Nutrien Dryer Exhaust Challenge

The Challenge

Currently in use across our sites are wet scrubbers or electrostatic precipitators. Both work well at removing small (sub 10 micron) particulates and meeting regulations which require less than 570 mg/drm3 particulate concentration in the final emissions; however we are interested in a technology that uses little or no water, while minimizing equipment size and power consumption as much as reasonably possible.

Context and Background

Concentrated KCl, recovered through flotation, is debrined and sent through a dryer to remove any remaining moisture from the product. The exhaust from these dryers contains fine KCl, NaCl, and insoluble particles, and in some cases HCl gas. The exhaust stream is sent through cyclones to recover of over 95% of the dust. The remaining fine particulates are then sent to a piece of equipment to remove the remainder of the particulates.

Problem Definition

To reduce our environmental footprint, we are in search of a novel piece of equipment that would remove fine particulates from the potash dryer exhaust stream while minimizing water use. The current known methods for particulate collection come with their own drawbacks that we are trying to minimize. Wet scrubbers are high water users, electrostatic precipitators require high CAPEX and maintenance, and baghouses have been tried in the past, but due to the nature of the product as well as residual organics coating the fine particulates, bags are prone to blinding and have proven to be an ineffective option.

Solution Parameter Requirements

The proposed solution should meet the following requirements:

• Commercial readiness is preferred.
• Piloting/or installation in another industrial application is desirable.
• Proposed design that can be piloted at a facility.
• Design Parameters: Temperature: 200C, Inlet particulate concentration (estimate): 7,000 mg/drm3, 500 kg/hr, Required Outlet Particulate Concentration: < 200 mg/drm3, Particulate Sizing: d50 5 micron.
• Ability for equipment to resist a high chloride environment.
• Will be retrofitted inside existing facilities.
• The solution provider is willing to work with Nutrien to support technology troubleshooting while in service.