Dual vessel chemical modification and heating of wood with optional vapor containment

A commercial-scale process for producing chemically-modified wood, said process comprising:

• (a) loading a quantity of wood into a chemical modification reactor, wherein said quantity of wood weighs at least 500 pounds when loaded into said reactor and wherein said chemical modification reactor defines an internal reactor volume of at least 100 cubic feet;
• (b) chemically modifying at least a portion of said quantity of wood to thereby provide a chemical-wet quantity of wood, wherein said chemical-wet quantity of wood comprises at least one heat-removable chemical component resulting from said chemically modifying;
• (c) transporting at least a portion of said chemical-wet quantity of wood out of said chemical modification reactor and into a microwave heater;
• (d) generating microwave energy with at least one microwave generator;
• (e) passing at least a portion of said microwave energy from said at least one microwave generator, through a microwave distribution system, and into said microwave heater, wherein said microwave distribution system comprises—
• at least one waveguide for transporting said microwave energy from said microwave generator to said microwave heater,
• at least one microwave launcher for discharging said microwave energy into the interior of said microwave heater through at least one uncovered launch opening, and
• at least one barrier assembly entirely disposed outside of said microwave heater between said microwave generator and said microwave launcher,
• wherein said barrier assembly fluidly isolates said microwave heater from an external environment outside said microwave heater while still permitting passage of said microwave energy therethrough, wherein said barrier assembly is configured to minimize arcing therein when said microwave energy passes therethrough at a rate of at least 30 kW and when said pressure within said microwave heater is not more than 350 torr,
• wherein said at least one waveguide includes at least a first waveguide segment and a second waveguide segment, wherein said first waveguide segment is positioned between said microwave generator and said barrier assembly and is configured to propagate microwave energy from said microwave generator to said barrier assembly, and wherein said second waveguide segment is positioned between said barrier assembly and said microwave launcher and is configured to propagate microwave energy from said barrier assembly to said microwave launcher, wherein said first waveguide segment is entirely disposed outside of said microwave heater and wherein said second waveguide is at least partially disposed outside of said microwave heater;
• and
• (f) heating at least a portion of said chemical-wet quantity of wood in said microwave heater under a pressure of not more than 350 torr to thereby vaporize at least a portion of said at least one heat-removable chemical component in said microwave heater to thereby provide a dried quantity of chemically-modified wood.