Agriculture Area Joints and Biogas Production

Water is one of the most valuable natural resources. Therefore, protecting groundwater from pollution is vital for our health, the environment, and agriculture. Agriculture itself is often a source of groundwater pollution from excessive fertilizers, pesticides, or intensive livestock farming.  

Liquid manure from livestock or silage leachate from feed silos contains high concentrations of organic acids and needs to be contained. Agricultural infrastructure is often made of precast concrete elements. Between the concrete panels, there are joints where leakage usually occurs. These joints need to be sealed with a sealant that resists organic acids.

Segmented steel tanks are used for the storage of liquids, treating effluent from industry and mining, and for processing organic waste like sewer or liquid manure, as well as in biogas tanks and digesters.

These tanks are built into segments that are bolted together. The segments must be sealed in the overlapping areas to the base plate to be tight. Sika has been supplying all major manufacturers of segmented steel tanks globally with sealant solutions for decades. As a market leader, we build on this expertise to develop solutions that are more reliable and durable, enabling better processing conditions in the tanks.

Sikaflex®-403 Tank & Silo is a one-part, moisture curing, polyurethane-based elastic sealant. The sealant is the next-generation solution for sealing in tank and silo applications. It shows enhanced stability in liquids containing high concentrations of organic acids such as lactic, butyric, and acetic acids formed during fermentation processes and uric acids found in excrement.

Globally there are big efforts to produce carbon-neutral fuels. Old, efficient, and proven technology is the production of biogas from organic waste, widely available as agricultural effluent, sewer, garden, and food waste.

Depending on the feed and control of the anaerobic digestion in the tank, this can be done mesophilic at temperatures around 37°C or thermophile around 57°C. Sikaflex®-403 Tank & Silo can resist high concentrations of organic acids up to temperatures of 65°C, enabling more efficient biogas production. It is designed to reliably and durably seal movement and connection joints exposed to organic acids found in anaerobic digestion tanks for processing organic waste to biogas. Sikaflex®-403 Tank & Silo is the sealant for a more sustainable future.

Wastewater treatment is a key part of any agglomeration for the health and safety of the inhabitance and the environment. Like agricultural and tank applications, wastewater contains organic waste that produces organic acids during bacteria digestion. Only quality sealants that can stand organic acids will seal the countless joints of the sewer system sustainably. Sikaflex® sealants meet these criteria, offering durability and reliability even in the presence of organic acids.

Polyurethane is the preferred technology for Tank and Silo applications for several reasons:

When exposed to organic acids, common sealants are attacked and degraded as their fillers are dissolved. Sikaflex-403 Tank & Silo has a special designed polymer and resistant filler. The chemical stability in organic acids even at elevated temperatures is amazing.

The test cycle is 180 days (about 6 months) in silage liquid at 40°C followed by 152 days (about 5 months) in silage liquid at 23°C.

We challenged this by storage at 60°C in silage liquid for 180 days (the temperature of thermophilic digestor tanks for highly efficient biogas production) followed by 152 days (about 5 months) in silage liquid at 23°C.

The change of the module when elongated to 60% is measured. The results show no difference in module between 40°C and 60°C and very stable values over the duration of the test.

Sikaflex®-403 Tank & Silo, for reliable and durable sealing!

Resistance Against Silage Liquid at 40°C (Mesophilic) vs. 60 °C (Thermophilic) for 180 Days