Refining Processes Handbook
Filled with handy process flow diagrams, this comprehensive reference covers the technologies and operations of petroleum refineries and provides material on operating a jointly owned and operated refinery.
TABLE OF CONTENTS Refining Processes Handbook
Chapter Five: Hydrogen Production and Recovery
Hydrogen is required in refineries for a large number of hydrotreating and hydrocracking processes, to remove sulfur, nitrogen, and other impurities from hydrotreater feed and to hydrocrack the heavier gas oils to distillates. A limited quantity of hydrogen is produced in the catalytic reforming of naphthas, but generally the quantity is insufficient to meet the requirements of hydrocracker and hydrotreating units. As hydrogen production is capital intensive, it is always economical to recover hydrogen from low-purity hydrogen streams emanating from hydrotreating and hydrocracking units and minimize production from hydrogen units. In the absence of hydrogen recovery, these streams end up in fuel gas or sent to flare.
Most refinery hydrogen is produced by the steam reforming of natural gas. The conventional hydrogen production in the refineries involve the following steps: natural gas desulfurization, steam reforming, high- and low-temperature shift conversion and trace CO and CO 2 removal by methanation.
NATURAL GAS DESULFURIZATION
Compressed natural gas at 110 F and 480 psig, after passing through knockout (K.O.) drum V-101, flows to the bottom of sulfinol absorber C-101 (see Figure 5 1). Here, the gas is treated with sulfinol solvent flowing down from the top to remove most of the H 2S and CO 2 contained in the feed. The treated gas, which contain less than 1 ppmw H 2S, passes through knockout drum V-102 and is washed with water in C-102 to remove any traces of the sulfinol solvent. The sulfinol solvent is regenerated in sulfinol regeneration column C-103...
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