The image below shows the feeding-section of our gasification reactor being hoisted into place by All Star Crane Company of Riverside, CA. The gasifier spool-sections were bolted together on the ground in groups of three or four sections, so the crane could easily lift the sections into place. I learned this construction technique — using short spool-sections that bolt together — for pilot-plant applications back in the day at EER (Energy and Environmental Research Corporation, now GE Global Research, Irvine).
We typically use this method for pilot-plant construction because of the flexibility provided when reconfiguring the reactor, to repair or change conditions for example. Note that each spool-section is lined internally with 6-inches of high-temperature castable-refractory — an inner lining using 3″ of insulating material with low density (70 lbs/ft3), and an outer 3″ layer of hard-face high-density refractory (140 lbs/ft3) that is abrasion resistant and good to about 3000 F.