Potencial de produção de hidrogênio utilizando reforma a vapor do biogás de reatores UASB em ETES operadas pela Companhia de Água e Esgoto do Ceará

Abstract

The current configuration of the global energy matrix uses mostly non-renewable energy sources, as they are the cheapest and most convenient among energy resources. However, they are associated with several problems and generate economic, political and ecological concerns. In addition, the country also has deficiencies in sewage treatment, which sometimes compromises the health and quality of life of the population, as well as the preservation of the environment. One way to treat sewage is through the anaerobic digestion of organic matter, which has biogas formation as one of its residues. Many ETEs, sewage treatment plants, choose to simply burn the biogas before releasing it into the atmosphere, wasting its high energy potential and worsening the greenhouse effect, due to the methane present in its composition. In this scenario, an important innovative solution emerges, with a huge range of applications and uses. The use of hydrogen stands out as a highly efficient and low-polluting fuel that can be used in transportation, heating and power generation in hard-to-reach places. To obtain hydrogen gas, it is necessary to separate it from other elements such as water, fossil-based compounds and biomass. Currently, approximately half of the world's hydrogen production comes from the use of natural gas, which has a composition similar to biogas and can be used as an alternative raw material to conventional steam reforming technology for hydrogen generation. Based on the literature, this study aims to estimate the potential for hydrogen generation by steam reforming of biogas produced in WWTPs operated by CAGECE that use UASB technology for sewage treatment, in order to add value to the byproducts. To this end, it was estimated that 43 treatment plants operated by CAGECE, equipped with anaerobic reactors, process 12 billion liters of sewage per year. This volume has the potential to generate 25 million cubic meters of biogas annually, which would be enough to produce approximately 60 million cubic meters of hydrogen.