New process for preparing high-purity isobutene from tertiary butanol

The invention belongs to the field of chemical industry and relates to a preparation method of basic chemical organic raw material-isobutene, and particularly relates to a new process for preparing high-purity isobutene from tertiary butanol. The new process is used for various production devices for generating the isobutene by carrying out gas-phase catalysis on the tertiary butanol. The new process is characterized by adopting unique vaporization stripping process and structure, selecting the low-content industrial product tertiary butanol as a raw material, being ingeniously combined with an isobutene rectifying tower and achieving the purposes of tertiary butanol recovery and process wastewater separation by directly delivering residual liquid inside the rectifying tower into a vaporization stripping tower. The new process is also characterized in that a crude isobutene product is directly placed into the rectifying tower under the condition without being condensed for purification, and the process flow can achieve further energy conservation on the basis of the vaporization stripping process.