With the recent upward, albeit gradual, trend in oil prices, a degree of cautious optimism has returned to the oil industry. Last week, oil climbed above $50/bbl and the US rig count was up for the sixth straight week. If Boston-based Gradiant has its way, its deployment of mobile evaporators may soon be another metric used to gauge exploration and production activity.
Since it was founded four years ago, the company has focused on treating produced water. Its initial product was a humidification-dehumidificatiosystem based on its proprietary CGE (carrier gas extraction) process to concentrate brine while producing high quality distillate for reuse. The company has since expanded its product line to include other physical/chemical and membrane processes. However, its newest product harkens back to the company’s original CGE technology.
Gradiant’s new mobile brine concentration process employs a multi-stage bubble column evaporator—the humidificatin step of its CGE process—to concentrate brine. Rather than condensing the resulting pure water vapor—the dehumidificationstep of the CGE process—the vapor is simply vented to the atmosphere.
The trailer-mounted evaporator is available in 500 bbl/d and 1,000 bbl/d (80 and 160 m3/d) capacities that can concentrate the feed water to the saturation of salt, typically between 260,000 and 300,000 ppm, depending on water’s calcium:sodium ratio. The units are fully self-contained and require only electricity, gas and instrument air. They can be operated remotely, and include an automated clean-in-place function using a proprietary blend of ligand and catalyst.
Gradiant CTO Prakash Govindan told WDR, “One mobile bubble column evaporator has already been deployed in the Marcellus [Shale formation]. The unit was permitted by the Pennsylvania Department of Environmental Protection, which is particularly strict in regulating emissions. We expect to deliver four to six more over the next three quarters, and we’ve seen a lot of interest in Oklahoma, where there are concerns over seismic activity with deep well injection.”