SISTEMA PORTÁTIL AUTOMATIZADO PARA MEDIÇÃO DE POTENCIAL BIOQUÍMICO DE METANO

Abstract

AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL POTENTIAL OF METHANE. The present invention provides an automated portable device for performing the biochemical potential of methane (BMP) test with triplicates and a standard sample for comparison, thus making it possible to perform the test in the field, without the need to perform the test in a laboratory environment. Portability is ensured due to the heating system of the containers and their heat sinks (1), the motors for the stirrers (2), the supports for coupling the stirrers (3) and the container for washing the gas and measuring the volume of gas produced (6) being arranged in an organized manner to facilitate the transport and performance of the BMP test.All control systems, data display, measurements, and calculations are visualized in the graphical interface accessed from an internet browser on a mobile device connected to the Wi-Fi network generated by the equipment.

Description

/ 10 “AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL” FIELD OF THE INVENTION

[001] The present invention provides an automated portable device for performing the biochemical methane potential test in triplicate and a sample (blank) for comparison, making it possible to perform the test in situ, without the need for a laboratory environment. FUNDAMENTALS FOR INVENTION

[002] Anaerobic digestion (AD) is a process for treating and managing organic waste that can transform organic matter into renewable energy in the form of biogas, composed mainly of methane and stabilized organic fertilizer (Appels et al., 2008; Batstone and Jensen, 2011).

[003] The Biochemical Methane Potential (BMP) test is the most reliable method for determining the maximum methane production of a given sample, a key parameter for evaluating the feasibility of implementing a large-scale DA plant, as well as its optimization (e.g., co-digestion and pretreatment) (Angelidaki et al., 2009; Lesteur et al., 2010; Carrere et al., 2016; Koch et al., 2016; Sol and Lansing, 2013; Ward, 2016).

[004] In addition, the BMP test can also be used to estimate the kinetic constant (e.g., hydrolysis rate for highly particulate substrates) required to achieve the ideal design and operation of anaerobic digesters (Batstone et al., 2002, 2003; Batstone and Jensen, 2011; Lopez et al., 2015).

[005] The most common BMP tests use two main methods: manometric and volumetric. In the manometric method, the volume is kept constant and an increase in air pressure is measured and used to calculate the amount of gas produced. In the volumetric method, the pressure is kept constant and the volume of gas produced is measured by Petition 870200156915, dated 12 / 14 / 2020, page 17 / 27 / 10 volume displacement (Valero et al., 2016).

[006] Biochemical methane potential is a measure of the biodegradation of a sample, measuring the production of methane from the biodegradability of the residue (Owen et al., 1979) and has been widely used for this purpose. For Angelidaki et al. (2009), the BMP test results in the determination of methane from a given mass of substrate. In addition to determining the methane potential, factors such as low cost, reproducibility and ease of installation are some of the advantages of performing the BMP assay (Luna del Risco, 2011; Schirmer et al., 2014).

[007] The test also monitors the volume of biogas generated in a fraction of municipal solid waste, evaluating the biodegradability of the waste through the total production of methane (CH4). The tests are monitored through constant measurements of internal pressures and temperatures in addition to ambient pressure. For the BMP test, samples containing a small fraction of solid waste, culture medium and inoculum are inoculated.

[008] The methane yield from a specific substrate can be affected by several factors, including, but not limited to, inoculum, inoculum / substrate ratio, buffering system, substrate / buffer ratio, operating temperature, assay duration, and the specific BMP technique employed. A wide range of methane yields has been reported, even for a relatively homogeneous and industrially synthesized feedstock such as cellulose (Raposo et al., 2011). However, in the interlaboratory study (19 participating laboratories) reported by Raposo et al. (2011), laboratories using manometric BMP methods reported lower methane yields from cellulose than those using volumetric BMP methods. Furthermore, when compared in controlled experiments, McEniry et al. (2014), Nolan et al. (2016), and Wang et al. (2014) reported a lower methane yield from cellulose using the BMP method compared to an automated volumetric method.Furthermore, Logan et al. (2002) reported a lower biogas yield. Petition 870200156915, dated 12 / 14 / 2020, page 18 / 27 / 10, comparing a manometric method with a respirometer (a variation of the volumetric method). SUMMARY OF THE INVENTION

[009] The challenges for the successful practical implementation of a portable BMP test device are process automation to obtain the best result, physical construction to characterize the portability of the system, and remote connectivity for monitoring the operation and commands of the system.

[010] The present invention provides an automated portable apparatus for measuring biomethane potential with triplicate measurements and a standard sample for comparison, thus making it possible to perform the test in the field, without the need to perform the test in a laboratory environment.

[011] The functionality of the device is provided by the sample mixing mechanisms, heating system and sample temperature control, as well as the measurement of the volume of methane produced. All control, data visualization and actions can be accessed through the graphical interface from the internet browser on a mobile device connected to the Wi-Fi network generated by the equipment.

[012] The heating control system, consisting of four modules, is controlled by the internal temperature of each container flask, ensuring that the temperature remains within a set range.

[013] The mixing mechanism is necessary so that the contents inside the container are agitated continuously, applying the same speed in each of the containers. Each container has a motor in a sealed lid, where the motor shaft is coupled to a rod on the inside of the container.

[014] The methane volume meter receives the biogas produced in each container individually and estimates the volume produced. This mechanism works by inducing the biogas produced in each container. Petition 870200156915, dated 12 / 14 / 2020, page 19 / 27 / 10 individually to another smaller container, which contains a sodium hydroxide solution, washing the biogas to measure the volume of methane gas only. After this process, the washed gas is directed to the electronic sensor to measure the volume of methane.

[015] The system also has remote connection, with data such as individual temperature of each container, stirring speed and volume of methane produced in each container being shown on a web page that can be accessed from the Wi-Fi network connection generated by the device on a remote device, such as a mobile phone or tablet. BRIEF DESCRIPTION OF THE DRAWINGS

[016] The invention can be better understood through the following detailed description, in accordance with the attached figures. These figures are merely illustrative and may present variations, provided they do not deviate from what was initially claimed.

[017] Figure 1 shows a graphical representation of the isometric view of the open equipment;

[018] Figure 2 shows a graphical representation of the exploded view of the equipment;

[019] Figure 3 shows a schematic drawing of the front view of the equipment;

[020] Figure 4 shows a schematic drawing of the top view of the equipment and;

[021] Figure 5 shows an isometric schematic drawing of the assembly of the heating, stirring, washing and gas volume measurement system of the equipment. DETAILED DESCRIPTION OF THE INVENTION

[022] In general, the embodiments described herein are directed to the automated portable system for measuring the biochemical potential of methane in a biosample. As necessary, embodiments of the present utility model are disclosed herein. Petition 870200156915, dated 12 / 14 / 2020, page 20 / 27 / 10 However, the embodiments disclosed are merely exemplary, and it should be understood that the utility model can be incorporated in many varied and alternative forms.

[023] The figures are not to scale and some features may be exaggerated or minimized to show particular details and elements. Specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a basis for the claims and as a representative basis for showing a person skilled in the art how to employ the present utility model variably.

[024] Referring to Figure 1, the open apparatus is shown where the mechanisms and containers for performing the BMP test can be observed disassembled and arranged for transport.

[025] Figure 2 refers to the exploded view of the open apparatus, in which it is possible to see the heating system of the containers and their heat sinks (1), the motors for the stirrers (2), the supports for coupling the stirrers (3), the containers for carrying out the BMP test (4), the partitions for storing the equipment devices (5), the container for washing the gas and measuring the volume of gas produced (6), receptacle for storing removable connections (7) and the receptacle for the electronic and automation system of the apparatus (8).

[026] The schematic drawings presented in Figures 3 and 4 show the arrangement of the equipment's allocated mechanisms for transport from the top and front view of the open equipment.

[027] Figure 5 shows a detailed view of the assembly of the heating and heat dissipation system, the motor assembly on the supports attached to the BMP test containers, as well as the stirring rod (9) and the temperature sensor (10) placed in the container for internal temperature control.

[028] The agitators perform the mixing inside each container and Petition 870200156915, dated 12 / 14 / 2020, p. 21 / 27 / 10 are controlled by a graphical interface that can be accessed remotely from a mobile device connected to the Wi-Fi network generated by the equipment. The four heating systems are independent of each other and are controlled by temperature sensors placed on the outside of the containers for measurement, by thermal conduction, and isolated from the external environment. The sensors are calibrated and programmed for a specific temperature, around 35 °C, and the heating system is switched on at a temperature 1 °C lower than the programmed temperature, i.e., 34 °C, and switched off at a temperature 1 °C higher than the programmed temperature, 36 °C, ensuring the temperature is ±1 °C from the programmed temperature. The gas produced from each container is conducted through hoses to the gas washing and measurement system, where the gas passes through a sodium hydroxide solution.All control systems, data display, measurements, and calculations are visualized in the graphical interface accessed from an internet browser on a mobile device connected to the Wi-Fi network generated by the equipment. MATERIALS AND METHODS

[029] Volumetric methods are based on determining the volume of biogas or methane produced in a reaction flask. In this procedure, glass flasks (antibiotic type, for example) are inoculated with biomass to be tested, substrate and nutrient solution, and incubated at an ideal temperature for the growth of microorganisms for a period ranging from 7 to 20 days. The test is finished when the accumulated methane production stabilizes and begins to decline, that is, it is essential that the maximum methane production rate (point of maximum slope on the curve obtained in a graph of accumulated methane volume versus incubation time) is obtained before the test is terminated.

[030] During the BMP test, it must be ensured that there is sufficient contact between the biomass and the substrate and that there is no limitation on the mass transfer of the substrate and nutrients. Therefore, it is common to incubate the reaction flasks under constant agitation, although there is no Petition 870200156915, dated 12 / 14 / 2020, pp. 22 / 27 7 / 10 in the literature conclusive results on the influence of intermittent agitation, and the type of agitator used (orbital agitation versus magnetic agitation) in the tests (AQUINO et al., 2007).

[031] Regarding temperature, there is consensus in the literature that the BMP test should be performed in the range of 30 to 35 °C, so that mesophilic methanogenic microorganisms have the best growth conditions. Some researchers use a temperature of 30 °C (CHERNICHARO, 1997; SOUZA et al, 2005) while others prefer a temperature of 35 °C (ALVES et al, 2005; MONTEGGIA, 1997; FDZ-POLANCO, 2005). As the BMP test indicates the capacity for methane formation, the value obtained can be used to determine the organic load that could be applied to the anaerobic reactor containing a certain amount of biomass.

[032] For direct measurement of methane, the biogas should be washed with a soda solution (e.g., 15% NaOH) to absorb CO2. This procedure assumes that CO2 and CH4 are the main constituents of the biogas formed during the BMP test. This assumption is valid since at neutral pH most of the ammonia (NH3) and half of the hydrogen sulfide (H2S), if present, are ionized and dissolved in the liquid phase as NH4+ and HS-.

[033] The equipment was tested for the functionality of each of the previously presented components according to the methods mentioned above. The agitators were tested using water and a few drops of food coloring to observe the mixture inside each flask, varying the speed of the agitators based on commands from a remote device. The gas volume meter was tested using an electric air compressor with a known flow rate to calibrate the electronic sensor. For flask temperature control, the system was adjusted to a range of 35 °C ± 1 °C, i.e., the heating system, which was on, would turn off when it reached 36 °C, and turn on again when it reached a temperature of 34 °C. It was also tested that Petition 870200156915, dated 12 / 14 / 2020, page 23 / 27 / 10 remote communication for the presentation of temperature data, engine speed and gas volume measurement on a remote device, such as a cell phone, from the connection to the WiFi network generated by the device and accessed by an internet browser installed on the cell phone. REFERENCES ALVES, RGCM; et al. Anaerobic digesters for swine manure treatment - initial evaluation for different reactor configurations. In: 23rd Brazilian Congress of Sanitary and Environmental Engineering, Campo Grande, 2005. ANGELIDAKI, I.; ALVES, M.; BOLZONELLA, D.; BORZACCONI, L.; CAMPOS, JL; GUWY, A.J.; KALYUZHNYI, S.; JENICEK, P.; VAN LIER, JB Defining the biomethane potential (BMP) of solid organic wastes and energy crops: A proposed protocol for batch assays. Water Science & Technology, 2009, v. 59, n. 5, p. 927-934. AQUINO, SF et al. Methodologies for determining specific methanogenic activity (SMA) in anaerobic sludge. Sanitary and Environmental Engineering, 2007, v. 12, n. 2, p. 192-201. BELLO-MENDOZA, R.; SHARRATT, PN. Modeling the effects of imperfect mixing on the performance of anaerobic reactors for sewage sludge treatment, J Chem Techno Biotechnology, 71, 1998, pp. 121-130. CHERNICHARO, CAL, et al. Development of an automated respirometer for evaluating anaerobic microbial activity. Revista de Engenharia Sanitária, 1997, v. 2, n. 3-4, p. 120-126. FDZ-POLANCO, F., et al. Application of a manometric method Petition 870200156915, dated 12 / 14 / 2020, p. 24 / 27 / 10 automatic for the determination of the anaerobi toxicity of chemical compounds. In: VIII LATIN AMERICAN SYM. ON ANAEROBIC DIGESTION, Uruguay, 2005. LOGAN, B.E., OH, S.E., KIM, I.S., VAN GINKEL, S. Biological hydrogen production measured in batch anaerobic respirometers. Environ. Sci. Technol, 2002, 36 (11), 2530-2535. LUNA DEL RISCO, M. A. Biochemical methane potential of Estonian substrates and evaluation of some inhibitors of anaerobic digestion. 2011. 124 f. Tese (Doutorado) - Estonian University of Life Sciences, 2011. MCENIRY, J., O’KIELY, P. Anaerobic methane production from five common grassland species at sequential stages of maturity. Bioresour. Technol, 2013, 127, 143-150. MCENIRY, J., ALLEN, E., MURPHY, J.D., O’KIELY, P. Grass for biogas production: the impact of silage fermentation characteristics on methane yield in two contrasting biomethane potential test systems. Renew. Energy, 2014, 63, 524-530. MONTEGGIA, L. Proposal of a methodology for evaluating the parameter Specific Methanogenic Activity. In: 19th BRAZILIAN CONGRESS OF SANITARY AND ENVIRONMENTAL ENGINEERING, ABES, Foz do Iguaçu, 1997. NOLAN, P., LUOSTARINEN, S., DOYLE, EM, O'KIELY, P. Anaerobic digestion of perennial grass prepared by cryogenic freezing versus thermal drying methods, using contrast in in vitro batch digestion systems. Renew. Energy, 87, 2016, 273-278. Petition 870200156915, dated 12 / 14 / 2020, pp. 25 / 27 / 10 OWEN, W F.; STUCKEY, DC; HEALY JR., JB; YOUNG, LY; McCARTY, PL. Bioassay for biochemical monitoring of methane potential and anaerobic toxicity. Water Research, 1979, v. 13, n. 6, p. 485-492. RAPOSO, F., FERNÁNDEZ-CEGRÍ, V., DE LA RUBIA, M., BORJA, R., BÉLINE, F., CAVINATO, C., DEMIRER, G., FERNÁNDEZ, B., FERNÁNDEZ-POLANCO, M., FRIGON, J. Biochemical methane potential (BMP) of solid organic substrates: evaluation of anaerobic biodegradability using data from an international interlaboratory study. J. Chem. Technol. Biotechnol, 2011, 86 (8), 1088-1098. SOUZA, CL, AQUINO, SF, CHERNICHARO, CAL Determination of the anaerobic and aerobic biodegradability of scum produced in UASB reactors treating domestic sewage. In: XV NATIONAL SYMPOSIUM ON BIOPROCESSES, Recife, 2005. VALERO, D., MONTES, JA, RICO, JL, RICO, C. Influence of headspace pressure on methane production in biochemical methane potential (BMP) tests. Waste Management. 48, 2016, 193-198. WANG, B., NGES, IA, NISTOR, M., LIU, J. Determination of methane yield from cellulose using different experimental settings. Water Sci. Technol. 2014, 70 (4), 599-604. Petition 870200156915, dated 12 / 14 / 2020, pp. 26 / 27

Claims

1 / 3 CLAIMS 1. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL consisting of a control and automation system, mixing mechanisms, heating system and measurement of the volume of gas produced, characterized by connectivity from a wireless network generated by the device, portable system for performing the analysis remotely.

2. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 1 and characterized by its portability through control and commands from a web browser on portable equipment that has this feature.

3. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 2 and characterized by the physical arrangement of the heating system for the containers and their heat sinks (1), the motors for the stirrers (2), the supports for coupling the stirrers (3), the containers for performing the BMP test (4), the partitions for storing the equipment devices (5), the container for washing the gas and measuring the volume of gas produced (6), receptacle for storing removable connections (7) and the receptacle for the electronic and automation system of the apparatus (8).

4. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 3 and characterized by the dimensions of the equipment, when closed and arranged for transport, having values ​​of 521.2 mm in width, 334.6 mm in length and 216.3 mm in height. Petition 870200156915, dated 12 / 14 / 2020, page 14 / 27 2 / 3 5. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 3 and characterized by the heating system (1) constructed with thermoelectric peltier pads fitted into a metal heat sink with fins and electric cooler fixed to an upper metal disc by thermal paste.

6. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 5 and characterized by the heating system (1) with dimensions of 68 mm wide, 60 mm long, 44 mm high and the metal disc with a diameter of 70 mm.

7. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 3 and characterized by the supports for coupling the stirrers (3) to the lid of the test container, support for the stirrers (2) and connection for gas outlet.

8. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 7 and characterized by the coupling support (3) with dimensions of 85.4 mm in height and 51 mm in diameter, a 25 mm diameter hole at the bottom for sealing and coupling to the container and a 25 mm diameter hole at the top for coupling the stirrers.

9. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL METHANE POTENTIAL, according to claim 3 and characterized by the container for washing the gas and measuring the volume of gas produced (6) from a bottle for the solution used for washing the gas and a system for measuring the volume of gas from an electronic sensor.

10. AUTOMATED PORTABLE SYSTEM FOR MEASURING BIOCHEMICAL POTENTIAL OF METHANE, as per Petition 870200156915, dated 12 / 14 / 2020, p. 15 / 27 3 / 3 claim 9 and characterized by the container for gas scrubbing and measuring the volume of gas produced (6) in cylindrical form with dimensions of 69 mm in height and 30 mm in diameter for the gas scrubber and 51 mm in height and 30 mm in diameter at the top for the gas measuring system, with an orifice at the top for the gas outlet after measurement. Petition 870200156915, dated 12 / 14 / 2020, p. 16 / 27

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