# Virudhachalam ceramic and refractory kilns burn firewood, coal, petcoke and RPO: what is the cluster's footprint?

Canonical: https://senseible.earth/answers/virudhachalam-ceramic-refractory-kiln-fuel-carbon

Firewood is the biggest, then imported coal, petcoke and rubber process oil. About 300 small and micro units near Virudhachalam made about 60,000 t a year on 10,079 toe in 2015, 99% of it kiln fuel. Fossil CO2 comes to roughly 23,000 t, about 0.39 t per tonne, with wood CO2 reported separately.

## Each kiln type has its own fuel

- Tunnel kilns, 5: three fire ceramics on RPO or LDO at about 7.5 tpd; two fire high alumina refractory bricks on petcoke and imported coal dust at about 20 tpd.
- Shuttle kilns, 20: batch firing of toys and art ware on RPO.
- Rotary kilns, 10: pulverised imported coal.
- Downdraft kilns, about 100 built, about 20 still firing: wood, mainly for the bottom boring sets steel plants buy.

## Heat per kg tells you which kiln to fix

- Downdraft: 4,200 kcal per kg
- Shuttle: 3,779 kcal per kg
- Tunnel: 1,740 kcal per kg
- Rotary: 1,413 kcal per kg

## The cluster's fuel bill

Firewood 18,000 t (4,140 toe), imported coal 4,800 t (3,360 toe), petcoke 1,440 t (1,267 toe), RPO 1,316 kL (1,211 toe) and 1.18 million kWh of TANGEDCO power (102 toe). Downdraft kilns took 41% of the energy and rotary kilns 34%. Energy was about half of production cost. A refractory tunnel kiln unit used about 644 toe a year; a shuttle kiln toy unit about 41.

## What cuts fuel, and by how much

- Lighter tunnel kiln cars with hollow ceramic pipes, fibre blankets and cordierite blocks: about 3% of heat input, 52 toe a year across the cluster.
- Automatic air to fuel control and better burners on tunnel and shuttle kilns: about 3%, 178 toe.
- Combustion air preheating from shuttle kiln flue gas at 900 to 1,000 °C: about 7%, 57 toe.
- Moving downdraft work into continuous kilns is the big step: a downdraft kiln uses about 2.4 times the heat per kg of a tunnel kiln.

## Estimate: cluster CO2 by fuel

- Imported coal: 3,360 toe x 41.868 GJ x 94.6 kg CO2 per GJ = about 13,300 t
- Petcoke: 1,267 toe x 41.868 x 97.5 = about 5,200 t
- RPO, taken as fuel oil: 1,211 toe x 41.868 x 77.4 = about 3,900 t
- Power: 1.18 million kWh x 0.675 = about 800 t; fossil total about 23,200 t, or 0.39 t per tonne of 60,000 t
- Firewood, biogenic and reported separately: 4,140 toe x 41.868 x 112 = about 19,400 t

An estimate using IPCC 2006 default factors and the CEA FY 2025-26 grid factor; RPO has no IPCC default of its own. Use your own fuel invoices and test reports.

## What Senseible does here

Senseible reads RPO, coal, petcoke and wood purchase invoices and TANGEDCO bills into a monthly record for your unit, keeping wood as biogenic, so you have your own figure per tonne when a steel plant or exporter asks.

- [Your carbon number for buyers and banks](https://senseible.earth/msme-carbon-number)
- [Refractory kiln CO2 per tonne](https://senseible.earth/answers/asansol-refractory-plant-kiln-co2-per-tonne)
- [Are refractories covered by CBAM?](https://senseible.earth/answers/are-refractories-covered-by-cbam)

Sources: [TERI, Cluster profile: Vriddhachalam ceramics and refractory industries (2015)](https://sameeeksha.org/pdf/clusterprofile/Virudhachalam-Ceramics-Refractories-TamilNadu.pdf), [IPCC 2006 Guidelines, Volume 2 Energy](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0](https://cea.nic.in/cdm-co2-baseline-view?mappingId=234&lang=en)

Last reviewed 2026-10-31. Data are TERI's 2015 estimates. Fuel mix shifts with prices (RPO was replacing LDO then); re-check against a newer profile if one appears.