Gas turbines in the brewing and beverage industry

Schematic process diagram of a microturbine

Jet-stabilized combustion chamber system

The German Aerospace Center (DLR) has developed a jet-stabilized combustion chamber system for micro gas turbines with an output of 100 to 400 kW. This system can also use fuels that are generated in the production process of breweries. Until now, these were not only often left unused as waste materials, but were also sometimes disposed of at great expense.
The high technology used is based on the wealth of experience of the DLR Institute of Combustion Technology and can now be used in medium-sized companies and industrial operations.

How relevant is the microturbine technology for brewery operations?

Jet-stabilized combustion chamber systems for gas turbines represent an ultra-modern form of combustion system. They are characterized by high flexibility with regard to the load range and the fuels used and produce only low pollutant emissions.
The key new development is that these combustion chamber systems can switch seamlessly between different fuels, even in changing mixing ratios, including:

• Natural gas;
• biogas from the fermentation of organic materials such as biomass or waste;
• gaseous ethanol and butane;
• synthesis gas (syngas), a mixture of hydrogen and carbon monoxide;
• hydrogen.

This versatility gives breweries the opportunity to design their energy supply in a renewable and cost-efficient way by using existing side streams as fuels while minimizing the environmental impact.

View into a cut-open turbine module

Flexible gas mixing with up to 100 per cent hydrogen content

The jet-stabilized combustion chamber systems are extremely versatile and allow their size to be scaled for gaseous fuels, including 100 percent hydrogen. This facilitates their application in different types of gas turbines.
During tests with 40 to 100 percent hydrogen content, the range of operating results underlined the stability of the microturbine. The legal NOx emission requirements are met [1].

Installation detail of the jet-stabilized combustion chamber

Energy efficiency of microturbines

In a combined heat and power application, the micro gas turbines provided with jet-stabilized combustion chamber systems enable a fuel utilization rate of over 90 percent.

Gradual transition to renewable fuels

A microturbine plant with a jet-stabilized combustion chamber system enables breweries to make a gradual transition to renewable fuels without having to change the entire system. This means that breweries can switch flexibly to different fuels.

These include those produced in the brewery itself, such as ethanol and biogases from wastewater treatment or waste recycling. The system can also efficiently process mixtures of these fuels.

Typical installation situation of a microturbine system

Selection of a suitable combined heat and power system

Operational requirements, the type of fuels available and their mixing ratios are decisive for the design, performance and efficiency of the system. It is therefore of great importance that the plant is designed for the brewery’s current and future requirements and for the specific fuel type.

This not only ensures optimal use of the available resources, but also helps to minimize the environmental impact and increase the profitability of the brewery’s operations.

Utilising the energy source from your own operation

Nowadays, as already mentioned, it is also possible to use fuels that result from the production process itself. A notable example of this is the production of non-alcoholic beer, which usually produces ethanol. This ethanol is often left unused or even disposed of at increased cost. In a micro gas turbine, this previously unused ethanol could be converted into valuable high-temperature heat or electrical energy in a resource-efficient manner.

In addition, there is the possibility of using biogas from waste recycling or wastewater treatment as a fuel, which represents a further boost for energy efficiency.

A retrofitted fuel mixing system can provide flexibility in the use of fuels

Reduce dependence on gas supply and achieve climate protection targets

By using micro gas turbine plants with jet-stabilized combustion chamber systems, breweries can significantly reduce their dependence on public gas suppliers and make a decisive contribution to achieving climate protection targets. This means that public gas can be replaced by using the fuels resulting from the production process, regardless of the quantity already available. This also applies to existing plants. The conversion of existing micro gas turbines to jet-stabilized combustion chamber systems and the use of the described fuels and/or their mixtures are possible depending on the manufacturer of the micro gas turbines.

Retrofitting existing systems

The conversion of suitable existing systems is a comparatively simple process that involves replacing the turbine combustion chamber, adapting the turbine software and the fuel supply system. Otherwise, no changes to the turbine, the generator, the recuperator, the exhaust tract or the power electronics of an existing microturbine system are required. If a variable fuel mixture is to be used, a limited fuel mixing device can be added to the existing plant.

Machine translated

This article is based on an article first published in BRAUWELT No. 1, 2024.

Source

1. Assadi, M.; Banihabib, R.; Kutne, P.; Lingstädt, T.; Wersland, M.: „Development and testing of a 100 kW fuel-flexible micro gas turbine running on 100 % hydrogen“, International Journal of Hydrogen Energy, 2023.