Dennis Aaberg has recently retired from Cummins Power Generation after a thirty-seven-year career in noise and vibration control. He is a recognized expert on the subject and the author of articles appearing in our Gas Turbine, Reciprocating Engine Decision Guide. During his career, which began with Onan Corporation before it was purchased by Cummins, Inc. and became Cummins Power Generation, he worked within the Applied Technology Group to reduce product noise levels and improve sound quality on small gas and diesel engines, generator sets, garden tractors, welders, and a variety of other engine-driven applications. Dennis has also worked integrally with customers to solve community noise issues, and application noise issues.

Dennis’ acoustical and vibration knowledge has developed through hands on experience working on engineering projects and research experiments over that thirty-seven-year period and attending seminars and classes at such higher education outlets as Massachusetts Institute of Technology, Purdue University, University of Wisconsin, University of Minnesota, and numerous other seminars taught by industry experts and data acquisition equipment manufacturers.

Dennis agreed to answer our specific questions.

McIlvaine: What are the advantages of customizing silencer solutions?

Dennis: To provide fairly accurate insertion loss predictions (i.e. within 1-3 dB(A) or better) for a given internal combustion engine driven product the silencers must be custom made for each engine driven application because a given muffler will perform differently for each different engine it is integrated with.

Exhaust silencing systems act as a system with the engine, so any modeling work must include physical internal dimensions of the engine exhaust system and engine; along with all the engine operating parameters. That is partially why when you look in exhaust silencer manufacturer catalogues you typically see a 10 dB(A) expected exhaust noise insertion loss range, because it can vary greatly from engine to engine. Therefore, to custom design a product to meet a strict noise level, several iterations of modeling, analysis, test, and validation typically need to be made. This can be time-consuming and expensive, but perhaps necessary in critical noise control applications; which are becoming much more common globally.

Since the speed of sound changes with temperature, this can also complicate the expected insertion loss of the muffler for any particular engine because the broadband effectiveness of the silencer can vary as the engine exhaust temperatures change as the silencing effectiveness at various frequencies can change as the engine and silencer temperatures change.

That is why reputable design and test facilities allow and engine to stabilize at each load and speed for approximately 15 minutes typically before measuring the sound levels.

McIlvaine: The CO₂ from engines is particularly beneficial for greenhouses. What noise challenges does this pose?

Dennis: I am not familiar with using CO₂ from engines for greenhouses, but I do know that emissions regulations are getting increasingly stricter to reduce CO₂ emissions.

Exhaust silencing systems have been, and are continuing to be developed to reduce exhaust gas emissions. These systems require extensive design considerations, involve using chemical injections into the diesel exhaust gas stream, and are very expensive; but they are becoming available.

McIlvaine: How do noise regulations vary around the world, and how strict are they?

Dennis: In North America, sound levels are regulated at property lines. Therefore, when selling products, the sales force must rely on the company providing accurate sound levels for the products, and when the capability exists, predicting sound levels at the property line for the application so they can avoid any fines or loss of sales due to not being able to meet the noise regulations. (Side note: I used an environmental noise modeling program called SoundPLAN for this purpose in several situations. SoundPLAN is generally accepted globally as the premier software modeling program for this purpose)

In the European Union, and generally in other parts of the world, sound levels are regulated at the source: meaning the products up through 400 kW cannot be sold into the European Union if they exceed the regulated noise limits, specified in A-weighted Sound Power Level (i.e. dB(A) Lw, or SPWL).

In India, generator sets for outdoor installations must be installed in a sound enclosure, and the sound levels measured 1 meter from the generator set cannot exceed 75 dB(A). This is regulated by their Pollution Control Board.

Noise is increasingly becoming a more sensitive issue globally and regulations globally are driving acceptable noise levels lower. Therefore, going forward companies selling products that are regulated by noise ordinances, regulations, and laws will want to invest in staff, equipment, and software to effectively and efficiently design their products with high confidence levels that their final production products will meet the required sound levels in the markets they plan to sell in to.

McIlvaine: What are some noise reduction considerations for recreational vehicles and boats?

Dennis: Everything has natural frequencies that they like to vibrate at, including humans. When input forces match the natural frequencies things go into what we call resonance. These are frequencies where energy is easily transferred and accepted and can cause the vibrating object to move violently and fatigue sometimes very quickly and break. At the very least, it will cause more than usual noise caused by the vibration, since sound is simply pressure variations caused by vibration in an elastic medium. The higher the levels of vibration: the higher the noise level.

Recreational vehicles and boats tend to have large lightly damped structures that like to vibrate at low frequencies. Generator set primary operating speeds many times line up closely with these natural frequencies so great care must be exercised in the placement of the generator set and providing a large impedance mismatch between the generator set and boat or recreational vehicle structure to provide the isolation necessary to keep the energy transfer to a minimum. This is usually a challenge and can be very difficult.

If not critically isolated or if placed in a part of the structure that is particularly receptive of force inputs, the vibration forces entering the structure can easily travel from one end of the structure to the other and cause unacceptable sound and vibration levels inside to the horror of the people inside the vehicle or boat. As with all applications, this is a system problem that is best resolved by manufactures of the boats, recreational vehicles, and generator sets working together to solve the system problem effectively and efficiently as possible. This can be a challenge, but is the best approach.

McIlvaine: What about sound quality? When does that become a factor?

Dennis: Sound quality over the past twenty years or so has become increasingly more important in Consumer Product Markets, such as the recreational vehicle and marine applications. I have witnessed cases where overall sound levels of a product acceptable to the customer are higher in amplitude than ones that are not acceptable simply due to the quality of the sound.

Increasingly owners of recreational vehicles and boats are saying they don’t want to hear their generator set operating. They want to flip a switch and get power but not the noise of the generator set to go with it. As with most things, we want everything, but we are only willing to pay for so much. This is where sound quality becomes especially important. If we can improve the quality of the sound to be unobtrusive even though audible, the customer is willing to accept that.

I might also add that it is possible to design an application in such a way that the generator set would be silent in respect to the natural ambient sound levels, but it requires larger sound enclosures, and almost certainly use of “active sound and vibration systems” that cancel the acoustic and vibration signals going into the structure by monitoring the signal and sending a signal back 180 degrees out of phase to cancel it. Since active cancellation systems are still fairly expensive as compared to passive systems, most customers are not willing to pay for that increase noise attenuation yet, but the option exists.

Also, since internal space availability in boats and recreational vehicles is a premium for customers, they are not yet willing to sacrifice the space for less noise. Perhaps in the future this will change as the population gets progressively accustomed to lower noise levels in the environment. As with everything in life, as higher expectations are satisfied it just drives expectations even higher.

McIlvaine: What are considerations for engines and generator sets installed inside a building or on a building’s roof?

Dennis: If installed in buildings, the primary considerations are air flow silencing for the room inlet and outlet air systems. Typical installations have the generator sets mounted on isolation springs of properly designed stiffness to reduce vibration energy from transmitting through the floor to the building structure: or in the case of roof-mounted generator sets, transmitting through the roof to the building structure.

If installed in a building’s room, the wall mass usually provides the necessary transmission loss, especially if the walls are sand-filled, which they many times are to provide the extra mass and damping needed for good sound transmission loss.

Another consideration is the exhaust silencer system. These systems typically are designed to run vertically above the building’s roof level, so they must consider the backpressure produced in overcoming the pressure to push the exhaust gases up the silencer’s piping system and how that affects the generator set’s available power output.

McIlvaine: There seem to be a variety of designs, costs, and performance of sound enclosures. What tips do you have for purchasers?

Dennis: There are a wide variety of sound reduction enclosure offerings depending on the installation sensitivity to sound.

The very basic sheet metal enclosure that is meant to simply protect the unit from the weather may have louvered openings all around and no sound reduction materials or sound reduction ductwork. These relatively flimsy enclosures, in vibration terms, may even increase noise levels because they are not designed to be noise reduction enclosures, and they will typically vibrate enough to cause an increase in overall sound level, or at best, provide no sound attenuation.

Above that, there are typically several levels of noise reduction offerings based on application needs. These range from approximately 10 dB(A) reduction to over 20 dB(A) reduction or more in the case of well-designed drop-over sound enclosures that provide the necessary space to design high transmission loss walls and high noise reduction air inlet and outlet ductwork. A 10 dB(A) sound attenuation enclosure with sound absorption material, a medium grade exhaust silencer, and relatively unsophisticated air inlet and outlet ductwork for air-flow is usually attained without much effort.

I must add, however, that all sound attenuation enclosures must be designed, tested, and analyzed by competent engineering staff to ensure especially that the cooling capacity needs of the generator set are maintained to prevent overheating and reduced power output.

McIlvaine: Can cooling systems add to the noise problem in an enclosure?

Dennis: As power density increases in generator set products, cooling system packages are many times producing higher sound levels than the generator set (engine/generator). This has resulted in the difficult position of providing a sound enclosure in a reasonable skid-mounted size that can effectively reduce the noise of the cooling system, which tends to generate high sound levels at typically low blade-pass frequencies that can be difficult to attenuate without long acoustically treated air flow ducts.

This is another reason why companies producing such products can benefit from a staff with good acoustical sound attenuation knowledge, state-of-the-art data acquisition and analysis equipment, acoustical modeling expertise, and facilities capable of performing accurate acoustical measurements in accordance with ISO requirements and recommendations.

McIlvaine: Any other tips for sound enclosure purchasers?

Dennis: Keeping in mind that sound is vibration in an elastic medium, and the fact sound enclosures have large, flat, and usually lightly damped structures, enclosures are especially susceptible to any vibration paths from the generator set to the sound enclosure and skid base they are mounted to. Short-circuit paths can greatly reduce the effectiveness of an otherwise well-designed sound enclosure.

Short-circuits include anything that connects directly from the operating generator set to the enclosure: such as ground cables, stiff hoses, exhaust piping touching walls they pass through, vibrating cables, any compression points between acoustical sound absorption insulation and the generator set, and etcetera.

Excessively stiff isolation mounts between the generator set and skid base is another factor. The isolation mounts should be as soft as possible while still providing sufficient load capacity. Orientation and location of the isolation mounts can also be a significant factor.

Skid base stiffness is also an important consideration. It is prudent to determine the natural frequencies in the skid base and design a skid base with proper stiffness to avoid natural frequencies that coincide with the operating frequencies produced by the generator set.

INDUSTRY NEWS

Clarcor to Become Sole Supplier of Inlet Filtration Systems for GE’s H-Class Gas Turbines

Clarcor has entered into a ten-year agreement with GE to become the sole filtration supplier to its H-class power turbine. The agreement also has provisions for Clarcor to work with GE in developing the next generation air inlet filtration system for the H-class platform. GE’s H-class gas turbine is one of the world’s largest and most efficient turbines in the business. Clarcor had acquired the air filtration business from GE in December 2013, and it has worked for nearly a year to clinch this deal.

Clarcor will be providing filters and other components to GE at a discount to cost. The company expects to realize a sizable aftermarket benefit starting four years after the sale of the original equipment.

Powerphase Receives Patent for Technology to Help Turbines Operate at High Ambient Temps and Elevations

Powerphase, a developer of upgrades for gas turbines, has been issued a U.S. patent for a technology that improves the output, fuel efficiency and responsiveness of gas turbines operating at high ambient temperatures or elevations.

The technology, Turbophase, uses a fuel driven engine and its waste heat, along with a highly efficient compressor in a cogeneration process to generate hot, compressed air approximately 35 percent more efficiently that the gas turbine itself. The highly efficient air is then injected into the gas turbine, allowing it to produce its optimum output in all ambient conditions. Because the incremental air is created so efficiently, not only does the gas turbine generate more megawatt hours, but it also makes all of its megawatt hours more fuel efficiently.

The company has installed Turbophase on the two most widely used gas turbines, the 6B and the 7FA, both manufactured by GE. Because all gas turbines use copious amounts of air in their combustion processes, greater air efficiency leads to greater fuel efficiency.

"Our innovative use of air creates a generational leap is gas turbine fuel efficiency,” says Bob Kraft, the inventor of Turbophase. “We like to say, 'Air is cheaper than fuel.'"

GE and Tata Collaborate to Reduce Gas Turbine Manufacturing Cost

GE and Tata Consultancy Services have developed a technology that will revolutionize the gas turbine manufacturing process using smart LEDs and GE’s Predix operating system. The solution will analyze temperatures at various points on the metal turbine parts as they are assembled and cooled, allowing operators to know when the next operation can be performed, reducing wait time between operations and improving quality monitoring. A pilot application has been built at GE Power’s gas turbine manufacturing plant in Greenville, South Carolina.

During the turbine manufacturing process, rotor stacking is a key process and needs extremely high levels of precision. If the rotor wheels are stacked incorrectly due to differences in the surface temperature, it will require reassembly, incurring heavy additional costs and two to three weeks of shipment delays. Tata’s new digital solution provides automatic data collection of ambient room and rotor surface temperatures, notifying workers when the next operation may proceed and alerting workers to any non-uniformity.

The platform is composed of smart LED fixtures from Current, powered by GE, integrated with sensors that monitor temperature, humidity and any physical object presence, transmitting the data to an Intel Atom-based gateway where the information is streamed to the Predix cloud.

GTRE second section

Houweling’s will Install Two 4.4 MW GE Engines in BC Greenhouse

Houweling’s Nurseries Ltd. (dba, Houweling’s Tomatoes) operates a 20-hectare greenhouse facility in Delta, B.C., producing both fresh tomatoes and propagated vegetable seedlings for other greenhouse vegetable growers. The heat and CO2 requirements are supplied by five natural gas fired boilers which have an estimated efficiency of approximately 84%. The estimated emissions produced by the current operation of the natural gas fired boilers are 23.7 tons annually.

The boilers operate throughout the day to produce heat which is stored in a 1.5-million-gallon reserve tank and subsequently used as required in the greenhouse. Some amounts of the CO2-enriched exhaust are used to promote a healthy crop and vegetable production. An additional 1,000 tons of liquid CO₂ is purchased for their seedling propagation department, as the CO₂ generated from the current system is not acceptable for growing seedlings.

This limitation creates additional waste during the months of October to February as crop production is reduced and seedling propagation is at its peak production. During this period the boilers are only in operation for heating generation. As a result, the exhaust from the boilers is released into the atmosphere, while liquid CO₂ must still be purchased.

Houweling’s Tomatoes proposes the installation of two 4.4 MW GE Jenbacher natural gas-fired, combustion engine driven, cogeneration units. The CO₂ enriched gases from the engines will be treated using selective catalytic reduction (Hanwel COdiNOX system) to reduce the NO_x levels in the exhaust, meeting the requirements of the seedling crops as well as promoting healthy crop enhancement in the tomato production area. This flue gas cleaner ensures the flue gases from CHP gas engines are converted into food grade CO₂, which can then be used immediately for plant and seedling fertilization. This will eliminate the need to purchase, transport and store liquid CO₂. The anticipated emissions from the Co-Gen units will be less than 11.5 tons annually, reducing emissions output by at least 50 percent.

Houweling’s is also Operating GE Engines at is Camarillo California Plant

GE engines have been providing heat, power, and CO₂ to a California greenhouse for the last several years. Houwelings Tomatoes, is operating the first combined heat and power (CHP) greenhouse project in America that captures carbon dioxide (CO₂) for use in plant fertilization. Using two of GE’s 4.36-megawatt (MW) units, Jenbacher J624 two-staged turbocharged natural gas engines and a GE-designed CO₂ fertilization system, the plant provides heat, power and CO₂ to Houwelings 125-acre tomato greenhouse in Camarillo, Calif.

GE has installed more than 800 gas engine CHP units in greenhouses globally. This represents approximately 2 gigawatts of power generation plus CO₂ fertilization systems. With the installation of Houwelings engines GE has its first U.S.-based system.

The first greenhouse CHP project in the U.S. also gives an added boost to California’s goal to generate 6,500 MW of new CHP generation in the state by 2020. The project represents the launch of GE’s J624 two-staged turbocharged gas engines for the 60 Hz segment and the first of these engines sold in the U.S. Introduced by GE in 2007; the J624 is the world’s first 24-cylinder gas engine for commercial power generation and can be used in various applications. It also is the first gas engine featuring double turbo charging, which makes it even more efficient.

PACIFICORP SPECIAL COVERAGE

PacifiCorp Activities to Receive Special Coverage in GTRE Decisions

McIlvaine has been conducting a series of five webinars for PacifiCorp to help them with their decisions on NO_x control at coal-fired power plants. The webinars are organized around the information which is gathered for Power Plant Air Quality Decisions. This effort is being expanded to cover activities at all the PacifiCorp power plants. The purpose of adding information on PacifiCorp gas turbine and gas engine activities is to demonstrate the value of GTRE Decisions to any power plant

Person to person communication optimization is just as challenging as machine to machine. Suppliers and consultants as well as individuals within PacifiCorp can benefit from the communication regarding activities at all the plants. All the newer thermal power plants operated by the company are fueled with natural gas.

GE Provided Op Flex Optimization Software at PacifiCorp Currant Creek for $7.8 million. What was the payback?

An upgrade was supplied several years ago. We would like to report on the current status and include options by one and all on the approach.

The Currant Creek project is a grassroots 525-megawatt natural gas-fired power plant consisting of a 2 x 1 combined cycle power block. The plant was constructed in two phases: Phase 1 consisted of the installation of two GE 7FA combustion turbine generators to operate in simple cycle mode, and Phase II called for the installation of two heat recovery steam generators (HSRGs) and a steam turbine generator.

The two HRSGs constructed in Phase II were a 10-module tube bundle design. PCL’s work included installation of the Low Pressure (LP), Intermediate Pressure (IP), and High Pressure (HP) steam drums, boiler piping, soot blowers, platforms, grating, and associated equipment.

PacifiCorp entered into a sole source contract with General Electric International to install its Op-Flex cold day performance package on the Currant Creek plant. The estimated amount of this purchase is $7,819,500.

Under the contract General Electric was to provide three equipment packages designed to increase the cold weather performance, gas turbine operational flexibility, increase base load output, and enhance combustion dynamics monitoring at the Currant Creek plant. The “Op-Flex Cold Day Performance” package is designed to provide increased output and improved heat rate during cold weather conditions. The “Op-Flex Turndown” package provides the ability for plant turndown (reduction in load) to be reduced from 80% to 70%. This package will result in lower operating costs, increased low load reliability, less fuel consumption to stay on line, and expanded emission compliance. The “Continuous Dynamics Monitoring” package enables the first two packages to work.

PacifiCorp said that they had exhausted competitive alternatives to the engine control packages offered by General Electric. These packages can only be provided by General Electric, the original equipment manufacturer and owner of the proprietary engine control system. Payment for the equipment packages is based on a sliding scale based on performance. If the unit performance meets or exceeds the guaranteed performance levels, payment will be at the level stated above. If unit performance does not meet the guaranteed level, the payment is reduced accordingly down to a minimum level of $319,500.

If you have any contributions to update us on this, it would be appreciated.

Currant Creek Plant is CHP with Successful Tomato Growing Operation

The Currant creek plant provides heat and CO₂ to a large on site tomato greenhouse. It involves a large duct providing waste heat and CO₂ as shown in the picture below. It has been quite successful but one Pacific Corp source said that in the future the hot water from the HRSG a smaller duct with just enough flow to provide the CO₂would be an even better solution.

A duct connects Rocky Mountain Power's Currant Creek Plant with the Houweling’s Tomatoes greenhouse. The power plant heats the greenhouse and it provides nutrients and condensed water to the tomato plants.

The 28-acre Houweling’s Tomatoes greenhouse near Mona, Utah, is among the first of its kind in the world to draw its heat and plant-nourishing carbon dioxide from a neighboring power plant. A bonus for Houweling’s is the water it condenses from the flue gas is used to irrigate the tomato plants.

Brad Richards, manager at Rocky Mountain Power’s Currant Creek Plant explained, “The manufacturer of the boiler and stack engineered the penetration in the stack and determined there wouldn’t be any issues with our operations or with our emissions monitoring equipment.”

A plant outage was required to complete construction of the duct. So Houwelings and Rocky Mountain Power coordinated the work during planned maintenance on a weekend in April 2015.

The Houweling’s Tomatoes heat recovery system inside its boiler building connects to the 10-foot-diameter duct from Currant Creek Plant.

“We’ve been upfront with Houweling’s from the beginning that our customers are first priority with everything having to do with safety and plant operations,” said Ian Andrews, Rocky Mountain Power resource development director. “We had to coordinate a phased construction process to work around the plant’s planned outage schedule.”

Houweling’s began construction of the 475-foot-long duct from the plant to the greenhouse in July 2015. The 10-foot-diameter duct stands 25 to 30 feet above the ground.

“We didn’t expect any effects on plant performance or reliability, and there haven’t been any,” Richards reported. “The system is working well and was designed with very few changes to our normal operation.”

Using an Argus control system, waste exhaust is drawn off the side of the stack, diverting it into Houwelings energy building where thermal energy is captured and stored for on-demand heat. Condensation from this process is captured and used to supplement irrigation water, and the remaining exhaust CO₂ is released directly into the greenhouse to promote plant growth. The custom Argus system controls the equipment that extracts the CO₂ and the heat from the stack gas and sends signals to and from the power plant, including general status, alarm points and portions of dampers, CO₂ demand, boiler status, and temperature and efficiency readings. The control system also monitors gas flow and temperature, concentration of CO and NOx, and controls the condenser fans, condenser pumps and dampers on this project.

Yurij Duda, Argus Controls General Manager congratulated Houweling’s on the award: “Houwelings is a real leader in sustainable agriculture and is truly committed to innovation in energy management. Argus was honored to be selected as their control system partner to help make this unique project a reality.”

Energy Saving Projects at Washington Plants

PacifiCorp Energy has seven generation facilities in their fleet that provide electricity to the State of Washington. These units vary from coal-fired to natural gas to wind. The State of Washington has recently passed legislation requiring PacifiCorp to complete all cost effective energy efficiency measures in these generation facilities.

The purpose of a 2011 report was to outline the systems investigated and detail the cost effective measures at three of the seven locations: Jim Bridger (Unit #1 only), Chehalis and Goodnoe Hills. This 2011 report is displayed in full in the PPAQD Intelligence System.

One of the biggest potential improvements at the time of the report was adding VFD to pumps and fans. For example, VFD could be installed at Jim Bridger for RO feed and condensate pumps.

This system consists of three RO system trains; A, B and C. Trains A and B utilize three 60 HP RO feed pumps and train C has two 75 HP pumps. Trains A and B use a discharge control valve to deliver about 270 gpm of filtered water to the RO membranes. During normal operation two of the three trains are in operation. When Trains A and B are in operation only 2 of the three pumps are needed. Train C only needs one of two pumps to operate.

Proposed: RO feed pumps on Trains A and B should be upgraded with VFDs and controls to vary pump speed to deliver the required flow to the RO membranes.

This measure would add the following equipment:

· Six 60 HP pump VFDs

· VFD controls

Condensate Pumps Baseline: The condensate pump system consists of three 700 HP 7,200 volt pumps that transport condensate from the discharge of the main turbine to the Deaerator (DA) tank.

During normal operation two of the three pumps are needed to maintain the tank level in the DA tank. Two parallel discharge control valves are modulated to the desired DA tank level.

Proposed: The proposed changes would install new inverter rated motors with VFDs and necessary controls to regulate the pump speed. The pump speed will be varied to maintain the DA tank level. The existing control valves should be fully opened during normal operation.

This measure would add the following equipment:

· Three 700 HP 7,200-volt pump VFDs

· Three 700 HP 7,200-volt inverter duty motors

· VFD controls

Forced Draft Fans Baseline: This system consists of two 2,250 HP 7,200 volt centrifugal fans that operate in parallel to provide secondary and overfire combustion air to the boiler. Capacity control is achieved by variable inlet vanes. The fans maintain a static pressure of approximately 16 in WC in the duct. Both fans are needed during normal operation.

Proposed: The proposed ECM is to install new 7,200-volt invertor duty motors and VFDs with controls. The existing inlet vane dampers should be removed and speed control used to meet the required flow and pressure based on unit load. This measure would add the following equipment:

· Two 2,250 HP invertor duty 7,200 volt motors

· Two correctly sized VFDs

· VFD controls

Other pumps and fans were included. Also included is the analysis for the520 MW gas turbine combined cycle plant located in Chehalis.

Approved gas turbine component supplier list for PacifiCorp

Preferred vendors based on the Currant Creek 2 plant are designated. For example, Cuno is the approved supplier for the condensate filters. However, in 2011 at Wyodak the Pall filter was installed to replace the existing Cuno string wound filters and positive results such as less iron deposition were experienced. Has this information been transferred to those making up bidders’ lists?

NEW ENTRIES IN GTRE DECISIONS

Here are new entries in the GTRE Decisions. You can click on the title for the full text.

Wartsila has many applications in baseload, standby and emergency power

Applications include airport installations with heat, cooling, and power. One installation is run with vegetable oil as a fuel and does include SCR. CHP provides up to 90% efficiency.

Revision Date: 9/7/2016

Tags: Wartsila, NOx

Oil & Gas Slides - Hot Topic Hour August 26, 2016

The Oil and Gas webinar conducted by McIlvaine was primarily focused on the opportunities created by the growth of gas by over 50 quads over the next 25 years.

Revision Date: 8/26/2016

Tags: 221112 - Fossil Fuel 化石燃料, 324110 - Petroleum Refineries 石油精炼

Oil & Gas Webinar - Hot Topic Hour August 25, 2016

Maximizing flow control and treatment revenues is a volatile market.

Revision Date: 8/25/2016

Tags: 221112 - Fossil Fuel 化石燃料, 324110 - Petroleum Refineries 石油精炼

Lower emission limits for biogas engines in SCAQMD as of January 2016

SCAQMD rule for biogas effective 2016 limits emissions to 11 ppmv NOx – 30 ppmv VOC – 250 ppmv CO. Stakeholders have commented that the capital and operating costs for cleaning up the biogas are very high and post-combustion control technologies such as Catalytic Oxidation and Selective Catalytic Reduction (SCR) are expensive to install and operate and argued that many of them will resort to flaring as a less costly alternative. Response: •The costs are significant but the environmental benefits are also significant. •Proposed controls are very cost effective. •Reasonable emission reductions such as those from biogas engines needed to meet the ambient air quality standards. •Flaring of a renewable energy source is undesirable. •Biogas flaring, except for a small Greenhouse Gas disbenefit, has a much lower criteria pollutant footprint compared to biogas engines, even considering power that needs to be generated by central power plants.