How much gas does an efficient burner save on a tea factory dryer?

About 10%. BEE's Jorhat report puts an adjustable burner on a 200 kg an hour dryer at 0.46 scm of gas per kg of made tea instead of 0.51, saving 36,000 scm a year. That is about 74 t CO2, not the report's 79 t. Cost Rs 2.46 lakh, payback 0.82 years (2010).

Why the old burner wastes gas

• The dryer's ID fan pulls combustion air into the burner chamber while gas goes in at a fixed rate, whatever the draft. Nobody can adjust the air to gas ratio.
• BEE measured 0.51 scm a kg of made tea. Taking 1.45 kg of water out of the leaf for each kg of made tea needs about 885 kcal, so only about 20% of the gas heat does useful drying.
• The proposed burner has its own fan for combustion air and a knob on the gas line. The operator turns it until the flame goes bluish, then leaves it.

The project in numbers

• Dryer: 200 kg of made tea an hour, 12 hours a day, 300 days, 3,600 hours.
• Gas: 367,200 scm a year before, 331,200 after, 10 scm an hour saved.
• At Rs 8.30 a scm, Rs 2.99 lakh a year.
• Cost: Rs 2.14 lakh burner, Rs 0.11 lakh fitting, Rs 0.21 lakh contingency, Rs 2.46 lakh in all. One day of downtime.
• Efficiency moves only from about 19.8% to 22%; the dryer itself still loses most of the heat, so look at insulation and exhaust next.

Prove it with your own bills

1. Before fitting, log gas scm and kg of made tea per dryer for two weeks.
2. After fitting, log the same for two weeks at similar leaf moisture.
3. Compare scm per kg, not monthly gas totals, which swing with the crop.

One dryer, one season

• Made tea: 200 kg x 3,600 h = 720 t
• Gas saved: 0.05 scm x 720,000 kg = 36,000 scm
• CO2 saved: 36,000 x 2.05 = 73.8 t
• Dryer gas CO2 per kg of made tea: 1.05 kg before, 0.94 kg after
• The report's 79.43 t used 9,400 kcal a scm and 56.06 kg CO2 a GJ

Natural gas at our factor of 2.05 kg CO2 a scm, an estimate.

What Senseible does here

Senseible reads monthly gas bills in scm into records with CO2 at 2.05 kg a scm, so the drop after a burner change shows in the factory's monthly figure. The green loan check shows what a lender asks for on an equipment loan.

• Green loan readiness check
• Jorhat tea factories: coal, gas and CO2
• Tea factory footprint per kg
• Tea withering fans on VFDs

Sources: BEE, Detailed project report: energy efficient natural gas burner for drier, Jorhat tea cluster (2010, SAMEEEKSHA), IPCC 2006 Guidelines, Volume 2 Energy, Tables 1.2 and 1.4

Last reviewed 2026-10-31. Report figures are from a BEE SME programme project report; costs and paybacks are at 2010 prices. Check today's gas price before you rely on the payback.