摘要:
An optimized system and process for heating wood using a microwave heater. The optimized system/process directs microwave energy towards different regions of the wood at different times during heating. In certain situations, microwave energy is introduced into the heater using microwave launchers and the system includes one or more microwave switches that control distribution of microwave energy to the microwave launchers so that two adjacent and/or opposing microwave launchers do not simultaneously introduce microwave energy into the heater. The optimized heating process also includes heating wood using a plurality of sequential heating cycles carried out at different conditions. For example, at least one of the heating cycles can be carried out at a lower input rate of microwave energy and/or at a lower pressure than one of the previous heating cycles.
摘要:
A microwave heater capable of heating a bundle of wood and equipped with an optimized system for launching and/or dispersing microwave energy. The microwave launching system can include one or more split microwave launchers at least partly disposed in the interior of the heater. The microwave dispersing system can include one or more moving reflectors for rastering microwave energy emitted from the split launchers.
摘要:
A microwave heater capable of heating a bundle of wood and equipped with an optimized system for introducing microwave energy into the heater. The system uses a high-efficiency elongated waveguide launcher having a plurality of launch openings defined in relatively thin walls. The waveguide launcher can exhibit a launch efficiency of at least 50 percent, thereby providing substantially energy savings over conventional waveguide launchers.
摘要:
A commercial scale system and process for chemically modifying wood and then heating the chemically-modified wood. The system/process separates the chemical modification step from the heating step by utilizing two different vessels for the modification and heating steps. The system and process can, in certain situations, include a containment room for preventing escape of vapors from a chemical wood modification reactor, a wood heater, and/or a chemically-modified bundle of wood as the bundle is transported from the wood modification reactor to the wood heater.
摘要:
A microwave heater equipped with a microwave choke and suitable for heating wood under vacuum. The microwave choke inhibits leakage of microwave energy between a door of the heater and a main vessel body of the heater without causing arcing at the choke, even at low pressures. In certain situations, the microwave choke can be configured with side-by-side choke cavities. In certain situations, the microwave choke can be removably coupled to the door and/or vessel body for easier fabrication, installation, and/or replacement.
摘要:
A commercial scale microwave system that includes a heater having enhanced heat distribution and minimized void space. The enhanced heat distribution can be provided by a unique launcher and/or reflector configuration disposed in the interior of the microwave heater. The microwave system can be operated to prevent the wood from both overheating (which results in scorching) and under-heating (which results in inadequate drying and/or inadequate thermal-modification). The microwave heating system can provide enhanced microwave energy distribution for large quantities of wood, even large quantities of wood heated under vacuum and/or in the presence of one or more chemical reagents.
摘要:
A microwave heater capable of heating a bundle of wood and equipped with an optimized system for introducing microwave energy into the heater is provided. Also provided is an enhanced system for launching and dispersing within the heater. The system uses one or more TMab microwave launchers to emit microwave energy in the interior of the microwave heater in a TMab mode, where a is 0 and b is an integer between 1 and 5. The TMab launchers can be configured to emit microwave energy through an open outlet that faces generally parallel to the nearest wall of the heater. In certain situations, it can be advantageous to use at least two TMab microwave launchers having open outlets that face towards one another. In certain situations, it can be advantageous to use at least two TMab microwave launchers located on generally opposite sides of the microwave heater. In certain situations, the system can also include one or more moving reflectors for dispersing microwave energy emitted from the TMab microwave launchers.
摘要:
A microwave heater capable of heating a bundle of wood and equipped with an optimized system for launching and/or dispersing microwave energy. The microwave launching system can include one or more split microwave launchers at least partly disposed in the interior of the heater. The microwave dispersing system can include one or more moving reflectors for rastering microwave energy emitted from the split launchers.
摘要:
Disclosed is process for the production of symmetrical fluoro-substituted anhydrides from mixed or unsymmetrical anhydrides, i.e., wherein the two carboxylic acid acyl groups of the anhydrides are different, by subjecting an unsymmetrical anhydrides to reactive distillation to produce a lower boiling product comprising a symmetrical fluorocarboxylic acid anhydride and a higher boiling product comprising a second symmetrical anhydride. The process is particularly useful for the coproduction of trifluoroacetic anhydride (TFAA) and acetic anhydride (Ac2O) from ketene and trifluoroacetic acid wherein ketene and trifluoroacetic acid (TFA) are reacted to produce a mixed anhydride, acetyl trifluoroacetate (Ac-TFA), which then is subjected to reactive distillation to produce a vapor product comprising TFAA and a liquid product comprising Ac2O.
摘要:
A process for recovering a desired organic acid from a solution includes the steps of: providing an aqueous solution including at least one desired organic acid or its acid anion; adjusting the proton concentration in the aqueous solution to a desired level, with the desired proton concentration being selected, at least in part, by the amount of available protons needed to associate with the acid anions of the desired organic acid(s) to be recovered and/or acid anions that are weaker than the desired organic acids; and recovering at least a portion of the at least one desired organic acid from the aqueous phase. The desired proton concentration can be based on the amount of available protons being greater than, less than or substantially equal, to the amount of protons needed to associate with the anion of the desired organic acid(s) and acid anions that are weaker than the desired organic acid(s). Specific examples of suitable organic acids include, but are not limited to, ascorbic, succinic, tartaric, glyconic, gulonic, citric, lactic, hialic, maleic, acetic, formic, gluconic pyruvic, propionic, butyric, itaconic acids and mixtures thereof. One embodiment of the present invention relates to the recovery of 2-keto-L-gulonic acid (KLG) from aqueous solutions such as fermentation baths.