Two related but fundamentally different burner-based catalyst evaluation systems has been invented and developed by SwRI®. The first system developed is referred to as FOCAS. FOCAS is a stoichiometric burner in which the full flow of exhaust is passed through the burner and the exhaust temperature is controlled by a water cooled heat exchanger. FOCAS is predominantly used for catalyst aging activities.
The FOCAS Hot Gas Transient Reactor (HGTR®) bench, is a high flow, diesel-fueled, burner-based catalyst performance evaluation and aging system which expands on the capabilities of the SwRI FOCAS burner technologies. The HGTR is a burner-based, fully transient continuous flow reactor system designed to accommodate full size truck catalysts and enable transient engine simulation. The HGTR is predominantly used for catalyst performance evaluation, mapping and screening, engine/catalyst calibration integration, engine cycle simulation and engine calibration development for catalyst system performance. The HGTR is also capable of providing catalyst aging activities.
HGTR Reactor System
The FOCAS HGTR bench is a computer-controlled diesel fuelled, burner-based full flow reactor system designed to simulate the lean exhaust conditions produced by a medium-duty to line-haul truck size engine. The HGTR is the first fully transient, full size reactor type system and is typically used for performing catalyst control development and screening. Unlike a typical small core gas reactor which use bottled gas to simulate exhaust conditions, the HGTR produces a continuous exhaust flow through combustion of fuels and compounds, producing an exhaust gas composition that more closely simulates the species found from the combustion of fuels in an engine. The exhaust gas conditions are generated through independent, model-based control and allow any combination of flow, temperature, NOX, HC, H2O and O2 concentration within its window of operation. The system is fully capable of transient control of all independent variables, allowing for simulation of any transient engine emission test cycle (such as the heavy duty FTP) as well as producing any combination of exhaust variables. This feature enables the reactor to be used for calibration, full dimensional mapping, control model calibration and strategy development on full-sized parts.
HGTR sales and services are provided through SwRI. FOCAS HGTR is a modular test stand that is available in varying levels of complexity. Capability builds as the system level is increased above the base level. Tables 1-4 described the varying levels of the complete system. Future capabilities will be available as add-on features. Please contact us for more information. FOCAS sales and service are provided through our licensed service provider in Taylor, Mi.
FOCAS Catalyst Aging Systems
Burner-based catalyst aging allows independent control of thermal effects and the effects caused by lubrication oil poisoning. Unlike engine-based aging, where oil consumption is inherent to engine operation and changes with engine wear, the FOCAS system consumes no oil during fuel-air combustion. Lube oil may be injected into the hot combustion products with a metering and measurement system. This process allows the user to age catalysts with or without oil poisoning effects.
Catalyst aging temperature is precisely controlled with less variation and to higher extremes than can be obtained from an engine based system. The burner based system is not susceptible to engine related failure modes that can cause misfires and uncontrolled catalyst exotherms. This translates into fewer failures of expensive prototype catalysts.