Biogas Flowmeter-FAQ

In 21 years, BCST has become the top manufacturer of the flowmeter in China. BCST offers the complete package regarding the controlling solutions and flow measurement. It includes different kinds of flowmeters and transmitters such as biogas flowmeter, turbine flowmeter, vortex flowmeter, pressure transmitter, and much more. Along with manufacturing, BCST also exports the biogas flowmeter to more than 100 countries for their industrial applications. In addition, BCST manufactures a thermal mass biogas flowmeter for measuring the mass and volumetric flow rate of the biogas.

Following are the answers and details of all the queries about the biogas flowmeter.

1. What is Biogas?

Biogas is renewable fuel manufactured by the breakdown of raw materials like food scraps and animal waste. It’s an environmentally-friendly, renewable energy source. They are often used in different ways, including as vehicle fuel and for heating and electricity generation.

Biogas is produced when bacteria digest organic matter (biomass) within the absence of oxygen. This process is termed anaerobic digestion. Simply put, there’s a fermentation process that breaks down organic matter, turning what once was waste into a source of energy that may be wont to heat, cool, cook, or for average electricity production once it’s burned.

Food scraps, animal waste, sludge from wastewater treatment plants, animal manure and field biomass from agriculture, and other biodegradable waste byproducts from industrial facilities like slaughterhouses are mainly used for biogas production.

Biogas production can happen naturally across ecosystems. Either in rice farms and at the underside of the oceans, rivers, or lakes where sediments are bare to anaerobic conditions. Animals can produce biogas, mainly methane. Ruminants like cows, deer, sheep, camels, or lamas may also create methane during their digestive process while making food in their rumen (are part of those animals’ stomachs).

The composition of biogas may vary in step with the substrate they used and conditions available for anaerobic decomposition of substrate. It contains methane, dioxide, nitrogen, hydrogen, sulfide, and oxygen. Thus, biogas isn’t one gas. But instead, it’s a combination of gases.

Biogas production has been in severe trouble for ages. It’s an ancient method of manufacturing fuel and manure using mainly agricultural waste and trash. It’s done by the reaction of microorganisms like methanogens and eubacteria. Production of biogas is that the fermentation of biomass which is completed anaerobically in the presence of moisture.

1.1 What is the Usage of Biogas

• It is used as cooking gas in rural areas.
• They are often used for electricity production.
• It will be used for water heating, space heating, etc.
• It can replace compressed gas to be used as fuel in vehicles.
• It can displace greenhouse emissions in on-site CHP plants.
• It is being employed within the transport system.
• Production of biogas produced a beneficial dry solid byproduct which used as manure.
• It is used for street lighting purposes.
• It is employed in hydrogen fuel cells, moreover.

Biogas in real-world uses has many advantages. First, biogas doesn’t pollute the environment. Thus, it’s eco-friendly fuel. It’s a renewable source of energy. It reduces soil, water, and pollution. Third, it produces organic manure as a byproduct. Fourth, because it may be a low-cost method to provide power, it’s economically friendly. Further, it also encourages a circular economy and is helpful for all classes. Finally, it’s a healthy cooking alternative, especially for developing countries.

Sourcing energy from biogas seems the right solution to 2 problems faced within the modern world: mounting waste and the most rapid decarbonization within the face of increasingly volatile global temperatures.

2. What are the reasons to measure the flow of biogas?

Following are the main reasons for the measurement of the biogas:

• The biogas flowmeter helps in providing the data as a reference to the biogas station. The reason to install the biogas flowmeter in the supplying station of the biogas is to facilitate the data for supplying and controlling the biogas.
• The biogas flowmeter also keeps checking the efficiency of the fermentation tanks through the flow of the biogas. Therefore, you can quickly inspect the status within time in case if there are any fluctuations.
• It controls the combustion efficiency of the boiler. Whenever the biogas boiler starts boiling, it is essential to handle the flow of biogas to manage the manage ventilation of the boiler. Excess ventilation can decrease the temperature of the furnace. When the ventilation rate is meager and gas is not burning, it causes waste and pollution.
• They are controlling the emissions of greenhouse gases. For example, both methane and carbon dioxide in biogas is greenhouse gases. In these, methane is more dangerous than carbon dioxide.
• Mainly, the civil users install the biogas flowmeter for metering charging, and the rest of the management department carries out the cost accounting.

3. How to select a biogas flowmeter? 

During the selection of biogas flowmeter, must consider the parameters below:

• Flowing range and size of the pipe: The manufacturers of biogas flowmeters must know the size of the gas flow sensor through the flowing range and diameter of the line. In an ideal circumstance, the diameter of suitable flowmeters is similar to the size of the tube. But, during the measurement of flowing biogas, there is a possibility to choose the flowmeter larger or smaller than the pipeline.
• Processing condition of the flowmeter: You must inform the manufacturer of the biogas flowmeter regarding the type of process condition you are using. You can use a flange, insertion, or wafer type of biogas flowmeter. 
• Rate of flowing biogas in standard or natural state: You can measure the flow rate in an ideal or present condition. During the measurement of the flow rate, “N” means regular, and it shows that you can easily adjust the volume of the gas to the average temperature and pressure, which is usually 0 and 101.325kPa. The natural flow rate is the gas volume passing through the flowmeter in unit time. The thermal flowmeter is appropriate for measuring the flow rate, and the vortex flowmeter measures the biogas volumetric flow rate.
• Working temperature and pressure: The design of the biogas flowmeter is in such a way that it works below the pressure of 16bar. If the biogas flow sensor finds out the pressure above 16bar, you need to report the manufacturer or supplier of the biogas flowmeter. 
• Working of the flowmeter: one more important parameter is how you are using the biogas flowmeter. You can use the biogas flowmeter for multiple purposes such as digital display, remote display, hart protocol, pulse output, 4-20mA, or RS4845 Modbus RTU. After knowing your objective, talk to the biogas flowmeter manufacturer and select the biogas flowmeter according to your requirements.

4. What are the types of biogas flowmeters?

Nowadays, technologies for measuring biogas are available and commonly used. Mainly, it includes vortex flowmeter, thermal mass flowmeter, and turbine flowmeter.

• Vortex flowmeter: The vortex flowmeter is the flowmeter that measures the volumetric flow of the gas, liquid, or steam. Using the vortex flowmeter, you can measure the volume flow under specific conditions or the liquid and gas mass flow depending on the vortex principle. There is a formation of the vortex whenever the fluid passes from the dust collector rod of the vortex flowmeter. The frequency of the vortex dispatching is directly proportional to the velocity of the liquid. You can configure the temperature and pressure.
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• Thermal mass flowmeter: The thermal mass flowmeter is the actual mass flowmeter. There is no need to adjust the temperature and pressure. The thermal mass flowmeter design depends on the principle of thermal diffusion that includes coal gas, natural gas, argon, liquified gas, carbon dioxide, and measuring mix flow of the gases.
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• Turbines gas flowmeter: There is an integration of temperature, pressure, flow sensors, and intelligent flow totalizers in the turbine gas flowmeter. The accuracy rate of the turbine gas flowmeter is high and has good repeatability. So, the turbine gas flowmeter is suitable for detecting industrial processes and trading measurements. The turbine gas flowmeter is ideal for the different gases in petroleum, metallurgy, chemical, and industrial sectors. The turbine flowmeter cab measures propane, butane, natural gas, nitrogen, and other gases.
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5. What are the characteristics of a biogas flowmeter? 

• The biogas flow meter is suitable for handling the high pressures
• The battery is built-in in the biogas flowmeter along the totalizer that making it portable
• The biogas flowmeter is almost 3mm-12inch
• The electronics display is available in the biogas flowmeter 
• The body of the biogas flowmeter is made of stainless steel
• You can mount a biogas flowmeter in both directions, horizontally and vertically
• Certifications of explosive-proof and calibrations are present with every biogas flowmeter 
• The biogas flowmeter works best for the measurement of biogas that has carbon dioxide and moisture.
• The biogas flowmeter helps in manufacturing the fertilizers and fuels the vehicles.
• It also consumes and conserves energy.

6. What are the issues in measuring the biogas?

Biogas is a kind of gas that is difficult to measure due to the reasons below:

• External pressure: the actual stress from the fermentation tank mostly exceeds 0.1 kg (10kPa).
• Changes in the composition: The composition of the biogas is from the mixture of gases. Its production causes fluctuation that is mainly depending on the raw materials required for gas production.
• Large flow fluctuations: The output biogas flow rate affects significantly when there are changes in the raw materials of the biogas, changes in the temperature, and bacterial conditions. So, it would help if you had a biogas flowmeter that must have a large turndown ratio.
• Water vapor: Biogas production is through biomass fermentation, and the biogas’s water carries in the biogas. That’s why there are water vapors in the biogas.
• Corrosive: There is low content of hydrogen sulfide (H2S) in biogas. But it leads to the formation of corrosive hydrosulfuric acid after flowing through the water vapor. As a result, there is a greater chance of corrosion in the metering components.

7. What is an insertion thermal mass biogas flowmeter?

The thermal mass biogas flowmeter is the type of instrument that follows the principle of heat transfer, exchange of the heat between the flowing of the fluid and source of the heat for the measurement of the mass flow of the gas. Therefore, you can divide it into heat distribution and heat dissipation depending on the heat effect. The thermal mass flowmeter uses the effect of heat dissipation to measure the mass flow of the gas so it can avail the benefits, such as less loss of pressure, wide range for the measurement, high rate of accuracy, and high repeatability without any moving parts. These prominent advantages make the insertion thermal mass biogas flowmeter famous in the industries at domestic and international levels.

8. What are the technical parameters of insertion thermal mass biogas flowmeter? 

8. What is the working principle of insertion thermal mass biogas flowmeter? 

The principle of insertion thermal mass flowmeter is that the flowing fluid passes through the sensor and removes the specific quantity of heat. In the thermal flowmeter, the liquid has to flow from the two temperature sensors. One sensor is for receiving the reference value to measure the temperature of the process. Another sensor is the heating element and gets the energy for adjusting the dispersed heat and maintaining the temperature difference. More the mass flows by the heating temperature sensor, more heat production, and more input as the power for adjusting the temperature difference. Heating the current is the actual mass flowing of the gas.

The temperature of the sensor is always 30 degrees Celsius, more than the temperature of the medium. The insertion thermal mass gas flowmeter accepts the methodology of constant difference between the temperatures. So, the flowmeter doesn’t require adjusting the temperature and pressure

9. What are the advantages of using a biogas flowmeter? 

Sometimes, it is challenging to measure the accuracy and reliability of the biogas. It is all dependent on the source of the biogas and issues with the application. It would help if therefore, you considered these factors when you are using the biogas flowmeter. Below are the advantages of using a biogas flowmeter during the measurement of biogas:

• The measurement of the mass flow doesn’t require the correction of temperature and pressure.
• Different gases flow at low and different velocities. Therefore, the biogas flowmeter has a great sensitivity towards low-velocity gases compared to other kinds of flowmeters.
• The biogas is dirty that sometimes leads to the maintenance of the flowmeter. Therefore, the biogas flowmeter has a retraction device that periodically removes the probe to clean.

10. Who are the manufacturers of biogas flowmeters?

India and China are the top manufacturers of biogas flowmeters. In China, BCST is the leading manufacturer and supplier of biogas flowmeters across more than 100 countries. The insertion thermal mass biogas flow meter is a unique instrument of BCST that helps measure the mass and volume rate of the biogas. Biogas is a type of dirty gas that has moisture and some content. It clogs the measuring instruments, so there is a need for a biogas flowmeter. It measures the mass flow of the gas and neglects the pressure drop. This particular technology is suitable for low-pressure flow measurement.  

11. How to overcome the limitations of the thermal mass biogas flowmeter?

The thermal mass biogas flowmeter is the most common flowmeter to measure the biogas mass flow.  Following are solutions to overcome the limitations of the thermal mass biogas flowmeter before its implementation:

• The condensed moisture can result from inaccuracies: You can place the knockout drum or knockout pot that helps separate the moisture drops from the gas; whenever the gas starts flowing inside the vessel, the velocity of the gas decreases, which changes the direction of the flow. Gravity makes the moisture fall and makes the flow move direction upward. This technique helps in removing the moisture drops from the gas. One more way to remove the moisture is the position of the sensor. Place the sensor at such an angle that if condensation happens, it goes away from the sensor.

• Diminishing the sensitivity at the higher velocities: There is no relationship between the mass speed and heat transfer during the thermal mass measurement. Therefore, the sensitivity of the thermal mass biogas flowmeter is good for the low gas flow.  But, unfortunately, it starts losing sensitivity at the higher velocities. Therefore, it is better to use the differential pressure or vortex flowmeter for more than 150 PSI to resolve this limitation.

• Variation in the gas flow composition: The thermal mass biogas flowmeter needs calibration for the measuring gas. If there are any changes in the design of the gas, it delivers inaccurate results. The accuracy rate is dependent on the variation of the gas. Biogas is a mixture of different amounts of methane and carbon dioxide. In most situations, the changes in the heat transfer from the difference of the gas affect the accuracy to less than 5%. So, almost in all circumstances, it is acceptable. Moreover, in chemical and refinery industries, the changes in the gas composition impact the accuracy of the thermal mass biogas flowmeter.

• Calibration for the different types of gas: Each and every gas has various physical properties that affect heat transfer. Due to this reason, the thermal mass biogas flowmeter can only measure the gas accurately for whom the meter calibrate. While calibrating on the flow bench, the controlling amount of the particular gas flows through the sensor and measuring the signals. More than once, this process is repeated within the range for establishing the relationship between the mass flows, signals for the gas, and sensor calibration. Therefore, it is better to use the surrogate gas while performing the calibration with similar heat transfer characteristics. And also adjust according to the properties of heat transfer of the calibrating gases.

• Large ducts: The thermal mass biogas flowmeter probe gets inside the pipe, and the flowmeter measures the gas flow at the sensor’s location. You can receive accurate measurement when there is a recommendation and availability of straight run distance. The require straight-run is on the diameter of the pipe to obtain the length for the large ducts. It makes it difficult to measure the correct measurement. For improving overall accuracy, you can increase the number of measurement points. In these cases, you can use several flowmeters adjacent to the duct and measure the average flow to improve the accuracy rate.
• Low velocities: The thermal mass biogas flowmeter performs well in low-velocity measurements. The accurate size depends on the calibration of the flowmeter at meager flow rates. If your application has a low velocity, you must contact the manufacturer of the thermal mass biogas flowmeter to receive assurance regarding the capacity for the calibration over the particular velocity range in the correct manner.

12. What are the reasons to choose the biogas flowmeter for improving the methane recovery system?

The biogas measurement application faces the following challenges during the selection of the particular flowmeter:

• Low flowing sensitivity because of the soft flowing of the vapors recovering from the digester process
• Compensation of the temperature for the correct readings during the variations of the temperature
• Calibration of the composition of the mixture of methane and carbon dioxide or traces of the gases.
• Dirty and wet gas
• Installation of flammable or explosive gas environment
• Cost-efficient
• Easy to install and requires less maintenance

The biogas flowmeter is the right choice that uses the power technology constantly for the wet, dirty air and gases. The purpose of designing the biogas flowmeter is to present it as an economical solution to resolve all the issues to metering all the flow in the digester process generating methane. The main reason for selecting the biogas flowmeter is its ability to keep operating and it is high measurement accuracy and repeatability. There are no moving parts in the biogas flowmeter, and the designing of thermal mass flow dispersion is so that it is highly resistant to clogging. It means that there is no need for downtime for maintenance and increases productivity. The explosive-proof transmitter is also appropriate for the biogas environments and fulfills the safety requirements—no interruption in the processes to clean the biogas flowmeter.

Final thoughts: 

The biogas flow meter is an instrument for measuring biogas. The materials of the biogas flowmeter are stainless steel that makes the biogas flowmeter reliable and durable. The biogas flowmeter is cost-efficient as well. BCST is offering a thermal mass biogas flowmeter for measuring the volumetric flow rate of biogas. Contact our teammates to know all the details regarding the biogas flowmeter and variety of instruments. We always assure the delivery of high-quality products and are available for assistance. Order the biogas flowmeter from our official website. The customer care agents of BCST are also receiving orders on WhatsApp and Skype. Purchase the biogas flowmeter now and get it deliver in 7-10 working days at your doorstep.