Oil refining capacity is increasing worldwide to meet rising needs for energy and chemical products.
Gas compressors are used extensively in refinery process units, including hydrocracking, hydrotreating, diesel desulfurization, gasoline desulfurization, CCR (continuous catalytic reforming), FCC (fluid catalytic cracking), delayed coking, hydrogen plants, PSA (pressure swing adsorption), SMR (steam methane reforming), flare gas recovery and more.
The primary gas to be compressed in refinery process units is hydrogen (H2).
For high-pressure hydrogen service [> 100 barg (1,500 psig)], such as hydrocracking, reciprocating compressors are used for make-up gas service and centrifugal compressors are typically employed for recycle gas service.
For mid-pressure hydrogen service [< 100 barg (1,500 psig)], such as hydrotreating, gasoline/diesel desulfurization and CCR processes, oil-injected screw compressors are often used. Their high reliability, low maintenance and longer continuous operation are key advantages. Kobelco screw compressors also offer significant power savings because of their built-in, stepless unloading system (called a "slide valve"), which accommodates changing operating conditions and provides environmental benefits.
For hydrogen plant, PSA and SMR services, oil-injected screw compressors are most often used because the lubricant acts as a sealant and keeps the gas from escaping.
For heavier gas, dirty gas and difficult gas (such as heavy hydrocarbons), oil-free screw compressors are required. These positive-displacement type compressors eliminate concerns regarding gas and oil contamination because there is no lubricant in the compressor chamber. Oil-free screw compressors easily and reliably compress any gas, such as FCC wet gas, coker gas and flare/vent/off gas.
Kobelco has considerable expertise with all types of process gas compressors (reciprocating, centrifugal and screw), providing a single source of compression solutions for all refinery processes.