Andrea Giorgetti

With the valuable collaboration of Lluís Castaño, Product Manager at Kromschroeder, S.A. (Automa’s partner in Spain)

Biomethane represents a key resource for the energy transition, but its injection into distribution networks poses operational and technological challenges related to pressure and service continuity. In fact, before being injected, biomethane must meet strict quality standards regarding gas quality, measurement, treatment, pressure regulation, and odorization.

These challenges require innovative solutions. AUTOMA has therefore developed specific algorithms for its GOLEM system for dynamic gas pressure regulation in networks. The main application field of GOLEM was indeed the management of natural gas networks, but thanks to newly developed algorithms, now the system can also be applied to the biomethane sector with the aim of injecting biomethane into distribution networks while dynamically regulating the pressure of natural gas in the network.

Biomethane and distribution networks

The production of biomethane starts from waste produced by human activities, such as solid waste, sewage, livestock, and forestry residues. When biogas remains in the waste treatment plant, it is not advisable to release it into the atmosphere because it produces very harmful effects, such as the greenhouse effect.

This combustible gas can be treated in the plant itself through electricity generators to produce electricity, and if we have an electricity grid nearby, we can inject the electricity into the grid.

And what if there is no electricity grid nearby? What we can do with the excess gas is reach an agreement with gas distribution companies to inject biogas into their gas distribution networks.

This can only be done on the condition that such gas is treated to be interchangeable with the methane present in the network, thanks to a process called upgrading: biogas can be considered biomethane and thus injected into the gas distribution network.

A gas distribution network has a certain constant volume. At any point in the network, there can be consumption, while gas is injected at one or more points in the network to try to maintain a pressure defined by the set point of the pressure regulators at the injection points. In steady-state conditions, there is an equilibrium between the flows at the injection points and the flows at the consumption points. The result is a constant pressure.

The critical issues of biomethane networks

Most biomethane injection points are characterized by small diameter pipes and a not very high available gas volume dependent on production capacity, subject to daily and seasonal fluctuations. Since at low-capacity biomethane production points the flow is very limited, anomalous operations of traditional pneumatic pressure regulators can occur.

Essentially, the main identified critical issues are four:

1. Reduction in production: a decrease in production can lower pressure, compromising the continuous injection of biomethane into the network.
2. Service interruption: sometimes, the interruption of service is caused by failures in the upgrading system, which is unable to maintain sufficient pressure or provide consistent quality gas.
3. Overproduction of biomethane: an increase in production beyond operational limits can compromise the safety of the network and/or the contractual terms between producer and operator.
4. Overpressure in the network: a temporary and spontaneous increase in network pressure can cause the interruption of injection.

The normal operation of a pressure regulator consists of opening when it is necessary to reach a certain pressure point based on its set point. If this value is not reached, the regulator opens fully, consuming the available amount of biomethane in a very short time, if limited by the capacity of the biogas plant. As the available amount of biomethane is consumed, a rapid depressurization of the production system occurs. The immediate effect can be the suspension of biomethane injection.

The cause of all these problems is the way static pressure regulators operate. In this context, the ability to dynamically regulate the pressure upstream of the regulator becomes a strategic function to ensure continuity and quality of service.

The Automa solution: the GOLEM technology for dynamic management of biomethane injection

In this specific case we are illustrating, we have made an adaptation of GOLEM to the operational needs of a gas distribution company that requested a solution for the regulation of biomethane injection in a distribution network. GOLEM by AUTOMA allows for dynamic management of biomethane injection, improving service continuity and reducing operational risks.

Golem technology is based on a mechanical servomechanism that interacts directly with the pilot of the pressure regulators, supported by an advanced electronic system. Thanks to the intelligence incorporated in the system, Golem can operate in autonomous mode, reducing the need for manual interventions. The system is applicable to any controller model and can be easily integrated into existing networks thanks to custom-designed adapters.

The characteristics of the GOLEM system are represented by four types of pressure and flow modulation:

• Pressure modulation is the ability to vary and maintain pressure, based on the set point.
• Flow limitation is the ability to keep the flow below a certain maximum value, while always providing the maximum possible pressure value.
• A weekly programming of pressure values for time slots is possible, for example, at night the pressure is lower than during the day.
• It is possible to compensate the flow by applying pressure values to a portion of a given maximum flow.

When a target pressure is assigned to the system that is higher or lower than the initial pressure read by the system, an algorithm with a condition analysis time is initiated. When it is necessary to increase or decrease the pressure, a motor movement is initiated. The period during which the engine moves is strictly controlled to ensure the amount of movement actually required, observing and analysing the variations in pressure and flow rate. A necessary, positive or negative movement is then appliedto increase or decrease the pressure and achieve the set target for the system.

This gradual approach will eventually lead to reaching or even exceeding the target pressure. If the target pressure is exceeded in the subsequent analysis, a countermeasure is decided upon for a time equal to half of the previous time. This progressive correction of the control screw movement ends when the target is reached within a given tolerance. The same logic of the algorithm is applied to maintain a flow restriction below a maximum value while always trying to maintain the highest possible pressure.

The GOLEM system examines the flow rate and pressure. If the flow rate is sufficiently high, but still within the safety range, the system will decide to open the regulator and deliver that amount of gas. In this way, the flow rate we had will tend to decrease, as will the inlet pressure. When the GOLEM system, continuously analysing these parameters, verifies that the pressure is approaching a value very close to the network pressure, it will close the gas transport to avoid the risk of gas flow interruption and thus redirect the biomethane to the storage tank of the upgrading system (overpressure condition).

As soon as the flow rate becomes dangerously low and approaches the lower limit, the GOLEM system reduces the gas flow to recover both the flow rate and the pressure. At some point, a constant flow should be reached.

The results of the Automa solution

Thanks to the implementation of GOLEM for the regulation of biomethane injection into the distribution network managed by our client, the dynamic flow management has kept pressures within the operating range even in the event of sudden production fluctuations, improving the overall stability of the network.

 Important results have therefore been achieved:

• Reduction of injection interruptions caused by pressure drops.
• Optimised management of biomethane overproduction.
• Greater resilience of the network in biomethane supply operations.

This paves the way for a safer, more efficient and sustainable management of the biomethane resource.

How was it possible to achieve these results? AUTOMA has been active since 1987 in the development of hardware and software solutions for the remote monitoring and control of gas transport and distribution networks, functional to their operational management.

Research and development of increasingly high-performance and innovative solutions is our daily commitment. To date, over 50,000 Automa devices are installed in more than 40 countries worldwide.

Do you want to manage the injection of biomethane in a more dynamic, flexible, and safe way?

Contact our team without obligation and we’ll tell you how we can optimise the control and management of your infrastructure.

Ensuring gas flow rates always within the meter rangeability acting on the automatic regulation pressure value: in this article we tell you about the challenge won by AUTOMA’s GOLEM technology with the installation on an off-take station serving an antenna gas distribution network.

A project that ensures compliance with resolution 512/2021/R/gas, issued by the Italian Regulatory Authority for Energy, Networks and the Environment (ARERA), which requires the gas flow to be maintained within the limits allowed by the meter’s measurement range and, consequently, requires accurate monitoring and adequate flow control.

The Automa solution: GOLEM technology applied to flow control

The GOLEM technology, which is characterised by the ability to make the regulation of gas pressure dynamic and automatic without requiring substantial changes to existing systems, is based on a mechanically coupled servo mechanism which manages the adjustment screw of the regulator and makes it controllable.

Thanks to this innovative adaptation technology, the System can be applied to any pressure regulator, piloted or direct-acting, with a simple retrofit intervention. A solution that can be readily adapted and implemented, and which contributed to our client’s choice of GOLEM.

In this specific case, the operating logic of the GOLEM System has been modified to enable it to keep operating flow rates within the correct rangeability for which the meter was designed.

Considering that it cannot directly influence the plant’s gas demand – since this is determined by the downstream collection –, the System intervenes directly on the network pressure, modifying it to adapt the flow rate in cubic meters to the rangeability of the meter. Specifically, lowering the pressure lowers the flow rate in cubic meters and vice versa. This ability to directly regulate the pressure in the off-take station allows, actually, a direct control over flow rate in cubic meters to the meter.

In addition, the GOLEM operating logic has been optimised to allow flow rate control simultaneously with the management of an hourly pressure profile. Specifically, the pressure is lowered during the night and then brought back up to the desired range during the day, with a consequent significant reduction in fugitive emissions. 

Furthermore, to guarantee the safety and continuity of the System’s service, in addition to GOLEM’s internal algorithmic logic, there are mechanical limit switches that constantly monitor the pressure, ensuring that it does not exceed the set thresholds. Mechanical limit switches offer additional safety compared to algorithmic logic alone, protecting against any system anomalies. Indeed, when a limit switch is reached, the system stops and returns the pressure to its origin.

The results obtained thanks to GOLEM by AUTOMA

The implementation of GOLEM can be defined Plug&Play, as it does not require significant interventions on the mechanical and pneumatic part of the system. It is not necessary to modify the motorisation pressures or review existing connections, which considerably simplifies the installation process, and therefore the subsequent management and maintenance of the plant. This was a first, very important advantage for our customer.

From the very first months of activity, following the tuning phase in which the System was calibrated, the implementation of GOLEM on the off-take stations has allowed us to:

•  get a significant reduction in out-of-threshold measurements
•  make the measurement system more efficient
•  significantly reduce the economic sanctions for measures outside the threshold
•  significantly reduce fugitive emissions

Even the maintenance of the system proved to be extremely simple for our client to manage. In fact, with a simple action on a screw, it is possible to manually regulate the controller pilot or remove the servo motor and restore the reduction system to its original configuration in about 10 seconds. This greatly facilitates the work of maintenance technicians, allowing them to intervene on the pressure regulator, pilots, monitors and other components of the off-take station to carry out maintenance work in full compliance to current regulations.

The implementation of GOLEM in this project has produced extremely satisfactory results for our customer, while also improving operational efficiency.

With the AUTOMA solution it is possible to benefit from an immediate increase in efficiency and precision of pressure regulation, resulting in reduced gas leaks and operating costs. In addition, thanks to GOLEM, the system is able to reduce inefficiencies linked to changes in gas supply and demand. With a view to a possible integration of renewable sources, GOLEM is designed to also manage the injection of biomethane within natural gas networks, unlike many other solutions on the market.

AUTOMA has been active since 1987 in the development of hardware and software solutions for the monitoring and the remote control of gas transportation and distribution networks, functional to their operational management. As yet over 50,000 Automa devices are installed in more than 40 countries in the world.

Do you want to ensure that you regulate the gas network pressure safely and efficiently?

Contact our team without obligation and we’ll tell you how we can optimise the control and management of your infrastructure.

The Global Methane Tracker 2024 report published by the International Energy Agency (IEA) reveals discouraging data: in 2023, methane emissions in the energy sector rose by 3 million tonnes compared to the previous year. This brought their total to 120 million tonnes.

Despite the efforts made by the sector to reduce losses, methane emissions in the energy sector remain a significant challenge. Drastically limiting these losses is essential not only to improve the efficiency of energy networks but also to combat the climate emergency.

The problem of overpressure

An important part of gas losses is related to overpressure in plants and networks: this term refers to a condition in which the operating pressure within gas distribution networks is often higher than optimal levels while still complying with safety standards and operational management for proper functioning, creating risks for safety, the environment, and the infrastructures themselves.

Fugitive emissions, that is, the uncontrolled release of gas (such as methane) into the environment, are proportional to the operating pressure, so optimising and reducing the latter leads to an immediate reduction in emissions.

In addition to this, overpressure can accelerate the deterioration of pipes and network components, increasing the risk of structural failures and reducing overall operational efficiency.

How is it possible to reduce the issues related to gas network pressure without compromising the supply? A concrete and effective response comes from dynamic regulation.

What does dynamic regulation mean

Dynamic regulation allows for real-time adjustment of pressure in gas distribution networks to actual demand. In practice, the system based on the principle of dynamic regulation automatically adjusts the pressure according to variations in consumption:

• During periods of low demand (for example, during the night), the pressure is reduced to avoid overpressure and minimise gas losses.
• During peak consumption times, the pressure is increased to ensure that the gas flow meets the demand, always within safe limits.

In summary, adopting a dynamic pressure regulation on networks means:

1) an exponential decrease in the volume of gas lost

2) more efficient operation of the network, subjecting it to less stress, thus also reducing the frequency of failures in the long term.

Dynamic regulation occurs through data-driven technology. This, indeed, allows for the collection of real-time data that is then analysed with intelligent algorithms that calculate the necessary corrective actions to maintain the pressure at an optimal value. In the case of particularly complex systems, the system is able to anticipate changes in demand or network conditions by leveraging predictive analysis and artificial intelligence.

A system of this kind must therefore combine monitoring capabilities on one side and control capabilities on the other.

The ideal solution must consequently integrate:

– Edge Computing features, which allow for faster responses and make the system more robust and reliable.

– Artificial Intelligence for big data management, capable of finding a model to classify information, make decisions or predict the future trend of events.

– Cybersecurity, essential for the protection of this type of data.

– Ability to reduce inefficiencies related to fluctuations in gas demand and supply, to ensure service continuity.

With these characteristics, the system is able to estimate the demand required by users in each execution cycle, and to adjust the network management parameters when necessary to keep the pressure to a minimum during hours of lower demand and to increase it when user demand also rises.

The result? An optimal compensation that limits leaks while ensuring efficient network management.

The Automa solution: the GOLEM technology

The GOLEM technology of AUTOMA, developed to dynamically control regulators, also adjusts the pressure on demand in order to reduce emissions and optimise flow rates.

Simplifying to the maximum, we can say that GOLEM transforms any existing pressure regulator into an element that can be controlled remotely. In this way, it is possible to remotely control the gas pressure based on a desired value, whether it is a measurement coming from the termination point or a local measurement in the pressure reducing station (PRI).

The system allows, for example, to set daily pressure profiles, that is, to pursue target flow rates or pressures. Thanks to the built-in protections, such as mechanical limits and energy reserves, GOLEM ensures continuous and reliable operation.

GOLEM also stands out for its ability to make the regulation of gas pressure dynamic and automatic without requiring substantial modifications to existing plants, easily integrating with already present regulators, both direct and pilot-operated. Another significant advantage is that GOLEM does not require the use of venting, a noteworthy aspect especially after the new European Regulation on emissions has prohibited its use in industrial processes.

Unlike other similar solutions available on the market, the GOLEM application is not limited to the remote control of gas in natural gas distribution networks; indeed, it has been designed to also manage the injection of biomethane into natural gas networks, thus addressing the growing need to integrate renewable sources into distribution networks.

AUTOMA develops hardware and software solutions for the monitoring and remote control of gas transport and distribution networks, functional to their operational management.

We were born in 1987 in Italy, and today over 50,000 Automa devices are installed in more than 40 countries around the world.

Do you want to ensure that you regulate the gas network pressure safely and efficiently?

Contact our team without obligation and we will tell you what we can do to help you limit losses and always maintain an adequate level of service.