5 Liquid Knockout3- 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.
8 Sour Gas Treatments Liquid Scavenger Solid Scavenger Liquid Redox Amine+Claus+TailgasGases treatedAcid GasYesNatural GasNoTurndownSensitiveNot SensitiveProducts StreamsBiodegradable LiquidNon-Hazardous SolidSulfur Cake for FertilizerPure SulfurOperating Costs$10/lb. of S$3.50/lb. Sulfur$0.15/lb. of SSmallEquipment CostsLowModerateHighGeneral Application Guidlines100 lb. of sulfur per day300 lb. of sulfur per dayLess than 20 tons of sulfur per dayGreater than 15 tons of sulfur perday and greater than 15% H2S
9 Why LO-CAT II? -System Stability -Ease of operation and Catalyst consumption-Chemical Cost is roughly 1/2 to 1/3 of aSulferox Unit-Uses a Patented chelate system that is moreresistant to Oxidation
12 Gas Dehydration & CO2 Rejection The methods of dehydration looked into are lean gas absorption, adsorption and membrane separation.AbsorptionAdsorptionTEG dehydrationMole sieve dehydrationGlycol is cost effectiveAdsorbent like silica gel is expensiveFor removing large quantities of waterRequired for cryogenic systems which need low moisture contentGlycol can be replaced continuouslyMultiple adsorption beds are required forcontinuous use.Does not remove CO2Removes CO2
15 NGL Recovery Mechanical Refrigeration Plant: - limited to -24 to -40 F - only 60% propaneLean oil absorption:- 40% ethane- 90% propane- 100% heavier hydrocarbons- Heating and cooling required- High operating costTurboexpander:% ethane% propane-100% of heavier hydrocarbons- Since high percent ethane recovery is needed, this is the most economical way90
18 NGL StabilizationNGL'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.
21 Inert Removal-N2Available 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.
24 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.
26 Equipment Cost Estimates pump$20,000 to $85,000distillation column$600,000compressor$20,000 to $1,500,000cryo distillation column$700,000heat exchanger$50,000 to $100,000primary LNG cryo heat exchanger$3,000,000
27 Estimated Capital Cost Amine Treating cost for 5% acid gas removal $10.0MMDehydration cost $1.0MMCompression cost (7000hp x $1400/hp) $9.8MMCryogenic NGL recovery cost $23.0MMLiquid-Redox Sulfur Recovery at 5 T/d $4.0MMTotal cost of components $47.88MMOther costs and 30% $14.3MMTotal 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
28 Revenues Natural Gas: 300 Million $/year NGL: 110 Million $/year LNG: 50 Million $/yearElemental Sulfur: 50,000 $/year
29 Sample Calculations SCFD to Lb/Hr conversion: X Lb/hr = ( Y SCFD) / [ ( 24 hr/1d)*(1 lbmol/ Z Lb)*( SCF /lbmol) ]V/n = RT/P = 60FX : lb/hrY : SCFDZ: MWX bbl = ( Y lbmol * MW lb/lbmol) / (5.615 ft^3/bbl*Z lb/ft^3)X= volumeY= n molesZ = density