Recycling options

Energetic

Utilisation as fuel

The energetic use of biomass from paludiculture (paludi biomass) allows the use of heterogeneous stands of stalk-like biomass such as reeds, reed canary grass and sedges. Wood for energy production can also be obtained by growing black alder in coppice. Use as fuel usually has lower quality requirements than material utilisation.

A high calorific value of the biomass combined with high combustion efficiency and the availability of proven firing technology using straw are promising for thermal utilisation. There is a demand and a market for the produced heat and electricity.

Nevertheless, energy production with biomass is a transitional technology that will have to be replaced by material recycling or cascade utilisation (sequential use of leftover resource from previous used substances) in the next decades. Promising material utilisation options exist for paludiculture biomass.

An overview of paludiculture biomass used as a fuel is provided in the brochure “Halmgutartige Festbrennstoffe aus nassen Mooren“ (Stalk-type Solid Fuels from Wet Peatlands).

Substrate for biogas plants

Biogas is produced from the fermentation of organic matter and can be used for heat generation, electricity generation, or as a fuel. In wet fermentation, paludiculture biomass is suitable as a co-substrate in conventional wet fermentation plants, in the form of silage (preserved biomass) or as fresh biomass. Biomass harvested in early summer is suitable for silage, as the contents of easily soluble carbohydrates and proteins are highest then.

In solid-state fermentation, it is also possible to use only paludiculture biomass harvested later. The biogas yield from paludiculture biomass is good but requires significantly longer retention times than corn. Experiments from Weihenstephan-Triesdorf University of Applied Sciences show that the specific biogas yield decreases with increasing age of the biomass, and finely ground biomass tends to provide higher biogas yields. Sometimes additional preparation is required and may include digestion and use of an extruder and agitator. Innovative dry fermenters are currently under development. Verbio AG has been producing natural gas-quality biomethane from 100% straw since 2014.

Synthetic fuels

Synthetic fuels can be produced by converting gases created from the thermo-chemical gasification of biogenic solid fuels. Gasification plants already exist for wood. However, there are not yet well-developed processes and techniques for paludiculture biomass for synthesizing liquid or gaseous biofuels.

Material

Using paludiculture biomass as materials often generates higher value than use for energy. Additionally, material use means carbon is fixed in the product and does not enter the atmosphere. Paludiculture biomass can be produced sustainably, used as an eco product, and is easily disposed of later.

 

Building materials

Cattails and reeds in particular are suitable building materials. Using reeds as a roofing material is a traditional use and is widespread mainly in northern Germany, the Netherlands, Poland, and Denmark, among others. Straight reed 1.4 - 2 m long and 3 - 9 mm thick are suitable for use as roof reed.

Moulding and panels can also be made from reeds and bulrushes. Cattail has an air-filled internal structure and thus is particularly suitable as an insulating material. Additionally, the moisture-regulating properties of cattail contribute to a healthy indoor climate. Cattail can be used as blow-in insulation or in the form of insulation mats. Reed is also suitable for insulation, construction, and insulation boards and meets the highest requirements of fire protection. Reed is also suitable for making insulating plaster supports and can be used in earthen construction. For heat-insulating earthen building materials, the shrinkage behavior and drying time can be reduced by adding reed fibers.

The soft and light wood of the alder is suitable for furniture or construction timber. Depending on the quality, it can be used as wood veneer, wood for solid furniture and interior fittings, or for the production of chipboard, fiberboard and OSB boards.

The company Hiss Reet, for example, offers an extensive range of reed products including thatched roofs, building materials (thermal insulation, shuttering panels, bases for plaster), partition walls, reed as privacy screens, for garden design, as panels to influence room acoustics or in the form of straw screens. Other products using paludiculture products include Typhatechnik and Naparo which are made from reeds.

Factsheets on building materials from paludiculture