Removal of nitrogen compounds through biological processes represents the highest energy consumption in conventional centralised wastewater treatment facilities. Alternatively, segregated systems, where wastewater is treated at its source, present the potential to provide value to nitrogen-rich compounds contained in wastewater like urea. This paper demonstrates the feasibility of a novel process to recover energy from human urine based on the pre-isolation of urea to decrease the energy requirements for its thermal decomposition compared to the conventional thermal treatment when in solution, followed by its decomposition into hydrogen. Herein, urea is separated from an aqueous solution by adsorption onto activated carbon. Thermal urea desorption and decomposition into ammonia and CO₂ at 250°C leads to full regeneration of the carbon, showing a constant adsorption capacity for at least 5 consecutive adsorption/desorption cycles. Finally, when the regeneration and urea decomposition step is coupled to an ammonia decomposition catalyst, hydrogen is produced to be used as an energy fuel. This process opens the door to a new way of circular economy by energy recovery from hydrogen-rich components in segregated wastewater streams. Preliminary energy balances show that the adoption of this energy recovery system in a city of 160,000 inhabitants would lead to a daily hydrogen production of 430 kg, with a net energy production of 2,500 kWh/day. In addition, such waste-to-energy process would lead to energy savings of 4,600 kWh/day in a conventional wastewater treatment plant reducing its energy consumption by around 35%.

在传统的集中式废水处理设施中，通过生物过程去除氮化合物是最高的能耗。或者，在废水源头进行处理的隔离系统具有为尿素等废水中含有的富氮化合物提供价值的潜力。本文展示了一种新工艺从人尿中回收能量的可行性，该工艺基于尿素的预分离，与溶液中的常规热处理相比，减少其热分解所需的能量，然后将其分解为氢气。在此，尿素通过吸附在活性炭上而从水溶液中分离出来。尿素热解吸分解成氨和CO ₂在 250°C 导致碳完全再生，在至少 5 个连续的吸附/解吸循环中显示出恒定的吸附容量。最后，当再生和尿素分解步骤与氨分解催化剂结合时，产生氢气以用作能源燃料。该过程通过从分离的废水流中的富氢成分中回收能量，为循环经济的新途径打开了大门。初步能源平衡表明，在一个拥有 160,000 居民的城市中采用这种能源回收系统将导致每天产生 430 公斤的氢气，净能源产量为 2,500 千瓦时/天。此外，这种垃圾发电过程将使传统污水处理厂每天节能 4,600 千瓦时，将其能耗降低约 35%。