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    Louisiana Clean Fuels Seeks Nominations for the Katry Martin Award

    Awards Ceremony to be held November 5, 2020, at the LCF 20th Anniversary Gala and Annual Clean Fuel Leader Awards

    Every two years, LCF honors one person whose kindness, positive attitude, and passion for alternative fuels sets them apart from their peers. The award's namesake, Katry Martin, served as the Executive Director of St. Landry Parish Solid Waste. Under his leadership, St Landry Parish was the first landfill in Louisiana to successfully commission, operate and monetize Environmental Attributes. While many others talked about the merits of carbon offsets, St. Landry Parish planned and executed. Additionally, St. Landry Parish was one of the first to build, own and operate a Renewable Natural Gas (CNG) Project at the landfill. This project is the template for smaller RNG (CNG) Projects on a global basis. Katry was revered for being a visionary who was also able to take his ideas and put them into practice.

    LCF awarded Katry and St. Landry with the Innovative Project award at our 15th Anniversary Celebration in 2015, something that he was extremely proud of. Anyone who met him knew him to be a kind, humble, and passionate man who was responsible for dreaming up and making St. Landry's groundbreaking RNG facility a reality. Katry passed away on October 10, 2017, after a brief battle with cancer. The Katry Martin Award serves as a chance for LCF to honor his legacy and recognize his contributions to alternative fuels.

    Winner of the First-Ever Katry Martin Award in 2018:  Faltery "F.J." Jolivette

    Anyone who has ever met F.J. will understand why he was selected to honor his former boss as the first-ever winner of the Katry Martin Award. His kindness, humility, and passion for his job set him apart from his peers and endear him to everyone he meets. As the operator of St. Landry Parish Solid Waste's landfill gas to renewable natural gas facility, F.J. has been an integral part of the renewable natural gas industry for many years. His incredible work at St. Landry has been recognized across the nation and internationally – he once gave a presentation in Africa on the use of landfill gas as a vehicle fuel! His industry leadership has kept St. Landry's project thriving since 2012, and he truly exemplifies the qualities that were so well-loved in Katry Martin.

     

    LCF is asking for nominations of one individual in Louisiana whose character and contribution to Clean Cities, alternative fuels, petroleum and/or emissions reduction honors the legacy and spirit of Katry Martin.

    Nominations for the 2020 Katry Martin Award are due Friday, September 4, 2020.

    submit a nomination

    Note: Louisiana Clean Fuels staff are not eligible for this award.


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    LCF Staff Pick: Top 5 tools on the AFDC

    By Samantha Breax, LCF Intern

    Whether you’re working at home, looking for data from the office, or interested in starting your alternative fuel journey, the Alternative Fuels Data Center (AFDC) provides free access to all of the tools you need. As an unbiased resource from the US Department of Energy, AFDC offers calculators, interactive maps, and data searches to assist fleets, fuel providers, and the everyday driver in advancing alternative fuel and energy-efficient efforts.

    To access their entire collection of tools, visit https://afdc.energy.gov/tools.

    Here are five of our favorite AFDC tools:

    1) Electric Vehicle Infrastructure Projection Tool (EVI-Pro) Lite

    This calculator provides an estimate of how many public electric vehicle chargers would be necessary in a given state/urban area to support EV adoption. Along with its recommendation, it provides the number of currently available chargers and next-steps for new stations.

    View the EVI-Pro Lite Tool

    2) Alternative Fueling Station Locator

    The Alternative Fueling Station map shows public fueling stations across the United States and Canada. It includes mapping for all alternative fuels, including electric, CNG, LNG, propane, biodiesel, hydrogen, and ethanol. For private fleets, private fueling stations can also be located, along with unavailable and planned stations, by using the advanced filters option. The route mapping feature allows you to plan travel with fueling stops in mind.

    View the Station Locator

    3) Vehicle Cost Calculator

    This tool allows you to compare the cost of ownership, annual fuel and electricity use, and expected emissions between up to 8 vehicles simultaneously. Basic information about your driving habits is used to calculate costs and emissions for makes and models of most vehicles manufactured since 2005.

    View the vehicle cost calculator

    4) AFLEET tool 

    The AFLEET tool uses data from Argonne National Labs’ GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) to calculate a fleet’s petroleum use, greenhouse gas and air pollutant emissions, and cost of ownership. The spreadsheet uses simple inputs such as vehicle type, year, and mileage to calculate emissions per year and per vehicle lifetime. The most recent version allows for analysis of off-road equipment as well as light-duty and heavy-duty vehicles. This tool is for those who are comfortable with and are well versed in Excel. If you would like assistance with this tool, please email us at [email protected].

    View the AFLEET tool


    5) State Information

    The State Information data search pulls information for your state about laws and incentives, fueling stations, Clean Cities Coalitions, fuel prices, vehicle emissions, and more. It contains links to other tools provided by AFDC, such as the Clean Cities Coalitions Locator and Laws and Incentives Search, acting as a one-stop shop for all state-wide information. 

    View state information

    learn more on the AFDC website


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    Baton Rouge Bikeshare Program Seeing Success Despite COVID-19

    By Olivia Montgomery, LCF Intern

    Across the country, cities are rethinking the way they invest in transportation infrastructure. Baton Rouge in particular has joined a growing list of cities investing in bikeshare programs, one piece of a larger trend of services known as shared micromobility, which generally refers to share programs offering bikes, scooters, or e-bikes. Gotcha bikes, offered in the Baton Rouge area, are e-bikes that allow the rider to pedal or coast with the electric motor.

    From a sustainability perspective, these programs offer a great way to reduce automobile use by providing a quick and easy means of transportation for those rides that are too short for a drive and too long for a conventional bike. More broadly, bikeshare programs also offer economic benefits in that they can encourage economic development in certain areas, expand the reach of current public transit options, and improve public health.

    How to Ride

    As of July 2019, Gotcha bikes are available to rent on a pay-per-minute basis in Baton Rouge. Riders can download the Gotcha app to sign up, find docking station locations, and scan the bike to pay and ride. Once finished, riders can deposit the bike at any other station in the city. There are 17 locations downtown, in addition to stations near LSU, Southern University, and the Perkins Road overpass. The cost to rent is currently a $2 fee, plus $.10 per minute, or riders can purchase yearly or monthly subscriptions.

    Current Success

    According to the National Association of City Transportation Officials, the number of shared micromobility rides doubled from 2017 to 2018. Today, COVID-19 seems to be aiding the trend of growth. Nationwide, cities have closed streets or limited their capacity to create more space for socially distanced foot and bike traffic and to reduce reliance upon crowded public transit, naturally creating more demand for bikeshare rides.

    Though Baton Rouge has not made major changes to traffic flow, the impact of COVID-19 on bikeshare rides is similar in the capital area. On May 4, 2020, the Baton Rouge Area Foundation’s newsletter reported “Ridership is up 213% overall even though LSU students are no longer on campus. Trips per day had grown to nearly 600 on April 26, when the bikeshare company reported its latest activity. Weekly active riders soared to 1,500 in late April from less than 100 before COVID-19.”

    Some see this moment as an opportunity for changes that last beyond the pandemic. Former New York City transit commissioner Jannette Sadik-Kahn recently stated that this is a “once-in-a-lifetime chance to change course and repair the damage from a century of car-focused streets.” Coincidentally, one challenge Baton Rouge faces in growing its bikeshare program is the lack of comfortable bike paths and trails throughout the city. In fact, there are few, if any, comfortable trails connecting the clusters of docking stations throughout the city (i.e. LSU or Southern to downtown). Further, the City’s Bike Share Business and Implementation Plan includes expanding docking locations into different areas in a series of phases. However, one must ask how beneficial bikeshare access will be in areas with no sidewalks or bike lanes.

    Considering the increased demand for bikeshare rides, further strengthened by the COVID-19 pandemic, now is the time for Baton Rouge streets to become more bike-friendly. Over time, as shared micromobility increases, the positive impact on the city’s carbon emissions, car-congested streets, and more will become apparent.

    For more information, check out the following resources:

    Baton Rouge Ride Gotcha

    Baton Rouge's bike-sharing program sees dramatic uptick in ridership amid coronavirus pandemic

    COVID-19 Reveals How Micromobility Can Build Resilient Cities

    Webinars on COVID-19 and Micromobility

    Biking Provides a Critical Lifeline During the Coronavirus Crisis 


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    FOTW #1138: New Light-Duty Vehicle Fuel Economy in the United States Has Nearly Doubled Since 1975

    Originally posted by the Department of Energy Office of Energy Efficiency and Renewable Energy | Original Article

    From 1975 to 2019, fuel economy for all new light-duty vehicles produced for sale in the United States has increased from an average of 13.1 miles per gallon (mpg) to 25.5 mpg, a 95% increase. This is a significant improvement considering the new vehicle mix has recently shifted heavily towards SUVs and pickups, which generally have lower fuel economy than cars. The car SUV category showed the most improvement from 1975 to 2019 with a 143% increase in fuel economy. Cars, truck SUVs and vans each increased by more than 100% in that same time frame, while pickups increased by 63%.

    Note: Data for 2019 are preliminary. Data are production weighted. The “Car SUV” category includes 2-wheel drive SUV with inertia weight of 4,000 lb. or less.

    Source: U.S. Environmental Protection Agency, 2019 EPA Automotive Trends Report, EPA-420-R-20-006, March 2020.

    Fact #1138 Dataset

    READ the original article


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    Wheels Keep Turning on Innovations for More Efficient and Clean Vehicles

    Originally posted by the Department of Energy Office of Energy Efficiency and Renewable Energy | Original Article

    While approximately 30% of today’s new cars can boast fuel economy of at least 30 miles per gallon, there is still the opportunity for further efficiency gains. In addition, while trucks make up just 4% of all U.S. automobiles, they account for more than 25% of transportation-related fuel consumption, and diesel averages 44 cents more per gallon than gasoline.

    Top scientists, engineers, and analysts with the U.S. Department of Energy’s (DOE’s) Co-Optimization of Fuels & Engines (Co-Optima) initiative are examining how simultaneous improvements to fuels and engines can improve efficiency and reduce emissions and costs of the entire on-road fleet, including light-duty (LD), medium-duty (MD), and heavy-duty (HD) internal combustion vehicles that are likely to make up the majority of the U.S. automotive market for decades to come.

    After completing a major body of research focused on turbocharged spark ignition engines in Fiscal Year (FY) 2018, Co-Optima’s FY2019 LD research and development (R&D) shifted focus to multimode solutions that employ multiple engine operating modes to maximize engine efficiency and fuel economy. A new report highlights the most significant Co-Optima R&D accomplishments from FY 2019, with details on findings that straddle LD, MD, and HD technologies.

    Co-Optima is jointly sponsored by DOE’s Office of Energy Efficiency and Renewable Energy’s Bioenergy Technologies and Vehicle Technologies offices. Partners include nine National Laboratories, along with more than 20 university and industry partners.

    Get more details on the report and learn more about the Co-Optima initiative.

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    SWEPCO's Level 2 Home EV Charging Station Rebate Program

    Electric vehicle owners in Southwestern Electric Power Company's (SWEPCO) territory could receive payment for installing a Level 2 electric vehicle charger in their homes. SWEPCO is now offering a new $250 rebate for their residential customers "who own or rent a single-family home" and "install an ENERGY STAR-certified Level 2 EV Charging Station." Currently, the rebate is available for SWEPCO customers in Louisiana and Texas, and SWEPCO is hoping to offer the rebate to Arkansas customers in the future.

    To qualify for the rebate, customers must install the ENERGY STAR-certified Level 2 charging station and save their receipt for proof of purchase. According to SWEPCO, qualifying ENERGY STAR-certified Level 2 EV Charging Stations can be purchased "online, from a local retailer or a dealership." You can learn more about ENERGY STAR-certified chargers on the ENERGY STAR website.

    Important to note are the rules of the rebate program, which can be found on SWEPCO's website. These rules specify that the rebate is limited to two Level 2 EV Charging Station per home and that funding is limited and will be distributed on a first-come, first-served basis. The rebate also only applies to charging stations installed in 2020, and application information "must be submitted within 30 days of equipment installation and set up."

    SWEPCO customers who wish to learn more about the rebate program can find more information on SWEPCO's Rebate Program page. Customers wishing to claim the rebate should fill out SWEPCO's online application.

    LEARN MORE


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    FOTW #1135: Corporate Average Fuel Economy Standards Finalized Through 2026

    Originally posted by the Department of Energy Office of Energy Efficiency and Renewable Energy | Original Article

    On March 31, 2020, the National Highway Traffic Safety Administration posted the final Safer Affordable Fuel-Efficient Vehicles Rule, which finalizes the Corporate Average Fuel Economy (CAFE) standards through 2026. Estimates of CAFE requirements for cars reach 47.7 miles per gallon (mpg) in 2026 and for light trucks reach 34.1 mpg.

    Source: U.S. Department of Transportation, National Highway Traffic Safety Administration, The Safer Affordable Fuel-Efficient 'SAFE' Vehicles Rule, Final Rule, Tables II-15 and II-16.

    Fact #1135 Dataset

    read the original article


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    2020 Enrollment for LCF’s Green Fleets Program is now open!

    Louisiana Clean Fuels (LCF) has opened the 2020 enrollment period for our Green Fleets Certification program! The LCF Green Fleets Program is designed to recognize fleets for their progress towards their emission reduction goals as well as to assist fleets in deploying solutions that improve the economic and environmental performance of vehicle operations.

    What is Green Fleets Certification?

    Through Green Fleets, Louisiana Clean Fuels conducts emissions analysis and quantification of on-road vehicles for fleets throughout the state of Louisiana. Fleets can also promote their Certified Green Fleets status, showing their commitment to reducing emissions. Once certified, your organization will receive a report detailing your emissions reductions and scoring under the program along with permission to use the Green Fleets certification seal for your certification level on any and all of your organization’s publications for one year.

    Benefits of being an LCF Certified Green Fleet

    • Educational opportunities with workshops, training, and more.
    • Recognition and certification for environmental fleet leaders.
    • Branding and promotional tools for fleet achievement.
    • Informational resources on technology options and available incentives.
    • Connections with vendors offering advanced fuel and vehicle technologies, equipment, conversion systems, and more.
    • Funding assistance with grant opportunities; better data makes a better application. 

    Past Participants

    Examples of past participants include Republic Services, SporTran, the City of Lake Charles, Corporate Green, and UPS. all of which achieved certification through the Louisiana Clean Fuels Green Fleets Program. It takes significant effort to achieve any certification level, and Louisiana Clean Fuels is proud to offer recognition to fleets dedicated to reducing emissions. 

    The City of Lake Charles

    The City of Lake Charles achieved a 1-star certification through the Greet Fleets Program for the Lake Charles Public Works Transit Division in 2019. Lake Charles operates propane para-transit buses in their fleet.

    Republic Services

    Across the country, refuse companies are great examples of successful natural gas programs. Republic Services - also recognized as LCF’s 2019 Clean Fuel Champion at the Clean Fuel Leader Awards - achieved a 5-star certification through the 2019 Green Fleets Program. Republic Services utilizes compressed natural gas (CNG) in LCF’s territory to fuel their refuse trucks. Additionally, Republic Services reduces their emissions and fuel usage through other methods, including idle reduction, vehicle miles traveled (VMT) reduction, and fuel economy improvements.

    SporTran

    Shreveport’s transit company, SporTran, achieved a 5-star certification through the Green Fleets Program in 2019. SporTran’s bus fleet runs on 100% alternative fuels and consists of 33 CNG-powered buses and 5 electric buses.

    How to Enroll

    Enrolling in our Green Fleets program is simple and free.

    1. Fill out this short form or email LCF’s Co-Coordinator Tyler Herrmann at [email protected] to express your interest in the program.
    2. We will work with you to collect your relevant fleet data, such as vehicle types, model years, number of vehicles, fuel used, and fuel types.
    3. LCF will provide your fleet with a report that you can use as a benchmark for future fuel consumption and emission reduction programs. We will work with you to track your progress over time and provide guidance to help your fleet achieve emissions-reduction goals.

    With just a few extra steps, fleets who participated in our 2019 Annual Report can enroll in Green Fleets. The Annual Report survey asks users to indicate whether or not they’d like the data they’ve provided in the survey to be used to enroll them in the Green Fleets program. Most of the information needed for Green Fleets enrollment is already being provided for the Annual Report, so we can use that information to start the enrollment for the Green Fleets program if a fleet is interested. Then we will contact that fleet for further informational requirements at a later date.

    Learn more about the LCF Green Fleets Program and enrollment requirements on our Green Fleets Certification Program page.


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    FOTW #1131: Average Fuel Economy for Model Year 2019 Light-Duty Vehicles Was 95% Better than Model Year 1975

    Originally posted by the Department of Energy Office of Energy Efficiency and Renewable Energy | Original Article

    The average production-weighted fuel economy for all new light-duty vehicles in model year (MY) 2019 was 95% better than in MY 1975, while average horsepower was 78% higher and weight was 1% higher. From the late 1980s to the mid-2000s, fuel economy generally declined while horsepower and weight increased. Since 2004, due to technical innovations, fuel economy and horsepower have increased while vehicle weight has stayed about the same.

    Note: Data for 2019 are preliminary. All data are production weighted.

    Source: U.S. Environmental Protection Agency, 2019 EPA Automotive Trends Report, EPA-420-R-20-006, March 2020

    Fact #1131 Dataset

    read the original article


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    Waste to Fuel: On the Making of Renewable Natural Gas

    Natural gas remains one of the most-used alternative fuels in Louisiana. According to Louisiana Clean Fuels’ (LCF) 2018 Annual Report, in 2018 alone, natural gas (CNG) was responsible for offsetting over 5 million gasoline gallon equivalents (GGEs) in the state [1].

    Though the majority of natural gas used in Louisiana comes from fossil-sources, a small percentage is renewable natural gas (RNG), which is chemically identical to natural gas from fossil-sources but comes instead from renewable sources such as food waste, manure, and other decomposing organic materials.

    DID YOU KNOW?
    Methane is 20-30x worse than carbon dioxide as a greenhouse gas. Burning methane turns it into carbon dioxide, reducing its global warming potential. Landfills are the third-largest anthropogenic (human-caused) methane source in the U.S. Manure management is the fourth largest anthropogenic methane source. Much of the methane produced by these sources (wastewater treatment plants, landfills, and farms) is normally released into the atmosphere, but RNG projects instead collect and use this methane as natural gas, lowering the overall emissions of these industries. [2]


    St. Landry Parish Solid Waste creates and uses RNG in central Louisiana; they collect methane (CH4) from their landfill which is then cleaned and used as RNG to fuel their trash trucks. St. Landry’s RNG project, which began operation in 2012, was the first of its kind in the United States. Over the last two years, LCF has worked closely with St. Landry to create an operations manual for their RNG project. Once the manual is complete, we will begin work on an RNG curriculum to teach the process to other landfills and increase the amount of RNG used in Louisiana.

    RNG has grown in popularity across the United States in recent years, with the number of operational projects increasing from 60 projects at the end of 2017 to 89 projects at the end of March 2019 and the total production capacity of these projects increasing by approximately 25% over that same 15 month period. Additionally, a recent study by the Colorado Energy Office found that by utilizing RNG, Colorado can replace 24% of its annual diesel usage, eliminating 1.4 million metric tons of carbon dioxide (CO2) every year [3]. Interest in RNG has also dramatically increased, and there have been numerous articles written in the last year to explain the generalities of RNG production. Considering our working relationship with the St. Landry Parish project, LCF is uniquely situated to shed light on some of the deeper complexities of the subject, and our hope is to provide insight into how these types of projects actually operate. This article will hopefully serve as a midpoint between a 30,000 ft view and a deep technical dive.

    The Process

    RNG can be created from several different sources or feedstocks, but three of the most common are landfills, farms, and wastewater treatment plants. There are three basic steps to producing usable RNG: raw gas collection, conditioning/cleaning, and distribution. These steps are the same regardless of feedstock; in this article, we’ll be focusing on how this process works for landfills.

    Collection

    In a landfill, trash, which includes organic matter (food waste, paper waste, farming waste, etc.), is placed in a pit, called a cell, which is specially prepared to receive and contain trash with as little environmental impact as possible. The trash is dumped into the cell and covered with dirt, clay, and eventually an impermeable liner to prevent odors, liquids, and landfill gas (LFG) from escaping. This produces an anaerobic (oxygen-free) environment within the landfill. Most modern landfills are classified as Sanitary Landfills, which are designed to reduce their environmental impact as much as possible. This includes trapping the LFG and burning it.

    DID YOU KNOW?

    Anytime organic matter is present in an anaerobic environment, a huge host of microbes will eventually break the organics down into carbon dioxide (CO2) and methane (CH4) in a process called anaerobic digestion. This is true of landfills, but this same process happens with other feedstocks as well, such as wastewater treatment plants and farms. The decomposing organic matter within the landfill produces a mixture of gases known as landfill gas or LFG; gas collected from other sources is referred to as “biogas”.

    Each landfill cell will hold a certain amount of trash before it’s completed and covered with an impermeable liner (basically a gigantic plastic sheet) that traps all the LFG. Wells are then drilled into the cell to collect that gas. These wells are large pipes with holes in them, allowing the LFG to pass through but not the solid trash. The pipes are all connected to each other in a huge network called a well-field and then connected to a vacuum pump that literally sucks the gas out of the landfill. Each well has its own wellhead, which is a valve that can control the amount of suction at that well without needing an individual vacuum pump for each well.


    If the LFG isn’t removed from the landfill, pressure will build, eventually releasing methane and other harmful gases into the atmosphere. If the pump pulls too hard on the wells, air can get into the landfill, introducing nitrogen and oxygen to the landfill. The presence of oxygen inhibits anaerobic digestion and can contribute to the formation of landfill fires. Landfill fires release harmful emissions and are very difficult to extinguish, sometimes burning for weeks or even years. Nitrogen intrusion can also be very problematic due to the difficulty of separating nitrogen from the LFG during the conditioning process. Pulling too hard on the wells introduces nitrogen and oxygen, and not pulling hard enough releases raw LFG into the atmosphere. This balancing act is one of the most important pieces of any landfill RNG project.


    LCF Co-Coordinator Tyler Herrmann (right) showing LCF's interns a well-head at the St. Landry Parish Solid Waste landfill.

    Traditionally, the LFG is simply dried and then sent to a flare to burn all the methane and other unwanted compounds, reducing their environmental impact. Burning methane converts it to carbon dioxide, which is less harmful as a greenhouse gas, and also helps to remove harmful gases such as Volatile Organic Compounds (VOCs), a class of chemicals which includes carcinogens such as benzene. In a landfill RNG project, the LFG is diverted from the flare and sent to a separate conditioning/cleaning facility to be made into usable natural gas. Under EPA regulations, landfills above a certain size are required to collect and flare the LFG they produce [4]. This is one of the big benefits of a landfill RNG project: the first step in the RNG process - collecting the gas - is something the landfills are already required to do.

    Conditioning/Cleaning

    The level to which the gas must be cleaned is heavily dependent on its end-use. If the gas will be put into a pipeline, it must be cleaned according to the specifications of that pipeline. If the intention is to use it for electricity production, there are separate requirements for that as well. To use RNG as a vehicle fuel in natural gas vehicles, the gas needs to meet Society of Automotive Engineers (SAE) standards.

    The makeup of raw LFG is generally about half methane and half carbon dioxide. The gas can also contain unwanted by-products that must be removed, including hydrogen sulfide, siloxanes, carbon monoxide, VOCs (which can include benzene, butane, ethane, or a massive variety of carbon-based compounds), along with many other unwanted chemicals. The specific mix of these chemicals is heavily dependent on the feedstock. For example, if someone throws old air-conditioning equipment into a landfill, the LFG may temporarily include freon (a type of VOC), which will also need to be removed. Weather also affects raw gas quality; both of these factors require the conditioning process to be robust enough to maintain the product gas specs year-round.

    DID YOU KNOW?

    Pipeline quality natural gas is usually around 94% methane and 6% balance gas, a term used to refer to inert gases that are harmless to the system, namely nitrogen and carbon dioxide. If the gas being injected into the pipeline does not meet the required BTU (British Thermal Units) specs, gases such as propane, butane, and hydrogen may be added.

    Since raw gas is around 50% methane and pipelines require around 94% methane, the carbon dioxide and other impurities need to be removed. There are many terms used to describe or name this cleaning process, including upgrading, cleaning, or conditioning. [5]


    The first step in conditioning is to remove hydrogen sulfide (H2S). This is usually done by chemically filtering the gas through a special type of activated carbon or other filtration media that strips out the hydrogen sulfide. Hydrogen sulfide needs to be filtered out for two major reasons:

    • Hydrogen sulfide can form sulfur oxides (SOx) when burned. SOx is a criteria pollutant under National Ambient Air Quality Standards (NAAQS) [6]. SOx emissions have effects on lung health and can contribute to the formation of both harmful particulate matter in the atmosphere and acid rain.
    • To protect the CO2 membranes later in the process (explained below).

    The second step in conditioning is to remove Volatile Organic Compounds (VOCs). This is also often done through chemical filtration with a different type of activated carbon. VOCs are filtered out for two major reasons:

    • Many VOCs have negative health effects, and some are carcinogenic.
    • To protect the CO2 membranes and siloxane filters later in the process.

    VOCs can include butane, ethane, and propane, all of which are allowable and often desirable in pipeline natural gas, but they are removed along with other VOCs during conditioning to protect the siloxane media and carbon dioxide membranes.

    Often, the third step in RNG conditioning is to remove siloxanes. These are silicon compounds that generally come from cosmetics, which means they're present in landfills and wastewater treatment facilities, but not in farms Siloxanes can be filtered out by passing the LFG through a special type of silica pellet, by condensation, or by water/solvent absorption. In the case of silica pellets, the pellets will also absorb VOCs and hydrogen sulfide, so they can become saturated and lose effectiveness if these are not effectively filtered out first.

    Siloxanes are not toxic; they’re removed to protect other equipment down the line. When siloxanes are burned, they produce non-toxic silicon powder which can clog sensors in a natural gas engine and act as an abrasive. This is so dangerous that a single tank of bad natural gas in a CNG vehicle can cause catastrophic engine failure. Siloxanes can also damage electricity generators if they use microturbines or post-combustion catalysts. Since siloxanes don't damage other filtration and don't harm all use-cases, this step is sometimes skipped depending on the intended end-use of the gas [7].

    The fourth step is to remove carbon dioxide. Carbon dioxide makes up between 40-60% of the raw gas, so it may need to be removed to raise the BTU content to meet the specific needs of the use-case. Some use-cases can handle 50% methane, and carbon dioxide filtration is skipped, but this isn't common. Carbon dioxide can be filtered out in two main ways:

    CO2 Filtration Membranes

    These membranes are essentially tiny plastic tubes with holes approximately the size of carbon dioxide molecules that act as a physical filter, separating methane from carbon dioxide. As the raw gas is pumped through the tubes at a fairly high pressure (>100 PSI), the carbon dioxide escapes through the holes in the tubes, and what’s left is a gas with a higher concentration of methane.

    One of the benefits of using a membrane is that it's a purely physical filtration method; a CO2 membrane will effectively last forever. A drawback is that the membranes are really sensitive to VOCs and hydrogen sulfide. Any breakthrough of VOCs or hydrogen sulfide will poison the CO2 membranes, rendering them useless. CO2 membranes are also very expensive, potentially costing tens of thousands of dollars, even for a small project. This is why so much care is given to separating VOCs earlier in the process.

    There are many types of CO2 membranes, some of which can be used to filter hydrogen sulfide as well as carbon dioxide. St. Landry Parish Solid Waste uses the type described above.

    Pressure-Swing Adsorption (PSA)

    For this method, there is a surface that selectively adsorbs carbon dioxide, but only at certain pressures. The gas is brought to that pressure, the carbon dioxide molecules attach to the surface, the remaining gas (which is higher purity than the raw gas) is stripped away, and then the pressure is changed so that the filtered carbon dioxide releases from the surface. PSA filtration is an active filtration process, requiring a more complex system than passive filtration by a membrane. Both systems have various advantages and disadvantages that may make one more attractive than another for a specific project.

    While it isn’t common, nitrogen may also need to be removed from the gas. Nitrogen is mostly inert, so it only needs to be removed in order to increase the product gas BTU content. Given that nitrogen is inert, it is fairly difficult to remove through chemical filtration, though it is possible. It is also difficult to remove nitrogen through physical filtration as is done for carbon dioxide because nitrogen molecules are close to the same physical size as methane molecules. An expensive, but effective filtration method is to liquefy the natural gas; since nitrogen’s boiling point is much lower than that of methane, nitrogen will remain as a gas that can be separated from the liquefied methane. This is more common in very high-volume projects, whereas smaller projects are more likely to use PSA filtration systems [8].

    Additionally, it is worth noting that a conditioning facility will have various heat exchangers, compressors, and gas dryers throughout these steps to prepare the gas for the next step of the process. Depending on the use-case, the conditioner may also add an odorant, ethyl mercaptan, to the product gas.

    Distribution

    Since the RNG is now chemically identical to fossil natural gas, this section will be brief. Here are the three main use-cases:

    For onsite vehicle-fueling, there will be a large, low-pressure (50-150 PSI, in the case of St. Landry’s RNG project) gas storage tank that the conditioners will fill as they clean the gas. This low-pressure storage will feed a series of high-pressure tanks (around 4500 PSI) that are compressed by dedicated, high-pressure compressors as-needed. These high-pressure tanks fuel the vehicles directly and are filled by the compressors as-needed.


    Ribbon-cutting for the opening of St. Landry Parish Solid Waste's BioCNG Fueling Station in 2012

    For pipeline injection, the gas is compressed to match the pressure of the pipeline, which usually ranges between 400-1200 PSIG (gauge-pressure). In this case, there may be a low-pressure storage tank to act as a buffer, and the compressors will connect directly to the pipeline [9].

    For on-site electricity generation, there is generally a storage tank to act as a buffer, a compressor to fill this storage tank, and a pipe connecting to the gas generators.

    The Future of RNG

    The use of RNG is increasing across the United States as more and more projects are developed. As of the writing of this article, there are 38 RNG projects currently under construction [10], with that number likely to grow. LCF looks forward to working with partners like St. Landry Parish Solid Waste and other Clean Cities coalitions as RNG use continues to grow across the country.

    More Information

    For more information and resources on RNG please visit:

    For a thorough technical description of Landfill Gas RNG Project Development, check out the EPA Landfill Gas Energy Project Development Handbook at https://www.epa.gov/lmop/landfill-gas-energy-project-development-handbook-files. For more information on St. Landry Parish Solid Waste's RNG project, check out the 2018 MotorWeek episode on the project at www.fuelsfix.com/2018/03/st-landry-parish-turns-garbage-into-renewable-natural-gas.

    Sources

    [1] LCF Publishes 2018 Annual Report Data: https://louisianacleanfuels.org/blog/id/381

    [2] EPA Overview of Greenhouse Gases: https://www.epa.gov/ghgemissions/overview-greenhouse-gases#methane

    [3] Colorado Energy Office Study Finds State Could Eliminate 1.4M Metric Tons of Emissions Annually by Utilizing Renewable Natural Gas: https://energyoffice.colorado.gov/press-release/colorado-energy-office-study-finds-state-could-eliminate-14m-metric-tons-emissions

    [4] EPA Basic Information About Landfill Gas: https://www.epa.gov/lmop/basic-information-about-landfill-gas

    [5], [9] Pipeline Gas Specifications: https://www.sciencedirect.com/topics/engineering/pipeline-gas-specifications

    [6] NAAQS Table: https://www.epa.gov/criteria-air-pollutants/naaqs-table

    [7] Performance and Economics of Currently Available Technologies for Removal of Siloxane from Biogas: https://www.scsengineers.com/scs-articles/performance-economics-currently-available-technologies-removal-siloxane-biogas/

    [8] Pros and cons of different Nitrogen Removal Unit (NRU) technology: https://www.sciencedirect.com/science/article/abs/pii/S1875510012000170

    [10] Argonne National Laboratory's Renewable Natural Gas Database: https://www.anl.gov/es/reference/renewable-natural-gas-database

    About St. Landry Parish Solid Waste

    St. Landry Parish Solid Waste Disposal District provides residential and commercial solid waste collection and disposal, as well as operation of the St. Landry Parish Landfill and Recycling Centers. For more information, please visit slpsolidwaste.org.

    About Louisiana Clean Fuels

    Louisiana Clean Fuels is a US Department of Energy Clean Cities Coalition, supported by the Louisiana Department of Natural Resources and member organizations. We are a non-profit organization serving fleets for 20 years.

    The mission of Louisiana Clean Fuels, Inc. is to advance the nation’s environmental, economic, and energy security by supporting local actions to diversify transportation fuel options. Our goal is to show how advanced technologies and alternative fuels can help meet business and environmental goals. By providing objective data, technical resources, and the right connections, we help fleets find reliable alternative fuel vehicles that will stabilize or lower fuel costs.


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