Knowledge Base

Liquid feedstock is an organic input material with a low dry matter content that is pumpable and flows freely into an anaerobic digester. Examples include liquid manure, de-packaged food waste, glycerin, and flotation sludge. Because it can be pumped directly, liquid feedstock is typically received and stored in liquid storage tanks before being dosed into the digester.

What is liquid feedstock?

Liquid feedstock is an organic input material with a low dry matter content that flows and pumps easily, unlike solid or fibrous feedstocks that need mechanical feeding equipment. Common examples include liquid manure, de-packaged food waste, glycerin, and flotation sludge.

HoSt receives and stores these liquid products in HoSt Liquid Storage® tanks-underground/above-ground tanks (concrete or steel) and/or polyester silos, which can be heated or unheated depending on the feedstock and climate, before pumping them into the digester using pumping technology suited to the specific input material. Larger particles that may still be present in the liquid stream are removed upstream by the HoSt Filter Basket®, protecting pumps and other equipment. Once inside the digester, liquid feedstock is kept in motion by mixers such as the HoSt PropMix® and HoSt SpiralMix®, which are particularly effective at lower dry matter content, supporting a stable, biologically active digestion process.

Some liquid feedstocks release odours and can generate hydrogen sulphide (H₂S), which is toxic and corrosive, so storage and handling are designed to contain emissions and protect personnel and equipment. Enclosed tanks, controlled venting, and suitable material choices help manage odour, corrosion, and gas safety across the storage and feeding system.