DESOX Solutions for Sulfur Oxide (SOx) Control

Introduction

Controlling air pollution is no longer optional — it’s a necessity. Sulfur oxides (SOx), especially sulfur dioxide (SO₂), are harmful pollutants released primarily from the combustion of fossil fuels in power plants, boilers, and industrial kilns. These emissions contribute to acid rain, corrosion, and respiratory issues.

At Vel Innovative Technologies Pvt Ltd, our DESOX Systems are designed to provide cost-effective, high-efficiency SOx emission control using wet slurry-based reagent injection. This ensures environmental compliance, reliable performance, and long-term sustainability.

How the DESOX Process Works?

Our DESOX technology utilizes slurry-phase chemical injection of alkaline agents such as calcium hydroxide (slurry/powder) or sodium bicarbonate solution to neutralize SOx in the flue gas stream.

Process Steps

Flue Gas Conditioning
Hot flue gas from the boiler or incinerator is directed into the DESOX chamber where it is brought to an optimal temperature range for reaction (typically 380–200°C).
Injection System
A controlled amount of calcium hydroxide (slurry/powder)or sodium bicarbonate slurry/powder is injected directly into the flue gas through atomizing nozzles or spray lances.

In case of slurry system

The liquid droplets ensure maximum surface contact for gas-liquid chemical reaction.
Chemical Reaction (SOx Neutralization)
SO₂ reacts with the alkaline slurry in the gas stream forming non-toxic salts such as calcium sulfite (CaSO₃), calcium sulfate (CaSO₄), or sodium sulfate (Na₂SO₄).

Key Reactions:

Ca(OH)₂ + SO₂ → CaSO₃ + H₂O

Ca(OH)₂ + SO₂ + ½O₂ → CaSO₄ + H₂O

NaHCO₃ + SO₂ → NaHSO₃ + CO₂

NaHSO₃ + NaHCO₃ → Na₂SO₃ + CO₂ + H₂O
Droplet Evaporation & Salt Formation
As the slurry droplets evaporate, fine solid byproducts (sulfite/sulfate salts) are formed and carried with the flue gas.
Particulate Capture
These solid residues are collected downstream using high-efficiency bag filters or electrostatic precipitators (ESPs), ensuring clean, SOx-free exhaust gas.

Key Benefits

High SOx Removal Efficiency – Up to 98% SO₂ capture rate.
Liquid Injection Advantage in case of slurry basedsystem – Superior reaction kinetics due to gas-liquid interface.
Compact System Footprint – Ideal for both new and retrofit installations.
Water-Based System – Reduces dust handling and particulate re-entrainment.
Low Operating Costs – Minimal power requirement, high reliability.
Eco-Friendly – Helps meet CPCB, EPA, and EU SOx emission norms.

Our Scope of Supply

Process Design & Engineering
Slurry Preparation Units
Injection Lances & Skid Systems
Reaction Duct/Chamber Design
Bag Filter / ESP Integration
ID Fan and Ducting
Instrumentation, PLC Panel & SCADA
Commissioning and Operator Training

System Features

Feature	Description
Sorbents Used	Calcium Hydroxide (Slurry or dry powder )/ Sodium Bicarbonate Solution
Injection Technology	Multi-nozzle atomized liquid spray system
Reaction Chamber	Custom-engineered for optimized residence time and turbulence
Particulate Capture	Bag Filters / ESP for dry salt removal
Automation	SCADA/PLC-based dosing control with real-time SO₂ sensors
Maintenance	Easy access, CIP (clean-in-place) for spray nozzles
Flexibility	Suitable for a wide range of fuel types and flue gas compositions

Technical Specifications

Parameter	Specification
SOx Removal Efficiency	Up to 98%
Slurry Concentration(in case of slurry based calcium hydroxide system)	10–15% for Ca(OH)₂ / NaHCO₃
Operating Temperature	380–200°C
Flue Gas Capacity	Any Range
pH Control	Online pH sensors with automated dosing
Salt Removal	Ash handling system downstream
Control System	PLC/SCADA-based auto-control loop
Compliance	CPCB / MOEF / US EPA / EU Industrial Norms