BTA® Process for mechanical biological waste treatment
The BTA® Process is the original of wet mechanical pre-treatment of waste. It comprises two central steps:
- the BTA® Hydromechanical Pre-treatment
- the subsequent anaerobic digestion of the cleaned organic suspension
BTA® Hydromechanical Pre-Treatment
The BTA® Hydromechanical Pre-treatment facilitates efficient removal of impurities as well as complete transfer of digestible organic components into an organic suspension for further anaerobic digestion. This happens within two core components, the BTA® Waste Pulper and the BTA® Grit Removal System.
The BTA® Waste Pulper - optimum separation into fractions
Within the BTA® Waste Pulper the feedstock is added to pre-filled process water in order to separate the waste mixture into fractions by taking advantage of natural buoyancy and sedimentation forces. Moreover, non-soluble organic components are reduced to fibers by shearing forces and brought into suspension. Thus, heavy materials are fed aside and light materials are skimmed off. In total, three fractions are effectively separated.
- Digestible organic materials
- Light fraction: plastics, foil, textile, wood, etc.
- Heavyfraction: stone, bones, batteries, etc.
The BTA® Grit Removal System - no silting up of the fermenter
Having passed the BTA® Waste Pulper, the organic suspension still contains sand and fine impurities, which are safely removed by the BTA® Grit Removal System. The efficient sand removal reliably ensures protection of downstream plant components from wear, silting up, sediments, and obstruction.
Wet mechanical pre-treatment is the most efficient and successful way to process wastes before the anaerobic biogas production.
Anaerobic digestion of the organic fraction of waste
The cleared organic suspension is temporarily stored in a suspension tank. This way, the processing stage is decoupled from the digestion itself, keeping the latter independent from the working cycle of the waste reception unit.
The organic fraction is digested within the fermenter, generally under mesophilic conditions between 35 - 38°C. Fermenter layout and operation mode depend on the kind of feedstock as well as on project-specific requirements concerning microbiological breakdown and biogas yield.
Exploiting synergies: fermenter agitation through biogas
In practice, stirring of the fermenter ist often hampered with great problems for many systems. The BTA® Waste Pre-Treatment ensures an almost impurity-free organic suspension at high homogeneity. Therefore, by pressing in biogas it is possible to keep the fermenter load homogenous, which brings about decided advantages.
- Safe agitation of the entire fermenter volume
- High utilisation of the energy input
- Low susceptibility to faults due to the lack of moving parts within the fermenter and therefore high process security
- No maintenance work required inside the fermenter
- No loss of fermenter volume by sedimentation
Further processing of the digested organic suspension
Further treatment of the digested substrate can be adjusted according to the respective project. Generally, a decanter centrifuge for continuous separation of solids from liquids is employed. The dewatered digestate (ca. 30 % dry matter) is perfectly suitable for its further stabilisation and production of quality compost. In most cases the supernatant is utilised as process water and is retained within the cycle. This results in decreased freshwater consumption.
The BTA® Process - valuable know-how
The core components as well as the BTA® Process as a whole are protected by international patents and trademark rights. Our clients can be assured that the choice for the BTA® Process is the choice for a technology reliable and advanced over decades. Our clients benefit from the original.