Carbon Dioxide Removal via BECCS in a Carbon-Neutral Europe

Carbon Dioxide Removal via BECCS in a Carbon-Neutral Europe

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- Welcome, everyone, to the latest webinar of the Institute for Carbon Removal Law and Policy at American University. My name is Wil Burns, and I serve as the co-director. The Institute's mission is to engage in research and public engagement related to carbon dioxide removal approaches. Our focus is on aspects of governance, policy making, and ethical and justice considerations.

As many of you know, as we look at the terrain of carbon dioxide removal approaches, at least much of the initial emphasis has been on two options: afforestation and reforestation, as well as bioenergy with carbon capture and storage. In the latter context, one of the bedeviling questions has been how to move from a conceptual embrace of BECCS to operationalizing this approach so that it can be scaled to a point that it can become a viable part of a portfolio of carbon dioxide removal approaches. And so we're pleased today to have the lead author of a piece that was published in Energy and Environmental Science recently, entitled "Assessment of a Carbon Dioxide Removal Potential via BECCS in a carbon-neutral Europe," which does exactly that.

It seeks to look at critical considerations of sourcing feedstocks, transportation, storage of carbon dioxide, and the role of European countries in doing so, and the role of science, technology, law, and policymaking to make that happen. Our speaker today is Lorenzo Rosa. Dr. Rosa is a postdoctoral fellow at ETH Zurich in the Institute of Energy and Process Engineering.

He obtained his PhD from the University of California Berkeley in the environmental science, policy, and management program. For his contributions to studying sustainable water, energy, and food systems, he was recently named to the Forbes 30 Under 30 list. And in his presentation, he'll both focus on the article as well as some extensions of that research, including aspects of water in implementing BECCS at a very large scale. And so with that, I will turn it over to Dr. Rosa. - Thank you very much, Wil. Let me share the screen.

In this webinar, I will talk about the climate mitigation potential of carbon dioxide removal via BECCS in a carbon-neutral Europe. In the coming decades, population growth and rising incomes, as well as an increase in food, fiber, and energy demand, will place unprecedented pressures on the earth's natural resources. And in particular, this increase in demand for food and energy will also push the earth system beyond planetary boundaries.

There are two additional challenges that humanity is facing. One is climate change and global warming, and the other one is the collapse of biodiversity. And to mitigate climate change, it is needed to reach net-zero CO2 emissions.

And in this figure, we see what is needed to reach the 1.5 degrees scenario with respect to the pre-industrial Europe, which was the target which was set during the Paris agreement. And to mitigate climate change, two main things are needed. one is a deep emission reduction, which can be achieved with decarbonization or shifting from fossil fuels to renewable energy, such as wind and solar, but also by using hydrogen, in particular low-carbon hydrogen. Another way to reduce emission is increasing energy efficiency.

And the other way, according to many models, is to retrofit with carbon capture and storage existing industrial facilities that are emitting fossil CO2. In addition, there will be harder to abate emissions, such as agriculture, steel and concrete production, that will be needed to mitigate using some form of carbon dioxide removal. And there are different solutions that are proposed for carbon dioxide removal. And according to many models, bioenergy with carbon capture and storage, or BECCS, will be needed to be deployed at the gigaton scale to reach net-zero emissions. And for example, Europe, which has set the target to be climate neutral by 2050, will have likely to implement BECCS and remove up to 7.5 billion tons of CO2 by 2050. BECCS, or bioenergy with carbon capture and storage, consists of a complex supply chain.

We have the biomass that is grown. Biomass then is collected, transported to a bioenergy facility. In this bioenergy facility, there are different energy technologies that depending on the biomass type, they can convert the biomass into bioenergy. And for example, some example of energy that can be produced are electricity, power, but also fuels like ethanol or hydrogen.

And during energy production, some form of biogenic CO2 is produced. And this CO2 is a high-purity stream that could be captured, transported, and permanently sequestered to perform carbon dioxide removal. However, BECCS has several challenges, in particular due to the use of biomass feedstocks to produce bioenergy. And biomass requires a lot of land, which is going to compete with the increasing demand that we have for food.

For example, by 2050, to meet future food demand, it will be necessary to double food production. So there will be a huge competition between land for food production and land for bioenergy production. And additionally, biomass feedstocks requires a lot of water, and they create also biodiversity loss. And a particular concern regarding the biomass for BECCS is the use of purpose-grown, often monoculture, biomass plantations.

And the use of these monocultural plantations can have several socio-environmental externalities, one of which is biodiversity loss. So what I'm doing in my PhD, in my post-doc, excuse me, at the ETH Zurich is to quantify the opportunities to use sustainable biomass feedstocks for BECCS. And in particular, I'm considering biomass feedstocks that do not create impacts on natural resources and do not create additional competition with food production and biodiversity loss. And indeed, there are many opportunities to use biomass feedstocks that are already present, left often on the field unused, such as agricultural residues, forestry residues, waste biomass, and there are also existing point sources, so existing emitters that emit biogenic CO2 when they produce energy, such as waste to energy facilities for municipal solid waste incineration.

Then we have also bio-power plants, which are biomass co-fired power plants, where both biomass and fossil fuels are burned to produce power. Then we have pulp and paper mills and wastewater treatment facilities. So what we did in this study was to quantify the potential for biogenic carbon dioxide removal from existing point sources in Europe.

And we considered incinerators, pulp and paper mills, wastewater treatment facilities, and bio-power plants. And as you can see in the figure on the left, incinerators emit, between 40% and 60% of the CO2 that they emit is biogenic. The remaining fraction is fossil. Pulp and paper mills and wastewater treatment facilities emit between 75 and 100% of biogenic CO2. So by capturing 90% or 99% of this CO2, depending on different CO2 capture rates, it would be possible to perform carbon dioxide removal.

And we quantified this for all the existing infrastructure in Europe, the map on the right. And aggregating these results at the European and country level, we find that Europe has the potential to capture 125 million tons of biogenic CO2 from already existing infrastructure. At the same time, capturing this CO2 would also need, would also capture 120 million tons of fossil CO2. And we can see that the countries have different potentials. For example, Sweden has the potential to remove a lot of biogenic CO2 by capturing CO2 from already existing infrastructure, and capture as well a smaller fraction of fossil CO2, while other countries like Germany and the Netherlands, by capturing CO2 from existing point sources, would capture a small amount of biogenic CO2, but a larger amount of fossil CO2. So this has implications, such as that capturing CO2 from these existing point sources would enable a mitigation of fossil CO2 emissions from pulp and paper mills, incinerators, bio-power plants, and wastewater treatment facilities.

However, the downside is that it would require to transport large quantities of CO2 without delivering large quantities of biogenic carbon dioxide removal. We then quantified the potential to perform biogenic carbon dioxide removal from distributed biomass feedstocks in Europe. And as you can see in the map, this is the geospatial distribution of these biomass feedstocks, which are livestock manure, agricultural and forestry residues, waste biomass, and food waste. And these biomass feedstocks, which I define as sustainable biomass feedstocks because they don't require additional land, water, and they don't create a competition with food production and biodiversity loss, are already present, are already produced, and they are often left on the field to decompose.

So in a carbon-neutral Europe, it would be possible to use these biomass resources to perform carbon dioxide removal. However, these biomass feedstocks are a limited resource. And one way to recover all the carbon that is contained in this biomass is hydrogen, so is to produce hydrogen from biomass. And hydrogen is an important element as well that is needed that in a net-zero economy. In fact, it is forecasted that a net-zero economy will have to use 10 to 25% of its final energy consumption from low-carbon hydrogen.

And there are different ways to produce low-carbon hydrogen. The focus so far has been mainly on green and blue hydrogen. Blue hydrogen is hydrogen which is produced from fossil methane with steam methane reforming and carbon capture and storage, while green hydrogen is hydrogen that is produced from water electrolysis from renewables such as wind and solar power. However, hydrogen can also be produced from biomass. And biomass can produce low-carbon hydrogen, but at the same time perform some form of carbon dioxide removal. And however, despite the potential of hydrogen production with biomass and carbon capture storage, so far this hydrogen production route has been overlooked.

So what we did in this study was to quantify the hydrogen that can be produced from sustainable biomass feedstocks, manure, food waste, and agricultural residues, in Europe. And we design a BECCS supply chain that collect biomass, transport this biomass to an anaerobic digestion facility, where biogas is produced. Biogas is about 50% CO2 and 50% methane. CO2 can be captured during biogas upgrading, and the captured CO2 can be transported for permanent geological sequestration.

Upgraded bio-methane can be used to produce hydrogen through steam methane reforming. And during steam methane reforming, most of the CO2 can be captured for permanent sequestration as well. So this way to produce hydrogen from biomass represent a near-term opportunity to generate both low-carbon hydrogen and carbon dioxide removal. And what I mean for near-term opportunity, I mean that we are using the technologies that are already in use. In fact, anaerobic digestion and steam methane reforming are already used at commercial scale in Europe, but also in other countries, like such as North America and China.

And therefore would just need to shift the production of hydrogen from fossil methane to bio-methane. And we quantified the potential that there is for bio-hydrogen production in Europe. And we find that sustainable biomass can produce 3% of European final energy consumption using biomass.

This 3% corresponded to 12.5 million tons of hydrogen per year, which is comparable to the quantity of hydrogen that is currently used in Europe, or 10 million tons of hydrogen per year. But importantly, in a net-zero economy, 10 to 25% of final energy consumption will have to come from low-carbon hydrogen. So biomass can only produce 3% of final energy consumption. The remaining fraction to reach 10 or 25% will have to come from alternative hydrogen production routes such as blue hydrogen or green hydrogen. We then quantified the additional biogenic carbon dioxide removal that would be feasible with production of hydrogen from biomass.

And we find that an additional 125 million tons can be produced from biogas upgrading and hydrogen production from biogas. They are there at 125 million tons are from existing point sources, as I mentioned before. And we find that the total potential in Europe for biogenic carbon dioxide removal from BECCS is 7% of European greenhouse gas emissions, or about 250 million tons. And importantly, this potential is the lower bound of the carbon dioxide removal that will likely be needed to offset greenhouse gas emissions and reach net-zero emissions by 2050. In fact, as I mentioned, many sectors like concrete, steel, agriculture, will still emit greenhouse gas emissions in 2050, and 5 to 30% of the emissions, of the current emissions, are forecasted that will need to be offset with some form of carbon dioxide removal. In the figure on the right, we see the country-specific biogenic carbon dioxide removal potential.

And for example, we see that the Sweden has a lot of potential to perform BECCS using existing point sources, especially pulp and paper mills. And Sweden will be able to offset all its emissions with BECCS. Another country for example, Finland, will be able to offset 50% of its emissions with BECCS, especially with point sources of BECCS. Other countries, which are the largest emitters in Europe, such as Poland, Italy, France, UK, and Germany, will be able offset up to 5% of their emissions with BECCS and the additional amount of BECCS, of carbon dioxide removal that will be required to reach net-zero emissions will have to come from other carbon dioxide removal options, such as direct air capture, or these countries will have to further de-carbonize their economies. To perform carbon dioxide removal, it is also necessary to permanently sequester CO2. And one way to permanently sequester CO2 is through geological sequestration in appropriate CO2 storage sites.

In Europe, there are different prospective CO2 storage sites, as you can see in the map. And here we show the ten CO2 storage sites that are more prominent. Most, some of these projects are upcoming in the next few months or years. Others are just projected, and they may come online at the end of the decade. And what we did was to quantify the transportation distance from the CO2 capture site to the CO2 storage site.

And we find that 30% of biogenic carbon dioxide removal potential in Europe is located within 300 kilometers from these 10 CO2 storage sites. On the other hand, we find that fossil CO2 that will be captured with carbon capture from these BECCS point sources is available within 300 kilometers, 55% of fossil CO2 is available at this transportation distance. And so this map also shows that most of the CO2 storage sites are mainly located in the North Sea. And to reduce CO2 transportation distance, we imply that some additional CO2 storage sites are needed in the central part of Europe and in southern Europe to reduce the transportation distances. We then quantified the transportation distance that would happen to use hydrogen that would be produced from biomass.

And we used as hydrogen users ammonia fertilizer facilities, refineries, glass mills, steel mills, and cement production facilities, which are the facilities shown in the map. And we find that 20% or 2.5 million tons of hydrogen that can be produced from biomass are within 20 kilometers from these hard to electrify industries. And 50% of the hydrogen potential in Europe is located within 50 kilometers.

So for hydrogen, on the other hand, we have shorter transportation distances from hydrogen production to hydrogen use facilities. And importantly, most of these industries, such as refineries and ammonia production facilities, already use hydrogen and produce hydrogen in situ using steam methane reforming. So here is a real near-term opportunity to shift from fossil methane to bio-methane to produce hydrogen. Another important aspect that I would like to mention about carbon capture is that carbon capture is a process that is not free of environmental impacts. In particular, during my PhD studies, I studied the water usage of carbon capture processes. And as you can see in this figure, different carbon capture processes and technologies require water.

And in particular, we see that BECCS is a process that requires a lot of water, in particular during carbon capture, but also during the growth of biomass, during the photosynthesis process. And an important question, an important sustainability question, is if carbon capture can be achieved without creating water scarcity and compromising water resources. So what we did was to use coal power plants as a case study.

And as I mentioned for Europe, most of, some of these coal plants are biomass co-fired power plants, so they use both coal, but also as a smaller fraction they co-fire biomass. And these power plants, coal power plants, have a typical lifetime of 30 to 50 years. And most of these coal plants were built after year 2000, especially in China and India. So these coal plants commit humanity to emissions for other decades, greenhouse gas emissions for other decades. But at the same time, commit humanity to water usage. And therefore, they compel increasing attention to water scarcity.

So what I did was quantify the exposure to water scarcity of coal power plants under current conditions. And I find that 40% of global coal power plant capacity face water scarcity for one month per year. And 30% of coal plant capacity face water scarcity for five or more months per year. Since most of these coal power plants were built recently, and they will last other 10, 20, 30 years, there are two options to reach net-zero emissions. One option is to shut down these coal power plants, and therefore create the so-called stranded assets and all the investments that were required to build these coal power plants. Another option is to retrofit with carbon capture units these coal power plants.

And as I mentioned, carbon capture is a process that requires additional water compared to current coal power plant utilization. And I quantified the additional exposure to water scarcity of coal power plants built after year 2000. And I find that the addition of carbon capture would expose to longer periods of water scarcity 23% of the coal plant capacity built after year 2000. And most of these coal plants are located indeed in China and India. Some key messages that I would like to leave on this talk are that biomass is a limited resource, and in particular sustainable biomass. So biomass that is from agricultural waste and residues, and does not create additional impacts on land, water, and competition with food production.

And this sustainable biomass, while is a limited resource, has the potential to mitigate greenhouse gas emissions. In fact, we find that in Europe up to 7% of greenhouse gas emissions can be mitigated with biomass, with sustainable biomass. And one way to extract all the carbon that is contained in this biomass is hydrogen production. In fact, since biomass is a limited resource, the production of hydrogen can recover most of the carbon that is contained in this biomass for carbon dioxide removal. We also find that the geopolitical situation in different European countries is very different.

There are countries like Sweden and Finland that have huge potential for biogenic carbon dioxide removal via BECCS, while other countries have a smaller potential. And we also find that some countries have huge potential for BECCS by retrofitting with carbon capture existing point sources like incinerators and pulp and paper, while other countries have a larger potential with distributed biomass sources. And these distributed biomass sources will need an additional infrastructure to transport the biomass, to produce bioenergy, and capture and transport the CO2 that is produced during bioenergy. So they will require an additional infrastructure compared to carbon capture from point sources. Another important point is that BECCS is a complex supply chain.

And we find that in Europe, there are unfavorable source-sink transportation distances, especially for CO2 transport. And we posit the idea that it is necessary to have additional CO2 storage sites in continental and southern Europe. And importantly also, we think that it is necessary to realize a European-wide CO2 transportation network. And another key message that I would like to leave is that there are trade-offs between water usage and climate change mitigation with carbon capture. In fact, carbon capture requires a lot of water, and is very concerning in regions affected by water scarcity or where they will be exposed to water scarcity.

I thank you very much for your attention, and I leave the remaining time for your questions. Thank you very much. Wil, you are muted, sorry. - Sorry about that. Thank you, Lorenzo.

We have time for questions, approximately half an hour, and we have an abundance of them already. But I encourage you to type in additional questions as we move through that. So I will start looking through these. So first question, "Can you discuss the energy needs associated with reforming and other similar processes, where this energy would come from, and the CO2 implications?" - Yes, so this is part of work that has been done in my current research group.

And basically they design the process to produce hydrogen from biogas. And the energy will come from, the energy will come from bio-methane combustion during biogas production. So it does not require additional energy. And this is part of a study that does a techno-economic assessment using process engineering of the feasibility to produce hydrogen with steam methane reforming from biogas. - Okay, thank you. Next question.

"How many million tons of hydrogen will Europe need in 2030 or 2050 to be able to reduce their CO2 emissions to meet the temperature goals that they've outlined?" - Yes, so as I mentioned, 10 to 25% of final energy consumption is forecasted to be needed, to be met with low-carbon hydrogen. And current, the potential of bio-hydrogen is 3%. So currently 3% is 12.5 million tons. So to reach about 30% is 10 times more. So 120 million tons, or 40 to 120 million tons of hydrogen would be required to meet the 10 to 25% of final energy consumption. As a very quicker calculation, that should be the number.

And I think the key message here is that biomass, especially sustainable biomass, can produce only 3% of final energy consumption through hydrogen. And we will have to rely on other forms of hydrogen, such as green hydrogen or blue hydrogen, to meet that 10 or 25% of final energy consumption that will be needed to be produced, to be met with low-carbon hydrogen. - Okay, thank you very much.

"In determining the amount of carbon dioxide that needs to be removed to meet the 1.5 or 2 C targets, how do you model considerations such as solar energy, population, geological energy, and so forth?" - Well, this is a preliminary study, so is one of the first studies that could quantify this potential for biogenic carbon dioxide removal, especially in Europe. And in this study, we didn't consider population growth, or for example, scenarios of agricultural residues, future crop productivity under climate change, or future food waste, just an example. So we used static conditions.

Of course, in the next 20, 30 years, so by 2050, climate conditions are going to change. It's forecasted it that we will likely overshoot the 1.5 degrees and maybe reach two or even three degrees. And this obviously is going to affect the biomass production from agriculture but also from forests. And also population is going to change in these 30 years.

But to my understanding, population in Europe is going to be pretty much stable. Is not like other countries as Sub-Saharan Africa or Eastern Asia, where population is booming. In Europe, we are going to stay about 500 million in the next 20, 30 years, at least to my understanding, according to the UN population projections. - Okay, thank you.

Let's see. "How many million tons," oh, I'm sorry. I've already done that. "Given the competing uses that could be posed for biomass, including things such as materials production or sustainable aviation fuels, and the limited availability of these resources, how do you consider the trade-offs when according priority to biogenic hydrogen production in CDR over other uses that may not have non-bio alternatives?" - We didn't do economical consideration in this study.

We quantified the technical potential for biogenic carbon dioxide removal. So this is an important point, and should be part of future work. I agree with this. The most thing is that this biomass, which is sustainable, is a limited resource. And we should use it in a way that maximize its use. And in a net-zero economy, so in a hypothetical 2050 when we have to be net-zero, this sustainable biomass should be used in a way that maximize carbon dioxide removal.

And I think the way to maximize carbon dioxide removal is BECCS through hydrogen production, as I have shown. Of course, there are different, other technologies like jet fuels, as you mention, or also biomass co-firing to produce cement, but these are alternative ways. - Okay, thank you. So, "Given the fact that you contemplate storing CO2, how will the installations guarantee that there will be no leakages of carbon dioxide, and how do you guarantee the security?" - Yes, so this is not totally my expertise, but in the carbon capture class, if you attend a carbon capture class, they always tell you that this is a proven technology. Like we basically put CO2 back where there were oil and gas for millions of years.

And there is monitoring, and all these technologies that can prove that we don't have leakages of CO2. I think the main issue here is to capture the CO2, especially the biogenic CO2, and transport the CO2 over very long distances. And the only infrastructure that you need is to transport the CO2. As I mentioned, we will need a European-wide CO2 transportation network.

So for example, transporting CO2 from Switzerland, Zurich, to the North Sea, where there are all these CO2 storage sites requires long distance transportation and cooperation with other countries like Germany, in the case they go north. And I think this is going to be the main issue, so to create a network of pipelines or trucks or ships that transport the CO2. I think this is going to be the main issue. And in my research group, in my department, we are currently working on this, the design of supply chains for carbon capture and transportation along Europe. - I was just curious in that context, are you also looking at the potential role of public resistance to things like pipelines, right? I know in Germany, a couple of pilot CCS projects, right, were scuppered because of local resistance to transport of CO2 or storage of CO2.

Are you looking at those social aspects? - I am not directly working on it, but in my group at ETH Zurich they are also working on this. There is a European and Swiss-funded project where they are specifically looking into these social consequences with CO2 transport. - Okay, great, thank you. Next question, could you talk about the ability to scale up and connect anaerobic digesters to the national grid? How mature is that technology? The comment was, "The last time I was engaged with this was several years ago, and it was small-scale and problematic in the UK, at least, at the time." - Yes, so in Europe, biogas is, biogas production through anaerobic digestion is a commercially available technology. So it's feasible and we can do it.

The main issue is that many of these anaerobic digesters are very small. So in many cases is not economically feasible to perform carbon capture, so to upgrade biogas to bio-methane. So what they do is to use the biogas, which is about half CO2 and half methane, and use it onsite.

So they burn it and they produce ether to run the farm, to produce warm water, for a dairy production, for example, or district heating, like localized. There are a few facilities that produce bio-methane, so they upgrade biogas, but this is, biogas upgrading is increasing a lot in Europe, especially in the past few years, because it's becoming increasingly economically feasible and there are incentives to use bio-methane instead of fossil methane. And I think the next incentive is going to capture these biogenic CO2 to perform carbon dioxide removal. So yes, it's more expensive, but you have two advantages: shifting from fossil methane to bio-methane, where you can have an economic incentive to do it; and at the same time, capturing this biogenic CO2 to perform carbon dioxide removal, which is going to be likely needed to mitigate climate change.

So we need to use this biogenic CO2 that we currently emit back in the atmosphere. But it is low-hanging fruit to be captured, because it has very high purity, and so it's not very expensive compared to other sources like coal power plants to be captured. And I think that could be one of the early movers way to start to perform biogenic carbon dioxide removal, so capturing CO2 from biogas facilities. - Okay, thank you.

Next question. "What policies and market incentives would you recommend in Europe to deploy BECCS and bio-hydrogen production at scale?" (Wil laughs) Nice, easy- - This is, (laughs) okay. I am a scientist, you know, I am not a politician. But, well, so I think there is a pressing need to deploy these technologies. And as we mentioned before, whether it's bio-hydrogen, biogas, or jet fuel, converting like from fossil jet fuel to biogenic jet fuel, we need to deploy these technologies.

And obviously the solution is going to be a broad range of technologies, and not saying we have to deploy just one technology. But I think the aim of this study is to show obviously the scientific value and the potential of these technologies, of these routes to mitigate climate change. And we show that if we follow this route with biogenic carbon dioxide removal, we can mitigate (computer obscures speech) of carbon (computer obscures speech) which is not trivial. And so if we really want to reach net-zero emissions. this can be a way, or part of the solutions to mitigate emissions.

I think it's not going to be easy to implement this, especially because of the additional costs. And as I mentioned, of the transport of CO2 and biomass to bioenergy facilities and CO2 storage sites. So it's going to be a huge challenge that we face in the next 20, 30 years.

But I think we will have to do some form of BECCS sooner or later. - Okay. Next question.

"Europe has ignored onshore CCS and CCU. From your work, would onshore CCS and CCU have an advantage with respect to biomass and coal plants in terms of maximizing the utility of resources and optimizing the use of capital?" - Yeah, these are good points. So all the prospective CO2 storage sites for geological carbon sequestration are offshore. And this is mainly because of social concerns, I guess. They are all in the North Sea, and only one in the northeast part of Italy, which is just suggested.

We don't know if it's coming online and when it's coming online. And yes, there is definitely a need of CO2 storage sites, especially in southern and central Europe. And in southern Europe, we can locate them close to the sea, or offshore. So that would avoid that social concern. But I agree, I agree with you that some CO2 storage sites may be needed also onshore.

And for example, the US does not have this issue of long transport distances, because they have a lot of prospective storage sites that are onshore, while here in Europe we have this issue of long transportation distance, because all the storage sites are located far away from emissions and where population is located. - All right, thank you. "How is sustainable biomass defined in your research, and are there conflicting definitions of sustainable biomass?" - Yes, I define it as sustainable biomass because also of the work that I have in my background. So in my PhD, I focused on food security and the need of land and water resources to meet the future demand for food. As I mentioned, by 2050 it's forecast that future food production will have to double to meet the demand. So this is a huge challenge.

And as you may know, agriculture is already creating a lot of environmental impacts. It's contributing to climate change, land use, water use, biodiversity loss. So if we have to double food production, so we require increased food production and maybe even additional land, and then we start to do also bioenergy, and producing biomass feedstocks that as well, they are like, they are biomass, you know, so they require land, water, and additional resources. I think this is pretty sure the earth system is not going to stay within the planetary boundaries. So if we perform BECCS using purpose-grown biomass plantations, we are going to exceed the planetary boundaries.

And the aim of this study was to show the potential of biomass that is already available and is left on the field unused. Most of these biomass is on the field, left to decompose. And it makes CO2 and methane while they decompose.

If we can collect, transport, and transform part of this biomass, we can do some biogenic carbon dioxide removal without adding additional impacts on land, water, and biodiversity loss. Because this biomass is already there. So we will not add additional environmental impacts. And this is why I define it as sustainable biomass. In contrast to biomass that, most of the studies so far focus on monocultural plantations for BECCS.

So they forecast to plant a huge swath of trees or some kind of biomass feedstocks at expenses of land, fertile land that could be used for agriculture or is currently used for agriculture. And I think like the novel part of this study is also this, that we show where there is, what is the potential using biomass that does not conflict with food, land, and water. - I wanted to ask you something in that context about agricultural residues. So there's been some studies that have said that if you remove agricultural residues, they're a critical source of ensuring optimal yields, right? And as a consequence, you might need to divert other land to agricultural production to compensate for that. And then there's studies that say that agricultural residues contribute to soil health, to the point where they effectuate enough uptake of CO2 to offset all of, more than offset all of the CO2 releases and methane releases. Could you speak to those arguments? - Yes, this is a very good point.

And actually in this study, we account for these factors. So we account, you have the agricultural residues, and we account that only a part of agricultural residues, manure and forestry residues, can be used for BECCS. Meaning that, for example, for agricultural residues, some of these agricultural residues must be left on the field to preserve the organic carbon that is present in the soil, and therefore avoid the depletion of soils and the erosion of soils. So in our assessment, it's conservative, our assessment, because we already account for these factors, so that a certain fraction of agricultural residues is to be left on the field to avoid depletion of soils, in particular of organic carbon in soils. - Okay, thank you for that. Next question.

"There are concerns with the short-term climate forcing effects of leaked hydrogen. Have you considered hydrogen use scenarios that minimize leakage potential, such as onsite usage?" - No, I didn't. We just consider the potential that we have for hydrogen, and compare this hydrogen potential from biomass with the hydrogen that will be likely needed to reach net-zero emissions.

- Okay, great, thank you. Let's see. This is maybe a challenge as much as a question, but it says, "Bio-CCS from bio-gas is not more carbon-neutral than carbon removal?" - It's not? I don't get the question. - Yeah, I,

yeah, it seems like that's the the argument, that bio-CCS from biogas is not more carbon-neutral than carbon removal is. - It's not the same thing. I don't get the question, sorry.

Like, so I can elaborate a little bit. So we have biogas production, and during the biogas production as I mentioned we have half by volume that is CO2 and half by volume that is methane. We can upgrade biogas to bio-methane, and in some cases we actually capture CO2 and we can do carbon dioxide removal.

So this is how we can do biogenic carbon dioxide removal or BECCS from biogas. I don't get the difference that is asking in the question, I'm sorry. - Yeah, I'll ask for a clarification from, on that query if you wish, and I'll come back to it.

- Yeah, you can even contact me by mail directly if you want. Yeah, I don't know what's the question, but yeah, if you are listening. - That sounds great. We'll archive all of the questions, as we always do at the end. Next question. "Why not just convert the CO2 to new products instead of building new pipelines? This makes no sense."

- Well, I gave an answer. So they already did some calculations, and these volume of CO2 are huge, are a lot, is a lot of CO2. And it would require to produce a lot of material, and it will not work to remove all this CO2 just using utilization.

Utilization can be part of the solution, so carbon capture, utilization, and storage. But we have also to keep in mind that some form of utilization, they don't perform permanent carbon capture and storage. So they don't perform permanent removal.

And one way to perform permanent carbon dioxide removal is indeed to put it back from where it come from, so put it underground. And so that is why we consider carbon capture and storage in geological, through geological sequestration. - Okay, thank you.

Next question, "Which kinds of forest residues did you consider in your study?" - Yeah, forestry residues. So I did my PhD in California, and right there is a classic example. There are a lot of trees that are dead due to the drought, that are still there. And they cause all the fires that we heard in the news. So that could be an example of forestry residue.

So dead trees or branches that are left in the forest. Another example is that some forests are overpopulated. So there are too many trees. And so these do not create a healthy forest.

And there is the so-called forest thinning phenomenon, which is a practice to cut down some of the trees to make other trees flourish, no, in the forest, and have a therefore healthy ecosystem. So this could be another example of forestry residues. Other forestry residues are the one that are left on the field when we do logging in different regions, and they are currently left on the field and unused.

- Okay, great. Thank you very much. Next question, "Are you aware of any comprehensive study of the impact of a global hydrogen economy on the global hydrological system?" - These are good questions.

So you mean hydrogen production through water electrolysis? If this is your question, I think they already proved that that the water usage of hydrogen from electrolysis is not relevant from the hydrological cycle. And I think there is, or there are already publications that show the water footprint of hydrogen production from the so-called green hydrogen, or water splitting or electrolysis. And I think it's not going to be a main issue. Obviously, if you place gigawatt-level electrolyzers in the middle of the desert, I think it's going to be an issue with water scarcity. But otherwise, I don't think it's going to be a main driver to water scarcity and the change in the hydrological cycle, like other factors like monoculture plantation for BECCS or widespread irrigation for biomass or agriculture.

- Okay. Next question is related to hydrogen also. (laughs) "Leakage of hydrogen can have an impact from a greenhouse gas perspective.

Do these calculations factor in the impacts of leakage?" - Yes, this is part of the study that I mention, that we refer to, that did this techno-economic analysis through a life cycle assessment of hydrogen production from biogas, and they account also for biogas, bio-methane leakage during biogas production. - Okay. Let's see. This may be a question that's more policy-oriented than you want to tackle, but "In the case of BECCS for hydrogen production, who would own the emission reduction or avoidance rights?" - Excuse me, can you repeat it? I'm sorry. - Oh, yeah. So I think it's policy-oriented question.

As I said, (laughs) you may or may not want to tackle it, but "In the case of BECCS for hydrogen production, who would own the emission reduction or avoidance rights?" - No, hydrogen production from biomass is low-carbon hydrogen, right? So using the results of the study, the study from my research group, they found that using a life cycle assessment analysis, the emissions for hydrogen production are carbon-neutral. If you do carbon capture and storage, this generates negative emissions, considering the food supply chain with a life cycle assessment. So they are about, I don't want to give a wrong number now, but it's about minus nine kilos of CO2 per kilo of hydrogen produced. So you remove 9 kilos of CO2, every kilo of hydrogen that is produced. So these are negative emissions, if obviously you do carbon capture and permanent sequestration.

And therefore you produce low-carbon hydrogen, and you have this CO2 that, if you release it in the atmosphere, of course you are carbon-neutral or lightly carbon-positive. But if you do carbon capture and storage of the CO2 produced during biogas and hydrogen production with steam methane reforming, you capture biogenic CO2, and you can perform negative emissions. - Okay.

All right, thank you very much for that. So we have reached the top of the hour. And so, first of all, I'd like to once again thank you, Lorenzo, for an excellent presentation and helping us to look at some of the issues that obviously will be pertinent in Europe, but will be pertinent wherever, to some degree, we site BECCS facilities in the future. And it's good food for thought, both on the technology side and some of the social factors that we discussed today. And I'd also like to thank our audience, as always, for the excellent questions. As always, it's always good news, I think, we weren't able to get to all the questions.

But as I said, we will archive them. And if Lorenzo wishes to answer additional questions, the answers will be kept there. So thank you very much. I hope many of you can join us for upcoming webinars that we will produce in the next couple of months. And thanks again to everyone, and goodbye now.

2021-09-26 01:46

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