Acid wash color

To meet acid wash color specifications, stabilizer bottoms are passed through a fixed-bed clay treater, then distilled (4) to produce the desired specification benzene. The cryogenic purification of recycle hydrogen to reduce the make-up hydrogen requirement is optional (6). 

ASTM D 848-97. Standard test method for acid wash color of industrial aromatic hydrocarbons. 

The benzene process is designed to produce high-purity benzene and heavy aromatics from a mixture of toluene and heavier aromatics (Figure 11-1). Heated hydrogen and feedstock are (1) passed over a special catalyst bed that reacts to form a mixture of benzene, unreacted toluene, xylene, and heavy aromatics. This mixture is (2) condensed in a drum and (3) stabilized. Stabilized bottoms are sent to a fixed-bed clay treater for acid wash color specifications and then (4) distilled to separate benzene, xylenes, toluene, and C9-i- aromatics. 

Cetane quality of diesel fuels 0848, Acid wash color of aromatics X X ... 

Acid Wash Color of Industrial Aromatic Hydrocarbons ... 

This test method covers the determination of the acid wash color of benzene, toluene, xylenes, refined solvent naphthas, and similar industrial aromatic hydrocarbons. 

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