swana 2011 landfill gas utilization excellance award nomination

SWANA 2011 LANDFILL GAS UTILIZATION EXCELLANCE AWARD NOMINATION Table of Contents

MONGOMERY REGIONAL SOLID WASTE AUTHORITY SWANA 2011 LANDFILL GAS UTILIZATION EXCELLENCE

AWARD NOMINATION Mid-County Landfill

TABLE OF CONTENTS

EXECUTIVE SUMMARY ...........................................................................................................1

1.0 DESIGN AND CONSTRUCTION ...................................................................................2

2.0 ENVIRONMENTAL CONTROLS ..................................................................................4

3.0 REGULATORY COMPLIANCE ....................................................................................4

4.0 PLANNING. OPERATIONS, AND FINANCIAL MANAGEMENT ..........................5

5.0 UTILIZATION OF EQUIPMENT/SYSTEMS AND TECHNOLOGIES ...................6

6.0 PUBLIC ACCEPTANCE, APPEARANCE AND AESTHETICS ................................7

7.0 INNOVATION AND CREATIVITY ...............................................................................8

APPENDIX Appendix I December 2010 Virginia Department of Environmental Quality Inspection Report

SWANA 2011 LANDFILL GAS UTILIZATION EXCELLANCE AWARD NOMINATION Page 1 of 8

EXECUTIVE SUMMARY

The Montgomery Regional Solid Waste Authority (MRSWA) manages and maintains the Mid-County Closed Sanitary Landfill, located in Christiansburg, Virginia. The landfill first accepted waste in 1983, stopped accepting waste in 2001 closing with approximately 1.3 million tons of waste in place. Since 2006, MRSWA has been exploring the feasibility of beneficially utilizing the landfill gas generated by the Mid-County landfill. Given that the landfill is closed, the age of the landfill, and the lower overall flow rate (<300 scfm), the landfill was not considered attractive for a large scale beneficial use project. The key to creating a financially viable landfill gas to energy project at MRSWA was reducing capital costs without compromising safety, reliability, aesthetics, or environmental compliance. The Project Team was able to modify the landfill gas collection system, and design, and construct a landfill gas to energy plant that is able to utilize a large percentage of the landfill gas collected. The power generated will be utilized by MRSWA's administrative offices and a recycling center. Excess power will be sold to Appalachian Power Company. Between $10,000 and $15,000 of the revenue from the sale of the energy will be put toward MRSWA’s green education programs.


1.0 DESIGN AND CONSTRUCTION

The Montgomery Regional Solid Waste Authority (MRSWA) began exploring the feasibility of beneficially utilizing the landfill gas generated by the Mid-County landfill since 2006. Given that the landfill is closed, the age of the landfill, and the lower overall flow rate (<300 scfm), the landfill was not considered attractive for a large scale beneficial use project. The key to creating a financially viable landfill gas to energy (LFGTE) project at MRSWA was reducing capital costs without compromising safety, reliability, aesthetics, or environmental compliance. This objective could not be achieved by deploying novel technologies but rather with a focus on efficiency and simplicity with respect to the process. Given these objectives, MRSWA decided a successful project could be developed by partnering with Green kW Energy, Inc. and Joyce Engineering, Inc. Prior to the installation of an active landfill gas collection system, MRSWA voluntarily passively collected landfill gas through a series of header pipes and combusted the gas in a candlestick flare. Rather than replace the existing landfill gas collection infrastructure, the equipment was upgraded and incorporated into the design of the LFGTE project. Additionally, the Project Team decided to locate the LFGTE plant directly adjacent to the existing collection system. This location was selected for several reasons. First, the capital costs of landfill gas transmission from the collection network to the LFGTE plant were significantly lowered. Second, the local electrical utility transmission lines are located approximately 200 feet from the proposed site, which significantly reduced the interconnection cost. Finally, the site did not require any significant grading or site preparation.


Planning and innovative approaches to asset acquisition also contributed to the success of the project. Laboratory testing of the landfill gas was completed in the early stages of design. The sampling indicated relatively low siloxane and sulfur concentrations in the landfill gas. As a result, pre-processing of the landfill gas was minimal, consisting of two particulate removal units and one after‐cooler. With a thorough understanding of the landfill gas quality, the equipment necessary for the project was determined. Typically, the equipment is ordered through the manufacturer or a distributor. However, the project team, in the interest of reducing capital costs, turned to some unconventional equipment sources, eBay® and Craigslist®. There is an amazing variety of new or nearly new equipment currently available on these sites. All of the following items were acquired new on eBay at a cost much lower than the manufacturer’s “recommended” price and arrived within one week of purchase:

• Kaser‐Omega positive displacement gas compressor • Magnatrol solenoid gas valves • Maxitrol pressure regulators • Square D high amperage circuit breakers • Alfa Laval heat exchanger

None of these items were in any way a compromise but represented the best equipment available for the project’s particular application. The most significant cost reduction was achieved by keeping the project team small. The project team consisted of four engineers, one scientist, and one pipefitter/fabricator/welder. Although the building construction and electrical infrastructure work was contracted out, all critical functions such as process design, permitting, fabrication, equipment installation, and commissioning (start-up testing) were performed by team members. Additional cost reductions were achieved by sourcing materials and utilizing local contractors. By keeping all critical functions in-house, the LFGTE process was constructed efficiently in terms of both materials and time. Commissioning was achieved within 11 months of the groundbreaking. An additional benefit of all team members having a hands-on role in design and construction was that opportunities indentified during construction to improve the process were seamlessly integrated into the final product.


2.0 ENVIRONMENTAL CONTROLS As previously discussed, landfill gas is collected from the Mid-County landfill through a series of header pipes. The landfill gas extracted from the landfill is composed of approximately 50 percent methane and 45 percent carbon dioxide. Landfills represent the largest source of man-made methane emissions. Methane has 21 times the greenhouse gas warming potential than carbon dioxide. As previously mentioned, the MRSWA voluntary installed the landfill gas collection system to reduce greenhouse gas emissions from the site. With the addition of the LFGTE plant, the facility is continuing to reduce greenhouse gas emissions, while generating clean, renewable energy. The LFGTE system was designed to efficiently utilize the maximum amount of landfill gas possible, but allow sufficient gas for the candlestick flare to operate continuously. This ensures the continuous destruction of the landfill gas even if the LFGTE plant is not in operation.

Once the landfill gas reaches the LFGTE plant, moisture is removed via a condensate knock out pot. From there, the landfill gas passes through two particulate removal units and one after‐cooler. The project team utilized a rotary lobe blower with a variable frequency drive and pressure sensor to ensure landfill gas fuel is fed into the generator set at a constant 2 pounds per square inch. Landfill gas is saturated as it is extracted from the landfill. However, some of this moisture condenses in the header pipe. The condensate is drained by gravity to two condensate sumps at the site. From the sumps, condensate is pumped into the MRSWA on-site leachate pretreatment system. The pretreatment system reduces the concentration of several key compounds to ensure the leachate will not negatively affect the City of Christiansburg Publically Owned Treatment Works. 3.0 REGULATORY COMPLIANCE

The MRSWA is an integrated solid waste management system which is committed to excellence in solid waste management. MRSWA provides a variety of services which include a transfer station, mulch facility, white goods facility, tire facility, electronic and universal waste facility, buy-back facility and a dual-stream material recycling facility. MRSWA is the designated lead agency for a planning region comprised of Montgomery


County, the Towns of Blacksburg and Christiansburg and the Virginia Polytechnic Institute and State University (Virginia Tech). A 5-Year Update for the MRSWA Solid Waste Management Plan (SWMP) was submitted to the Virginia Department of Environmental Quality (VDEQ) and approved on August 10, 2010. The SWMP outlines long term strategies and goals for the planning period of 2004 through 2024 and is an integrated solid waste hierarchy which includes the following waste management alternatives, listed in order of decreasing preference: source reduction, reuse, recycling, resource recovery (methane gas to electricity), incineration and landfilling. MRSWA staff ensures that the facility is in compliance with local, state, and federal rules and regulations. MRSWA prides itself in successfully running a safety program which includes weekly and monthly safety meetings. A copy of the most recent VDEQ compliance inspection report has been included in Appendix 1. The LFGTE system is also managed and operated in compliance with all federal, state, and local laws, rules, and regulations. MRSWA’s LFGTE Project was honored as the Small Engine Project of the Year on January 19, 2011 at EPA’s 14th Annual Landfill Methane Outreach Program (LMOP) Conference and Project Expo in Baltimore, Maryland.

4.0 PLANNING, OPERATIONS, AND FINANCIAL MANAGEMENT

Operating the LFGTE plant requires a tight focus on engine controls and equipment maintenance to maximize process uptime. Due to LFG contaminants and variable methane content, equipment life and process maintenance costs would be unacceptable without effective engine monitoring and control systems along with frequent preventative maintenance. Target process uptime is 85%. The biggest challenge to engine life and air emissions minimization is properly controlling air/fuel ratio. Because the LFG methane content can change by as much 25% within a 24-hour period the air/fuel ratio must be monitored and adjusted frequently. This is particularly true of the Waukesha generator set. If the air/fuel ratio becomes too rich, detonation can occur resulting in catastrophic engine damage. For this reason the Waukesha generator set has been equipped with an automatic air/fuel ratio control device. An exhaust gas analyzer is used to adjust the air/fuel ratio on the 75 kW generator set twice per day.


To ensure extended generator set bearing life, engine oil formulated for LFG fuel is utilized and changed frequently. Additional routine maintenance includes spark plug and compressor oil replacement. Both generator sets are equipped with monitoring and control systems that will safely shut-down equipment in the event of temperature excursions and low coolant and oil levels. The annual maintenance budget is $41,100 per year and includes reserves for annual top-end overhauls and complete overhauls every three years for both prime movers. The building foot print contains sufficient room for one additional 75 kW generator set that will be deployed provided that a planned expansion of the LFG well field results in LFG flow is sufficient to fuel the additional generator set. The process is operated by the Project Team members that designed and installed the process. These members possess several decades of experience operating industrial process and have completed Hazardous Waste Operator, fire safety, and general industrial safety training. In addition, written procedures documenting start-up, shut-down, maintenance, and repair procedures have been developed and implemented.

5.0 UTILIZATION OF EQUIPMENT/SYSTEMS AND TECHNOLOGIES

5.1 Landfill Gas Equipment

The heart of the LFGTE plant is a 265 kW generator set equipped with a Waukesha engine. While current flow rates could support additional Waukesha units, the project team opted to utilize a proprietary 75 kW generator set designed and constructed by members of the project team. There are several advantages to utilizing these units. First, they require less landfill gas compared to the larger unit which allows the project to better match the landfill gas flow rate. Graph 1 depicts the how the energy generation matches the flow rate utilizing the large 265kW units. Graph 2 depicts energy generation utilizing a combination of the 265kW and 75kW units. Initial estimates indicate utilizing a combination of generator sets to efficiently utilize the maximum amount of landfill gas could produce an additional 9,200 megawatts over the 10 year project.


Graph 1

Graph 2

Use of a combination of high and low flow rate units also allows the project to continue to generate electricity as landfill gas flow rates decrease. Second, use of a combination of large and small unit allows maintenance to be performed on one unit, while the other continues to operate. This ensures the plant is continuously generating electricity. 5.2 Routine Maintenance and Training

The active landfill gas collection system is balanced and maintained on a monthly basis. Balancing the collection system helps to ensure each extraction well is performing safely and optimally. Optimization of the landfill gas collection and control system will limit landfill gas migration potential and help maintain compliance with the Virginia Solid Waste Management Regulations. As a result, the landfill gas system will provide the maximum volume of landfill gas available to the LFGTE plant, at the highest quality and quantity, thus maximizing the amount of electricity generated.

6.0 PUBLIC ACCEPTANCE, APPEARANCE AND AESTHETICS

A clean and green design was used with the LFGTE project. Building construction was chosen for its durability and economy. The LFGTE plant has an attractive appearance and is located away from domiciles and traffic, and intermingles very well with the landfill gas equipment (blower and flare) that have been located on site for over five years. The green exterior of the building also blends in with the surrounding landscaping. A ribbon cutting ceremony was held at the facility on October 14, 2010. Many citizens, public officials, and media attended the event. Tours were conducted and the public got to witness how capturing and using landfill gas reduces air pollution, minimizes safety risks associated with unharnessed gas, and taps into an otherwise wasted source of usable energy. Landfill staff continues to provide educational programs and tours for schools, businesses, and local civic organizations not only for the LFGTE system, but for other facilities at MRSWA.


7.0 INNOVATION AND CREATIVITY

Though the MRSWA Mid-County landfill is closed, it still provides a service to the community. In partnering with Green kW Energy and Joyce Engineering, MRSWA has completed a project to capture gas generated by only 1.3 million tons of waste in the landfill and to convert it into renewable energy. The project team took steps to reduce project costs by obtaining new equipment (gas compressor, solenoid gas valves, pressure regulators, high amperage circuit breakers and heat exchanger) on eBay® at costs significantly lower than the manufacturer recommended prices. The team also kept processes as simple as possible, which enabled it to locally obtain many of the skills and materials required to build, operate, and maintain the project. In addition, by maintaining a versatile and efficient project team and focusing on project functionality and aesthetics, the team built and currently operates a financially viable landfill gas to energy project at a small site. The MRSWA Mid-County closed landfill (56 acres) will generate an estimated 160,000 kilowatt-hours of green electricity per month. In June of 2012, after MRSWA’s current electric power agreement expires, the landfill gas to energy facility will power MRSWA’s administrative offices, material recycling facility, and all other facilities on site. The current process of selling excess power to the Appalachian Power Company will also continue as part of the operation of the LFGTE facility. Part of the revenue from selling the energy helps fund MRSWA, generating a revenue stream which will be used for green education programs, such as the design and construction of a new education and training facility. The closed Mid-County landfill is now a community asset contributing to cleaner air and generating renewable energy. The LFGTE facility is the first of its kind in the western half of Virginia and demonstrates that MRSWA is always thinking of ways to be a better neighbor and to attract unique business opportunities to the area.

APPENDIX 1

swana 2011 landfill gas utilization excellance award nomination

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