Oil Refineries to Test Sensor Tags

By Beth Bacheldor

The facilities will outfit oil tanks and cooling fans with sensor-enabled active RFID tags that can create a wireless mesh network to communicate data and initiate appropriate actions.

MachineTalker, a maker of active RFID tags designed to serve as wireless network nodes, has partnered with Sense-Comm Technology, a developer, distributor and integrator of wireless sensor networks, to test a network of intelligent RFID-enabled tags at several large oil refineries. The companies are hoping the system will provide an easier method to collect and automatically act on a variety of critical information from tanks, machinery and other equipment out in the field.

The system uses iRFID (Intelligent Radio Frequency Identification) active tags with integrated on-board sensors for measuring temperature, battery level, vibration, light or other conditions. The tags operate at 900 MHz, communicating via a proprietary air-interface protocol. When in proximity with other iRFID tags, they automatically form a wireless mesh network to communicate sensor data among themselves. Operators can access and program the devices via a Java application-programming interface (API).

"The best way to view this is that we have developed an approach where a wireless device with a processor in it can be used as a proxy, or representative, to whatever it is attached to," says Roland Bryan, MachineTalker's president and CEO. "It is an intelligent device that, if attached to a shipping container, could have a shipping manifest, as well as sensors, monitoring the container."

The iRFID tags are sealed in a plastic encasement measuring 8 inches by 2.3 inches by 1 inch. Using a built-in whip antenna to transit and receive RF signals, the devices provide a communication range of 200 meters in free (unobstructed) air. When a group of iRFID tags are transmitting signals within range of each other, they can form a wireless mesh network (mesh network allows for continuous connections and reconfiguration by "hopping" from node to node). Depending on how the devices are implemented, one can be configured with an access point able to communicate with other data systems, via either Wi-Fi or wired networking protocols.

Sense-Comm is designing three different pilots using the i-Sense Talker, a version of the iRFID tag containing sensors different from those normally embedded in the iRFID tag. This is being done for three separate refineries, says Mikell Becker, the company's president, though he declines to name the refineries, which have asked not to be identified at this juncture. All three pilots are slated to commence in March.

In the first pilot, scheduled to be held at a Houston refinery, the i-Sense Talkers will incorporate sensors that rely on radar technology to sense the level of oil in two groups of tanks consisting of five tanks apiece. An i-Sense Talker device will be deployed on each of the 10 tanks, with each group communicating with an access point affixed to a small building or input-output (IO) point. According to Becker, the Houston refinery has more than 200 tanks. Such facilities typically have IO points scattered throughout. These IO points serve as mini control rooms that collect data from numerous field controls and relay that data back to a central control room used by the refinery to monitor its operations.

Generally, fluid levels in tanks are monitored by a mechanical gauge that must be manually checked. At other times, the levels are collected by dipping a wired sensor down into the tank. Neither solution is optimal, however, Becker says. "Because these are very hazardous areas, it is very expensive to do this with wires, or manual checks," he explains.

In the second pilot, at a refinery in Northern California, the i-Sense Talkers will include motion sensors to monitor the vibration levels of large cooling fans used in the oil-refining processes.

The goal, says Becker, will be to check the vibration metrics collected by the sensors against a benchmark representing optimal vibrations that is stored in the i-Sense Talker's memory. "Anytime there is an excursion outside of that range," Becker states, "[i-Sense Talker] will take an action, such as someone being notified. If [the measurement] is radical enough, the device could turn off the fan."

The third pilot, currently in development at yet another refinery, will monitor and facilitate the mixing of different crude oil levels during the formation of gasoline, using either a sensor that monitors fluid viscosity, or one able to track fluid levels. "This third pilot is still in discussion as to what sensors and processes to use," says Becker.

All three pilots are slated to run for three months, then be expanded to include additional RFID-based sensors, as well as possibly tighter integration with the refineries' distributed control systems. "Safety is a very critical issue," Becker explains. "If you were to have to shut down a process, it could cost hundreds of thousands or millions of dollars an hour, so everything has to be tested and retested vigorously before you let a machine-to-machine process take over."

Both Becker and Bryan say the RFID-enabled intelligent devices they are developing have great promise for a variety of applications. In fact, MachineTalker's technology has already been tested by LogConGroup, a logistics consulting firm that is employing the devices in a logistics pilot for the U.S. Army Garrison Rock Island Arsenal.

An iRFID-based device is entirely different than current RFID tags on the market, Becker notes, adding, "While it can be made to talk to an RFID reader, it has so much more capability. I think you are going to see these types of devices supersede current RFID tags. There is a cost issue that arises because they are more expensive, but the capabilities for logistics and process control and enhancement of or assurance of something being delivered far exceeds the capabilities of current RFID devices."