can be deployed at distributed municipal wastewater treatment plants (WWTP), creating opportunity for reduction in carbon emissions through direct and indirect use of the electrolysis output. A novel energy shifting process where the co-produced oxygen is compressed and stored to enhance the utilisation of intermittent renewable electricity is analysed. The hydrogen produced can be used in local fuel cell electric buses to replace incumbent diesel buses for public transport. However, quantifying the extent of carbon emission reduction of this conceptual integrated system is key. In this study, the integration of hydrogen production at a case study WWTP of 26,000 EP capacity and using the hydrogen in buses was compared with two conventional systems: the base case of a WWTP with grid electricity consumption offset by solar PV and the community\'s independent use of diesel buses for transport, and the non-integrated configuration with hydrogen produced at the bus refuelling location operated independently of the WWTP. The system response was analysed using a Microsoft Excel simulation model with hourly time steps over a 12-month time frame. The model included a control scheme for the reliable supply of hydrogen for public transport and oxygen to the WWTP, and considered expected reductions in carbon intensity of the national grid, level of solar PV curtailment, electrolyser efficiency and size of the solar PV system. Results showed that by 2031, when Australia\'s national electricity is forecast to achieve a carbon intensity of less than 0.186 kg CO2-e/kWh, integrating water electrolysis at a municipal WWTP for producing hydrogen for use in local hydrogen buses produced less carbon emissions than continuing to use diesel buses and offsetting emissions by exporting renewable electricity to the grid. By 2034, an annual reduction of 390 t-CO2-e is expected after changing to the integrated configuration. Considering electrolyser efficiency improvements and curtailment of renewable electricity, the reduction increases to 872.8 t-CO2-e.
摘要：
用于起飞应用的可再生氢供应的可靠性对于未来的可持续能源经济至关重要。可在分布式市政污水处理厂（WWTP）部署集成水电解，通过直接和间接使用电解输出创造减少碳排放的机会。分析了一种新颖的能量转换过程，其中将共同生产的氧气压缩并存储以提高间歇性可再生电力的利用率。产生的氢气可用于当地的燃料电池电动公交车，以取代现有的柴油公交车用于公共交通。然而,量化这一概念集成系统的碳减排程度是关键。在这项研究中,在26,000EP容量的WWTP案例研究中，氢气生产的集成与两种常规系统进行了比较：WWTP的基本情况下，电网电力消耗被太阳能光伏抵消，社区独立使用柴油巴士运输，以及在公交车加油位置生产的氢气的非集成配置，独立于污水处理厂运行。使用MicrosoftExcel仿真模型分析了系统响应，该模型在12个月的时间范围内具有每小时的时间步长。该模型包括一个控制方案，用于为公共交通提供可靠的氢气和向污水处理厂提供氧气，并考虑了国家电网碳强度的预期降低，太阳能光伏削减水平，太阳能光伏系统的电解槽效率和尺寸。结果表明，到2031年，当澳大利亚的国家电力预计达到低于0.186kgCO2-e/kWh的碳强度时，与继续使用柴油公交车和通过向电网出口可再生电力来抵消排放相比，在市政污水处理厂整合水电解以生产用于本地氢气公交车的氢气，产生的碳排放量更少。到2034年，在更改为集成配置后，预计每年减少390t-CO2-e。考虑到电解槽效率的提高和可再生电力的削减，减少量增加到872.8t-CO2-e。
