Over the past decades, hydrogen has been identified as a potential clean fuel, although its mass adoption has been hampered by the abundance of oil and low relative prices of fossil fuels, as well as, in recent years, by the advance of the battery electric vehicle. Today, while technological advances have brought down the costs of hydrogen production and use, it is essential to scale up these technologies and define a roadmap to optimise the necessary investments. The current energy transition points to an era of sustainable energy gases, and the consumption of renewable hydrogen and methane is expected to surpass that of coal and oil in the 21st century. In this context, renewable hydrogen, or hydrogen produced with low CO2 emissions, emerges as a key player in the decarbonisation of the global economy.
Biohydrogen is a specific type of renewable hydrogen defined as hydrogen produced by biological processes or from biomass as feedstock. Biomass, one of the most abundant renewable resources on all continents, is the subject of increasing research into its alternative uses and valorisation. This interest is also focused on the conversation of waste streams into energy, because of the potential to transform large quantities of agricultural, forestry, industrial and municipal waste into biohydrogen and other renewable gases, thus benefiting sustainable development. The efficient use of renewable feedstocks derived from biomass and waste as a fuel source clearly presents a significant opportunity for a more sustainable planet.
“Biohydrogen. Specific type of renewable hydrogen defined as hydrogen produced by biological processes or from biomass as feedstock”
Biohydrogen has characteristics that make it a renewable element capable of providing safe, economically competitive and 100% carbone dioxide-free energy in its production and use. Despite this, the penetration of this low-carbon hydrogen remains limited. It is crucial to understand the reasons for this situation, the emerging trends and the technological route that will enable its consolidation as an energy vector.
Biohydrogen production
Biohydrogen production has gained worldwide attention due to its potential to become an inexhaustible, low-cost, renewable source of clean energy. Feedstocks for its production include lignocellulosic products, agricultural residues, food processing residues, aquatic plants and algae, and human effluents such as sewage sludge. Under proper control, these resources will become a major source of energy in the future. Biomass has the potential to be an important source of renewable hydrogen, complementing other processes that produce biomaterials.
The main methode of obtaining biohydrogen is from biomethane generated in anaerobic digestion, through a process known as reforming. Gasification, on the other hand, converts organic matter into hydrogen-rich synthesis gas. Alongside these thermochemical technologies, biological hydrogen production, such as dark fermentation and the use of microalgae, offer additional promising methods. Dark fermentation uses anaerobic bacteria to break down organic matter and produce hydrogen. Microalgae, on the other hand, can generate hydrogen through biophotolysis, a process that converts sunlight and water into hydrogen and oxygen. This set of technologies presents a wide range of possibilities for biohydrogen production.
Storage and distribution
The storage and distribution of hydrogen in general, and biohydrogen in particular, represent crucial aspects of its large-scale adoption. Storage in high-pressure tanks is currently the preferred option, although other methods exist, such as injection into existing gas infrastructure of storage in chemical materials. Hydrogen can be stored in a gaseous or liquid state, either on the surface or in solids, or in hydrogen-bearing chemical compounds. These storage options aim to overcome current limitations and facilitate the uptake of hydrogen as an energy carrier.
Applications and uses
The current interest in the hydrogen economy is due to its enormous opportunities for penetration in the energy sector, especially in mobility and chemicalstorage of renewable energy. In the case of biohydrogen, it is also an efficient method of managing organic waste streams. The production of renewable hydrogen has increased in recent years, mainly used in the manufactureof ammonia. Renewable ammonia can also be used as an energy storage medium, energy carrier or fuel. Hydrogen production therefore not only has industrial applications, but also offers innovative energy solutions.
In metallurgy, hydrogen is used in the direct reduction of iron for steel production, and in transport, it can generate clean energy in vehicles. These diversified applications demonstrate the potential of biohydrogen to transform key sectors of the economy. However, its large-scale adoption requires overcoming technological, logistical and market barriers, as well as establishing appropriate policies for its regulation and development.
Biohydrogen perspectives
Biohydrogen, like other energy carriers, has advantages and disadvantages. While other forms of energy already have an established position, hydrogen, and in particular biohydrogen, is progressively advancing in trying to replace options such as coal or natural gas in sectors such as energy, industry and transport. The main driver for this is the need to reduce pollutant emissions, which has generated considerable interest in this energy vector. However, low energy density, infrastructure and installation costs, and factors associated with security are the main barriers slowing down its implementation. While some of these barriers can be removed by cost reductions resulting from research breakthroughs, others, such as energy density, cannot be changed. Here, the use of derivatives mainly from the chemical industry can play a key role in the energy system or in the transport sector.
Barriers can be addressed or adapted, but this will not be achieved without a joint effort by both the private and public sectors. There must be joint objectives and policies on aspects such as the homogenisation of standards that affect, above all, storage limits. Currently, there is no robust global market due to low demand, which is partly a consequence of low generation and direct consumption at generation sites. As biohydrogen progressively breaks through, demand will increase and generation will have to be done on a large scale. This increase in generation and demand will make material transport routes, which are cost-effective especially over long distances, viable. Hydrogen-specific pipelines, trucks and shipping routes will emerge to meet this demand. With this opening and development of adapted means for hydrogen and biohydrogen, a progressive increase in the areas of potential use will be observed, where transport, especially by heavy vehicles and ships, and energy storage in liquid ammonia tanks will play a key role.
Biohydrogen has the potential to solve today’s pollution problems, but its widespread use is not immediate. The change starts now and the willingness to change must be evident. The next steps include research into all biohydrogen production processes to increase their efficiency and thus their competitiveness; integration of distribution and demand interfaces; management of global policies and technologies; coordination in the face of multilateral sectoral initiatives; and the creation of a knowledge base to serve as a model for the establishment of initiatives.
More information about this theme:
Hidalgo, D., Martín-Marroquín, J. M., & Díez, D. (2022). Biohydrogen: future energy source for the society. In Organic Waste to Biohydrogen (pp. 271-288). Singapore: Springer Nature Singapore.
Fermentation is perhaps one of the oldest technologies that has accompanied humanity for thousand of years. Throughout history, numerous evidences and traces have been found that demonstrate the use of fermentation by several cultures and civilisations, as a common and fundamental practice in the production of food and beverages, or even for medicinal and ceremonial purposes.
For example, archaeological remains have been found in China (7000-6600 BC ) of a fermented drink made from rice, honey and fruit in ceramic vessels, or in Iran (5000 BC) ceramic jars with wine residues, or Egyptian hieroglyphs and papyri (2500 BC) describing the production of beer and wine, as well as their consumption in religious ceremonies everyday life.
In addition, the analysis of botanical remains (seeds, plant fragments) has provided evidence of the use of fermented plants, or more recently the analysis and study of the DNA of yeasts and other microorganisms has provided genetic evidence of the use of fermentation since ancient times. These ancient methodes laid the foundations for the use and evolution of a practice that has evolved significantly over time.
The application of biotechnological techniques for the manufacture of pharmaceutical, biofuels, fertilisers and nutritional supplements has proven to be an age-old tool that has been adapted and sophisticated to suit today´s needs.
Global challenges such as environmental sustainability, food security, food scarcity, waste reduction and recovery find in fermentation a powerful tool to address these problems.
In this way, the use of different microorganisms can be the key to the revalorisation of different by-products and waste from industry, transforming them into high-value products such as biofuels (biodiesel, biogas), biodegradable compounds (bioplastics), or molecules of interest (lipids, organic acids, dyes, etc.) that can be incorporated back into the value chain thus contributing to a circular economy.
Fermentation can transform some agri-food by-products, which would otherwise be wasted, into products with an improved organoleptic profile by reducing or transforming undesirable compounds that negatively affect taste and texture. In this way, fermentation processes can improve the organoleptic profile and, thus the acceptability of certain by-products, which can then be incorporated back into the value chain.
Another future challenges is the increase in the world´s population, which brings with it an increase in demand for protein and poses challenges to the sustainability of traditional protein sources such as meat and dairy products. This is where the use of microorganisms, in this case fungi fermentation, emerges as an alternative to traditional protein sources. Fungi fermentation is key to obtaining microproteins that allow the development of flavours and textures that mimic meat and are sensorially appealing to the consumer. These types of proteins are rich in high quality nutrients, and are also presented as an alternative that requires fewer natural resources (water and land) and produces fewer greenhouse gases.
Fermentation also has the potential to mitigate pollution, playing an important role in waste management and pollutant reduction. Thus, certain organic wastes (waste oils, industrial waste, polluted waters) can be fermented to produce biogas, fertilisers and bioplastics, or it can be used to treat wastewater by reducing organic compounds before they are released into the environment. These processes can also be used in biorremediation processes, soil and contaminated area treatments.
According to the latest research, certain bacteria and fungi could be used to ferment and degradeplastics, such as polyethylene and polyester, or even use them as a source of carbon to obtain compounds of interest.
Therefore, fermentation today isn´t restricted to its use in the food industry for the production of fermented foods. Society must recognise and explore the alternatives offered by biotechnology, and in particular fermentative processes, to face present and future challenges.
Harnessing the abilities of bacteria, yeasts and fungi to transform waste materials into useful products, reduce waste and pollution will allow us to move towards a cleaner and sustainable future, thanks to micro-organisms, felow travellers that have served mankind for thousand of years, and may now be the solution to many of our future challenges.
Water security is an essential concept defined as ´the ability of humankind to protect sustainable access to water, ensuring well-being, livelihoods and socio-economic development´. This concept includes taking measures to protect the ecosystems that provide this vital resource and to secure the ecosystem services linked to water. It is not only about ensuring that there is enough water, but also that it meets high quality standards and meets the agricultural, industrial, energy and domestic needs of a specific region.
The preservation of environmental systems, which constitute the natural sources of water and related ecosystem services becomes essential.
The Global Water Partnership1, an international network dedicated to sustainable water management, describes a water secure world as one in which every person has access to safe and affordablewater for a healthy and productive life, and in which communities are protected from floods, droughts and water-borne diseases. It adds that water security promotes environmental protection and social justice in the face of conflicts over shared resources.
Source: Rául Sánchez Francés. CARTIF
The UN has sounded the alarm about the water deficit that is expected in the future. According to its estimates, by 2030 the Earth could face a 40% deficit if current consumption patterns are not changed. Population growth, especially in urban areas, has increased pollution that affects water quality, not only through air pollution, but also through changes in land use. Water consumption has doubled in the last half century, and it is estimated that by 2025 at least two-thirds of the world´s population will live in areas of high water stress.
Climate change also poses an additional risk to water security, reducing water availability and making it increasingly unpredictable in many parts of the world, leading to major supply problems. In addition, extreme weather events, such as droughts and floods, affect rich and poor alike, disrupting traditional livelihoods and production patterns.
In Castilla y León, water security is already a critical issue, given the importance of our agricultural sector in food production, twhich is highly dependent on a constatn supply of water. The region´s agriculture relies heavily on the production of cereals, wine and horticultural products, and is being affected by climate variability, including prolonged droughts that deplete water resources and jeopardise the sustainability of crops. Similarly, the region is experiencing increasing water stress aggravated by climate change, which threatens food production and affects the balance of the rural economy, thus increasing the already pressing problem of depopulation of our villages or rural environments.
Farmers face an increasingly difficult challenge: maintaining productivity in a context of limited water resources. Many have had to adapt their techniques, investing in efficient irrigation and crop diversification to mitigate the impact of droughts. However, these solutions come at a high cost that not everyone can afford, highlighting the urgency of finding more inclusive approaches. This is where Nature based Solutions (NbS) come in, offering a sustainable alternative to follow.
Source: CARTIF
Nature-Based Solutions are vital to address these problems in a creative way and at the same time provide additional sustainability benefits. UNESCO, in its World Water Development Report, argues that NbS can improve water supply and quality while mitigating the impact of natural disasters. A clear example is restored watersheds and wetlands, which act as natural filters for water purification. By mimicking natural processes, NbS improve water availability and quality and reduce water-related risks.
It is essential to highlight the importance of conserving wetlands and restoring river basins the region, as they act as natural filters, improving water quality and regulating flow in times of drought. Techniques such as agro-forestry and crop rotation can also be explored to maintain soil fertility and reduce dependence on intensive irrigation systems. These practices mimic natural processes and help maintain a balance between production and conservation.
The Global Water Security Index (GWSI)3 , which integrates criteria such as water availability, accesibility, security and quality, standardises water vulnerabilities and risks, helping to identify priority areas where action is urgently needed. This index also highlights the need for innovative strategies that combine green infrastructure with traditional solutions, maximising value for society.
Proyecto NATMED. FIA system (Forested Infiltration Area). SbN implemented in Sassari (Cerdeña – Italia). Source: Raúl Sánchez Francés.
It is also important to highlight the relevance and scope of water security in urban settings, where it encompasses five dimensions: environmental, domestic, economic, urban and resilience to natural disasters. All these aspects make the lack of water security one of the greatest risks to global prosperity and underline the urgent need to take care of the natural resource “water”. This implies sustainbale management, responsible consumption, combating degradation and reuse.
In the Natural Resources and Climate Area of CARTIF, we develop diverse projects related to sustainable water management as basis for water insurance, both for human consumption and for agricultural consumption.
We coordinate the PRIMA NAT-med project, in which we aim to develop, implement and validate a set of Nature-based Solutions, combined in Full Water Cycle-NbS (FWC-Nbs), integrated in existing water infrastructures (grey or natural) and based on specific phases of the water cycle, to optimise the provision of water-related ecosystem services (quality and quantity) and water-dependent ecosystem services (social, economic and environmental aspects), empowering stakeholders and local communities in the Mediterranean region. NATMed will also demonstrate the effect of different SbN-CCA in five case studies located in Spain, Greece, Italy, Turkey, Algeria.
Similarly, through our CIRAWA project coordination work, we work in 8 regions in Cape Verde, Ghana, Senegal and The Gambia to improve agriculture by developing new agroecology-based practices that build on existing local and scientific knowledge to help create more resilient food supply chains in West Africa, and where sustainable water resource management is essential.
CIRAWA project. Access points to water for agriculture at the Maio Island (Cape Verde). Source: Raúl Sánchez Francés.
From the Natural Resources Area of CARTIF, like many other ´guardians of water`, we work to improve water security, using Nature-based Solutions, as part of our vital commitment to the future of the planet. Only through intelligent and collaborative management can we build a world in which every person has access to water and can live with dignity, ensuring that future generations will also enjoy it.
2 WWAP & ONU-Agua. (2018). Informe Mundial de las Naciones Unidas sobre el Desarrollo de los Recursos Hídricos 2018: Soluciones basadas en la naturaleza para la gestión del agua. París: UNESCO.
In the fight against climate change, technological innovations is one of our most powerful allies. One of the most promising and challenging areas in this regard is the transformation of carbon dioxide (CO2), a prevalent greenhouse gas, into useful raw materials for industry and transport. This approach not only promises to mitigate greenhouse gas emissions, but also opens the door to a circular economy where waste becomes a resource.
Challenges and opportunities of CO2 as raw materia for industry
CO2 is the main contributor to global warming, arising mainly from the burning of fossil fuels and deforestation. The concentration of CO2 in the atmosphere has unprecedented levels, making it imperative to find effective ways to reduce these emissions. Capturing and utilising of CO2 is a promising strategy, transforming this gas into valuable products, which could revolutionise sectors such as transport and manufacturing, significantly reducing our carbon footprint.
Converting CO2 into value-added products: key technologies to meet the challenge of decarbonisation of industry and economy
CO2 transformation into raw materials involves several methods, including electrochemistry, catalysis and biotechnology. These technologies aim to convert CO2 into fuels, plastics, building materials and other industrial chemicals, which basically fall into three types:
Biotechnology: based on biological fermentation processes with gas-liquid phase substrate. It uses genetically modified organisms, such as microalgae and bacteria, to absorb CO2 and convert it into biofuels an chemicals. This approach offers the potential for highly sustainable processes that can operate under ambient conditions.
Methanol
Electrochemical technology: based on the use of electrical energy and potential difference between two electrodes to reduce CO2 into value-added chemicals (e.g. methanol, formic acid, etc.) which can be used as e-fuel, H2-bearing green molecules, or chemical precursos for industrial use. The efficiency of these processes has improved significantly, but they still face challenges in terms of scalability and costs.
Chemical-catalytic processes: based on the use of catalysers to active and accelerate the chemical reaction and transformation of CO2 into value-added products (methane, methanol, dimethyl ether, ,etc.)Current research lines are exploring new catalysts that can operate at low temperatures and pressures, making the process more energy efficient and economically viable.
On the other hand, CO2 transformation faces technical, economic and regulatory hurdles. Energy efficiency, cost reduction and integration of these technologies into existing infrastructure are key challenges. In addition, a regulatory framework is required to promote investment in these technologies and the use of CO2 products.
Despite these challenges, the capture and uses of CO2 as a renewable carbon source and to contribute to the decarbonisation of industry and transport, offers an unprecedented opportunity to mitigate climate change and advance towards a more sustainable and circular economy. By turning a problem into a solution, we can unlock new pathways for environmental sustainability, technological innovation and economic growth. Collaboration between governments, industries and scientific communities will be essential to overcome these challenges and harness the potential of these technologies for a greener future.
R&D projects such as CO2SMOS, coordinated by CARTIF´s Biotechnology and Sustainable Chemistry area, aims to develop a set of innovative, scalable and directly applied technologies in the bio-based industries sector that will help to convert biogenic CO2 emissions into value-added chemicals for direct use in the synthesis of low carbon footprint material bioproducts. To this end,and integrated hybrid solution is proposed that combines innovative technologies and intensified electrochemical/catalytic conversion and precision fermentation processes, together with the use of renewable vector soruces such as green H2 and biomass. Key elements to achieve the indsutry´s goal of zero-emissions and climate neutrality.
Biogas as an energy source is becoming more and more popular, but what is biogas and how does it differ from natural gas? The difference is that natural gas is a fossil fuel, while biogenic gas is renewable.
Natural gas was formed millions of years ago, at the age of the dinosaurs, like oil or coal. The accumulation of plankton as well as animal and plant rests on the seabed, buried by layers of soil, caused it to be produced in anaerobic conditions, that is, without oxygen.
Biological bacteria decomposed the organic matter and the gases generated bubbled upwards, and where there was an impermeable layer, they accumulated, giving birth to gas pockets or reservoirs. It is therefore a finite resource; once it is exhausted, there will be no more to supply human energy demands.
Natural gas consists mainly of methane, ethane and carbon dioxide, although it usually has other components or impurities, so the energy is obtained by combustion, compared to other fossil fuels it is more efficient and cleaner in terms of emissions, although it depends on the impurities.
Biogenic gas is also produced by the decomposition of organic matter under the action of bacteria, in the absence of oxygen, which is why it is also called Biogenic Natural Gas, but in this case in a tank with controlled conditions of temperature and pressure.
But in biogenic gas, the organic matter used comes from by-products of farms, crops or industries, so it is a renewable energy. The composition of biogenic gas is similar, but with fewer impurities, as the quality is improved by upgrading, which is explained in this blog post.
Moreover, natural gas is thousands of kilometres away, but biogenic gas can be produced in small tanks for self-supply, e.g. on a farm, or on a large scale in a sewage treatment plant, and existing natural gas pipelines can be used.
It may seem to be all advantages, but this is not the case, which is why CARTIF organised the first meeting of the Community of Practice within the Horizon Europe CRONUS project on 20 March 2024.
The Communities of Practice consist of the grouping of different actors in the biogas sector, such as universities, research centres, producers or distributors, among others, and act as spokespersons for the sector for both citizens and administrations, assessing the strengths and weaknesses, facilities and barriers to the use of biogas in order to make responsible use throughout the value chain.
At this first meeting, three main challenges were addressed:
Raw materials
Technology
Regulations: Logistical, Productive, Social
THE FIRST CHALLENGE, RAW MATERIALS
In the first challenge, the issue of raw materials was addressed. At present, there are no problems in finding them, but there are problems in obtaining supplies, the question is: is this a logistical or quantity limit? In terms of accessibility, it is not as accessible in the mountains as it is on the plateau, and in terms of plant and supplier size.
There is also concern that, in the future, due to the law of supply and demand, both raw materials and transport will reach exorbitant prices. It is necessary to start regulating and organising the market to ensure a supply where the whole value chain benefits.
It is important to consider the methanogenic potential, i.e. how much gas a plant can produce with a given raw material, this determines its viability, therefore the raw materials must meet certain standards and heterogeneity all year round, in order to obtain a constant production, both in quality and quantity.
This leads to the question of the suitability of single or multiple feedstock feeding. In some cases, it is necessary to pre-treat these feedstocks and due to the technical complexity they are not cost-effective, so having flexibility in the use of feedstocks is an advantage.
The most worrying aspect is the injection into the grid. There are problems when it comes to incorporating the gas produced into the existing national distribution network, which in some cases favours the self-consumption of gas, but in others, the waste of this energy source is wasted.
It is a mature technology, but there is still innovation to be done, especially with the bacteria, points of improvement such as new strains are still being discovered, and they make the process and therefore its efficiency is much better known.
In the end, it is an investment, so it is necessary to conscientiously measure the risk and profitability vs. administrative and legal barriers, and although more and more people are opting for it, there would be more if there was a financial push with subsidies, but they would not be the basis of the product.
THE SECOND CHALLENGE, TECHNOLOGY
The second challenge was to know the opinions about the FP5 prototype that is being developed in CARTIF within the CRONUS project. That can be seen in this video.
The expert assistants pointed out that it competes directly with upgrading, so it may not be economically viable on a large scale, but for small plants, it is a good solution, as it does not need to undergo such a large purification process.
On the other hand, it needs a hydrolysis stage, which requires energy, but it is a self-sustainable process, so it is able to be self-sufficient. Technology must favour profitability, as money is always a constraint, both for development and production.
Its strong point was highlighted, which is that it can valorise and reduce the CO2 generated in the AD, obtaining a higher quality biomethane than through traditional processes, especially because cogeneration is more interesting than gas for sale.
As it is the first meeting only the laboratory prototype could be seen, so they perceived that there could be problems in the scaling in the electrodes, as they have to be larger, and there is no microbial electrolysis cell-assisted anaerobic digestion technology (MEC-AD) on the market, but CARTIF already commented that there are more options to integrate MEC-AD in the digester.
It also raised the possibility of problems with having to restart the plant, after a shutdown, which can be slow and complex, but it is a continuous system so it will not be so slow.
The Community is optimistic about CARTIF’s FP5 prototype and is looking forward to seeing its progress in the next calls for proposals.
THE THIRD CHALLENGE, REGULATION: LOGISTIC, PRODUCTIVE, SOCIAL
This challenge is where there was the greatest participation and unanimity. It seems that the Public Administration is not advancing as fast as biogenic gas is. One barrier is the processing time, which can take up to 3 years for project approval, to which environmental authorisations must be added, and the time dedicated to the plant’s engineering project.
This could be favoured with legislation that favours self-consumption, such as premiums or payments for the generation and sale of energy. It would be interesting to map waste production throughout the country.
In the case of Castilla y León, there is the obligation to become an authorised waste manager and limitations on the maximum distance allowed for the transport of digestate, as in the transport of slurry, which shows that the administration is prepared.
But the definition of waste needs to be revised, in order to revalorise by-products for use in anaerobic digestion and also the resulting digestate as it has many potential uses, such as stripping/scrubbing or crystallisation of struvite, which can even be considered as an environmentally friendly product, as fertiliser.
Raw materials, such as slurry, must be used responsibly due to the contamination of aquifers by nitrates, so the use for biogas generation is a solution for this waste, and the resulting digestate could be revalued as fertiliser or as an ingredient for compost.
The growing demand for biogas highlights the need for the modernisation of farms to increase their income from the sale of waste and reduce energy costs by using biogas.
On the other hand, there is a need for the Administration to update its technicians with specific training, since, when evaluating a project, there is no clarity in the criteria, standards and administrative procedures to be applied, and there are differences between technicians.
In short, more support is needed from the Administration, especially with the private companies that control the distribution networks and establish the technical and economic requirements for connection and injection into the network, resulting in abusive technical and economic conditions. The Community of Practice considers this barrier easy to remove.
There is a lack of dissemination and knowledge, which is why citizens associate it with bad smells, noisy lorry movements and a lack of safety, which is why the Community of Practice is doing a good job of disseminating and raising awareness in society of how biogenic gas works and the technology associated with it.
There are both urban and rural barriers, each with its own complexity, in addition to the fact that each Autonomous Community has its regulations in this regard, so each plant in each area must be approached individually, through conferences, citizen participation, a network of interaction with citizens in other areas that already have this technology in place, but above all with transparency.
The reality is that the development of biogenic gas will contribute to rural repopulation, job creation, as well as energy production and the development of the Circular Economy, which is a pending issue in the 2030 agenda.
The majority of plastics used in the world today come from non-renewable and non-biodegradable sources. In an effort to reduce the impact of plastics on the environment, alternative methods of production and waste management have been studied for decades. Several microorganisms have the ability to produce plastics naturally, using different substrates, which are biodegradable and biocompatible under certain conditions.
During the last few years, acidogenic fermentation for the production of volatile fatty acids (VFA) has been identified as a promising approach to utilise organic waste as a valuable resource. VFA have a wide potential for applications ranging from carbon source for biological nutrient removal processes to use as a bioenergy resource for the generation of hydrogen and liquid biofuels. VFA-rich streams produced from organic waste fermentation can also be used as biopolymer precursors in the bioplastics industry, as they are a suitable feedstock for the production of polyhydroxyalkanoates (PHA).
To address the growing problem of bio-waste generation and the increasing demand for bio-based feedstocks, the ELLIPSE project is working in the biotechnology sector with the aim of valorising heterogeneous waste streams generated in significant quantities in Europe, slaughterhouse waste (contained in the belly or rumen) and paper and pulp sludge, to produce cost-effective polyhydroxyalkanoates (PHA) for agricultural and personal care applications, through co-processing with other organic wastes such as sludge from the dairy industry and glycerol from the biodiesel industry, as well as nutrient recovery to produce bio-based fertilisers. The integration of these waste streams as biorefinery feedstocks will reduce landfill waste volumes, open up new pathways for the production of chemicals and bioplastics and, at the same time, create additional income for the related industries that generate them, with the added benefits of water recycling, reduced soil degradation, groundwater contamination and methane emissions.
PHA belongs to a family of 100% bio-based polymers with versatile biodegradability properties in most environments, recyclable and exhibiting a wide range of physical and mechanical properties depending on their chemical composition, from the very flexible poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) to the rigid polyhydroxybutyrate (PHB), showing similar properties to some fossil-based materials such as polypropylene (PP) and polyethylene (PE) and better gas and liquid barrier properties than other bioplastics such as polylactic acid (PLA), being a good biodegradable and compostable alternative in agricultural and personal care applications.
One of the objectives is to maximise the production of VFA derived from acidogenic fermentation by optimising the process using innovative technologies, such as the use of an anaerobic membrane bioreactor (AnMBR). The project contributes to the circular economy by promoting sustainability and zero waste by demonstrating the technical feasibility of recovering nutrients from the waste stream (digestate) through a hybrid autotrophic-heterotrophic process of microalgae cultivation, which results in the production of a biofertiliser.
The project has 5 phases dealing with pre-treatment of waste and obtaining VFA, production of PHA, possible applications of bioplastics, life cycle analysis study and exploitation of the results.
Pliot plants of the ELLIPSE project
In Pilot 1, pre-treatment and valorisation of sludge from the processing of slaughterhouse waste for the production of rigid packaging and plastic mulch will be carried out. A co-digestion of raw materials will be carried out in order to ensure the most optimal conditions for producing VFA.
Pilot 3 will be developed simultaneously with Pilot 1 to recover N and P nutrients for biofertiliser production. Different technologies will be validated:
The biological technology of the hybrid autotrophic and heterotrophic microalgae culture system, and the physical methods of pressure-drive membrane technology (ultrafiltration and reverse osmosis) and membrane contactors, to recover ammonia, as ammonium sulphate.
Pilot 2 will treat and recover waste from the paper industry to produce bioplastic coatings for the personal care and agricultural sectors.
The demonstration of the possibility to transform complex bio-waste stream into high-value bio-based and biodegradable products in multiple sectors, accompanied by the validation of multiple end-of life routes for the biobased and biodegradable products achieved within the project will provide novel and tangible results for further promoting public awareness and acceptance of biodegradable and bio-based solutions. Apart from all this, during ELLIPSE project the pulp and paper industry will be able to utilize products (PHA coated paper for flexible packaging as counterpart of current PE coated paper) produced from its wastes. This is a good showcase for circular economy and has the potential to increase awareness and acceptance of bio-based solutions.
