The Howrah galvanizing manual says its measures could cut about 517 tonnes of sulphur dioxide (SO2) a year if all are carried out. Is that right?

Probably not. The electricity cells in its SO2 table, 507 and 3,817, are the same numbers as in its carbon dioxide (CO2) table. Without them the possible SO2 cut is 10.6 tonnes of 29.3, not 517 of 3,846. The manual does not explain, so this is my reading.

The two tables side by side

• CO2 reduction in tonnes a year, Table 4.1: coal 992, wood 93, light diesel oil 54, furnace oil 799, electricity 507, liquefied petroleum gas (LPG) 80. The row adds to 2,525, as printed.
• CO2 emitted, same table: 1,358 + 1,728 + 85 + 2,205 + 3,817 + 404 = 9,597, as printed.
• SO2 reduction, Table 4.2: coal 7.97, wood 1, light diesel oil 0.06, furnace oil 1.56, electricity 507, LPG 0. Printed total 517; the cells add to 517.59.
• SO2 emitted, Table 4.2: 10.91, 14, 0.10, 4.30, 3,817 and 0. Printed total 3,846; the cells add to 3,846.31.

Why I read the electricity cells as copies

1. They are identical to the CO2 table's cells, 507 and 3,817, with the same column heading.
2. For every other fuel the SO2 figure is a small fraction of the CO2 figure: 0.8% for coal, 1.1% for wood, 0.1% for diesel and 0.2% for furnace oil. Electricity alone is 100%.
3. The manual's text then repeats the totals: about 517 tonnes of SO2 reduced out of 3,846 a year in 15 units.

What the cells add to without the copy

• Reduction: 7.97 + 1 + 0.06 + 1.56 = 10.59 tonnes a year.
• Emitted: 10.91 + 14 + 0.10 + 4.30 = 29.31 tonnes a year.
• The manual gives no figure for the grid's share of SO2, so there is nothing to put in that column.
• The CO2 rows add up as printed (2,525 and 9,597); this page did not test them further. Against the manual's saved quantities the reduction cells do not match the emitted-row factors, for example electricity 507 tonnes over 571,718 kWh is 0.89 kg a kWh against 1.23 in the emitted row.

What to quote

Do not repeat 517 or 3,846. If a buyer or auditor asks about air emissions, give your own stack or fuel data, or use the four fuel cells above and say they come from an undated manual of about 2010 to 2011 covering 15 units. SO2 is an air pollutant, not a greenhouse gas, so none of it belongs in a carbon figure.

The sums

• Reduction as printed: 7.97 + 1 + 0.06 + 1.56 + 507 + 0 = 517.59
• Reduction without the electricity cell: 10.59
• Emitted as printed: 10.91 + 14 + 0.10 + 4.30 + 3,817 + 0 = 3,846.31
• Emitted without it: 29.31, so the measures could cut about 36% of the audited units' fuel-borne SO2 on the manual's own cells (10.59 / 29.31)

All cells are the manual's own, from an undated manual of about 2010 to 2011 (its references were read in 2010). The 36% is my arithmetic on those cells and is not in the manual.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so your own oil, coal and power lines are on file month by month. It does not check a published manual for you.

• Howrah galvanizing and wire: fuel and Carbon Border Adjustment Mechanism (CBAM)
• Howrah manual: coal total below its parts
• Howrah savings: 11.3 crore or 11.9 crore
• Galvanizing coal furnace to biomass gasifier

Sources: Bureau of Energy Efficiency (BEE), Manual on energy conservation measures in the galvanizing and wire drawing sector, Howrah cluster (SAMEEEKSHA)

Last reviewed 2026-11-05. Figures are the manual's, from an undated manual of about 2010 to 2011. The manual does not say why the electricity cells match; treating them as copied from the CO2 table is my reading, not a correction by its authors.