air pollution control and environmental...

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Air Pollution Control and Environmental Solutions

By Alok ChandVice President . Boldrocchi India

Air Pollution Control Business

INTRODUCTION – BOLDROCCHI AT A GLANCE

More than 100 years of experience in design, engineering,supply, erection & commissioning

Product range includes fans, blowers, compressors, heatexchangers, coolers, gas turbine systems, noise protectionsystems, heavy duty diverters, dampers

More than 88000 orders executed worldwide

State of the art technology for air pollution control: Dust removal Organic micro pollutants removal Gaseous acids removal Vaporized metals removal Sulphur and nitrogen oxides removal

INTRODUCTION – BOLDROCCHI AT A GLANCE

Solutions offered by Boldrocchi for Air Pollution Control

This presentation highlights the technologyand solutions provided by Boldrocchi forcleaning of flue gases arising out of variousindustrial processes.

As a case study, flue gas cleaning systemfor waste to energy plants and biomassplants has been illustrated in thispresentation.

Dry sorbent injection system (hydrated lime)(also sodium bicarbonate injection system is being applied)

Activated Carbon injection system Dry Reactor (with or without recirculation of reagents) Water injection system with zero liquid discharge DeSox Reactor Bag filter based cleaning DeNox with SCR/ SNCR DeNox with combined SCR and SNCR

Above solutions are applicable also for steel, power, cementand other allied industries and Boldrocchi has severalreferences for the same.

Technology and Systems adopted for case study:

Rapid technological development over the last few years

Stringent norms for pollution control necessitating reliabletechnology for reduced emissions

Huge potential in India - accelerated by Government of India under“Swach Bharat Mission” (Clean India Mission)

Five running plants in India Many others under construction Numerous others in planning stage About 200 WTE plants to come up in next 3-5 years

Non uniform quality of waste particularly in India (high moisture)

Typical configuration of waste to energy plants in India

Waste treatment capacity of 450-2000 T of waste per day 4 to 30 MW of electrical power generation by combining one or more

than one boilers

Waste to Energy Sector at a glance:

TYPICAL SECTIONS IN WASTE TO ENERGY PLANTS

Flue Gas Treatment System

Processo IndustrialeFonte di Emissioni

Waste Combustion

Heavy Metals

Carbon compounds

Hg, Cd, Tl, As, Ni, Pb

CO2, CO, hydrocarbons (VOCs), PCDD/F

Key environmental issues in waste to energy and biomass plants

In fully oxidative incineration the main constituents of the flue-gas are water vapor, nitrogen, carbon dioxide and oxygen. Depending on the composition of the material incinerated and on the operating conditions, the main emissions are:

Flowsheet of a FGCSO

PRIMARY DEDUSTING

CYCLONE, ESP OR BAG FILTER

GAS TEMPERATURE REGULATION

BASIC REAGENTS STORAGE

ADSORBENT STORAGE

(ACTIV.CARBON)

PREPARATION; TRANSPORT;

DOSING

CONTACT REACTOR REAGENTS-FLUE GAS

BAG FILTER

DUST TRANSPORT SYSTEM

FILTER PREHEATER AND ACCESSORIES

FINAL GAS EXTRACTION FAN + STACK

HEAT EXCHANGERDeNOx REACTOR

DUST STORAGE

• High SO2 Removal Efficiency– Up to 99% removal

• Flexible– Multi-Pollutant Removal

• SO2, SO3, HCl, Hf, Dioxins, Furans• Hg Removal• Up to 50% NOx removal

– Fuel & process flexibility– Works in High Moisture Applications

• Low Capital & Operation Cost– Modular fabrication– Simplicity of design with small footprint– No slurry systems– Exotic Alloys not required– Low pressure drop– High recycle rate low reagent consumption – Significantly reduced maintenance and operation

cost compared to Spray Dryers and Wet Scrubbers

Salient Features of Boldrocchi’s DeSox

Complete Flue Gas Cleaning Plant

Reaction Tower

Bag house

Typical Arrangement - Example

Waste Silo

Reagent Silo

Salient Features of Boldrocchi’s DeSox / DeNox system

SCR reactor

Case Study-2 – Waste to Energy Power Plants in India (Municipal Waste based)

Case Study-1 - Biomass based power plant at Europe(Cereal straw & wood based)

Following case studies have been illustrated in this presentation

Case Study-1 - Biomass based power plant (Cereal straw & wood based)

General Plant Overview

Case Study 1 - Biomass power plant at Europe (Cereal straw & wood)

Project Background - Pollutants

Reference FuelConfigurations 100 %

55 % straw

45 % woodchips (40 %

55 % straw

45 % woodchips (50 %

Flue gas flowrate (Nm3/h) 100.817 109.936 114.030

Flue gas temperature at

boiler outlet (oC)139 143 143

Ash in the flue gas at boiler

outlet (g/Nm3 dry)

5,34 4,50 4,60

Flue gas composition (ash absent)

CO2 (% in mass) 20,30750 19,70684 19,52255

H2O (% in mass) 9,18136 11,28013 12,17492

SO2 (% in mass) 0,02956 0,02582 0,02589

N2 (% in mass) 65,70962 64,37260 63,70338

O2 (% in mass) 4,63258 4,52699 4,48117

HCl (% in mass) 0,13938 0,08762 0,09209

NOx (mg/Nm3 at 6 % of O2) 250-300 250-300 250-300

CO (mg/Nm3 at 6 % of O2) 100 100 100

Modality of combustion:

Combustion 100 % straw

Combustion of straw and woodchips (max 35 % on energy basis)

strictly confidential

Project Background - Emission Limits

Pollutant present

in the flue gas

(mg/Nm3)

Emission limits on the basis of

Authorization of the DPR

13/03/2013 n.58 (daily mean)

Emission limits on the basis of the

DLgs 152/2006, ref. NTP > 50 MW

(daily/hourly mean)

Emission limits on the

basis of the DM 06-07-

2012 (monthly mean)

Ash 5 30/- 5

CO 100 200/100 50

TOC 10 20/10 10

NOx 100 400/200 100

NH3 10 - 5

SOx 100 200/- 25

HCl 10 - 10

HF 1 - -

Mean values of the emission limits imposed by the Authority.Reference: 11 % of oxigen (O2), dry gas, normal condition of 1013 mbar and 0 °C.

Configuration of the FGCS

NOx abatement systems

NOx Abatement

SNCR + SCR

Principal reactions for nitrogen oxides (NOx) reduction through ammonia injection:

4 NO + 4 NH3 + O2 → 4 N2 + 6 H2O

2 NO2 + 4 NH3 + O2 → 3 N2 + 6 H2O

The most flexible solution

The ammonia solution is directly injected in the boiler(last part of the evaporator) by means of two levels oflances (each level consists of four lances).

Upstream the injection system (lances), a dosing skid isnecessary to obtain the required amount of ammoniasolution in terms of water content (dilution) and pressure.

Acid gases, dioxins and furans abatement

(SOx HCl e HF)

Dry Reactor (with or without dust

recirculation)

Bag Filter "Secondary Reactor"(thickness of the “cake”)

Principal reactions for acid gases abatement (SOx HCl e HF) through lime injection:

Ca(OH)2 + 2 HCl → CaCl2 + 2 H2O

Ca(OH)2 + 2 HF → CaF2 + 2 H2O

Ca(OH)2 + SO2 → CaSO3 + H2O

Ca(OH)2 + SO3 → CaSO4 + H2O

Dosing Lime

Dry reactor is positined downstream theboiler and upstream the bag filter.

Two storage silos (160 m3 each)equipped with vibrators and pneumatictransport system for reactor feeding.

The activated carbon, stocked in "big bags", are opportunelydosed and sent to the dry reactor (with the lime) by means of apneumatic transport system.

Two storage silos (250 m3 each)equipped with vibrators and electricalheaters.

Each silo consists of a telescopic dischargesystem for truck.

SCR – Ammonia Storage

Ammonia tank = 40 m3 (SS) Protected by a containment

structure. Safety relief valve on top of tank

to prevent ammonia dispersion. Common ammonia tank for both

SNCR and SCR. Safety system for unloading by

truck.

SCR Reactor

Two honeycomb structure reactors toincrease catalytic surface.

Placed downstream the bag filter (topreserve the catalytic surfaces).

Two heat exchanger (gas/gas andgas/steam) to mantain a constanttemperature (SCR inlet) of about 250°C (ideal for SCR).

• The ammonia solution is injected in astatic mixing chamber (upstream theSCR and downstream the HEs) bymeans of four lances.

Case Study-2 – Municipal waste based power plants in India

Parameters Unit InletInlet Temp Deg C Max 180-240Gas Flow NM3/Hr 125,000 – 200,000Water vapour % 23 - 25HCl mg/Nm3 Up-to 1500SO2 mg/Nm3 1000-1200CO mg/Nm3 50-100TOC mg/Nm3 20HF mg/Nm3 10Dioxins & Furans ngTEQ/Nm3 10Cd + Th + other compounds mg/Nm3 0.52Hg and its compunds mg/Nm3 0.07Sb+As+Pb+Cr+Co+Cu+Mn+Ni+V + their compunds

mg/Nm3 8.9

Total dust load mg/Nm3 6000-10000

Waste Treatment capacity: 450 - 2000 TPDPower Generation: 4 - 30 MW

Case Study-2 – Municipal Waste based Power Plant in India

Characteristics of flue gas at inlet of FGCS (at 12% O2 on dry basis)

Typical configuration:

Clean Flue Gas

Process Gas

Fresh Reagent

Recycle Loop

Flue Gas with Entrained Reagent

BaghouseReaction

Air Slide Conveyor

Reagent Silo

Spent Reagent to Waste

DP SOx

Technology Applied

Paramter Unit Inlet OutletHCl mg/Nm3 1500 10-20SO2 mg/Nm3 1000-1200 50-100CO mg/Nm3 50-100 <50TOC mg/Nm3 20 <10HF mg/Nm3 10 4Dioxins & Furans ngTEQ/Nm3 10 0.1Cd + Th + other compounds mg/Nm3 0.52 0.05Hg and its compunds mg/Nm3 0.07 0.05Sb+As+Pb+Cr+Co+Cu+Mn+Ni+V+ their compunds

mg/Nm3 8.9 0.5

Total dust load mg/Nm3 6000-10000 10

All above values corrected to 12% Oxygen on a dry basis

Flue gas requirement at outlet

Boldrocchi India is in the process of building 5 such flue gas treatment plants in India.

Reaction Tower - Characteristics

• Straight vessel without moving parts• Multi-Venturi design for large gas flows• Reagent recirculation above the venturis• Tower bottom waste discharge • Inlet vanes for proper gas distribution• Flue gas recirculation loop

Water Injection System - Features

• Air atomized / spill back lances• Redundant High pressure multistage

centrifugal pumps• Options of air atomized lance & spillback

return lance• Multiple lances for large gas flows• Design margin for temperature excursion• High turndown ratio• Barrier air to prevent lance clogging

Hydrated Lime Storage & Dosing System

• Pneumatic conveying from site hydration unit or truck

• Gravimetric dosing of hydrated lime to scrubber

• Loss-in-Weight (LIW) reagent feeding system by pneumatic conveying from hydrated lime silo to scrubber

• Two (2) LIW units for each reaction tower for redundancy and metering accuracy

• Flow enhancing device for trouble free flow

Reagent recycle & waste disposal features

• Recycle hopper with airslides• Fluidization air supplied by PD

blowers• Diverter valve for disposal of

by-product• Reagent surge bin• Pneumatic conveying from Re-

circulation hoppers to Waste silo

Fabric Filter Features• Long bags (up-to 10 mts long). Longer

bags ensure smaller foot print area• Intermediate pressure cleaning air

(3-4 bar)• Gas and dust distribution distribution

defined by CFD analysis, physical models and experience

• Cross flow design, promoting- More efficient cleaning- Levelised reagent recirculation - Reduced wear compared to conventional

hopper entry designs

Other References

Boldrocchi - Complete solution for flue gas cleaning

Thank you for your attention

Boldrocchi India Pvt Ltd1801, 1802, 1907, Tower 4, DLF Corporate Greens, Sector 74-A, Gurgaon-122004T. +91 8961562592, E-mail: alok@boldrocchi.in

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