Rather than deliberately extracting natural gas trapped in the ground, this green gas makes use of resources already present in our surroundings. RNG may be produced from current resources using advanced gas clean-up technology, resulting in a green gas that can be pumped into existing natural gas infrastructure.
But, before we discuss those, let's define what we mean by renewable natural gas:
What is Renewable Natural Gas?
Renewable natural gas (RNG) is a pipeline-quality gas that may be used in natural gas cars since it is entirely interchangeable with conventional natural gas.
RNG is simply biogas (methane – the gaseous byproduct of organic matter breakdown) that has been purified. RNG, like conventional natural gas, may be utilised as a transportation fuel in the same way as compressed natural gas (CNG) or liquefied natural gas (LNG) (LNG). The “Renewable Fuel Standard” classifies RNG as an advanced biofuel.
Another name for this refined pipeline-quality fuel is biomethane, which refers to biogas that has also been cleaned and conditioned to eliminate or decrease non-methane components. Instead of being used in automotive applications, this processed biogas is used as a replacement for regular natural gas to create combined electricity and heating for power plants.
Biogas is created from diverse biomass sources by a biochemical process such as anaerobic digestion or a thermochemical process such as gasification. Biogas may be utilised to create power and heat with a little cleaning. Biogas must be purified to a higher purity standard before it can be used to power vehicles.
Conditioning or upgrading refers to the removal of water, carbon dioxide, hydrogen sulphide, and other trace components. The resultant renewable natural gas RNG, or biomethane, contains more methane than raw biogas, making it similar to ordinary natural gas and therefore a useful energy source in all uses requiring pipeline-quality gas.
Advantages of Renewable Natural Gas Transport
Natural Gas Transport has advantages for air-quality when it replaces petrol and diesel fuels.
That's a fact, even if the natural gas source is fossil-fuel based and inevitably produces greenhouse gas emissions. The reason for that being the low-carbon emissions of this natural gas fuel when compared with say coal, and the clean-burning characteristics of methane (natural gas).
Another big advantage is that currently, taxation on this form of fuel is very low, or non-existent, which for the moment is another big incentive to use Natural Gas as a transport fuel. One day when biomethane is a commonly used fuel the government will have to tax it. But for now, many users won't be paying vehicle fuel tax for using it.
But why use natural gas? It's a fossil fuel.
What is even better than using the fossil fuel “natural gas”, is to source this fuel from a biogas plant. Do that and your energy is as sustainable as it gets! It's known as renewable Compressed Natural Gas or RNG/ LNG. That's because biogas is a renewable product and carbon neutral.
More about that later in this article!
However, before the use of Renewable Natural Gas in transportation (renewable Compressed Natural Gas)(and carried in cylinders on vehicles), is capable of becoming popular in the mass market one very big advance is needed.
The Need for Biomethane/ rCNG Filling Staitions
It will be necessary for a comprehensive network of filling stations to be established before we can all use natural gas transport.
At first glance, it might be expected that scarcity of refuelling locations would prevent natural gas transport from being adopted, at all. But, that is clearly not what is happening. Companies that run large fleets of heavy goods vehicles are equipping their trucks to run on renewable natural gas (biomethane).
They fuel them up at their depot and as long as these vehicles return to a company depot that evening, they can refuel at company depot fuelling points. However, without biomethane fuelling at public “petrol” stations, car travel use will be limited to a few enthusiasts.
In a number of nations, such as Sweden and Denmark there is now (in 2021) real progress in establishing such fueling stops. But, while this happens, of more interest to our readers is the growth in the use of biogas upgrading equipment.
Renewable Natural Gas Transport Sustainability
Improvements in upgrading technology are enabling the use of rCNG to move up one whole level on sustainability.
The “step-up” we refer to is producing from biogas which itself is solely made from waste feedstocks.
This fuel (known as rCNG, rLNG or rNG – again when compressed in cylinders ) is as sustainable as it is possible to get, and is truly “green” when distributed for use as fuel for natural gas transport use.
We have found a number of recent articles which follow and which show the high level of development activity in RNG, even back in 2016. There was in 2016 at least one application for rNG for transport fuel use, and it was not hampered by the lack of a national filling station network.
We refer to RNG from biogas in which companies operate is its use on farms where the biogas is produced, and on nearby farms, or where fleets of vehicles run out to make deliveries from farms and other biogas plant sites. Here they are starting to use natural gas transport in a big way.
Sources of Renewable Natural Gas Used for Transport
There are three main sources of RNG currently, these are:
- Commercial Biogas Plants (the anaerobic digestion process)
- Wastewater Treatment Plant (Sewage Works Digesters) where biogas is produced as a side-product while reducing and pasteurizing the sludge from foul sewage
- Gassing Landfills.
As biogas plants, as in 1. and 2, above are discussed fully elsewhere on this website we will not discuss them here.
Biogas may also be generated from lignocellulosic material (such as agricultural wastes, woody biomass, and specialised energy crops) by thermochemical conversions, co-digestion, and dry fermentation. These technologies are currently being developed in Europe, with quite limited applicability in the United States.
There are several other methods for methanizing carbon dioxide/monoxide and hydrogen, including biomethanation, the Sabatier process, and a novel electrochemical technique pioneered in the United States that is now being tested.
Landfills are authorised sites for the disposal of garbage from residential, industrial, and commercial enterprises.
According to the US Environmental Protection Agency, landfills are the third-largest source of human-related methane emissions in the United States (EPA).
Because the digestion process takes occur in the earth rather than an anaerobic digester, biogas from landfills is also known as landfill gas (LFG).
According to the EPA, there were around 564 operating LFG projects in the United States as of June 2020. However, the majority of these initiatives use biogas to generate electricity rather than natural gas cars.
The following case studies explain the early adoption of RNG/ Renewable Natural Gas Transport and date back to before May 2016 when this article was first published.
One example of RNG use is provided by the Agrowill Group, as follows:
Lithuania's largest organic farming and investment group and one of Europe's largest organic agricultural corporations Agrowill, has embraced renewable natural gas transportation.
By implementing its new concept of sustainable business, the firm is to become not just Europe's largest but also the most innovative organic farm. Implementing natural gas transportation, including the use of renewable natural gas (RNG) fuel for automobiles, is high on its priority list.
“We are committed to creating a new sustainable farming strategy over the next two years in order to entirely transform the present view of organic farming.” We believe that the future of organic farming is more than just avoiding chemical use. Our aim is for organic food items to be produced in the most sustainable way possible while being accessible to a larger range of customers. We will build it using cutting-edge modern technology and aim for sustainability by transitioning from the use of fossil fuels to biogas,”
said Kstutis Juius, chairman of the board of Agrowill Group.
Te Agrowill Group carries out scientific research and innovation, including the creation of next-generation dairy and poultry farms, the establishment of a new line of combination feedstuffs, and the expansion of organic seed production. These branches will get a total investment of EUR 17 million. Another EUR 3 million will be invested in biogas applications for tractor fuel and other natural gas transportation initiatives.
According to the estimates of Agrowill Group the manure of its livestock (3 500 milking cows) can be used to produce about 7.5 million tons of biogas per year. This would help to reduce CO2 emissions by 35 thousand tons annually. It is planned to avoid the emission of green house gases that naturally occurs during decomposition of manure. With application of purified compressed biogas fuel for tractors and other agricultural machinery the use of fossil fuel otherwise used for natural gas transport, will be reduced. (Source: Agrowill Group) via Huge Organic Farm Innovation Plan includes RNG for Tractors
These ambitious targets are typical of the rising confidence in the future for RNG, although it is more common to read about the uptake of this technology in individual farm businesses. An example of one such follows:
Methane-Powered Agricultural Tractor Trials Renewable Natural Gas Transport in Spanish Vineyard
Under a partnership agreement with the Italian manufacturer, part of CNH Industrial, Bodegas Torres, a historical wine-growing firm based in Pacs del Penedes, Spain, performed the first testing in Spain of a second-generation New Holland T6 methane tractor.
At Agritechnica 2015, New Holland initially revealed the prototype T6.140 Methane Power tractor as part of their sustainability strategy to ‘Energy Independent Farming,' an aim shared with Bodegas Torres.
Throughout the month of May, the winemaker is conducting experiments on the Bodegas farm in L'Aranyó, in the centre of Les Garrigues, in the province of Lleida, which includes 175 hectares of vines and 80 hectares of olive trees.
The test tractor is a conventional design with a 6-cylinder engine and 175 horsepower that runs on natural gas or biomethane (RNG) stored in nine cylinders. It has a total capacity of 300 litres of compressed methane, which is comparable to roughly 60 litres of diesel and provides the tractor with a range of nearly half a day under typical operations. The tractor features three catalysts and so fulfils Tier 4B emissions standards without the need for extra after-treatment equipment.
Image: Field trials of renewable natural gas transport at La Bellotta, Turin
The test tractor generates 80% fewer pollutants than a normal diesel tractor and may save 20 to 40% on gasoline. CO2 emissions may be further decreased by using biomethane, which farmers can manufacture themselves in the same building that houses the tractor.
The creation of alternative energy sources is central to New Holland's idea of energy independent farming, which was developed experimentally in La Bellotta, Turin, where trials on a sustainable farm were conducted.
Ramon Maya, Director of Marketing New Holland for Spain and Portugal, explained to Bodegas Torres that using methane as a fuel for vineyard work would be a way to close the production process circle and reduce CO2 emissions, with the winery's main concern being to mitigate the effects of climate change.
“You might use anaerobic digestion to create biogas from agricultural leftovers and derivatives from our own wine or brandy production. As a result, not only would we stop emitting greenhouse gases into the environment, but that fuel would be used for vineyard work,”
explains Xavier Sort, production manager at Bodegas Torres.(Source: New Holland) via Methane-Powered Agricultural Tractor Trials
And, it's not only the agricultural sector, nor only European businesses, which are converting to RNG for their renewable natural gas transport, bringing potential multiple benefits for their businesses:
Scavenger Derives Clean Energy from Collections
South San Francisco Scavenger Co., Inc. (Scavenger) is an oddly titled company. Nevertheless, it has used anaerobic digestion derived biogas to gather and process biogas from trash collected from governments in the San Francisco Bay Area.
These include facilities at San Francisco International Airport and it has been used it as fuel for fleet operations. It is a very successful closed-loop system made feasible by the collaboration of Clean Energy Fuels, a national natural gas station operator.
According to Recycling Today, each truck gathers enough organic waste on a single trip to fuel it for a full day, resulting in a true closed-loop system and the first initiative of its type in the United States. SSF Scavengers expects to achieve a 43% decrease in emissions from its total fleet of vehicles based on current predictions of the amount of fuel produced by the dry-AD Facility for its CNG fleet.
The organic waste collected generates up to 500 DGE/day of RNG and links to a Clean Energy fuelling station nearby. What remains in the digester is composted and used for farming and other purposes.
Scavenger is one of the few carbon-negative fleets in the United States, having a significantly lower carbon footprint than its competitors. Scavenger has garnered great community support and a competitive edge as a result of its dedication to operating a greener, compressed natural gas (CNG)-powered fleet for renewable natural gas transportation.
The CNG-powered vehicles rapidly demonstrated their dependability and operating cost reductions. Every year, the business began converting additional vehicles, recognising that CNG will play a significant part in their future fuelling plan.
Of course, the trend did start in the north Baltic states, and no article about Natural Gas Transport should end without an item that part of the world. So, can anyone beat 100% biogas! Read more below:
Moving with 100% Finnish Biogas
Niemi Services, Finland's top logistics and moving service provider, is updated its fleet [in 2016] and bought 15 gas-powered moving trucks.
At that time they announced that the gas vehicles would be available in three sizes, ranging from small cars for modest installation work to huge 18-tonne moving trucks. Using 100% Finnish Gasum biomethane (renewable natural gas), the firm was set to become the first in Finland to provide clean and ecological biogas transportation.
“As the market leader, we want to be a pioneer and pave the path for other businesses in our industry.”
To minimise any environmental burden created by Niemi Services, they set out to monitor the major environmental consequences of their activity and enhance their operations in accordance with the philosophy of continuous improvement.
“As the first firm in Finland, we are now able to provide our customers environmentally friendly and cleaner transfers. We also intend to increase the number of gas-powered cars as distribution networks develop in the future,”
added Niemi Director Juha Niemi.
“We are thrilled to be able to embark into a biogas collaboration with Niemi Services. Consumers are becoming more conscious of the importance of sustainability. “
By ensuring better air for people to breathe, the firm will contribute to reductions in carbon dioxide and local emissions,”
said Gasum CEO Johanna Lamminen.
The Finnish biofuel is always made from 100% renewable raw resources. Gasum processes garbage and generates biogas in seven biogas facilities in Turku, Vehmaa, Honkajoki, Huittinen, Kuopio, Oulu, and, beginning in late 2016, Riihimäki.
In February 2016, the biogas plant under construction in Riihimäki was named one of the Finnish Government's priority projects. Gasum also generates biogas in collaboration with partners in Espoo, Kouvola, and Lahti.
In the future, Gasum will create more than 300 GWh of 100 percent Finnish biogas per year and treat 425,000 tonnes of biodegradable waste.
(Source: Gasum Oy) via Moving with 100% Finnish Biogas
Oil Giants Support Renewable Natural Gas Transport
According to a March 18, 2021 announcement, BP is partnering with Aria Energy in a project to convert methane from California dairy farm waste into renewable natural gas.
This will increase its participation in the RNG transportation fuel industry as it strives to become a net-zero corporation by 2050 at the latest.
According to the announcement, BP will provide “the RNG to the transportation sector under a 20-year offtake deal negotiated by its low carbon trading company.”
According to a US Department of Energy research, RNG-powered cars emit up to 95% less pollution than gasoline or diesel-powered vehicles during their lifetime.
Because of its reduced carbon intensity, RNG is an appealing fuel for corporations with large fleets of cars looking to reduce their carbon impact.
[Original article posted May 2016. Updated September 2021.]