Senseible

How do I calculate CO2 per 1,000 bricks for a coal-fired brick kiln, and how much does a zigzag kiln reduce it?

Divide the season's coal use by bricks fired, then multiply by the coal factor: kg coal per 1,000 bricks x 2.42 kg CO2 per kg (IPCC 2006 default) gives kg CO2 per 1,000 bricks. A zigzag kiln cuts this only as far as it cuts your coal per brick, so measure coal per lakh bricks before and after conversion.

The inputs you need for one firing season

The formula

Coal combustion is Scope 1 for the kiln owner. For a builder buying the bricks, the same figure is part of the bricks' embodied carbon in Scope 3.

  1. Coal per 1,000 bricks (kg) = coal used (kg) / bricks fired x 1,000.
  2. CO2 per 1,000 bricks (kg) = coal per 1,000 bricks x 2.42 kg CO2 per kg.
  3. If your coal supplier gives a gross calorific value (GCV), a factor built from that GCV is more precise than the 2.42 default for Indian coal, which varies widely in quality.
  4. Add diesel at 2.68 kg CO2 per litre and grid electricity at 0.710 kg CO2 per kWh, divided by the same bricks, if they are in scope.

Why a zigzag kiln uses less coal

In a zigzag kiln the hot gases follow a zigzag path through the brick stack, driven by a fan or a tall chimney. Heat passes to the bricks more evenly and combustion is more complete, so less coal is needed per brick and less black smoke leaves the stack. The saving varies with how well the kiln is set and fired, so measure it from your own coal and production records rather than quoting a single industry figure.

Most of the visible benefit is lower particulate and black carbon. Black carbon is not counted in a CO2 inventory, so report the CO2 saving from coal on its own.

Rules that apply to brick kilns

MoEFCC notification G.S.R. 143(E) of 22 February 2022, an amendment to the Environment (Protection) Rules, 1986, allows new kilns only with zigzag or vertical shaft technology or PNG firing. Existing kilns were given one year to convert if within 10 km of a non-attainment city and two years elsewhere. Approved fuels are PNG, coal, firewood and agricultural residues; pet coke, tyres, plastic and hazardous waste are banned.

Deadlines have since been revised by later notifications and state boards, so confirm the date that applies to your kiln with your State Pollution Control Board.

Biomass and mixed firing

CO2 from rice husk, wood or crop residue is biogenic. Report it separately and leave it out of the fossil Scope 1 total. A kiln that replaces part of its coal with biomass lowers its fossil CO2 per 1,000 bricks in direct proportion to the coal it no longer buys.

Worked example: one kiln before and after zigzag conversion (illustrative figures)

The coal figures are illustrative, not benchmarks. Use your own purchase and production records for both seasons.

What Senseible does here

Senseible reads kilograms from coal invoices and litres from diesel invoices, applies the IPCC 2006 defaults (coal 2.42 kg CO2 per kg, diesel 2.68 kg CO2 per litre) and shows the factor on each line, with biomass reported as biogenic. Dividing by bricks fired needs your production figure, which it does not read from a register.

Sources: IPCC 2006 Guidelines, Volume 2 Energy, Chapter 2 Stationary Combustion, MoEFCC, G.S.R. 143(E), 22 February 2022, Environment (Protection) Amendment Rules for brick kilns

Last reviewed 2026-10-17. Brick kiln conversion deadlines and fuel rules are set by notification and state boards; recheck the 2022 rules and any amendments.