Landfill Gas Recovery Waste to Energy

Eliminating Crankcase Emissions

The Challenge:

The Operator of a closed landfill in Manchester, Connecticut wanted to recycle the methane gas he was paying thousands of dollars to flare off each year. His idea was to produce power on site and sell it to the grid during peak times. This can be a lucrative enterprise given the growing demand for electricity and U.S. Government Energy Tax Credits.

To accomplish this, he spent roughly $4,000,000.00 to build a facility and install two Caterpillar G3520 gen-sets. After installation and start-up, the Operator experienced significant visible crankcase emissions, and these were exhausted outside the building to the atmosphere. This environmental issue was troublesome since he was trying to protect the environment by installing the waste to energy gen-sets.

The Operator hired an engineering firm to design the plant, and after the emissions were deemed excessive, he asked them to find a solution. Not only did he want to eliminate the emissions, but he also wanted to maintain a constant pressure in the crankcase all while being maintenance free. Solberg was up to the challenge.

The Equipment:

Engine Gen-Set: Caterpillar G3520
Crankcase Flow: 35 CFM
Required Crankcase Pressure: -0” to -4” H₂0

The Solution:

Solberg designed a Vacuum Assisted Oil Mist Eliminator (VAE) to capture the blow-by emissions and regulate crankcase pressure. Additionally, a Variable Speed Drive was included to automatically control crankcase pressure in the absence of maintenance personnel. This was a collaborative process in which Solberg Engineers worked directly with the engineering firm and Operator to design the ideal system.

System Components :

1. Internal Air/Oil Separator Element: 99.97% efficient for 0.3 micron oil mist. Designed to eliminate visible blow-by emissions
2. Regenerative Blower: Creates vacuum to overcome differential pressure created by the separator element and to maintain negative pressure in the crankcase
3. Variable Speed Drive Control Box: Automatically maintains a constant vacuum level in the crankcase as differential pressure and blow-by parameters change
4. Relief Valve: Opens to allow air into the blower if vacuum exceeds -30” H₂0
5. Pressure Relief Valve: Opens at 1” of H₂0 positive pressure in the crankcase. Protects engine seals and prevents leakage

The Installation:

After the two VAE assemblies were delivered, installation was handled by the Operator. During the process, Solberg advised and provided information regarding mounting and start-up.

The Results:

During two subsequent visits by Solberg Engineers, the mist eliminators functioned well. Crankcase vacuum was maintained at approximately -3” H₂0 by function of the variable speed drive. Additionally, the previously visible blow-by emissions were eliminated.
Solberg staff will stay in contact with the Operator to ensure the VAE installation continues to satisfy his needs.

Landfill Gas Recovery Waste to Energy

Preventing Engine Seal Leakage

The Challenge:

The Operator of an active landfill in Marshall, Michigan uses three Waukesha engine gen-sets to turn waste methane gas into electricity, which is in turn used to power the plant. The engines are worn and have been overhauled multiple times. Each one was equipped with a Waukesha supplied crankcase breather. This unit tied into the engine intake creating a venturi effect to generate vacuum. The breather was designed to capture oil mist blow-by from the crankcase, and the vacuum
produced by the venturi was used to create a slight negative pressure in the crankcase.

The Operator had continual problems with the existing breathers. These units did not sufficiently stop the oil mist blow-by and the engine intakes became contaminated. The engines do not run efficiently when the intake air is dirty. Secondly, the breathers contributed significant back pressure
resulting in positive pressure in every engine. This pressure resulted in leaking seals and an oily mess on the surrounding floor. The waste to energy gen-sets were designed to protect the environment, so the oil leakage was unacceptable.

The Operator called Waukesha and asked for their guidance to solve the problems. Waukesha recommended Solberg Oil Mist Solutions based on some joint breather
development work.

The Equipment:

Engine Gen-Set: Waukesha 7042GL
Crankcase Flow: 110 CFM
Existing Crankcase Pressure: + 4” H₂0
Required Crankcase Pressure: - ½” H₂0
Raw Crankcase Blow-By Emissions: >450 mg/m³

The Solution:

Solberg designed a Vacuum Assisted Oil Mist
Eliminator (VAE) to create negative pressure in the crankcase, eliminate seal leakage and capture visible blow-by emissions. The design went through multiple iterations, and we finalized on the wall mounted unit shown above.

The Installation:

This was a collaborative process between the Operator and Solberg Manufacturing. We visited the site prior to our initial recommendation. The first VAE was designed as a prototype that was easy to
connect, remove and move from engine to engine if necessary. To accommodate this, it was mounted on a stand with locking casters to allow for easy transport. Also, to expedite set-up and testing, the collected oil was drained into a 5 gallon waste bucket. The final clean exhaust was then vented out of the engine room. Once the Operator was pleased with the performance, Solberg designed permanent leg supports to raise the unit to its proper height above the high oil level in the crankcase. At the Operator’s discretion, the drain line was routed back to the crankcase.

System Components :

1. Internal Air/Oil Separator Element: 99.97% efficient for .3 micron oil mist. Designed to eliminate the visible blow-by emissions.
2. Regenerative Blower w/ 4HP Motor: Creates vacuum to overcome differential pressure created by the separator element and to maintain negative pressure in the crankcase.
3. Pressure Relief Valve: Opens at 1” of H₂0 positive pressure in the crankcase. Protects engine seals from damage and leakage.
4. Ball Valve and Fresh Air Filter for Vacuum Control: As engine blow-by/flow increases over time, he separator element becomes dirty and the differential pressure increases. Without vacuum control, the result is positive crankcase pressure. In this case, the valve is closed to restrict fresh air flow, which increases vacuum produced by the blower. This simple device allows control through the life-cycle of the element and engine.
5. Oil Return Drain: This drain line runs back to the crankcase. To ensure proper drainage in this application, the port is located 24” above the high oil level and the line is submerged below the low oil level.

The Results:

During subsequent visits by Solberg personnel, both mist eliminators functioned well. The Operator was able to easily maintain -1/2” H₂0 in the crankcase through periodic manual valve adjustments. Also, visible blow-by emissions were eliminated and carry-over was measured at less than 5PPM. This allowed for the exhaust to be routed outside of the building and into the atmosphere. The Marshall site is planning to install a third Solberg VAE in 2008.
The Operator manages several sites nation-wide, and Solberg is partnering with them to introduce this solution to their network.

Natural Gas Booster

Inline Scrubber Application

The Challenge:

An existing Ariel JGH/2 turbine installation located in Pennsylvania had an operational problem on a gas turbine booster application.  The compressor system was designed to allow for the feeding of compressed natural gas at a constant discharge pressure into the turbine.  The volume of flow in the application is based on the requirements of the turbine which is dictated by the power demand on the system.  The scrubber that in place in the application was unable to provide the required dehydration of the moist air stream.  As a result, the compression rate and required system pressure was difficult to maintain.

The Equipment:

Turbine Model: JGH/2 Ariel
Flow Rate: 300 Cubic Feet per Min.
Temperature: 100 degree F
Flow Pressure: 125 PSI
Gas Stream: Saturated Methane

The inlet port and piping on the compressor was a 6-inch ANSI bolt pattern, raised face flange. The manufacturer recommends a pressure of 250-PSIG on the tank construction to allow for the necessary safety factor in design.

The Solution:

Replace the existing, undersized filter housing with a pressure filter of ASME code design with a design based on the flow rate and layout of the existing system. A Solberg Manufacturing, Inc. PCSS series was selected to handle the job.

The turbine OEM and the end-user enjoyed the fact that the system worked with their existing piping arrangement and could be installed with minimal system changes.  They also found the application assistance with properly sizing the element and the air flow rate to be a benefit.

The Solberg ASME Vessel:

PCSS series designs consist of pressure rated chamber and a coalescing filter.  Leg supports and gauging are often built into the system as optional features which aide in both the installation and service of the equipment.  The element is rated 99.97% efficient at the 0.3- micron particle size to remove the saturated gas and is designed for a service interval of 1-year, which makes the installation maintenance free.

The Installation:

Solberg technical support and engineering were in constant communication with the customer during installation to ensure that questions were answered and challenges resolved.  Periodic reviews are conducted with both the packager and the end-user to ensure that all of their needs have been met.

The Installation:

We specifically built the unit to fit within the customer’s space, and they will be installing the unit on the turbine package.

Vacuum Assisted Oil Mist Eliminator

Custom Built for Easy Maintenance and Installation

The Challenge:

A turbine packager in Ohio wanted to reduce the overall size of their current vacuum assisted oil mist eliminator in order to simplify the service and installation processes.

The customer’s existing design was excessively tall, which severely limited the service area needed to replace the internal coalescing filter element. Also, the overall size made it difficult to install within the allowable enclosed space.

Solberg's challenge was to reduce the overall size while providing the required flow and vacuum level (negative pressure).

The Equipment:

Turbine Model: MAN Turbo THM1304
Lube Oil Reservoir: 600 gallons
Required Flow Rate: 120 SCFM
Required Vacuum Level: -50mbar

The Solution:

Solberg designed a Vacuum Assisted Oil Mist Eliminator (VAE) to fit on the vent port of the lube system. When installed, this unit will create a vacuum (negative pressure) in the reservoir to prevent seal leakage. The VAE will also eliminate oil mist emissions and prevent these contaminants from being released into the atmosphere. All of this will be accomplished with a decreased overall height of 10+ inches.

The customer was appreciative of the fact that Solberg could build a customized solution, and they were also pleased that multiple options were available to satisfy their needs.

The Solberg VAE:

Vacuum Assisted Oil Mist Eliminator (VAE) designs consist of the following components:

1. Vacuum rated tank assembly
2. Regenerative blower system to create the required vacuum (negative pressure) level. An optional automated vacuum regulator allows the customer to monitor and adjust the vacuum level within their tank assembly from a remote computer. Solberg also included an adjustable band/bracket assembly, so the blower and motor can be adjusted if necessary.
3. Coalescing filter element to remove oil mist and smoke from the lubrication reservoir. To protect the surrounding environment, the coalescing filter is 99.97% D.O.P. efficient on .3 micron particles. It is designed for a service interval of 1 year.

The Installation:

The VAE was specifically built to fit within the customer's space and they will be installing the unit on a Man Turbo package.