Motivation 3 With natural gas prices trending down and an abundance of it available in Wiliston ND, a Midrex plant makes sense economically. The NPV for this plant is $1,030,000,000 Midrex process is more cost efficient and environmentally friendly than conventional blast furnaces.
Block Flow/Design Basis 4
Design Basis 2700 tons/day of natural gas feedstock will be supplied for process and fuel Natural gas and steam are the main sources of H 2 Air is used as the main source of N 2 Supply the back-end ammonia plant with H 2 and N 2 in a 3:1 molar ratio to make 3600 TPD of NH 3 5
Process Flow Diagram 6
Feed CH4 & recycle stream Exhaust going to ejector Air coming from air blower Heated process gas Reduction gas going to Oxy Fuel booster CH4 to combustion chamber Recycle gas to combustion chamber Heated gas from combustion Heated air to combustion chamber Recycle gas from CO2 Removal CH4, H2, CO, CO2, H20, N2 CO2, H2O, N2 N2, O2CH4, H2, CO, CO2, H20, N2 CH4, H2, CO, CO2, N2 CH4, N2CH4, H2, CO, CO2, H20, N2, O2 CO2, H2O, N2CH4, H2, CO, CO2, H20, N2 CH4, H2, CO, H20, N
Energy Sinks and Loads: Heat Exchangers 1076º F 75 psi 724 ºF 14.7 psi 180º F 75 psi 1878º F 14.7 psi 724º F 14.7 psi 420º F 14.7 psi 615º F 14.7 psi 77º F 14.7 psi Q=27 mmBtu/hrQ=113 mmBtu/hr Excess energy from the flue gas is used to heat the feed of gas in 8
Environmental Considerations 9 Midrex plants are designed with the goal of minimizing water, air, and noise pollution. In comparison to traditional blast furnaces, Midrex plants have much lower CO2 emissions due to using natural gas instead of coal, as well as having a reformer that can handle larger amounts of recycled CO2 than the average steam-methane reformer. 153 ton/year of CO2 emissions
Equipment 10 EquipmentEquipment Cost (USD)Total Installed Cost (USD) Primary Reformer46,000,000188,000,000 Shaft Furnace39,000,000168,000,000 Oxygen fuel booster11,000,00040,000,000 Scrubber650,0002,000,000 Main Air Blower500,0002,000,000 Heat Exchanger 1120,000510,000 Heat Exchanger 2 100,000436,000 Zinc Oxide Bed3,000,00010,000,000 Compressor4,000,00015,000,000 CO2 Removal (MDEA)7,000,00029,000,000 Storage facility-12,000,000 Rail and Loading-18,000,000 Total110,000,000483,000,000
Expenses 11 1 Year (USD)5 Year (USD)10 Year (USD) Loan29,000,00024,000,00017,000,000 Depreciation3,000,000 Electrical20,000,00022,000,00024,000,000 Natural Gas Cost Transfer From Alpha No Transfer CostBetween Groups Oxygen Cost Transfer From Matt’s group No Transfer CostBetween Groups Transportation Costs 72,000,00078,000,00086,000,000 Salaries and Fringes ($100/hr.) 11,000,00012,000,00014,000,000 Maintenance15,000,00016,000,00017,000,000 Feed Ore406,000,000439,000,000485,000,000 Total Expenses556,000,000594,000,000646,000,000
Revenue 12 Products Sell Cost/Ton ($) TPD$/Day$/Year DRI4255,0002,000,000790,000,000 Carbon Dioxide 15 Giving to India No Transfer Costs Between Groups Total-5,0002,000,000790,000,000
Profit 13 1 Year (USD)10 Year (USD)17 Year (USD) Total Expenses550,000,000640,000,000720,000,000 Total Revenue790,000,000860,000,0001,000,000,000 Income Before Taxes 240,000,000270,326,000370,000,000 Taxes (40%)97,000,000110,000,000150,000,000 Income After Taxes 150,000,000160,000,000220,000,000 Total Cumulative Income 150,000,0001,665,000,0003,000,000,000
Payback Period 14 NPV1,030,000,000 IRR32.85% Payback Period4 Years
Recommendations 15 We recommend proceeding with the completion of the Midrex plant at the Wiliston ND location. We recommend changing the process so that there is no recycled stream going into the combustion chamber of the reformer. Instead, burn the CO and CH4 with some O2, then dry the stream to remove the water and send the remainder of the stream over to team India as CO2. Natural gas is the cheapest commodity in this plant so it makes sense to use a little more of that for the combustion rather than implementing a pricy MDEA system to remove the CO2 and allow us to burn the little bit of recycled CO and CH4 that’s left.
Summary The process starts with 2,700 tons/day of natural gas feedstock and will give enough H 2 and N 2 to the back-end ammonia plant to produce 3,600 tons/day of NH 3 Natural gas feedstock and convection section optimization will reduce expenses and payback period Projected payback period is 6.8 years Net present value is 809 million USD (20 years) 16
Motivation Natural Gas cost is expected to decrease further 18