Dholera Industrial Boiler Emission Standards: GPCB Stack Norms

1. Statutory Emission Limits by Boiler Fuel Type

GPCB and DSIRDA classify industrial boilers by rated steam generation capacity (in metric tonnes per hour, TPH) and primary combustion fuel. Industrial units in TP1, TP2, and dedicated heavy/general manufacturing zones must comply with the following maximum permissible stack discharge concentrations:

Note: In accordance with DSIRDA green zone policies, dirty fossil fuels like untreated petcoke and high-sulfur raw lignite are strictly prohibited across all Town Planning schemes in Dholera SIR.

2. Minimum Stack Height Formula for Industrial Boilers

Under GPCB air pollution prevention rules and DSIRDA GDCR Section 12, chimney stack heights for industrial steam boilers must satisfy statutory physical dispersion equations. Stack height cannot be chosen arbitrarily and must equal or exceed the calculated threshold:

$$\text{Minimum Stack Height } (H) = 14 \times (Q)^{0.3}$$

Where: * $H$ = Physical stack height above ground level in meters. * $Q$ = Total emission rate of Sulfur Dioxide ($\text{SO}_2$) in kilograms per hour (kg/hr). * Absolute Minimum Height Floor: Regardless of the calculation, no industrial boiler chimney in Dholera SIR shall have a physical height less than 30 meters above finished ground level, or 3 meters above the highest point of the factory roof structure within a 50-meter radius, whichever is greater.

For boilers burning exclusively piped natural gas (PNG) where sulfur emissions are negligible, the stack height is governed by the steam output capacity formula:

$$H = 74 \times (Q_{\text{steam}})^{0.27}$$

Where $Q_{\text{steam}}$ is the maximum continuous rating (MCR) in metric tonnes of steam per hour.

3. Mandatory Online CEMS and Telemetry Specifications

To operate an industrial boiler in Dholera SIR, factory owners must install an automated Continuous Emission Monitoring System (CEMS) before commercial commissioning:

1. Monitored Parameters: Stack opacity/PM concentration (optical transmission or light scattering), $\text{SO}_2$ (UV resonance absorption), $\text{NO}_x$ (chemiluminescence or NDIR), $\text{CO}_2$, Flue gas temperature, and Flue gas velocity/volumetric flow.
2. Sampling Location: The sampling port and sensor probes must be installed at a height of at least 8 times the internal chimney diameter downstream from the nearest flanged duct bend or fan expansion, and at least 2 times the diameter upstream from the chimney top exit.
3. Data Transmission Interface: CEMS data loggers must broadcast encrypted 15-minute averaged telemetry packets via MQTT/REST API simultaneously to:
4. Operational Calibration: Automatic zero and span gas calibration routines must execute every 24 hours, with third-party NABL-accredited manual audit testing conducted once every quarter.

4. Boiler Fuel Handling and Ash Storage Setback Mandates

Industrial plots operating solid biomass or pellet-fired boilers must implement physical safety buffers under DSIRDA GDCR:

• Fuel Storage Yard Setbacks: All solid biomass or pellet fuel storage silos must maintain a minimum clear setback of 12 meters from industrial plot boundary walls and at least 15 meters from electrical sub-stations.
• Fly Ash Management: Fly ash collection hoppers beneath ESPs or baghouses must feature closed pneumatic conveying systems to sealed silos. Open tipping, unlined ash ponds, or outdoor ash mounds are illegal under DSIRDA Zero Fugitive Dust regulations.
• Ash Silo Buffer: Bottom ash and fly ash silos must provide at least 72 hours of peak boiler generation buffer capacity and include automated water conditioning sprays to maintain a 15% moisture ratio during tanker loading.

Frequently Asked Questions (FAQ)