Method and apparatus for destruction of volatile organic compound flows of varying concentration

An apparatus comprising:

• a gas stream containing volatile organic compound;
• a flameless, non-catalytic oxidizer having a gas inlet port in flow communication with the gas stream, a gas outlet port, and a matrix bed of non-catalytic, heat-resistant material located between the inlet port and the outlet port and comprising an upstream side in flow communication with the inlet port and a downstream side in flow communication with the outlet port;
• a catalytic oxidizer having an inlet and an outlet wherein the inlet is in flow communication with the downstream side of the matrix bed through a connection;
• means for selectively adding fuel and air to the flow on the upstream side of the matrix bed;
• means for selectively adding air to the flow between the downstream side of the matrix bed and the inlet to the catalytic oxidizer;
• a bypass conduit providing direct flow communication between the gas stream and the inlet of the catalytic oxidizer;
• and
• a control system controlling each of the amount of the gas stream delivered to the flameless, non-catalytic oxidizer, the amount of the gas stream diverted through the bypass conduit directly to the catalytic oxidizer, the amount of fuel or air added to the flow on the upstream side of the matrix bed, and the amount of air added to the flow between the downstream side of the matrix bed and the inlet to the catalytic oxidizer.

An apparatus for destruction of volatile organic compounds comprising:

• a source of one or more gas streams having uncontrolled volatile organic compound content;
• a flameless, non-catalytic oxidizer having:
• (a) an inlet port in flow communication with the gas stream source;
• (b) an outlet port;
• and
• (c) a section located between the inlet port and the outlet port including a matrix bed of non-catalytic, heat-resistant material comprising an upstream side in flow communication with the inlet port and a downstream side in flow communication with the outlet port;
• a catalytic oxidizer containing catalyst and having an inlet and an outlet;
• a connection between the outlet port of the flameless, non-catalytic oxidizer and the inlet of the catalytic oxidizer such that the downstream side of the matrix bed is in flow communication with the catalytic oxidizer;
• a preheater capable of preheating the matrix bed to a temperature above the autoignition temperature of the volatile organic compounds in the one or more gas streams;
• means for selectively adding supplemental fuel and air to the flow on the upstream side of the matrix bed;
• means for selectively adding air to the flow in the connection;
• a control means that controls the amount of supplemental fuel and air added to the flow on the upstream side of the matrix bed so that the temperature within the hottest portion of the matrix bed is maintained between about 1400.degree. F. (760.degree. C.) and about 3500.degree. F. (1925.degree. C.);
• a second control means that controls the amount of air added to the flow in the connection so that the temperature at the outlet of the catalytic oxidizer is maintained below the thermal, deactivation temperature of the catalyst;
• a bypass conduit directly connecting the connection to the source of one or more gas streams such that the one or more gas streams are in direct flow communication with the inlet of the catalytic oxidizer wherein the bypass conduit and the means for selectively adding air to the low in the connection are configured to inject any gas streams and air at a plurality of points around the circumference of the connection prior to the entry of such flows into the catalytic oxidizer;
• and
• a control system for selectively controlling the amount of the one or more gas streams delivered to the flameless, non-catalytic oxidizer and the amount diverted through the bypass conduit directly to the catalytic oxidizer, wherein the control system selectively delivers the one or more gas streams depending upon the concentration of VOC's in the one or more gas streams as determined from temperatures sensed within the matrix bed or connection by one or more temperature sensors.