Both biomethane and biohydrogen are two gases that have been going strong in our current energy landscape. Both have a renewable origin and their formation can be associated with CO2 capture and storage processes, another of the great objectives of our society to fight against global warming.
Biomethane is nothing other than methane with a renewable origin, as opposed to natural gas where methane has a fossil origin. Biomethane is typically generated by purifying the biogas produced in anaerobic digesters that treat waste streams such as sewage sludge, manure or other biodegradable streams. It is the operation generally known as the upgrading process [1]. Biomethane has the added advantage that it is chemically identical to natural gas, so it can be substituted in any of its applications. For this reason, biomethane is expected to play a transcendental role in the decarbonization of the Spanish and European economy with a view to 2050 [2].
If we return form biogas, its other major component is CO2, but there is the possibility of reintroducing this CO2 to the anaerobic digester or treating it in another reactor and, through what is known as the methane process, generating more biomethane [3]. That is, we can use CO2 to generate methane, who gives more? But this process is not as mature as that of conventional anaerobic digestion and, although it has been shown to be technically feasible (more than 100 operating plants are known in Europe), the performance of the process needs to improve so that its economic viability is out of all doubt.
Once we have the biomethane, another option we have is to generate green hydrogen (named for its renewable origin) through a well-known reforming process. The reforming of natural gas to produce hydrogen is a common industrial practice, so reforming biomethane is an entirely plausible option. The usual reforming is carried out by reacting methanewith water vapor, but there is already work that has shown the possibility of replacing this water with CO2, so we return to using carbon dioxide as a raw material, removing it from the atmosphere and instead producing the desired hydrogen.
But hydrogen can also have a biological origin, which is what is known as biohydrogen. In nature there are algae and bacteria that generate hydrogen through their metabolic cycles. These organisms, grown in a controlled environment, can also become a biohydrogen factory. In this case, and as it happened in the methanation processes, it has been shown that the processes work and can be scalable, but the yields that are currently achieved remain a barrier to their implementation for industrial purposes.
But that’s what research is for, to keep working and make these processes (and others that we will talk about on another occasion) a reality in the short-medium term.
[1] Hidalgo, D., Sanz-Bedate, S., Martín-Marroquín, J. M., Castro, J., & Antolín, G. (2020). Selective separation of CH4 and CO2 using membrane contactors. Renewable Energy, 150, 935-942.
[2] Elguera, N. M., Salas, M. D. C., Hidalgo, D., Marroquín, J. M., & Antolín, G. (2020). Biometano, el gas verde que pide paso en España. IndustriAmbiente: gestión medioambiental y energética, (30), 50-56.
[3] Hidalgo, D. Martín-Marroquín, J.M. (2020). Power-to-methane, coupling CO2 capture with fuel production: An overview. Renewable and Sustainable Energy Reviews, Volume 132, 110057.
Blockchain technology has been explained in a previous entry of this Blog, and another entry about Blockchain and the electric market customers is also available. This new entry is again focused on this technology but, in this case, it will be focused on all the opportunities offered by this technology in the environmental and energy sector.
Distributed Ledger Technologies (DLTs from now on) and, in particular, blockchain technology have the potential of transforming the energy sector. The World Economic Forum released a joint report identifying more than 65 blockchain use cases for the environment, including new business models for energy markets and, even more, moving carbon credits or renewable energy certificates onto the blockchain.
Its defining features are its distributed and immutable ledger and advance cryptography, which enable the transfer of a range of assets among parties securely and inexpensively without third-party intermediaries. Blockchain provides a new, decentralized and global computational infrastructure that is transforming many existing processes in business, governance and society, offering many opportunities to address multiple environmental challenges such al climate change, biodiversity loss and water scarcity.
Due to increasing integration of Distributed Energy Resources (DERs), many consumers have become prosumers, who can both generate and consume energy. As generation of DERs can be unpredictable and intermittent, prosumers may decide to store their surplus energy using storage energy devices, or supply others who are in energy deficit. This energy trading is called Peer-to-Peer (P2P) energy trading, and it is a novel paradigm of energy system generation where people can generate their own energy from (Renewable Energy Sources) RES in dwellings, offices and factories, and share it locally with each other. Waste heat and cold can be also traded in a similar way to energy from RES. One of the main contributions of DLTs in the scope of P2P Energy trading is to register all the transactions in a secure and non-mutable way, and to simplify the metering and billing system of the P2P energy trading market.
In the scope of the SO WHAT project, CARTIF has been involved in the definition of the business model linked with the use of Blockchain to exchange waste heat and cold. Besides, CARTIF has worked in a research internal project called OptiGrid which main aim was the development of innovative solutions in the scope of the smart grids. CARTIF is also working in a project called Energy Chain (subcontracted by Alpha Syltec Ingeniería) to jointly develop a platform to allow energy trading between prosumers. Both OptiGrid and Energy Chain are projects financed by the “Instituto de Competitividad e Innovación Empresarial” (ICE) and are focused on the use of blockchain as a driver to deploy platforms devoted to energy trading. In the scope of Energy Chain, Alpha Syltec Ingeniería will also develop machine learning algorithms that will interact with the blockchain platform providing useful data about generation and demand.
The use of blockchain in the scope of SmartCities is clear due to its applicability to transfer information in a secure and immutable way, reducing (and even removing) the amount of intermediaries. Blockchain can be used in multiple ways apart from the aforementioned one: it can push the use of electric vehicle (e.g., P2P Electric Vehicle Charging), it can be used as a driver of public empowerment (e.g., increasing the security level, the transparency and the reliability of elections, online surveys, referenda, etc.)…
Other examples of the use of blockchain is its use as a driver of off-set carbon footprint processes, increasing the transparency and security of the transactions, and its use to improve the traceability and transparency of green energy in relation to the Guarantee of origin (GoO). One example of the use of Blockchain in this sense is ClimateTrade, which main aim is to help companies to achieve carbon neutrality by offering them their carbon offsetting services.
Cities as New York and states as West Virginia have used blockchain to exchange energy or to vote using the mobile phone, Estonia is using it to manage personal data, and Dubai’s Smart City Program has addressed more than 500 blockchain projects that will change the way to interact with the city. Blockchain is a reality, and is here to stay.
Most users have been consuming electricity in the same way our entire lives. We simply know that we can plug in the electrical device wqe want at any time, and that, in return, at the end of the month, we get a bill (for many, more difficult to understand than an Egyptian hieroglyph, by the way). But this way of consuming electricity can change very soon (if it hasn´t already). Not for a long time, we can contribute with our own energy to the main grid without many complications, decide when is the best moment for us to consume, or partner with other users to benefit each other…or all these options at the same time.
In other words, the energy sector is moving from a model in which the user had a merely passive role, to a totally different one, where the user can have an active participation in the production, management and consumption of electricity. For this paradigm shift, a new word has emerged as a result of combining producer and consumer: prosumer.
Although the concept of prosumer is now broader, it originally refers to users who produces their own energy for their own consumption, and discharge the surpluses to the electrical network. In this way, not only we can consume less from the grid, but our electricity is also supplied to the main system, and we contribute to achieving a more sustainable model while we reduce our bill.
Given the rise of distributed generation facilities for self-consumption, largely driven by the publication of RD 244/2019 in Spain, it is not surprising that this type of prosumer is the most common. However, the options for prosumers are more and more varied, and are not only limited to installing solar panels on our roof.
For example, the interaction of the user with the main grid can also be more proactive by combining responsible electricity consumption with electricity tariffs which depend on the market price (rates indexed to the electricity pool market-the hourly market-, also called PVPCs tariffs in the case of Spain-stating for Small Consumer Voluntary Price-, for users with a contracted power lower than 10kW).With this type of tariff, every day you can know the hourly price of electricity for the next day, so that if today we are told that tomorrow morning the price of electricity will cost almost 90% less than it costs right now (as happened a few days ago in the Iberian Peninsula(, we can decide if we prefer no to turn on certain appliances today (e.g. washing machine, dryer or dishwasher, in the case of residential consumers), and use them tomorrow, hence getting some savings due to the energy term associated to their consumptions.
But, what happens when there is hardly any sun or wind, and the prices of the electricity market soar to all-time highs, as happened a few weeks ago during the storm Filomena in Spain? In the previous case,basically we would have to ´´ endure the downpour´ and pay it at the end of the month. How ever, if we had energy storage solutions, we could avoid these type of scenarios, and in general we could reduce our consumption from the grid durign periods when the price of energy is high. This prosumer alternative is also very simple: at night or in the morning, when electricity is cheaper, we could program the charging of our energy storage equipment (electric batteries, including our own electric vehicle, but also thrmal systems of thermoelectricc), so that when the price of electricity went up, we would not have to pay its exorbitant costs, but could use our stored energy.
Precisely, this combination of prosumer options– installation of a renewable production system, storage, dynamic rates and active management of our demand- is part of the study that is being considered in the MiniStor Project, where CARTIF has participated since last year. In this project, a thermoelectric storage system that integrates lithium batteries, phase change materials and a thermochemical reactor is being developed, also including hybrid solar panels that produce both heat and electricity and an optimal energy management, considering both the prediction of our consumption, the prediction of our systems production, and the electricicty costs. A very interesting challenge for which we will be able to tell you more about very soon.
As we have seen, the prosumers´ participation options go far beyond having our own self-consumption facility (which is not a small thing), and, although this time we have presented a few, the alternatives where this actor has a fundamental role are almost infinite (demand aggregators, blockchain integration, microgrids, energy communities…) Surely, in a short time others options will emerge, that at the moment we cannot imagine. What is clear, is that the role of prosumers is already considered as decisive, we are at the beginning of what can be a true paradigm shift in the energy sector, and from CARTIF we are on the trail to be leaders in this revolution.
As you may already know, the increase in greenhouse gas emissions (mainly carbon dioxide and methane) as a consequence of human activity is one of the main reasons behind the faster pace of the climate change in the last decades. And among the wide range of causes, passenger cars are one of the main sources of CO2 emissions, accounting for a 12% of the total emissions (European Commission).
For this reason, the European Union has been adopting increasingly stricter measures to regulate the levels of emissions. In 2015, a limit of 130 grams CO2/km was set. Moreover, by 2021 a more ambitious target is planned to be fixed at 95 grams CO2/km.
In this context, car manufacturers have been forced to reduce fuel consumption (or increasing the autonomy in electric vehicles) and emissions in his petrol and diesel-fuelled models. How can automakers do that? Besides designing more efficient engines, the main strategy is lightweighting. This technique consists of reducing the weight of the car by replacing the heavier materials (i.e. steel) by lighter ones such as plastic or composites.
However, currently the mismanagement and misuse of plastics rather than the material itself is one of the top environmental issues, since 8 million tons out of the 300 million tons of plastic which are annually produced end up in the ocean (According to data from the International Union for Conservation of Nature). So seems that increasing the use of plastics in cars does not look like and ideal solution, right? Well, how about using an alternative material with similar of even better performance than conventional plastics and reduced environmental footprint? It doesn’t seem an easy task, although bioplastics may be part of the answer.
What are bioplastics, and why they seem to be so trendy nowadays? According to European Bioplastics, it’s a heterogeneous set of materials with different properties and applications which can be biobased, biodegradable or both.
In other words, since they are biobased, their use potentially reduce the consumption of fossil fuels while their biodegradability widens the possibilities of treatment at the end-of-life stage. As a result, these materials could achieve the desired combination of performance and sustainability.
This is what the BIOMOTIVEproject is all about. It tries to develop materials (textile fibres, foams made of polyurethane for automotive seating and other polyurethane-based parts for the interior of cars) from biobased sources which combine good technical properties with reduced environmental impact. Starting from renewable raw materials such as forest biomass and vegetable oils not in competition with the food chain, it is expected to produce at industrial scale products with up to 80% biobased content.
The project has received funding under the European Union’s Horizon 2020 Research and Innovation Programme and gathers European private companies and institutions sharing the ideal of reducing the impact of the industry paving the way towards a more sustainable economy.
The role of CARTIFin the project is to perform the sustainability assessment of the final products, since the prefix “bio” does not necessarily mean that a product is better for the environment than its fossil-based counterpart. To determine that on a scientific basis, it is important to evaluate the impacts of the product along its whole life cycle (that is, from the extraction of raw materials to the end of life) considering not only the environmental impacts, but also social and economic aspects.
So the next time you are holding a plastic object, before throwing it away, it is worth considering from where it came and where will it go.
In the arduous path towards sustainable development, research to obtain alternative fuels to fossils is presented as a key point. In this framework, two interesting actors have emerged to stay: biogas and biomethane.
Before going into the subject, let’s dig a bit into the current national gas system. Natural gas is one of the fuels most used by society, both in industry and in homes. Chemically, it is a gas composed mainly of methane 95-99% (CH4) and small proportions of other compounds. From its treatment, management and consumption in Spain, we must know two important aspects:
Almost all the natural gas we consume in Spain comesfrom non-renewable sources.
All this gas is mainly imported from countries such as Algeria, Norway, Nigeria or Qatar, either through the network of gas pipelines or through the transport of liquefied natural gas in large gas tankers.
While it is true that in comparison with other fuels the use of natural gas is better seen as it reduces emissions of CO2, particles and NOx, it isstill a fossil fuel. World natural gas reserves are estimated on 193 trillion m3, enough to cover demand for 52 years.
Biogas and biomethane are considered an interesting sustainable alternative in the fuel supply chain. Biogas is the fuel gas resulting from the degradation of organic compounds through a biological process. Depending on the precursors used, the volume composition of biogas ranges between 50% and 70% methane and 50% and 30% CO2. Biogas is an ideal fuel to generate heat or electricity, but, due to its low concentration of methane, it can not be used in its original form as a fuel for transportation nor can it be injected into the natural gas network. However, it can be ‘upgraded’ to be suitable for these last two applications. This improved biogas is known as biomethane. The CH4 / CO2 ratio of biomethane ranges between 95/5 and 99/1, a composition very similar to natural gas.
The key to make biogas and biomethane sustainable gases is to use as waste raw material that can not be reused or recycled. Not only do we talk about the typical urban waste that goes to the landfill, but also agricultural, livestock or wastewater are of high interest. These residues, when degraded, spontaneously emit methane into the atmosphere, whose impact on greenhouse emissions (GHG) is 21 times higher than CO2. In this way, this methane is generated in a controlled manner and after combustion is transformed into CO2, thus reducing the impact of GHG emissions.
The potential that Spain has to develop biomethane is very wide. Agriculture and livestock, one of the main engines of the national economy, generate an extensive amount of waste that contains very good “methanisable” characteristics. Likewise, every year each Spaniard generates half a tonne of direct waste, which is around 22,000 tonnes/year. The fact of being able to convert this waste into a fuel makes it possible to reduce greenhouse effect emissions at the same time as covering part of the imported natural gas consumption. The advantages are not only environmental; this new model allows the creation of new green jobs.
For the generation of biomethane there are multiple technologies, the anaerobic digestion followed by an upgrading is one of the best known and exploited. Anaerobic digestion consists on introducing a residue in a digester in absence of oxygen. In this digester the waste comes into contact with a biological culture (yes, bacteria) that are responsible for breaking down (hydrolysis) the long carbon chains, typical of organic matter, into smaller chains. After a few days, these bacteria continue to degrade the most simple carbon chains into methane. The product of this process is a mixture of gases, known as biogas, mainly composed of 60% methane, 40% CO2 and a minimum concentration of impurities such as hydrogen sulphide. In the process is generated a liquid waste called digestate that can be reused as a fertilizer because it is rich in nitrogen and phosphorus.
Once the anaerobic digestion is finished it is necessary to improve the quality of the biogas so that it can be used as fuel for vehicles or injected into the natural gas grid, this process is known as upgrading. After upgrading, the biomethane has a concentration close to 99%. There are different technologies that allow this process to be carried out:
Amine Absorption: Amines have high selectivity to attract CO2. The process is about “showering” the biogas with a dissolution of amines, which will sweep away the CO2, leaving the methane almost pure. The major disadvantage of this process is that the amines are not environmentally favourable.
Pressure swing adsorption (PSA): At high pressures, gases tend to be attracted to solid surfaces, or “adsorbed”. The higher the pressure, the more gas is adsorbed. Once the pressure is reduced the gas is released or un-adsorbed. This process requires a very high initial investment.
Membranes: This is a physical separation, as the biogas stream is passed through a porous membrane. The CO2 passes through the pores, while the methane remains. In order to obtain good separation yields, it is necessary to apply high pressures, making the process more expensive. In addition, methane slip is usually around 20% through the membrane pores, especially as they deteriorate.
Membrane contactor: These are the newest of those exposed. This technology agglutinates numerous membranes in the same shell, allowing the gas to pass through the inside of the membranes and a liquid flow through the casing. This combines physical and chemical separation. In this way, it is possible to work at lower pressures than in traditional membranes, as the water is able to dissolve part of the CO2, as well as reducing methane slip.
Once purified the biomethane would be almost ready for final use, or injection into the network. The last necessary process would be to compress it until the normal working pressure, for example, the natural gas grid is at a pressure of between 16-60 bars, or if it is desired to use as fuel a pressure of approximately 200 bars is required.
In some European countries such as Germany or Italy there are already industrial facilities that allow the production of biomethane, however, in Spain the biomethane market is still to be exploited. Aware of the potential that we have to develop the technology, policies are needed to make this market open gradually and be able to produce our own biomethane. This would reduce gas imports, the amount of waste produced and greenhouse gas emissions (and their corresponding EU fines) at the same time as creating jobs.
Undoubtedly, the electric sector in Spain has evolved during the past years, especially with regard to self-supply aspects. Time has elapsed since 2004, when the premium regime for the renewable energies was established. Gone are the first regulations about self-supply (RD 1699/2011) which for the first time considered the existence of individual facilities within the houses and set out the procedure and administrative conditions that they must fulfil, at the expense of a new Royal Decree that, due to policy issues, never was materialized.
Also far away is the regulation about the elimination of the bonus for sustainable energies, being the first blow suffered by this sector; what followed was not better. The subsequent law 24/2013 was branded as restrictive and discriminatory by the National Energy Commission (CNE), since not only was the self-supply not fostered among citizens, but also the register required complex administrative procedure and the document was not clear. Besides that, it referred to a potential economic tax on the self-consumed energy.
The following years were governed by some uncertainty, since the Royal Decree that should legally regulate all the proposed aspects was not published, thus, although the previous RD was still in force, it was feared that the new regulation was published at any moment. This caused a big paralysation of the electric and sustainable sector, which meant a fastdisappearance of companies and jobs.
Finally, the so-feared Royal Decree (RD 900/2015), better known as the “sun taxed RD”, saw the light. Its more controversial aspect was the establishment of a tax on the self-consumed energy, which raised up plenty of social and environmental organizations and official organisms against it. This legislation considered some transitory provisions exempting the small facilities of paying some taxes but, due to its temporary nature, citizens did not show interest on this kind of investments.
After some years of inactivity for this sector and by means of a government change, some months ago the Royal Decree – Law 15/2018 was released, opening the door for the active participation of the citizens in the electric market through the self-supply, in line with the current European energy policies. Recently, the Royal-Decree 244/2019 described and regulated the administrative, technical and economic conditions of the electric self-supply, including concepts such as the collective facilities or the net-billing, besides different modalities not considered up to date, which will facilitate the creation and incorporation of energy communities to the electric system.
This will enable a faster transition towards a more sustainable energy system thanks to the increase of the renewable energy generation rate. A fairer system, as the real needs of the consumers will be considered. A more autonomous market, since the dependency on external fossil fuels for power generation will be reduced.
