A small-scale upgrading solution: SULAGO®
The Sulaway® system is designed to upgrade large-scale amounts of biogas into Renewable Natural Gas (RNG). For smaller capacities, Gazpack introduced the Sulago® system.
The concept behind Sulago® process is to be able to provide smaller, more compact and affordable Sulago® units for small-scale facilities.
Our Sulaway®, as mentioned earlier, was initially built to convert large capacities of biogas to biomethane (>1500 Nm³/h), while on today’s market, for example, India, there is a high demand for small upgrading capacities. Therefore, Gazpack invented Sulago®, thus we can deliver small-scale upgrading solutions according to customer specifications (<1500Nm³/h). However, Sulago® has an appealing CAPEX; OPEX ratio especially when it comes to capacities between 250 Nm³/h- 600 Nm³/h.
The Sulago® system consists of one water separator, one compressor/dryer set, and two Sulafer® filter towers, all of which are stored in one compact storage system. All systems are equipped with a gas leak alarm for safety measures.
For supply to the grid, we need to know the grid pressure required. The package is built in an enclosure with a ventilation system under pressure to avoid odor that will leave the enclosure. Thus, methane slip will not occur, as our package is built in a gas-tight enclosure.
How it works
Below you will find the initial steps of the Sulago® system as follows:
- Step 1: Sour gas passes a dryer-cooler with a filter separator to remove liquid water from the gas.
- Step 2: The gas is entering the first Sulago® tower to absorb the largest portion of H₂S. The second tower takes care of an absorption level of 3 ppmV H₂S.
- Step 3: The compressor is boosting the pressure up to 8 bar and leads it through two membranes.
- Step 4:The first membrane removes the largest CO₂ percentage and permeate it with the surplus of air into the atmosphere. The second membrane brings CO₂ load at spec – 3% into the gas stock.
At any given time, only one Sulago® filter tower will be in operation, actively monitored by an H2S sniffer. The other will be on stand-by mode. When the level of H2S collected reaches the pre-set amount an alarm will be triggered sending a message to the controller. The system will then automatically switch over to the second (stand-by) tower. A signal will also be sent to our head office, notifying us that the saturated tower is ready for regeneration. Regenerable adsorbent, Sulafer®, will be collected and regenerated within our own factory.
In contrast to other systems, which are using active coal, Sulago® is using our own developed Sulafer®. Sulafer® has the capability to regenerate three times without losing the ability to absorb H₂S. However, the cleaning of the absorbent is feasible within our factory. Besides that, Sulafer® has a minimum lifespan of one year, which equals 8000 operating hours.