# What does a coal gasifier save on a 100 tonne downdraft kiln in the Godavari refractory cluster?

Canonical: https://senseible.earth/answers/godavari-coal-gasifier-100-tonne-downdraft-kiln

In the Bureau of Energy Efficiency (BEE) Godavari report, a coal gasifier cuts a 100 tonne downdraft kiln from 140 to 106.67 tonnes of coal a batch: 666.7 tonnes a year over 20 batches, Rs 28.80 lakh after gasifier power, for Rs 62.17 lakh. Payback is 2.16 years.

## How the report gets 33.33 tonnes a batch

- Today: 140 tonnes of coal at 4,200 kilocalories (kcal) a kg for a 90 tonne firing, 588 million kcal. The report puts total heat losses at 55%, so 264.6 million kcal reach the bricks over 8 days: 33.075 million a day.
- The gasifier is rated 2 million kcal an hour. At 70% use that is 33.6 million kcal a day, the heat of 8.00 tonnes of coal a day.
- At 60% gasifier efficiency it takes 13.33 tonnes of coal a day: 106.67 tonnes over 8 days, 33.33 tonnes less than 140.

## The money

- 33.33 tonnes x Rs 4,500 = Rs 1.50 lakh a batch; 20 batches = Rs 30.0 lakh.
- Less Rs 0.06 lakh of gasifier power a batch, Rs 1.20 lakh a year: Rs 28.80 lakh.
- Cost Rs 62.17 lakh; 62.17 / 28.80 = 2.16 years. Net present value Rs 43.21 lakh, internal rate of return 29.19%, debt service coverage ratio 1.84.

## What to check

The report says no unit in the cluster has a coal gasifier, so these are design figures, not results from a running plant. The saving rests on the 55% loss and 60% gasifier efficiency. Ask a supplier for coal per batch from a comparable running kiln.

## Carbon dioxide (estimate)

- Coal saved: 33.33 tonnes x 20 batches = 666.7 tonnes a year
- At 1.76 tonnes of carbon dioxide (CO2) a tonne of Indian coal: 666.7 x 1.76 = 1,173 tonnes, before gasifier power
- The report says 1,200 tonnes, about 1.80 a tonne of coal

Coal at Senseible's Indian coal factor, an estimate. Heat and cost figures from the Bureau of Energy Efficiency (BEE) report at about 2010 prices.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records with carbon dioxide equivalent (CO2e), so coal bought before and after a gasifier is on record with its bills. The green loan check shows what a lender asks for.

- [Green loan readiness check](https://senseible.earth/green-loan-check)
- [Godavari refractory cluster: coal and carbon](https://senseible.earth/answers/godavari-refractory-cluster-coal-kiln-carbon)
- [Waste heat recovery on a downdraft kiln](https://senseible.earth/answers/downdraft-kiln-waste-heat-recovery-coal-saving)
- [Refractory kiln: coal to biomass gasifier](https://senseible.earth/answers/refractory-kiln-coal-to-biomass-gasifier-co2)

Sources: [BEE, Detailed project report: coal gasifier for a 100 tonne downdraft kiln, East and West Godavari refractories cluster (SAMEEEKSHA)](https://sameeeksha.org/pdf/dpr/East_and_West_Godavari_refractories_cluster/05_Coal_gasifier_system_100_tons_capacity_kiln_Godavari_Refr_cluster.pdf)

Last reviewed 2026-11-04. Report figures are from a Bureau of Energy Efficiency (BEE) Small and Medium Enterprises (SME) programme project report; costs and paybacks are at the report year's prices. Check today's prices and a current quote before you rely on the payback.