PROCESS FOR GENERATING BIOGAS USING ORGANIC SOLIDS FROM SANITARY SEWAGE AS A SUBSTRATE

Description

/ 6 PROCESS FOR GENERATING BIOGAS USING ORGANIC SOLIDS FROM SANITARY SEWAGE AS A SUBSTRATE Field of invention

[001] This patent application relates primarily to Environmental Engineering and describes a new process for the production of biogas and its derivatives. The invention innovatively utilizes sanitary sewage as a substrate for biodigesters aimed at the production of biogas. Fundamentals of the invention

[002] Conventional wastewater treatment technologies focus on the efficient removal of organic matter and the reduction of the effluent's polluting potential in treatment plants specifically built for this purpose.

[003] Although biogas production is a common byproduct in anaerobic wastewater treatment processes, conventional plants are not designed to maximize this production.

[004] The present invention proposes a paradigm shift, with the infrastructure being designed and built with the primary objective of generating biogas from sanitary sewage, and not just treating the effluent.

[005] The main distinction of this process lies in its innovative approach. Instead of considering biogas production as a byproduct, it places it at the center of the project, optimizing the entire system to maximize the generation of this renewable gas.

[006] Other important factors to be considered in this innovative process relate to the low implementation cost, low energy consumption and the fact that it does not require specialized labor for operation.

[007] The state of the art, illustrated by invention PI 0904959-2 A2, presents the production of biogas from wastewater from “processes, especially from the production Petition 870250014651, dated 24 / 02 / 2025, page 7 / 13 / 6 agricultural, such as sugar and ethanol production”. Therefore, although biogas is produced using effluents, the origin of the substrate is preferentially rural, thus differentiating it from the present invention which uses sanitary effluent as raw material.

[008] Patent CN111606419B, on the other hand, is summarized as “a system and method for treating wastewater with self-sufficient energy, in particular a system and method for treating wastewater with self-sufficient energy by adopting a combined process of anaerobic membrane reactor, membrane aeration, autotrophic nitrogen removal and sulfur source denitrification and phosphorus removal, deep treatment”.

[009] This invention differs from the present patent application from its very origin, namely, the treatment facilities are built for the purpose of sewage treatment, and not for the generation of biogas. It also differs in that it does not include preliminary treatment for the removal of coarse solids and sand, which are common in Brazilian sewage. Another difference concerns the production of biogas for use as an energy source for the operation of the sewage treatment plant itself, whereas the invention detailed here provides for the use of biogas for various purposes and, primarily, for commercialization.

[0010] It is also observed that the state of the art comprises the design, construction and operation of complex engineering structures that demand high implementation, operation, energy and specialized labor costs.

[0011] The present invention, on the other hand, requires simple structures for implementation, low operating costs and low energy consumption, and may even be profitable, producing electricity from the combustion of biogas, for example. Brief description of the drawings

[0012] The patent application uses Figure 1 as an illustration, which visually summarizes the macro-process of biogas production using sanitary sewage as a substrate to be discharged into biodigesters. Petition 870250014651, dated 24 / 02 / 2025, page 8 / 13 / 6 Description of the invention

[0013] The contemporary nature of the invention stands out due to its relevance in the Brazilian context, where low levels of basic sanitation directly impact water quality, especially surface water, due to the discharge of raw sewage into rivers and lakes.

[0014] The construction and operation of wastewater treatment plants (WWTPs) face complex challenges, including the high cost of investment in infrastructure, equipment and advanced technologies, as well as the technical complexity of treatment processes, which require specialized professionals and constant monitoring.

[0015] The environmental impact of wastewater treatment plants, such as noise and odors, and the need for rigorous environmental licensing, with detailed studies and potential delays, also represent significant obstacles. In the operational phase, in addition to ongoing maintenance and energy costs, it is necessary to ensure compliance with environmental standards and treatment efficiency, dealing with variations in the quantity and quality of wastewater, as well as preventing and solving technical and operational problems that may arise.

[0016] In this sense, the invention detailed here has the ability to treat sanitary sewage without the impacts and costs of conventional WWTPs, since it tends to have a lower operating cost, lower demand for electricity and has simplified processes.

[0017] Furthermore, the growing demand for energy, especially from clean sources, gives the invention an innovative and promising character. Sanitary sewage, once a problem, will be transformed into raw material for the generation of biogas, a renewable energy resource with vast applications, from the production of electricity and heat to its use as a vehicle biofuel (biomethane).

[0018] With regard to waste, conventional wastewater treatment plants generate sludge that is difficult to treat, has a high weight and an unpleasant odor, resulting in high disposal costs. The invention presented here, on the other hand, generates digestate, a virtually odorless residue that can be easily separated into solid and liquid phases. Furthermore, Petition 870250014651, dated 24 / 02 / 2025, page 9 / 13 / 6 the digestate has a high content of nutrients that are relevant for agricultural production, and can therefore be reused in a virtuous and sustainable cycle.

[0019] Biogas, the main product of the invention, has enormous potential as a renewable and sustainable energy source, especially in Brazil, a tropical country with a strong economic contribution from the agricultural industry and the challenge of increasing access rates to sewage collection and treatment.

[0020] The invention has features that allow the treatment system to be applied anywhere, especially in places where there are no conventional sewage treatment plants.

[0021] This patent application describes an innovative system for the efficient production of biogas from sanitary sewage, aiming to utilize the anaerobic digestion process sized and constructed for this purpose, that is, it differs, therefore, from conventional sewage treatment plants that generate biogas in smaller volumes since it is a byproduct or residue that generally has no added value to wastewater treatment plants.

[0022] The invention detailed here is also distinguished by integrating a loading tank for optimized substrate preparation, allowing adjustment of the Carbon / Nitrogen ratio and solids concentration, as well as promoting homogenization and pH control.

[0023] The process shown in Figure 1 is illustrated and begins with the receipt of sewage (1) at the biogas production station, by pumping (pressurized conduit) or gravity, depending on local conditions.

[0024] In the preliminary treatment stage (2), screening, grit removal, and removal of oils and materials that may harm subsequent processes take place.

[0025] Next, primary sedimentation (3) takes place, where solids are removed and directed (4) to biogas production.

[0026] Another distinguishing feature of the invention lies in the loading tank (5), where the wastewater is prepared before entering the biodigester (6). The Carbon / Nitrogen ratio is adjusted. Petition 870250014651, dated 24 / 02 / 2025, page 10 / 13 / 6 (ideal between 20:1 and 30:1) with the addition of crushed organic plant materials, such as dry grass, cereal straw, bagasse, etc. The solids concentration and pH (ideal between 6.5 and 7.5) are also adjusted, ensuring optimal conditions for the methanogenic bacteria present in the biodigesters (6).

[0027] After primary sedimentation (3), the effluent goes to an aerobic tank (7), which can be of the aerated lagoon or MBBR type, for consumption of the dissolved organic matter.

[0028] The effluent that exits the primary sedimentation (3) is then directed to the secondary sedimentation tank (8), where the solids from the excess biofilm are collected to be returned to the loading tank (5). The effluent water (9) from the secondary sedimentation tank can be directed for discharge into water resources or undergo further treatment to meet applicable environmental legal requirements.

[0029] In the biodigester (6), controlled anaerobic decomposition generates biogas, which is stored (10) for commercial uses. The digestate, a residue from the process, is sent to reservoirs with waterproofed walls and bottoms (11) with the main objective of separating the liquid and solid phases through sedimentation. The solid fraction can be composted, used in agriculture or for energy cogeneration. The liquid fraction can be evaporated, treated for reuse or used in fertigation (12).

[0030] The invention can be applied anywhere, especially in small communities or cities that do not have conventional wastewater treatment plants. Examples of embodiments of the invention

[0031] In the Brazilian context, where the lack of basic sanitation is an environmental and social challenge, the present invention stands out for offering an innovative and promising solution. By transforming sewage treatment into an economically viable activity, the system opens up a range of opportunities for entrepreneurs and investors. Petition 870250014651, dated 24 / 02 / 2025, page 11 / 13 / 6

[0032] The generation of biogas as a renewable energy source can boost the creation of new businesses and strengthen the local economy, generating a virtuous cycle of development. The reduction of water pollution and the improvement of sanitary conditions also contribute to the decrease in diseases related to lack of sanitation, with a consequent positive impact on public health and the quality of life of the population.

[0033] Implementing the invention in areas lacking conventional sewage treatment plants represents a significant advance in the management of water and energy resources. By eliminating pollution from waterways, the system contributes to the revitalization of local ecosystems, with positive effects on public health and the preservation of biodiversity.

[0034] Additionally, biogas generation technology as a byproduct of wastewater treatment offers a new vector for economic development in the region where it is applied.

[0035] The implementation of the biogas production station can generate direct and indirect jobs, from the construction and operation of the unit to the development of new economic activities related to the use of biogas and its derivatives. Petition 870250014651, dated 24 / 02 / 2025, page 12 / 13

Claims

CLAIMS 1. PROCESS FOR GENERATING BIOGAS USING ORGANIC SOLIDS FROM SANITARY SEWAGE AS A SUBSTRATE, characterized by comprising the generation of biogas from sanitary sewage, in facilities sized and constructed to optimize biogas production, and which differs from conventional sewage treatment plants that, in turn, are not sized for biogas production purposes; 2. PROCESS FOR GENERATING BIOGAS USING ORGANIC SOLIDS FROM SANITARY SEWAGE AS SUBSTRATE, according to claim 1, characterized by comprising receiving sewage (1) for subsequent preliminary treatment (2), primary sedimentation (3), aerobic tank (7) and secondary sedimentation tank (8) whose sewage treatments at each stage provide the raw material (substrate) for feeding the biodigesters that generate the biogas; 3. PROCESS FOR GENERATING BIOGAS USING ORGANIC SOLIDS FROM SANITARY SEWAGE AS SUBSTRATE, according to claims 1 and 2, characterized by having a loading tank (5) where the physical-chemical parameters are adjusted in order to optimize biogas generation in the biodigesters (6); 4. PROCESS FOR GENERATING BIOGAS USING ORGANIC SOLIDS FROM SANITARY SEWAGE AS SUBSTRATE, according to claims 1 to 3, characterized by environmentally sound management of the digestate generated as a residue from the treatment, aiming at its subsequent use as fertilizer in agriculture. Petition 870250014651, dated 24 / 02 / 2025, page 6 / 13

Images