Thermal Control as a Key Factor in Improving the Efficiency of Biogas and Biomethane Plants
In just a few years, biomethane has moved from being a promising alternative to becoming an industrial reality in Spain. Initiatives such as REPowerEU and the targets set out in the National Integrated Energy and Climate Plan (PNIEC) are driving its development. This is reinforced by the country’s significant potential to produce biomethane from agricultural, livestock, agro-industrial and urban waste, resources that can contribute both to advancing the circular economy and to reducing dependence on fossil fuels.
The growth of the sector is already beginning to be reflected in the number of facilities. While Spain had only one biomethane plant in operation in 2021, by the beginning of 2026 there were already 23 operational facilities, with a combined capacity of approximately 1.4 TWh per year. In addition, the PNIEC sets a target of reaching 20 TWh of biogas production by 2030, highlighting the considerable growth potential that still exists in this market.
However, the sector’s next challenge will not simply be to increase the amount of biomethane produced. As facilities reach a higher level of technological maturity, their competitiveness will increasingly depend on their ability to manage the energy used and generated throughout the process efficiently, reducing consumption and making better use of available resources.
Within this approach, there is one factor that, although it often receives less attention than digesters or upgrading systems, plays a direct role in a large part of the plant: thermal control.
The evolution of biogas and biomethane plants therefore depends not only on increasing production, but also on managing thermal energy more efficiently. Temperature is no longer simply a parameter that must be kept within certain limits; it is becoming a key design variable, with a direct impact on efficiency, process stability and the overall profitability of the facility.
Temperature as a Strategic Variable
Temperature control is present in virtually every stage of a biogas and biomethane plant.
Anaerobic digestion is probably the clearest example. The microorganisms responsible for converting organic matter into biogas need to operate under stable thermal conditions, both in mesophilic and thermophilic processes. Maintaining appropriate temperature regulation helps preserve the biological stability of the digester, supports biogas production and reduces the risk of process deviations.
Traditionally, the heat required to maintain these conditions has been supplied by boilers powered by fossil fuels or by using part of the biogas generated within the facility. However, the growing electrification of industrial processes is encouraging the introduction of industrial heat pumps, which are capable of supplying the required thermal energy with high efficiency while also making use of heat sources already available within the plant.
Thermal management is also essential during the biogas conditioning and purification stages. Before subsequent treatment stages, cooling allows the moisture contained in the gas to condense and be removed, helping to prevent corrosion problems and protecting downstream equipment. Later, during the upgrading process, in which carbon dioxide and other unwanted compounds are removed to obtain biomethane, temperature also has a direct influence on separation efficiency.
Once biomethane has been produced, compression represents another stage in which temperature control becomes particularly important. Increasing pressure also causes an increase in temperature which, if not properly controlled through adequate cooling, can reduce compressor efficiency and accelerate equipment wear. A correctly designed thermal system helps reduce energy consumption and improve the overall reliability of the facility.
Energy Integration Across the Plant
For many years, heating and cooling systems were mainly designed to meet the individual requirements of each process. However, the design of new plants is moving towards a more integrated approach, in which the generation and demand of heat and cooling are considered as parts of a single energy system.
Each stage of the plant can either require or generate thermal energy. Biogas compression processes produce waste heat, while refrigeration systems used, for example, in certain upgrading stages also release heat. At the same time, digesters require a constant heat supply to maintain the conditions necessary for biological activity. Integrating these different energy flows makes it possible to recover energy that might otherwise be wasted and reuse it wherever there is a thermal demand.
In this context, industrial heat pumps and refrigeration systems using natural refrigerants are becoming particularly relevant. These solutions make it possible to recover part of the waste heat generated within the facility and feed it back into the process, reducing both energy consumption and the emissions associated with plant operation.
The objective, therefore, is no longer simply to reach and maintain a certain temperature in each piece of equipment or process. The priority is to optimise the overall energy balance of the entire facility.
Towards More Efficient and Intelligent Plants
The technological evolution of the sector is reinforcing this trend. The electrification of thermal processes, more integrated energy management and the digitalisation of control systems are gradually changing the way new biogas and biomethane plants are designed and operated.
Continuous monitoring of the main process variables makes it possible to optimise equipment performance, detect potential deviations before they affect plant operation and reduce costs through predictive maintenance strategies. At the same time, greater integration of thermal flows contributes to improving the overall energy efficiency of the plant and reducing its carbon footprint.
Conclusion
In recent years, much of the development of the biomethane sector has focused on increasing production capacity and improving both digestion processes and upgrading technologies. However, the next stage in the evolution of these facilities will also be shaped by a less visible but decisive factor for their efficiency: thermal energy management.
Heating and cooling will no longer be regarded merely as auxiliary services required to support specific processes. Instead, they will increasingly be understood as energy resources that can be recovered, integrated and reused within the facility itself.
The future of biogas and biomethane plants will therefore depend not only on their ability to produce more biomethane, but also on how effectively they manage the energy available at each stage of the process. In this context, thermal control is set to play a fundamental role in the design and operation of a new generation of plants that are more efficient and better integrated from an energy perspective.
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