Gas heat exchangers
Before fuel gases can be used in CHP plant engines and converted into energy, they have to be cleaned and processed. This protects the engine and plant components and increases the service life significantly.
For these processes, we supply gas heat exchangers which cool the gas and precipitate condensate and additional heat exchangers which re-heat the gas for downstream processes in order to adjust the relative humidity.
Our gas heat exchangers can be used for a wide range of fuel gases.
Designs
Since our gas heat exchangers are designed and constructed on a project-specific basis, almost every one looks different and is suitable for a different application.
The most common designs are shown below.
Tube bundle
This is the simplest version of our gas heat exchanger. In this case only the tube bundle with connection flanges is supplied for installation in the pipe. Precipitating condensate must be drained separately in a different location. Gas heaters are typically shipped as tube bundles.
This design can be installed in the plant both horizontally and vertically.
Chambers
This version contains an outlet chamber with integrated demister and, if applicable, also an additional inlet chamber. The demister prevents precipitating condensate from being carried along into the downstream pipe. The condensate collects in the demister instead, drips down and can be removed via a condensate drain.
Upon request by the customer, a factory-installed siphon acting as a water and gas seal can also be integrated into the gas cooler condensate connection.
Gas cooling unit
In a gas cooling unit, the heat exchanger is equipped at the factory with a water chiller and mounted on a base frame and shipped as a closed, ready-to-connect system.
The system can be expanded with various options upon request, for example with a siphon or condensate collection container with electric trace heating. An additional heat exchanger can be installed directly at the gas cooler outlet for re-heating purposes.
Fields of use
The range of possible uses for our gas heat exchangers and gas cooling units in biogas, biomethane, sewage gas and pit gas plants as well as landfills is shown below.
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Applications
Biogas
Biogas is produced through the decomposition process of organic material, such as liquid manure or organic waste, in digesters and consists of approx. 50 - 65 % methane and 35 - 50 % carbon dioxide.
Additional substances such as nitrogen, oxygen, ammonia and hydrogen sulphide are also present in small quantities. Since hydrogen sulphide in particular would lead to corrosion in other plant components and in the CHP plant when combined with oxygen, the biogas has to be processed before it can be used.
This is done by first cooling and drying the gas using our gas heat exchangers and/or gas cooling units, which removes moisture from the gas. Then the remaining harmful components are removed using an activated carbon filter.
Biomethane
Biomethane is produced by processing biogas to remove the carbon dioxide through various processes. This gives biomethane the same properties as natural gas so that it can be fed into the natural gas network.
Among other things, the various processing treatments require gas heat exchangers which allow the biogas to reach different states and in the overall process result in the removal of as much condensate as possible.
We have also implemented a great many projects in this field and have acquired an extensive wealth of experience.
Sewage gas
Sewage gas is a form of biogas and is produced in the digesters of sewage treatment plants.
Since the sewage gas also contains various damaging components in addition to methane and carbon dioxide, it must be processed before it can be used in a CHP plant.
This is done using our gas heat exchangers and gas cooling units, which are used to cool the gas and remove moisture. The sewage gas is subsequently purified with an active carbon filter.
Landfill gas
In addition to methane and carbon dioxide, landfill gas also contains additional components such as nitrogen, hydrogen sulphide, water and thiols.
Landfill gas is not allowed to enter the atmosphere in an uncontrolled manner and must also be processed before being used in a CHP plant.
Our gas heat exchangers and gas cooling units are also suitable for this application.
Mine gas
Mine gas is released during coal mining and is withdrawn under high pressure through a shaft pipe. Then it is dried and can be converted to electricity and heat with a CHP plant.
The greenhouse effect can also be reduced significantly by utilizing mine gas.
Our mine gas coolers are designed specifically for use under high pressure and are typically TÜV approved for these requirements.
Wood gas
Wood gas is produced by burning wood at high temperatures of 700 °C to 800 °C in an oxygen-free environment. The resulting fuel gas can be used to drive a combustion engine in a CHP plant, which in turn generates electricity and heat.
Wood gasification produces certain residual materials such as tar and charcoal. Therefore the heat exchangers required for this application have to meet specific requirements.
enkotherm has many years of expertise in this field and supplies leading manufacturers in the wood gas industry.
Hydrogen
The production and storage of hydrogen will play a key role in future energy generation systems.
Excess electricity from renewable energies such as wind energy can be converted into oxygen and hydrogen through an electrolysis process. The hydrogen can be stored and converted back into energy in a CHP plant when needed.
There are currently various prospective processes for producing and storing hydrogen, which will also require the use of our gas heat exchangers.
Other applications
Our gas heat exchangers can also be used for many other applications in addition to the aforementioned ones.
For example to cool air, helium, oxygen or for synthesis, pyrolysis and propane gas applications.
Our gas heat exchangers are designed, planned and constructed specifically for the respective application.
