How much oil does an efficient oil-fired 1,200 kg/hr brass reheating furnace save?
37% less oil per tonne of billets in BEE's Jamnagar report: 23.26 litres instead of 37.03, or 33,048 litres a year on 2,400 t. CO2 falls about 90 t a year after the extra blower power, not the report's 107 t. Cost Rs 9.35 lakh, payback 1.08 years (2010).
What the audit measured
- A 1.2 t an hour furnace running 2,000 hours a year.
- 661 kg of billets heated from 80 C to 821 C on 25 litres of oil: 20.44% efficient by the direct method, 18.73% by the heat loss method.
- Flue gas at 423 C with 14.18% oxygen: about 208% excess air. Hot dry flue gas carried away 43.9% of the heat.
- Chimney in the middle of the furnace, red brick for insulation, locally made burners leaking oil.
What the new furnace changes
Waste heat recovery, a designed burner with air to fuel ratio control, proper insulation and temperature gauges, with efficiency taken at 28%. It adds a 7.5 HP blower and a 0.5 HP oil pump, 5.9 kW, or 11,800 kWh a year.
The money at 2010 prices
- 13.77 litres a tonne x 2,400 t = 33,048 litres x Rs 28 = Rs 9.25 lakh.
- Less 11,800 kWh at Rs 5 = Rs 0.59 lakh: Rs 8.66 lakh a year.
- Cost: Rs 8.50 lakh furnace, Rs 0.85 lakh erection. Payback 1.08 years; 7 days of downtime.
Efficient oil or gas
BEE's companion Jamnagar report prices a gas-fired 1,200 kg an hour furnace at Rs 15.20 lakh, using 26 Nm3 of gas a tonne. Gas cuts more CO2 per tonne; the efficient oil furnace costs Rs 5.85 lakh less and paid back faster at 2010 prices. If piped gas reaches your street, price both at today's rates before you choose.
Start with the air
At 208% excess air, most of the loss is air heated for nothing. Tuning the burner's air on the old furnace costs little and is worth doing while you wait for quotes.
Per tonne of billets
- Old furnace: 37.03 litres x 2.97 = 110 kg CO2
- Efficient oil furnace: 23.26 litres x 2.97 = 69 kg, plus 4.9 kWh x 0.675 = 3 kg: 72 kg
- Gas furnace in the companion report: 26 Nm3 x 2.05 = 53 kg, before its blower power
- Efficient oil on 2,400 t: 98.2 t less oil CO2, minus 8.0 t for power = about 90 t a year
Furnace oil at 2.97 kg CO2 a litre, natural gas at 2.05 kg per scm, grid at CEA's FY 2025-26 factor. The report's 107 t works out to 3.24 kg a litre with no deduction for the added power.
What Senseible does here
Senseible reads furnace oil and gas invoices and electricity bills into monthly records with CO2, at 2.97 kg a litre for furnace oil and 2.05 kg per scm for natural gas, so oil per tonne before and after shows on your own bills. Take that before and after figure to the green loan check to see whether a furnace loan fits.
- Green loan readiness check
- Brass reheating furnace: oil to gas
- Jamnagar brass cluster energy and carbon
- Recuperator: combustion air preheat
- Brass: coke pit furnace to induction
Sources: BEE, Detailed project report: energy efficient oil fired reheating furnace, 1,200 kg/hr, Jamnagar brass cluster (2010, SAMEEEKSHA), BEE, Detailed project report: energy efficient gas fired reheating furnace, 1,200 kg/hr, Jamnagar brass cluster (2010, SAMEEEKSHA), CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0 (FY 2025-26 grid factor)
Last reviewed 2026-11-01. Report figures are from a BEE SME programme project report; costs and paybacks are at the report year's prices. Check today's fuel and power prices and a current quote before you rely on the payback.