TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The first and second reactors each independently comprise at least one reactor bed.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The process (I) further comprises: introducing an acetic acid feed stream and a hydrogen feed stream to a vaporizer to produce the acetic acid vapor feed stream; separating at least a portion of the second reactor product in a flasher into a vapor stream and a liquid stream, where a portion of the vapor stream is directly or indirectly recycled as a recycle vapor stream to the first reactor and the second heat exchange stage further comprises heating the recycle vapor stream; and separating at least a portion of the liquid stream in at least one distillation column. In process (I), the first and second heat exchange stages further comprise: heating the acetic acid vapor feed stream prior to being introduced to the first reactor; heating a reboiler stream of a distillation column; heating the acetic acid feed stream; and heating the hydrogen feed stream. The first heating stage further comprises heating the portion of the liquid stream prior to being introduced to the distillation column. The second reactor product is cooled to a temperature that is less than the feed temperature to the first reactor. The process (II) further comprises: feeding the cooled portion of the third residue to the second column; introducing an acetic acid feed stream and hydrogen feed stream to a vaporizer to produce the acetic acid vapor feed stream; transferring the heat of the second distillate to a third heat exchange stage; and transferring heat of the third distillate to a fourth heat exchange stage. In process (II): the first, second and third heat exchange stages further comprise heating the portion of the liquid stream prior to being introduced to the first distillation column; the first heat exchange stage further comprises heating the acetic acid feed stream and the hydrogen feed stream in parallel; the second heat exchange stages further comprises heating the acetic acid feed stream and/or the hydrogen feed stream; and the fourth heat exchange stage further comprises heating the portion of the liquid stream prior to being introduced to the first distillation column, and heating the acetic acid feed stream and/or hydrogen feed stream. EXAMPLE - No suitable example given.