Patent ID: 7968756

Claim:
A process of manufacturing vinyl chloride monomers, comprising: cracking an ethylene dichloride feedstock in a pyrolysis furnace by feeding the feedstock through at least one heated process tube having first and second ends with an internal surface defining an interior space having a thermal protective layer disposed thereon, the thermal protective layer containing a. from about 5% to about 30% of an inorganic adhesive, from about 45% to about 92% of a filler, and from about 1% to about 20% of one or more emissivity agents, or b. from about 5% to about 35% of colloidal silica, colloidal alumina, or combinations thereof; from about 23% to about 79% of a filler, from about 1% to about 20% of one or more emissivity agents.