An entrant for FieldComm Group’s 2018 Plant of the Year Award, Natural Soda produces sodium bicarbonate from its extensive nahcolite leases, which cover more than 9,400 acres at our processing facility located in the Piceance Creek Basin in Colorado. The Piceance Creek Basin contains North America’s only known significant deposit of nahcolite and Natural Soda is currently the only company taking advantage of this world-class resource.
Natural Soda mines nahcolite using solution mining, a technique that drills pairs of wells into the mineral-bearing layer 1,900 feet below ground. Steam is injected via one well, and saturated nahcolite solution is pumped out of the other for further processing.
The original Natural Soda facility was built in 1990 with the capacity to produce 60,000 tons per annum (tpa) of feed-grade product to be sold domestically. Expansion in 1996 increased capacity to 125,000 tpa. In March 2013, Natural Soda completed construction of an additional production train, increasing annual production from 125,000 tpa to 250,000 tpa. The production site has grown in multiple ways: increasing production has meant adding new well pairs and the requirements for the amount of data collected has also increased. This has meant more instrumentation at each well.
Given the high cost of wiring for the additional instruments and reaching new injection wells progressively farther from the central facility, Natural Soda adopted WirelessHART for all of its wellheads. With the most recent expansions, the company has now deployed 60 wireless instruments across 10 wellheads.
Wireless transmitters make it possible to monitor remote injection wells to protect the environment, increase efficiency, and improve productivity. Natural Soda’s operating permits with the U.S. Bureau of Land Management (BLM) requires continuous monitoring and recording of fluid temperature, pressure, and flow rate in both the recovery and injection wells. Operators must also keep these parameters within specified ranges as detailed in a BLM-approved mine plan.
To help handle the distance on some legs in its WirelessHART network, which can be as long as one mile, Natural Soda added eight Rosemount 702 transmitters as repeaters. Instructions from the Emerson DeltaV process automation system to control valves at the wellheads are sent as serial data via a 900 MHz point-to-point licensed system. This radio system runs in parallel with the WirelessHART network as it brings data in from the field instruments. Until recently, the Emerson 1420 WirelessHART gateway and the 900 MHz radio both connected to the DeltaV system through a two-port RS232 serial I/O card.
As Natural Soda engineers were planning the most recent site expansion, they realized the capacity of their I/O card was already at maximum, which left them trying to figure out how to add more control valves. The solution proved easier than expected. The original WirelessHART gateway was replaced with a Wireless I/O Card (WIOC). The WIOC was installed in one of the site’s Distributed Control System (DCS) racks. It receives WirelessHART data and transfers it to the DCS. Functioning as both a gateway and I/O node for up to 100 wireless devices, the WIOC was employed at a fraction of the cost of hard wiring, and was easily installed within the required timeline. This simple change provided additional capacity to support future expansions.
Performance of the WirelessHART network has been flawless, and over five years, Natural Soda has only had to replace the power module on three wireless devices, even when running with 4- to 8-second update rates. In addition to performing required control and monitoring at a much lower cost, Natural Soda is able to provide reports to the BLM and show it is working within the required parameters.
Some of Natural Soda’s future plans call for installation of asset management software to enhance troubleshooting, including pump and motor health management.
For more information about the Plant of the Year award, please visit the FieldComm Group website.
