What do the numbers look like for gas turbine cogeneration in a ceramic plant?

BEE's Morbi report sizes two gas engines, 2.72 MW, for a vitrified tile plant: 4.08 million scm of gas a year makes 16.7 GWh, and engine heat replaces 1.64 million scm in the spray dryer. Net CO2 falls about 6,260 t a year. Cost Rs 899 lakh, payback 2.75 years (2010).

How the plant is set up

• Two engines of about 1.36 MW each carry the whole plant load of 2,109 kW, 24 hours a day for 330 days.
• Of the gas heat, about 40% becomes power, 30% leaves as exhaust that goes straight into the spray dryer, and 20% goes to jacket cooling water, a tenth of which is used to preheat air.
• The engines burn 515 scm an hour. Exhaust replaces 155 scm an hour of dryer gas and jacket heat another 52.
• The spray dryer needs flue gas at about 550 C and is a plant's largest heat user, so it can take the exhaust without extra fuel.

The money, at 2010 prices

• Grid power avoided: 16,695,360 kWh at Rs 4.15 = Rs 692.85 lakh.
• Dryer gas saved: 1,639,440 scm at Rs 15 = Rs 246 lakh.
• Engine gas bought: 4,080,914 scm at Rs 15 = Rs 612.13 lakh.
• Net: Rs 326.64 lakh a year on Rs 899.11 lakh, so 2.75 years.
• Cost includes Rs 494 lakh engines, Rs 105.22 lakh import duty, Rs 80 lakh heat recovery ducting and Rs 50 lakh civil work. Ten days of dryer downtime.

Ignore the cover table

The report's summary table shows Rs 1,904 lakh, 11.88 million scm, 23.06 GWh, 9.02 million scm saved and a 3.6 year payback. Its own workings do not produce any of those numbers; the figures above follow the workings. It also says turbine in places, but the equipment priced is gas engines.

What changes in your carbon figures

• Scope 2 from the grid falls to almost nothing; Scope 1 from gas rises by about 8,370 t.
• Each kWh from the engines carries about 0.50 kg CO2, or about 0.30 kg once the dryer gas it replaces is credited, against 0.675 kg from the grid.
• Gas engines also release a little unburnt methane, which a full inventory should include.
• The case rests on the gas to power price ratio; redo it with today's gas and tariff before you order anything.

One plant, one year

• Grid avoided: 16,695,360 kWh x 0.675 = 11,269 t
• Dryer gas saved: 1,639,440 scm x 2.05 = 3,361 t
• Engine gas burnt: 4,080,914 scm x 2.05 = 8,366 t
• Net cut: 11,269 + 3,361, less 8,366 = about 6,264 t
• The report says 7,405 t, using older grid factors

Natural gas at our factor of 2.05 kg CO2 a scm and grid at CEA's FY 2025-26 factor, both estimates.

What Senseible does here

Senseible reads gas bills and electricity bills into monthly records with CO2, so the move from Scope 2 to Scope 1 after cogeneration shows month by month. The green loan check shows what a lender asks for on a project this size.

• Green loan readiness check
• Splitting CHP emissions: power and steam
• Gas engine cogeneration methane slip
• Ceramic spray dryer CO2 per tonne

Sources: BEE, Detailed project report: gas engine based co-generation technology, 2.72 MW, Morbi ceramic cluster (2010, SAMEEEKSHA), CEA CO2 Baseline Database, version 22.0

Last reviewed 2026-10-31. Report figures are from a BEE SME programme project report at 2010 prices, when gas cost Rs 15 a scm. Gas and power prices have changed a lot; redo the payback with current prices and a current quote.