Mobile Process Engineering and Demonstration Unit
PNNL has a special facility available for onsite industrial testing of chemical processing systems. It is a trailer-mounted system with a complete continuous-flow high-pressure processing system including pumps, heat exchangers, and feed and product tanks. It is fully instrumented and has a computer-controlled data acquisition system. In addition, the trailer contains a control and analytical chemistry compartment for complete process management.
The processing system is designed to run at 60 gallons per day of feed. It has a positive-displacement reciprocating pump operable at up to 5000 psig fed from a 50 gallon, stirred feed tank. It has four 1.5-inch ID by 3.5 foot tall fixed-bed catalytic reactor tubes operable at up to 365°C and 3500 psig, each about 1 liter volume. Heat recovery is via a tube-in-tube heat exchanger and heat makeup is provided in a coiled tube heated by an electrical resistance furnace. Back-up product cooldown is accomplished with a forced air fan. Pressure is maintained in the reactor system by a back-pressure regulator. After pressure letdown, gas and liquid products enter a separator/liquid product tank from which gas products are vented. The system is 300 series stainless steel throughout.
This unit was originally designed for the catalytic gasification of organics in water. It has been used in onsite demonstrations in New York and Texas for treatment of organic contaminated wastewater from chemical production plants. The system was able to effectively process organics into a mixed product gas of methane and carbon dioxide while producing a relatively clean water stream with less than 1 g per kg of residual COD (chemical oxygen demand). In both cases, the unit was shipped to the processing plant, set up and operated for two weeks, shutdown and returned home. For such processing, the unit requires minimal setup. It has a single 480-volt input line. Feedstock is delivered to the unit in drums and pumped into the feedtank. The product gas is vented and the product liquids drained to storage drums.