Air Pollution Control Innovations

A specialty cellulose provider, Tembec, is upgrading a sulfite pulping mill in Eastern Canada to incorporate a new red liquor recovery boiler for power generation.  The boiler system increases annual green energy production by up to 40-megawatts, reduces sulfur dioxide emissions by 70%, and increases annual production capacity of specialty cellulose by 5,000 metric tonnes.  The off-gas from the recovery boiler contains a high concentration of SO2 which needs to be recovered for re-use in the production process. 

A cost effective solution was needed to recover sulfur and clean the stack gases to meet stringent particulate and SO2 emission limits.  The plant is located in a high labor rate area, which makes a field erected system very expensive due to lengthy installation time.

A case study is now available to describe how an Envitech scrubber/wet electrostatic precipitator (WESP) system solves this problem.

Please click on the icon below to download the case study.

A waste oil re-refiner in Southern California, Demenno Kerdoon, needed to retrofit an SO₂ scrubber downstream of a thermal oxidizer. The oxidizer treats vapor recovery and waste gas streams containing sulfur compounds.  California has some of the toughest standards in the country and required the facility to meet a permit limit of 2.7 ppmv. This limit exempts the facility from the SCAQMD SOx Reclaim program saving reporting and administrative costs.

A case study is now available to describe how an Envitech ultra low SO₂ scrubber solved this problem.

Please click on the icon below to download the case study.

 Follow the link to a previous blog post on this project to download a white paper from the international conference on thermal treatment technologies and hazardous waste combustors (IT3/HWC).

Envitech has received an order from Tembec to supply an ammonia based red liquor recovery boiler scrubber for the Temiscaming sulfite pulping mill in Québec, Canada.   The scrubber system will treat the off-gas from an upstream sulfite power boiler supplied by Andritz and will meet stringent emission standards for particulate and SO₂.

This system is part of a $190-million power generation project that will upgrade Tembec’s existing specialty cellulose manufacturing facility.  The upgrade will increase annual green energy production by up to 40-megawatts, reduce sulfur dioxide emissions by 70%, and increase annual production capacity of specialty cellulose by 5,000 metric tonnes.  The upgrade will make Temiscaming one of the lowest-cost specialty cellulose manufacturing facilities in the world.

The scrubber system is engineered to Tembec’s requirements and is the result of close collaboration with the customer over several months and their engineering firm Pöyry.   The design leverages experience from several other large volumetric flow rate applications including a coal dryer scrubber, secondary lead smelter wet electrostatic precipitator (WESP) system, and a hazardous waste incinerator scrubber.  The scope of supply includes an inlet duct from the boiler exhaust fan, quencher, ammonia scrubber, condenser, WESP, caustic scrubber, heat exchangers, structural steel, access platforms, and stack.  Primary vessels will be shop fabricated and shipped to the site for assembly and installation.  This provides a lower total installed cost, greater quality control over manufacturing, and shorter delivery and installation time.  System start-up will occur in the fall of 2013.

To read more about this system, download the case study below.

In previous blog posts we have discussed our continuing progress in the development and implementation of SO₂ Scrubber technology to control marine diesel engine emissions. We have recently finished manufacturing an exhaust gas cleaning system for SO₂ removal which is to be installed at a state of the art maritime engine test facility equipped with a 3MW diesel engine. Soon we will begin testing our system under a wide variety of conditions to fine-tune and validate our marine diesel engine emissions scrubbing technology. Once the testing is complete, we will apply for a maritime registration for our control technology.

Regulations on exhaust gas emitted from marine diesel engines are becoming increasingly stricter. The recently implemented MARPOL Annex VI specifies that the fuel used to power large sea bearing vessels must contain no more that 3.5% sulfur oxides by weight in non-Emission Control Areas and no more that 1.0% by weight in designated Emission Control Areas. This allowable weight percentage of SO_x will drastically decrease to 0.5% in 2020 for non-Emission Control Areas and 0.1% in designated Emission Control areas. One can easily predict that fuel expenses for ship-owners will increase along with the requirement for the use of lower sulfur content fuel. An economical alternative to using this more expensive fuel is to install a secondary exhaust gas cleaning system such as an SO₂ scrubber to clean diesel engine emissions before they are released to the atmosphere.

In addition to Envitech’s new ship-based marine diesel engine SO₂ scrubber demonstration system, we have seen continued success with meeting SO₂ emission limits with our land-based SO₂ marine scrubber which was installed this past March at the Port of Long Beach in Southern California. Our land based scrubber is used to clean the stack gases of ships that need to continue to run their engines to generate power while docked.

To read more about our products for marine diesel engines, download the case study below.

In previous blog posts I discussed an ultra-low SO2 (sulfur dioxide) scrubber using a 2-stage packed bed scrubber design.  The system treats the off-gas from a thermal oxidizer that oxidizes the waste gas streams from various sources at a waste oil re-refining facility in Southern, California.  The low emission limit enables the facility to remain outside of the South Coast Air Quality Management District (SCAQMD) Regional Clean Air Incentives Market   RECLAIM program.  To meet this objective, the scrubber system has to meet an emission limit of < 2.7 ppm outlet emission with an inlet load of approximately 104 lb/hr.  The limit must be met on a continuous basis which is monitored by a CEMs unit provided by Cemtek.  Envitech provided the scrubber as a turn-key installation and recently turned the system over to facility operations personnel. The CEMs unit is reporting emissions of < 0.5 ppm, well below the permit limit.

Please click on the icon below to download a paper on the scrubber system. 

In 2010 I blogged about a Marine Scrubber system to remove SO₂ from marine diesel engine exhaust gas.  This month, Envitech completed a 3MW marine diesel engine SO2 scrubber that will be used to clean the stack gases of ships while at dock at the Port of Long Beach, CA.   The scrubber will be used for the Advanced Maritime Emissions Control System (AMECs) by Advanced Cleanup Technologies, Inc..    The system will undergo duration tests at the port during 2012 and 2013 with the goal of obtaining a verification certificate by the California Air Resources Board (CARB). 

The AMECs system is a stationary system that uses a bonnet to capture the exhaust gas from the ships stack while at port. The exhaust gases are conveyed to the AMEC system to clean the gases of particulate (PM), NOx and SOx before exhausting to atmosphere. This allows the ship to operate its auxiliary engines and boiler system while at port to provide power to the ship.  The AMECs system provides a cost effective way for ships and port operators to reduce emissions and to meet tougher regulatory standards. 

In a parallel track, the maritime industry is looking for ways to meet tougher standards not only at port but while operating at sea based on the IMO Annex VI MARIPOL Tier III requirements. Envitech continues to develop De-SOx technology options for ship based marine diesel engines.  We are currently building a 3MW marine diesel SO₂ scrubber system that will be used in a demonstration unit for a complete after treatment system for SOx and NOx. The system will undergo validation testing in a state of the art marine engineering facility.  Testing will begin before the end of this year.

Please click on the icon below to download a case study on the Envitech HYSEA DeSOx scrubber.

I posted previous blogs discussing the South Coast Air Quality Management District (SCAQMD) Regional Clean Air Incentives Market   RECLAIM program and the A&WMA/AQMD SO_x Control Technology Conference held at Diamond Bar, CA on March 17^th.  During the conference I participated as a panel member to present Envitech’s Ultra-Low SO₂ scrubber design.  I will also be giving this presentation at the upcoming International Conference on Thermal Treatment Technologies (IT3) in Jacksonville, FL, May 10-13, 2011 and again at the Annual Air & Waste Management Conference in Orlando, FL June 21-24, 2011.  Envitech will have a booth at the IT3 conference.

Below is an abstact for discussing the Ultra-Low SO₂ scrubber design.  You can click the icon below to download the paper.

High Efficiency SO₂ Scrubber Design to Reduce Caustic Consumption

ABSTRACT 

An industrial facility located in Southern California operates a thermal oxidizer to treat vapor recovery and waste gas streams containing sulfur compounds.  The facility has an available source of alkali waste water which could be a potential scrubbing solution.  Several technologies were evaluated to replace the existing control equipment for reducing SO₂ emissions.  Incentives exist for similar facilities with the South Coast Air Quality Management District (SCAQMD) Regional Clean Air Incentives Program (RECLAIM) to reduce SO_x emissions below the facilities operating permit limits.  The RECLAIM program is requiring plants to achieve less than 5 ppm_v SO₂ stack emissions and greater than 99% SO₂ removal.

Plans are currently underway to replace the existing control equipment with a two stage packed bed scrubber system.  This arrangement enables the plant to achieve very low emission limits and reduce caustic consumption by as much as 28% compared to a single stage scrubber.  It also provides flexibility for future use of available alkali waste water to reduce caustic consumption by as much as 75% compared to a single stage caustic scrubber.  This reduction will save an estimated $165,000 per year in operating cost. This paper will discuss the system design and how it achieves low outlet emissions while reducing overall chemical consumption.  It will also discuss several other design considerations and benefits.  The design approach provides a viable alternative for other Southern California facilities impacted by the SO_x RECLAIM program as well as facilities in other regions.

Click on below icon to download whitepaper.

This is a follow-up to my blog post last week on SO_x scrubbers and the AQMD RECLAIM program.  I was a panel member duringone of the conference sessions for the SOx Control Technologies & Emissions Monitoring for Stationary Sources hosted by AQMD and the Air & Waste management Association (A&WMA).  The conference was held on March 17^th at the South Coast AQMD facility in Diamond Bar, CA.  There were about 90 attendees at the conference and my understanding is that all but one of the 11 major facilities impacted by the AQMD RECLAIM program had someone in attendance.

There were interesting presentations given in the morning sessions focused primarily on refinery applications. These included presentations by both INTERCAT and GRACE on additives that can be used in Fluid Catalytic Cracking Units (FCCU’s) to reduce SO_x emissions without add-on controls.  This type of approach will likely be used by most of the local refineries to meet shorter term requirements. However, the speakers noted limitations for achieving lower outlet emissions in the 5 ppm_v range.  These can include higher chemical consumption and impacts on opacity.  This suggests there may still be a need for back end controls to meet longer term requirements to achieve limits below 5 ppm_v.

PRAXAIR gave an informative presentation introducing their Refinery Gas Processor (RGP) technology.  This technology is targeted at treating non-H₂S sulfur compounds (Mercaptans, COS/Sulfides, Disulfides, Thiophenes) for use in conjunction with existing amine H₂S removal systems.  The RGP technology can enable a 90% reduction of non-H₂S sulfur  from refinery fuel gas.

Another issue discussed during the conference was the ability accurately measure and report outlet emissions as low as 5 ppm_v.  This will present a challenge for many facilities because most existing monitoring equipment are designed for measuring outlet emissions at higher concentrations.  However, several panel members from the afternoon session on emissions measurements provided useful information on how to address these challenges. These include presentations from:

• AMETEK
• HORIBA
• THERMO FISHER SCIENTIFIC
• PERMA PURE

I gave a talk during the afternoon session on control technologies. This session was dedicated to wet scrubber technology for achieving ultra-low SO_x emissions.  Ultra-low is loosely understood to be less than 5 ppm_v.  This is generally a longer term target for the AQMD RECLAIM program.  Most the technologies focused on wet gas scrubbers for refinery FCCU units.   I presented an innovative SO_x scrubber design to remove SO₂ from a thermal oxidizer exhaust at an industrial facility located in Southern California. The exhaust contains more than 1,000 ppm of SO₂ and the facility is required to achieve less than 5 ppm_v with greater than 99% removal efficiency.  There are several advantages of the scrubber design for applications requiring ultra-low SO₂ emissions.  The scrubber design may be a viable option for some of the facilities impacted by the AQMD RECLAIM program including FCCU units and glass manufacturers.  I’ll provide a future blog post that gives more information about the ultra-low SO₂ scrubber design.

If you would like to download the white paper on an ultra-low SO₂ scrubber design, click the link below.

A hot topic right now in California is the South Coast Air Quality Management District (SCAQMD) Regional Clean Air Incentives Market (RECLAIM), adopted in October 1993.  The purpose of the RECLAIM program is to reduce NO_x and SO_x emissions through a market-based program.  Reduction of these pollutants helps reduce smog and improve visibility.  Recent proposed amendments will affect eleven major facilities which emit and estimated 93% of the total emissions from the SO_x RECLAIM facilities.  These amendments will require many facilities to reduce SO_x emissions below the level of control they currently have in place.  Financial incentives exist for other facilities to reduce emissions below existing permit limits. 

The West Coast Section of the Air & Waste Management Association (A&WMA) is hosting a technical conference on innovative SO_x control strategies and technologies for stationary sources on March 17-18, in Diamond Bar, CA.  Part of the conference is dedicated to providing an overview of the regulatory landscape including new federal rules related to SO_x and the recently amended SO_x RECLAIM program.  I will be giving a presentation on an innovative SO₂ scrubber design used at an industrial facility in Southern California to remove SO₂ from a thermal oxidizer. The SO₂ scrubber is designed to achieve low outlet emissions below 5 ppmv and greater than 99% removal efficiency.  The presentation will discuss the advantages and benefits of the design, including reduction in caustic consumption. Continued efforts to deploy better technology and reduce emissions will enable clearer skies in the face of growing populations.

To learn more about achieving ultra low SO₂ emissions, please download our white paper.

Photo Credit, LA Smog - Recursive_1

Photo Credit, LA Clear Day - Nomadlovebird