The Triple A Process ( AmbientAminAbsorption ) Optimization of Biogas Upgrading based on Chemical Scrubbing with Amino Acid Salts for Scalable Expansion of Biomethane Production

The production structure of raw biogas in Germany is closely connected with the agricultural structure. As a result, it is characterized by smaller biogas plants (BGAs), which are in a performance class > 250 m³/h STP methane. There are similar economies of scale for the costs of common processing technologies, which are especially small for large factories. The biomethane processing plants therefore have an average capacity of 630 m³ N/h. Therefore, there is a need for new, low-cost, small-scale gas upgrading technologies that can also be easily integrated into farm effluent and circulation systems, that is the aim of this study. To achieve this goal, a biogas upgrading process, based on chemical purification (amino acid salts-scrubber), must be optimized at first in the laboratory stud and then upscaled to pilot plant.
The aim of the Triple-A project is to develop a novel robust and small-scale upgrading process. The so-called Triple-A technology uses amino acids (amine) under ambient conditions for chemical gas scrubbing (absorption). The concept and the scrubbing agent used result in advantages that have positive impacts on the operational process, the economic efficiency, and the implementation potential of the technology: (1) The scrubbing agent should be self-extractable from common biogas substrates such as silages and recycled after consumption in the digester and used for local bioeconomic cycles with short distances. (2) The process flow at ambient conditions allows a simple design with low requirements for plant components, safety and professional operation, low energy demand and thus high potential to reduce costs. (3) These characteristics allow a well scalable and cost-optimized operation for upgrading capacities smaller 250 m³ i.N. h.
Next to the problem and concept of the process as well as the corresponding research, the results of the first screening of solvents and the initial operating an established continuously operating plant will be presented. Also, different possible models for the construction of reactors of pilot plant will be introduced.