Greening Gas: Conference of the European Biogas Association Presents Emerging Technologies for European Energy Transition in a Circular Economy

February 08, 2018

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By Dan Quadros* (Advanced Biofuels USA) Antwerp, Belgium, is known for diamonds and fine chocolates. But what shined there a couple of weeks ago was the Conference of the European Biogas Association (EBA).

In my last article about biogas in Europe (advancedbiofuelsusa.info/biogas-in-europe-current-situation-and-perspectives/), I provide an overview to give us a better understanding of anaerobic digestion. Many statistics and useful links from EBA are cited.

From there to here, many things have changed. The long-term attractive contracts to supply green energy based on biogas are now restricted. In some countries, policies have already limited the utilization of energy crops. Actually, a gradual phase out of food-based biofuels to 7% in 2021 and 3.8% in 2030 is expected. Remember, some biogas plants use energy crops like corn to feed the system. Natural gas prices have fallen.

Despite these facts, the biogas sector bets on technology, increasing efficiency and using cheaper substrates.

The focus of the conference was “greening gas” in a circular economy. Biogas and biomethane (purified form of biogas) were presented as solutions to produce secure and renewable energy (electricity, heat, fuel), reduce greenhouse gas (GHG) emissions and develop rural areas.

WATCH VIDEO of interview with EBA President Jan Štambaský

Circular Economy is an industrial system that promotes greater resource productivity and also reduces waste and pollution. It aims to keep products, components and materials at their highest utility and value. The European Commission (EC) adopted the Circular Economy Package which establishes a program of actions covering the whole product cycle. In this context, anaerobic digestion, as a link in the biological cycle, transforms waste to energy and valuable products (Biogas Action, 2017).

The EU set three key targets to ensure the EU meets its climate and energy targets for the year 2020 (https://ec.europa.eu/clima/policies/strategies/2020_en):

20% cut in greenhouse gas emissions (from 1990 levels)
20% of EU energy from renewables
20% improvement in energy efficiency

In 2016, the EC published a formal proposal 1 to the EU Council and the European Parliament to recast Renewable Energy Directive (RED) 2009/28/EC2, which will expire at the end of 2020. The proposed new directive, called RED II, proposes a set of policy measures to achieve a 27% renewable energy share from energy consumed by electricity, heating and cooling, and transportation sectors, by 2030.

Regarding renewable energy for transportation, RED II would mandate that 6.8% of transportation fuels must derive from renewable sources, specifically advanced alternative fuels and renewable electricity. In addition, RED II proposes a sub-target of 3.6% blending for advanced biofuels (https://ec.europa.eu/energy/sites/ener/files/documents/1_en_act_part1_v7_1.pdf).

About RED, EBA recognizes the multiple contributions biomethane can make as a green gaseous fuel for lorries, buses and as marine fuel, as well as its complementary role with other renewable energy sources (RES) in the form of energy storage of electricity. Biomethane can strongly contribute with a potential production of almost 10% of the total projected natural gas consumption in 2030.

Biogas can be burned on-farm to generate electricity that is then exported to the grid. The marginal lifecycle GHGs of this farm-produced electricity ranges from -335 to 25 grams CO₂ per kilowatt hour (kWh). By comparison, the marginal GHGs of electricity generated by fossil fuels in the European Union (EU) is 752 grams CO₂ per kWh (Valli et al., 2017).

Biogas can also be upgraded to produce pipeline-quality biomethane, a direct substitute for natural gas. The marginal lifecycle GHGs of biomethane ranges from 10 to -36 grams CO₂ per megajoule (MJ) while the corresponding figure for a conventional biogas plant is 27 grams CO₂ per MJ. In comparison, natural gas in the EU produces 72 grams CO₂ per MJ and marginal fossil fuel in the EU generates 115 grams CO₂ per MJ (Valli et al., 2017).

To understand the definition of marginal lifecycle GHGs, the carbon dioxide (CO₂) emissions reduction afforded by a demand-side intervention in the electricity system is typically assessed by means of an assumed grid emissions rate, which measures the CO₂ intensity of electricity not used as a result of the intervention. This emissions rate is called the “marginal emissions factor” (Hawkes, 2010). The broad view of the process is considered in the life cycle assessments, which determines the environmental impacts of products, process or services, through their production, usage, and disposal.

Biomethane trade

Renewable gas has an important role as “green gas” in the European energy mix, focusing especially on biomethane. “Green gas” could be obtained by gasification also. From more than 17 thousand biogas plants in Europe, around 500 upgrade biogas into biomethane. This number trends to go up rapidly. Gas suppliers are very interested in purchasing biomethane.

Several countries have already established its national tracking system, the biogas register. Biomethane trade predominantly takes place in the country of its production. Barriers are often created by the different national regulatory frameworks (Strauch et al., 2013).

Then, cross-border trade aspects were debated, such as multilateral agreements, technical standards and sustainable indexes. It is clear existing infrastructure of gas distribution must be used.

Almost all member states have developed their own bioeconomy strategy. Differences in regulations create difficulties for multilateral trade agreements. Today, only bilateral agreements are working out. Trade-offs may be explained by high regulatory fragmentation and ineffective governance (Bartolini et al., 2017). This makes regulating the transition towards a bio-based economy a complex task.

ERGaR (European Renewable Gas Registry), a non-profit organization, has an initiative that tries to establish a scheme for mass balancing of biomethane and other renewable gases distributed along the European gas network. According to them, there are three pillars of the cross-border biomethane administration:

European natural gas network (consisting of the transmission and distribution systems) treated as single logistical facility with regard to injected biomethane.
Mass balancing of injected and withdrawn biomethane consignments within the European natural gas network.
Sustainability verification (prior to grid injection) and cross-border transfer of sustainability claims.

The EBA recommends EU nations increase the use of biogas as a fuel for electricity production and for transport to avoid uncontrolled greenhouse gas emissions.

In the RED and REDII, there is a lack of specific targets regarding biogas and biomethane. Currently, France took a significant step towards sustainability, setting a target of 10% of the gas consumption as “green gas” in 2030.

Power-to-gas

In my previous article, I said that an advantage of biogas is as a way to store energy to feed the grid during peak hours. Biogas not only can store energy coming from anaerobic digestion, but also renewable electric energy can be transformed into storable methane via electrolysis and subsequent methanation. To understand the technical and economic aspects of the technologies involved in this process, I recommend the reading of the paper of Götz et al. (2016).

The great advantage of power-to-gas is to convert the excess power from renewable energies into synthetic methane. In this way, it decarbonises and brings many opportunities to energy intensive sectors such as mobility, heating or chemistry.

Gasification

Undoubtedly, anaerobic digestion is the most consolidated technology to green the gas. However, gasification is an alternative option for obtaining methane using low-value feedstocks.

Gasification is a complete thermal breakdown of the biomass particles into a combustible gas, volatiles and ash in an enclosed reactor (gasifier) in the presence of any externally supplied oxidizing agent. Gasification is an intermediate step between pyrolysis and combustion. It converts any material containing carbon into synthesis gas (syngas). The syngas can be burned to produce electricity or further processed to manufacture liquid fuels, substitute natural gas (SNG), hydrogen, or chemicals.

This pathway has a considerable advantage to make possible the utilization of hard digestible feedstocks for anaerobic digestion, such as forest residues, straw and solid municipal waste. Task 33, which is a working group of international experts created by the International Energy Agency (IEA) with the aim of promoting efficient thermal biomass gasification processes, is a good starting point to keep updated about this technology (http://task33.ieabioenergy.com/content/taks_description).

New market opportunities

The role of biomethane (CH₄) as a building block for the chemical industry was revealed. To cover the entire demand of the chemical industry in 2050, will require 100 billion m³ of CH₄. Currently, EBA estimates the production of only 1.5% of the amount that will be needed in 2050.When the boom will happen is unpredictable, but it will.

The chemical industry does not buy CH₄. The companies buy building blocks. First, what is a building block? From the chemical standpoint, building block is a molecule which can be converted to various secondary chemicals and intermediates, and, in turn, into a broad range of different downstream uses. There are two types of biobased chemical building blocks:

Drop-in biobased chemicals: As they are chemically identical to existing hydrocarbon-based products, their use can reduce financial and technological risks and promote faster access to markets for producers.
Novel biobased chemicals: they can be used to produce products that cannot be obtained through traditional chemical reactions and products that may offer unique and superior properties that are unattainable with fossil-based alternatives, such as biodegradability.

However, methane is currently so abundant that the petrochemical industry burns it in gas flares around the world. Biomethane cannot compete in price directly with non-renewable sources at this time. Of course, it has many environmental advantages, consequently big companies are interested in including renewables in their products in the name of sustainability.

Other market opportunities were discussed such as digestate utilization, methane utilization in the fertilizer industry, and large-scale new methods for biomethane upgrades.

Digestate is something I would like to see more often in biogas events, because it plays an incommensurable role in agriculture. It is an organic fertilizer safer than manure. It also can replace mineral fertilizers, recycle nutrients and improve soil microbiota. In addition, it is a way towards an organic, biodynamic and sustainable agriculture, when applied according to a crop’s specific nutrient requirements.

Biomethane in the transportation sector

Biomethane plants have increased rapidly in the past few years, and the numbers might grow even more in the next years. Biomethane as BioCNG (CNG, Compressed Natural Gas) and BioLNG (LNG, Liquefied Natural Gas) should be considered as near-term, realistic, technically approved available options for renewable fuels.

Renewable gas can provide a significant contribution to decarbonization. All CNG and LNG vehicles are ready to run on 100% renewable energy.

Three big companies of long distance heavy load haulers (Volvo, Iveco and Scania) had a marked presence at the event. Power, performance, autonomy, fuel efficiency and costs must be considered when a gas engine is developed. There are many options now available in the market. Furthermore, gas buses can effectively contribute to reduction of air pollution in big cities.

It is clear, these companies are talking about natural gas, and we are interested in biogas. We expect that transition to the renewable fuel will occur. For example, 20 years ago Sweden started with a fossil-based LNG bus fleet. Today 70% of those buses run on biogas.

For example, 1 L of diesel can be replaced by 0.72 kg of LNG. The fuel costs can be reduced up to 70%, compared to diesel.

The best reduction rate is in the UK, where diesel taxation considers the output of all harmful emissions. On the other hand, in many countries diesel is subsidized. Actually, Governments of 11 European nations are providing subsidies totaling more than U$110bn a year to fossil fuel industries, including diesel subsidies. (https://www.theguardian.com/environment/2017/sep/28/european-countries-spend-billions-a-year-on-fossil-fuel-subsidies-survey-shows).

A great example worthy of attention comes from Kalmar County, Sweden. The country has no natural gas extraction, limited access to pipelines and plenty of biomass. They recognized biogas as part of the solution. Fossil free county in 2030 and fossil free public transportation in 2020 are the targets set by Climate Commission, composed of the County Administrative Board, Regional Council, private and public organizations, and lead by politicians.

In 2014 Kalmar County Traffic was commissioned to procure public road transports for a new period. Biogas was prioritized. In the main routes and cities (60% of traffic), the only fuel is biogas, while for the inland routes there are the possibility for the utilization of five alternative fuels. It is expected the reduction of 50% of GHG emissions will increase costs by only 3-4%.

More examples of successful biogas utilization in buses for public mobility can be found at: http://euinmyregion.blogactiv.eu/2016/07/04/biogas-buses-are-the-green-solution-for-cities/

References

Bartolini, F.; Gava, O.; Brunori, G. Biogas and EU's 2020 targets: Evidence from a regional case study in Italy. Energy Policy 109 (2017) 510–519.

Biogas Action. Circular Economy – a healthy transition driven also by Biogas. Available at: http://biogasaction.eu/circular-economy-a-healthy-transition-driven-also-by-biogas/ Accessed 01/31/18.

Götz, M.; Lefebvre, J.; Mörs, F. et al. Renewable Power-to-Gas: A technological and economic review. Renewable Energy 85 (2016) 1371-1390.

Hawkes, A.D. Estimating marginal CO₂ emissions rates for national electricity systems. Energy Policy 38 (2010) 5977-5987.

Strauch, S.; Krassowski, J.; Singhal, A. Biomethane Guide for Decision Makers: Policy guide on biogas injection into the natural gas grid. Available at: http://www.greengasgrids.eu/fileadmin/greengas/media/Downloads/Documentation_from_the _GreenGasGrids_project/Biomethane_Guide_for_Decision_Makers.pdf Access 01/31/18.

Valle, L.; Rossi, L.; Fabbri, C. et al. Greenhouse gas emissions of electricity and biomethane produced using the Biogasdoneright™ system: four case studies from Italy. Biofuels, Bioprod. Bioref. 11:847–860 (2017); DOI: 10.1002/bbb

*Dan Quadros is a professor at Bahia State University in Brazil and a traveling correspondent for Advanced Biofuels USA.

Photos courtesy D. Quadros