Mono-ethylene glycol (MEG) is added to natural gas for transport in pipelines to reduce corrosion and for dehydration. The efficient recovery of glycol is a key objective here. This requires systems that operate with low wear and low maintenance. BHS-Sonthofen has developed a fully automated process that meets these demands and reduces the loss of MEG by a factor of 30 compared to the use of sedimentation tanks and decanter centrifuges, even though this process is less expensive.
Efficient glycol recycling is playing an increasingly important role in operating gas pipelines in an environmentally friendly manner. BHS-Sonthofen has developed a new process which recycles significantly more glycol than the processes used previously. As part of the mega gas plant project in Saudi Arabia, BHS was commissioned to design and supply three filter units. The large-scale project was carried out in six phases, from process optimization through to system transport. The entire project is set to be completed by the end of 2019.
The divalent salts are precipitated during MEG regeneration and the solid matter is subsequently removed from the glycol. The innovative process from BHS reduces the glycol loss by using water to displace the glycol remaining in the filter cake.
The process comprises two stages: First the suspension is filtered and pre-thickened in candle filters (CF) from BHS. In the next stage, the thickened suspension is then filtered to form a cake in the BHS pressure plate filter (PF). The filter cake can be easily washed out with water and thus delivers a filter cake that is almost MEG free. The system operates fully automatically. Advantages: Glycol loss is reduced to an absolute minimum, and operating costs are significantly lower compared to the single-stage process.
Candle filters (CF) from BHS-Sonthofen help customers recover significantly more glycol in a single-stage process than with the traditional approach. Compared to cartridges, the total cost of ownership is considerably lower because the candle filters operate fully automatically and require little maintenance. BHS offers candle filter systems with precoating as a complete solution, including engineering, delivery, installation and commissioning.