360 likes | 702 Views
Gas Treatment Plant. Chris, Stephanie, Kyle, Mariam Mentor: Jerry Palmer . Outline. 1. Block Flow diagram 2. Mass Balance 2. Liquid Knockout 3. Sour Gas Treatments 4. Gas Dehydration 5. NGL Recovery and CO2 Removal 6. NGL Stabilization 7. Inert Removal-N2
E N D
Gas Treatment Plant Chris, Stephanie, Kyle, Mariam Mentor: Jerry Palmer
Outline 1. Block Flow diagram 2. Mass Balance 2. Liquid Knockout 3. Sour Gas Treatments 4. Gas Dehydration 5. NGL Recovery and CO2 Removal 6. NGL Stabilization 7. Inert Removal-N2 8. Equipment Cost 9. Capital Cost 10. Revenues 11. Sample Calculations 12. Question & Answer
Liquid Knockout 3- Horizontal Tanks and decreasing temperature and pressure. In a dynamic refinery environment it is important to have the capability to compensate for a surge of liquids and take out any non-volatile components which will cause issues in the future separation processes. 3 tanks are used because its the most efficient setup for large scale processes.
Why LO-CAT II? -System Stability -Ease of operation and Catalyst consumption -Chemical Cost is roughly 1/2 to 1/3 of a Sulferox Unit -Uses a Patented chelate system that is more resistant to Oxidation
Gas Dehydration & CO2 Rejection The methods of dehydration looked into are lean gas absorption, adsorption and membrane separation.
NGL Recovery Mechanical Refrigeration Plant: - limited to -24 to -40 F - only 60% propane Lean oil absorption: - 40% ethane - 90% propane - 100% heavier hydrocarbons - Heating and cooling required - High operating cost Turboexpander: - 60-90% ethane - 90-98% propane -100% of heavier hydrocarbons - Since high percent ethane recovery is needed, this is the most economical way
NGL Stabilization • NGL's need to be stabilized to a point that it can be stored and transported in non-pressurized vessels. • Enhances the safety in handling, and improving the liquid's marketability. • Stabilizing the liquid reduces the volatility.
Inert Removal-N2 Available options are cryogenic distillation, membrane separation and PSA. Cryogenic distillation has been selected on the basis that is very efficient for large scale separation facilities. Additionally because LNG is being produced in the following stage its worthwhile to expend the energy to process the methane.
LNG Production • LNG is produced under very low temperatures. • Effective for transportation of natural gas over long distances. • Safer than transporting compressed natural gas in vehicles because LNG is comparably low in pressure.
Estimated Capital Cost Amine Treating cost for 5% acid gas removal $10.0MM Dehydration cost $1.0MM Compression cost (7000hp x $1400/hp) $9.8MM Cryogenic NGL recovery cost $23.0MM Liquid-Redox Sulfur Recovery at 5 T/d $4.0MM Total cost of components $47.88MM Other costs and Contingency @ 30% $14.3MM Total Estimate Plant Cost $62.1MM -Based on a Natural Gas Treatment Facility that processes 100 MMscfd. -Prices based in 2008 and do not account for inflation. Employee payroll with fringe benefits $3.5MM/year
Revenues • Natural Gas: 300 Million $/year • NGL: 110 Million $/year • LNG: 50 Million $/year • Elemental Sulfur: 50,000 $/year
Sample Calculations SCFD to Lb/Hr conversion: X Lb/hr = ( Y SCFD) / [ ( 24 hr/1d)*(1 lbmol/ Z Lb)*(378.827 SCF /lbmol) ] V/n = RT/P = 378.827 @ 60F X : lb/hr Y : SCFD Z: MW X bbl = ( Y lbmol * MW lb/lbmol) / (5.615 ft^3/bbl*Z lb/ft^3) X= volume Y= n moles Z = density