Abstract:

The DCPD depolymerization system takes C₉ pyrolysis product as the raw material. Common tubular heat exchanger was used as the feed heater for depolymerization material in the original design, and the consumption of high-temperature heat transfer oil was high. The depolymerization system needed to be shut down for cleaning only after 30 days’ operation due to its coking problem. Combining spiral tube heat exchanger (STHE) technology with spiral plate heat exchanger (SPHE) technology can heat the raw materials separately. Reasonable flow rates and retention time were selected respectively for gas and liquid sections, and high-temperature heat transfer oil was replaced by medium-temperature heat transfer oil. The heat exchanger has been operated for more than four consecutive months without any disassembly and cleaning. This technology has reduced the consumption of heat transfer oil and increased the reaction temperature of material and the product yield.

Key words:  ')">

 , DCPD；depolymerization；high efficiency heat exchanger；operation cycle