BAAS Senior Project Crane Gas Plant Sergio Helguera

Crane Gas Plant Compression Amine treating Dehydration Cryogenics

Compression The Crane gas plant has 15 compressors 12 are three stage compressors. 1 st stage compresses gas from 5psi to 60psi 2 nd stage compresses gas from 60psi to 250psi 3 rd stage compresses gas from 250psi to 650psi.

Amine System After the gas is compressed it gets treated by amine Lean amine is used to get rid of the CO and H2S that might be in the gas. Lean amine is injected in an amine contactor that strips the H2S and CO The rich amine returns to the amine skid were it is regenerated and becomes lean again.

Dehydration We use two types of dehydration Glycol Mole sieves

Glycol Glycol is used to dry the gas by absorption Lean Glycol is injected in the Glycol contactor were it absorbs the water from the gas. The rich glycol is returned to the glycol skid were it is regenerated and becomes lean again.

Mole Sieves After the gas passes through the Glycol contactor it passes through the Mole Sieves for further dehydration. Here the water is stripped from the gas through adsorption with the filter media in the mole sieves. After the mole sieves become to saturated they are regenerated using residue gas.

4 th stage compression Right before the gas gets to the cryogenics process the gas is compressed again. It reaches a final discharge pressure of about 1050psi. It is compressed to this pressure to get more of a pressure drop in the turbo expander.

Cryogenics After the mole sieves, the gas then heads to the cryogenics skid. The skid consist of different exchangers, reboilers, chillers, and a cold separator. From here it heads to the turbo expander..

Expander The turbo expander has a compressor side and expander side. They work together to get a big pressure drop in the gas going to the demethanizer column.

Demethanizer column The demethanizer column is used to separate methane from heavier gasses This is accomplished by manipulating temperatures and pressures by using the exchangers, reboilers, chillers and separators in the cryogenics skid.

Sales The methane from the demethanizer column is used as regeneration gas for the mole sieves, and fuel gas for the compressors. The excess is sold down the Louis Dryfess pipeline The bottom of the Demethanizer column are sold as NGL’s to El Paso Products.