BIOCH4NGE®

BIOCH4NGE® is the AB solution for biogas-to-RNG upgrading through a membrane system: flexibility, scalability and low energy consumption for a real competitive advantage.

The operating process of BIOCH4NGE® starts with purifying the biogas coming from the anaerobic digestor, loaded with water and pollutants. The filtered and dehumidified gas is compressed, cooled and sent to the next treatment step.

By passing through a bed of activated charcoal, the biogas is purified of the pollutants. The charcoal configuration, in the "Lead-Lag" version, includes a series of valves that allow the inversion of flows, the bypass and the sectioning of the single filter, thus ensuring flexibility, reliability and continuity of service.

The pretreated and purified biogas is ready for the actual upgrading, i.e. the separation of methane from carbon dioxide. The process is optimized in terms of consumption and allows obtaining a biomethane with the desired characteristics for different uses, maximizing the recovery efficiency of CH₄ from the biogas.

Among the available RNG upgrading technologies, AB has chosen the membrane system, the most widespread and used in the world. The membranes are made up of particular polymeric materials that have a selective permeability for separating CH₄ and CO₂.

The pretreated gas is compressed in several phases and sent to different stages of membranes in order to optimize their operation and to ensure scalability. Two stages in series ensure compliance with network specifications while a third stage is dedicated to optimizing the recovery of methane and at the same time to limiting its emission into the atmosphere.

Thanks to the independent compression management, the control system is able to modulate the operating pressures of the separation stages and guarantee the required performance with the lowest possible energy consumption. The process takes place without intermediate stages and without the use of chemicals or consumables.

The high flexibility given by the operation, adjustable even with a partial load, combines with the economic savings related to the system, even for medium-small sizes.

BIOCH4NGE® is available in standardised units from 50 to 1,500 Nm³/h, complete with pre-treatment systems that can be used with existing biogas plants and integrated with possible extensions linked to the liquefaction of gas and the exploitation of CO₂. Solutions of different sizes can be “tailor-made”.