Biochar Needs for the Iron and Steel Industry

As awareness of climate change and global warming grows, along with the Paris Agreement and Net Zero Emissions (NZE) 2050 targets for decarbonization, the use of biomass to produce biocarbon products is increasing. The iron and steel industry, in particular, faces significant demand, while supply remains limited. This has prompted several large companies to invest in large-scale biocarbon production, particularly biochar/biocoke.

Such large-scale production naturally requires abundant biomass feedstock. Specifically, in Indonesia, biocoke/biochar production from palm kernel shells (PKS) reportedly began last year. PKS was chosen because it is a readily available biomass waste product from palm oil mills. PKS and palm oil mill production in Indonesia is estimated to be around 12.5 million tons/year, but because some of the PKS is used as boiler fuel, the estimated usable PKS or remaining boiler fuel is around 6.25 million tons/year. To increase the supply of PKS from palm oil mills, cogeneration of empty fruit bunches (EFB) can be used. For more details, read here.

In addition to the PKS, biocoke/biochar and even black pellets (torrified pellets) are also produced using wood from energy plantations. Energy plantations with short-rotating crops like calliandra and gliricidia have great potential to produce this wood. Currently, wood pellets (white pellets) are being produced from these wood plantations. For more details on whether wood from energy plantations is better for wood pellets (white pellets) or biocoke/biochar/charcoal, read here.

Biocoke, biochar, and charcoal are used in the iron and steel industry as a substitute for coal-based coke in blast furnaces, while wood pellets (white pellets) and torrified pellets (black pellets) are used in power plants using both cofiring and fulfiring. In addition to their higher calorific value (around 20% higher than wood pellets (white pellets)), torrefied pellets (black pellets) are also hydrophobic, allowing them to be stored outdoors, like coal.

In today's era, the use of biocoke / biochar / charcoal to replace coal coke in blast furnaces is becoming important. Biocoke / biochar / charcoal derived from biomass is a renewable material that is sustainable as a reducing agent or fuel in blast furnaces. The chemical reaction will separate oxygen atoms from iron atoms and this will emit CO2. This will convert iron ore (Fe2O3) into crude (pig) iron.

However, the difference lies in the fact that the carbon source used as a reducing agent or fuel in a blast furnace comes from renewable and sustainable sources, making it a carbon-neutral process. Conversely, using coke from coal, as it comes from a fossil source, makes it a carbon-positive process. Similarly, using natural gas, a fossil fuel, as a carbon source for the reducing agent or fuel in a blast furnace, despite its lower carbon intensity, is considered less carbon intensive. 

Washed PKS for Decarbonization of Iron and Steel Plants

The steel industry contributes 8% of global CO2 emissions, with each ton of steel produced producing an average of 1.85 tons of CO2 emissions. Compared to iron ore mining, iron and steel production contributes significantly more to CO2 emissions. Decarbonization efforts in the steel industry begin with the use of renewable energy for smelting. Biomass-based fuels, such as charcoal, which has a high carbon value, can replace the use of coke derived from coal. The use of hydrogen from renewable energy sources is the ultimate decarbonization target for the steel industry.

Currently, the steel industry largely uses coal as an energy source or reducing agent. This coal is processed into coke and used in blast furnaces. It is estimated that approximately 70% of global steel production uses the blast furnace or BF-BO process, and in China, over 90% of steel production uses the BF-BOF process. To reduce carbon intensity, natural gas is used as the fuel. The use of natural gas as a gaseous fuel also acts as a transition medium and, because it is derived from fossil fuels, is also a carbon-positive fuel.

Nearly all CO2 emissions in the steel production sector come from blast furnaces (BFs), which refine iron ore into crude iron or pig iron. The challenge is significant: there are approximately 1,850 steel mills worldwide, with approximately 1,000 using blast furnaces, producing approximately 1.5 billion tons of pig iron annually.

The use of charcoal in a blast furnace not only reduces carbon dioxide (CO2) emissions but also sulfur dioxide (SO2) emissions due to its very low sulfur content (approximately 100 times lower) than coke. Likewise, the use of limestone is reduced, thereby automatically reducing slag production. This also makes the blast furnace's operation acidic.

The use of biomass-based carbon fuel (biocarbon) in the form of charcoal has a better climate impact because it is carbon-neutral. Furthermore, technically, because it is a solid fuel, similar to coke derived from coal, it requires little or no changes or modifications to the smelting furnace. However, the availability of high-quality charcoal, large volumes, and a continuous supply remain major constraints.

This makes the use of charcoal to replace coal-based coke in blast furnaces crucial. Charcoal, derived from biomass, is a renewable, sustainable material used as a reducing agent or fuel in blast furnaces. The chemical reaction separates oxygen atoms from iron atoms, emitting CO2. This converts iron ore (Fe2O3) into crude (pig) iron.

However, the difference lies in the fact that the carbon source used as a reducing agent or fuel in a blast furnace comes from renewable and sustainable sources, making it a carbon-neutral process. Conversely, using coke from coal, as it comes from a fossil fuel, is a carbon-positive process. Similarly, using natural gas as a carbon source for reducing agents or fuel in a blast furnace, although it is said to have lower carbon intensity, is also considered a carbon-neutral process.

The use of charcoal or biocarbon materials for metallurgy or steelmaking has actually been commonplace for some time. In the early 1900s, global charcoal production reached its peak, exceeding 500,000 tons. In the 1940s, charcoal production declined to nearly half its early 1900s levels due to the replacement of other carbon materials, such as coke from coal, in the manufacture of steel and other metals.

Charcoal is a fuel and reducing agent derived from biomass that has significant potential for use during this transition phase. Palm kernel shells (PKS) are a potential biomass raw material for charcoal production. Palm kernel shells (PKS) are available in the millions of tons, ensuring a reliable supply. Charcoal, a product of biomass carbonization or pyrolysis, has a high calorific value, high fixed carbon content, and stability. However, another factor, ash chemistry, influences the quality of the resulting steel. This is somewhat similar to the ash chemistry of wood pellets from calliandra or gliricidia energy plantations.

When used as a reducing agent in blast furnaces, charcoal must have a low phosphorus content, while wood pellets from calliandra or gliricidia energy plantations must have low potassium, sodium, and chlorine content. The potassium, sodium, and chlorine content of wood pellets affects the quality of the wood pellets and their use in power generation. Pulverized combustion power plants, widely used worldwide, will reject wood pellets with this quality. Similarly, blast furnaces will reject charcoal with a high phosphorus content.

To achieve this quality, low-phosphorus content, the palm kernel shells (PKS) must first be washed. After washing, the phosphorus content decreases, and they are then dried and pyrolyzed, or carbonized, to produce palm kernel shell charcoal (PKSC). The same applies to wood pellets. The only difference is that wood pellet production doesn't involve pyrolysis or carbonization; instead, after drying and achieving the desired particle size, the pellets undergo biomass densification in a pelletizer.

Steel production requires an average of 6,000 MJ of energy per ton (equivalent to 50 kg of hydrogen) or 200 kg of charcoal, and requires approximately 600-800 kg of woody biomass as raw material. With a calorific value nearly identical to woody biomass, this is equivalent to using palm oil mills (PKS), which are plantation or agro-industrial waste.

Meanwhile, demand for low-carbon steel is growing rapidly as steel industries and governments worldwide commit to reducing carbon emissions from fossil fuels. The use of charcoal or biocarbon in blast furnaces is a key component of low-carbon steel production, as 100% of the steel is not yet produced using renewable energy. 

Exploring the Market for Bioenergy and Biocarbon Products in the Era of Global Decarbonization

The demand to lower the earth's temperature by reducing greenhouse gas concentrations through various global agreements such as the Paris Agreement and Net Zero Emissions (NZE) 2050, followed by technical follow-up through decarbonization for various sectors and industries, continues. This is the driving force for increasing renewable fuels, especially those based on biomass or bioenergy products, which have been implemented, but are experiencing dynamics in the form of fluctuations in demand and prices. Bioenergy, with its numerous advantages and uniqueness as a renewable energy, cannot be replaced in this era of global decarbonization, even though in the near future some subsidies for biomass fuels or bioenergy will be eliminated.

This is closely related to a government's decarbonization priorities, particularly among the various emerging options. Bioenergy products can vary in quality, but all have their own market segments within specific industries. Furthermore, the sustainability of biomass sources is also a crucial aspect in the business and use of bioenergy, and is strictly enforced by standards such as GGL, FSC, SBP, RED III, and SURE. Industrial groups such as cement, iron and steel, chemicals, and even the aviation sector, which previously relied 100% on fossil fuels or energy sources, are gradually shifting to renewable energy sources.

Bioenergy products such as industrial wood pellets and industrial wood briquettes are primarily marketed in the power generation industry and as fuel for industrial boilers. Industrial wood pellets are very popular and are produced in larger quantities than industrial wood briquettes. Due to the elimination of subsidies and the implementation of sustainability certification, biomass fuel producers are required to produce better quality products using environmentally friendly and accountable raw materials. This also applies to bioenergy derived from agricultural waste, which generally lacks sustainability certification at large production capacities.

Biomass power plants operating near carbon neutrality can then be upgraded to carbon-negative operation, or atmospheric carbon dioxide removal (CDR) by adding carbon dioxide capture and storage (CCS) equipment. Biomass power plants equipped with CCS devices are popularly called BECCS (Bio-Energy Carbon Capture and Storage). It is predicted that the BECCS era will not be far off, and countries with biomass power plants can easily upgrade to BECCS. Expensive CCS equipment and low carbon credit revenue from CDR remain current obstacles. Japan, with around 300 biomass power plants, has great potential to upgrade to BECCS. And as a biomass power plant, the need for fuel will always be needed, such as wood pellets and PKS (palm kernel shells). For more details, read here.

One successful example of BECCS is the Stockholm Exergi BECCS project. BECCS illustrates how existing biomass power generation infrastructure can be leveraged to generate sustainable carbon dioxide sequestration. The Stockholm project, based on sustainably sourced biomass fuel, secured one of the world’s largest carbon sequestration deals with Microsoft, a significant contract worth SEK 500 million (~89 billion rupiah). Their model integrates carbon capture with a district heating system, maximizing energy efficiency while achieving permanent carbon dioxide sequestration.

Similarly, several other large industries, such as cement, aluminum, and chemicals, are also gradually decarbonizing. Biomass fuels, such as wood pellets and agricultural/plantation waste like palm kernel shells (PKS), are preferred in this sector. Besides their high energy content, these biomass fuels are more affordable than derivatives like torrefied biomass and charcoal/biochar. With the gradual transition or decarbonization of these industries, the demand for biomass fuels will also continue to increase.

Meanwhile, biocarbon products such as torrified biomass (biocoal) and carbonized biomass (biochar/charcoal) are starting to attract attention and are expected to reach mass production levels in the near future. Power plants typically favor biocoal due to its higher energy content, hydrophobicity, which allows it to be stored in open areas like coal, and ease of crushing (high grindability index). Meanwhile, biochar/charcoal, especially in the iron and steel industry, is highly suitable for producing low-carbon steel and even green steel. The reductant for blast furnaces, which previously used coke from coal, can be replaced by charcoal or biochar. Charcoal or biochar with high purity (fixed carbon >85%) and low impurities are required for blast furnace reductants. For more details on this, please read here and here.

Meanwhile, the use of biomass for sustainable aviation fuel or SAF (Sustainable Aviation Fuel) is also very possible. This is because currently there are three leading production processes for SAF production: HEFA (Hydro-processed Esters and Fatty Acids), FT (Fischer-Tropsch), and ATJ (Alcohol to Jet Fuel). Biomass through thermochemical processes, namely in FT (Fischer-Tropsch) and biochemical processes, namely in ATJ (Alcohol to Jet Fuel), can be used as raw material or feedstock. Meanwhile, the raw material or feedstock for the HEFA process is not solid biomass but vegetable oil, used cooking oil, animal fats, and so on. So the broad application of biomass as various important energy sources in the era of global decarbonization is a driving force for biomass production both through the forestry sector and sustainable agriculture/plantations.

 

Biochar and Biographite for Decarbonization in the Iron and Steel Industry

The decarbonization trend continues across all sectors, particularly strategic industries such as the energy industry, iron and steel industry, and transportation. These industries contribute significantly to CO2 emissions, which increase atmospheric concentrations (carbon positive). The energy industry, particularly power generation, contributes 27.45%, the steel industry 8%, and the transportation sector 24%. With an estimated total CO2 emissions from fossil fuels of 36.3 gigatonnes (36.3 billion metric tons) in 2024, the iron and steel industry's contribution is approximately 2.9 gigatonnes (2.9 billion metric tons).

In the steel industry, carbon neutral production will be achieved when iron and steel production in the industry uses 100% renewable energy. The use of electric arc furnaces (EAFs) can be done as long as the electricity is generated from renewable energy sources. However, the use of EAFs that still use electricity from fossil fuels can be a transition medium before 100% carbon neutral production because of its lower CO2 emissions compared to blast furnaces that use coke from coal. CO2 emissions from blast furnaces are around 2.33 tons for each ton of crude iron / pig iron, while with EAFs, they are only around 0.66 tons for each ton of crude steel. The raw material processed with EAFs is steel scrap, and approximately 80% of steel scrap is currently recycled with EAFs. Globally, steel production with EAFs reaches approximately 22%.

And the fact is that currently, to achieve this goal is still far because the construction of blast furnaces - basic oxygen furnaces (BF -BOF) is still being carried out a lot, which should be EAF (Electric Arc Furnace) or currently only about 30% of the global iron and steel industry uses this EAF. The construction of new blast furnaces is indeed tending to increase, in fact, by mid-2024, around 207 million tons per year of new production has been announced and around 100 million tons per year is under construction.

Nearly all CO2 emissions in the steel production sector come from blast furnaces (BF) for refining iron ore into crude iron or pig iron. The challenge is enormous: there are approximately 1,850 steel mills worldwide, with approximately 1,000 using blast furnaces, with pig iron production reaching approximately 1.5 billion tons per year. The International Energy Association (IEA) has even highlighted this critical issue in achieving the Paris Agreement's net-zero target by 2050. With an average blast furnace lifespan of 20 years, the iron and steel industry's efforts to achieve this target must be well-formulated and programmed. Failure to replace blast furnaces within the specified timeframe will jeopardize the 2050 net-zero emissions target.

This makes the use of charcoal to replace coal-based coke in blast furnaces crucial. Charcoal derived from biomass is a renewable, sustainable material used as a reducing agent or fuel in blast furnaces. The chemical reaction separates oxygen atoms from iron atoms, releasing CO2. This converts iron ore (Fe2O3) into crude (pig) iron. The difference is that because the carbon source as a reducing agent or fuel in blast furnaces comes from renewable and sustainable sources, this process is carbon neutral. Using coke from coal, which comes from fossil fuels, is carbon positive. Similarly, using natural gas as a reducing agent or fuel in blast furnaces, despite its lower carbon intensity, is still carbon positive. 

However, if hydrogen from renewable energy sources (green hydrogen) is used as a reductant in the blast furnace, it will not produce carbon emissions but will produce water vapor (H2O), thus it is also a carbon neutral process. However, this will still take a long time, predicted to take several decades to implement. To produce a carbon negative process, the iron and steel mills that are already operating carbon neutrally must be equipped with CCS (Carbon Capture and Storage) devices, which will certainly be the next step. Furthermore, the use of renewable energy as an EAF energy source is also becoming increasingly important and must be accelerated, which should also be in line with the use of bio-graphite in the EAF.

The use of EAF in iron and steel mills is estimated to reach 550 units worldwide with steel production reaching around 548 million tons or around 30% of the world's steel production which will reach around 1.8 billion tons in 2024. The use of EAF requires graphite electrodes and every ton of steel produced requires an average of 3 kg of graphite. The current source of graphite is almost all derived from fossil sources so it is a source of carbon emissions (carbon positive) and also currently around 80% of the world's graphite supply comes from China. With steel production from EAF of 548 million tons, the annual graphite demand reaches more than 1.6 million tons. Every ton of graphite production from fossil materials emits CO2 emissions of 17-40 tons.

This makes the use of biographite crucial because it is carbon-neutral, producing CO2 emissions. Biographite is produced from biochar, or charcoal, which undergoes a special purification process. The biochar is converted into high-purity graphite suitable for EAF electrodes. Biographite is used for its strength, density, and conductivity, not only because of the CO2 emissions mentioned above, but also because of its technical advantages. Naturally mined graphite cannot meet these technical specifications, while synthetic graphite from fossil fuels is not environmentally friendly and is highly dependent on imports. This is the driving force behind biographite production.

The demand for biochar or charcoal as a reducing agent in BF will be very large, while for biographite as an EAF electrode is not as large as in BF. This makes it crucial to obtain a source of biomass raw materials as a source of biochar or charcoal in sufficient volume, good quality, and sustainable. Similarly, in terms of biochar or charcoal production, which primarily uses pyrolysis/carbonization technology, it must also be able to produce products with adequate quality and quantity, sustainably, and with a production process that is high in productivity, efficient, and environmentally friendly. Biochar or charcoal with specifications of at least 85% fixed carbon and a minimum conversion (gravimetric yield) of 30% is the reference for selecting this pyrolysis technology. 

In addition to biomass waste groups such as forestry waste and plantation waste, energy plantations can also be specifically created for this purpose, for more details read here. These energy plantations must also be created according to the land allocation and area of ​​monoculture energy plantations in accordance with proper planning and procedures, as well as efficient and environmentally friendly pyrolysis / carbonization technology. Biomass sources as raw materials for charcoal / biochar can also be said to be sustainable if the harvested product is less or at most equal to the growth of the plantation's wood. This is to prevent what happened in Brazil, namely in the state of Minas Gerais. Due to the large area of ​​monoculture eucalyptus plantations whose wood products are mostly for charcoal production for iron and steel mills, this has caused various negative impacts on the environment. Brazil is the world's largest charcoal producer and produced 5.2 million tons in 2017, 90% of which was used by the iron and steel industry, with 80% of the charcoal produced from eucalyptus plantation wood.

Approximately 70% of Brazil's iron and steel production occurs in the state of Minas Gerais, and this sector is unique in that 34% of iron production uses charcoal, not mineral coke/coal, and coke is also widely used in steel production. Historically, this was due to a lack of mineral coke in Brazil, but abundant forests for coke production. Minas Gerais currently has nine steel mills and 41 iron plants producing 3.1 million tons of crude iron in 2018, approximately 50% of which was exported. In 2018, Brazil had 5.7 million hectares of eucalyptus plantations, and Minas Gerais continues to have the largest plantation area in the country, covering 24% (1.4 million hectares) of Brazil's eucalyptus. Iron and steel companies also have eucalyptus plantations in an effort to secure a supply of charcoak for their iron and steel mills. Indonesia also has vast land potential, reaching hundreds of millions of hectares for these energy plantations. 

Biochar from Wood Waste and Forestry Waste

The era of decarbonization and bioeconomy continues and continues to grow over time. While some people focus on the carbon neutral sector such as the production of biomass fuels such as wood pellets, wood briquettes or wood chips, people who focus on negative carbon seem to be fewer, including the use of CCS (Carbon Capture and Storage) and biochar production. Compared to CCS, biochar production with pyrolysis is easier and cheaper so it is projected to become a future trend. Logically, the negative carbon scenario is actually much better because in addition to reducing the concentration of CO2 in the atmosphere, while the neutral carbon scenario only does not increase CO2 emissions in the atmosphere, but does not reduce or absorb CO2 in the atmosphere. CO2 sequestration or biochar carbon removal (BCR) is currently also the most industrially relevant carbon removal technology. BCR is a key solution for real climate change mitigation today and its development is very rapid. BCR also has a vital role in the carbon removal technology portfolio. 

Woody biomass, especially from wood industrial waste and forestry waste, is a potential raw material for biochar production, even this type of wood biomass is the best raw material because it can produce high quality biochar, namely fixed carbon of more than 80%. The potential for wood biomass raw materials in Indonesia is very large, estimated at 29 million m3/year from forest harvesting waste, and 2 million m3/year from wood processing industry waste including 0.78 million m3 in the form of sawdust (the yield of the sawmill industry ranges from 50-60% and as much as 15-20% consists of sawdust). And that does not include if there is a biomass plantation or energy plantation dedicated to biochar production.

With the condition of agricultural land, plantations and forestry which are experiencing a lot of degradation, the need for biochar is also very large. Among the factors causing the decline in land fertility is the use of chemical fertilizers and pesticides for decades continuously and tends to be excessive. This causes a decline in soil quality which has an impact on crop production because it makes the land more acidic and hard which is estimated to reach millions of hectares. In addition, the price of chemical fertilizers is increasingly expensive and difficult to obtain, which results in low agricultural production, so the government is forced to import several agricultural commodities to meet the needs of the community. This actually does not need to happen considering the potential land in Indonesia is very large, it only needs to improve the condition of the land so that it can be optimal again. Making damaged land fertile is not difficult, it only takes perseverance to repair and care for the land so that it continues to be fertile.

Meanwhile, dry land consists of ultisol soil of 47.5 million ha and oxisol of 18 million ha. Indonesia has a coastline of 106,000 km with a potential land area of ​​1,060,000 ha, generally including marginal land. Millions of hectares of marginal land are spread across several islands, have good prospects for agricultural development but are currently not well managed. The land has a low fertility rate, so technological innovation is needed to improve and increase its productivity. Not to mention post-mining land which is almost all very damaged and also covers millions of hectares. And biochar is the right solution that can restore the condition of the land to be fertile again. 

Slow pyrolysis is the best technology for biochar production. But the technology used must be efficient and emissions meet the threshold standards of the country concerned. In addition, excess heat and/or liquid products and gas products from pyrolysis should also be utilized. With the criteria for pyrolysis technology as above, in addition to the quality and quantity of products, namely biochar, can be maximized, the production process also does not cause new problems in the form of environmental pollution. This is very much in line with biochar business activities so that it becomes a solution to the problem of industrial biomass waste from wood and forestry waste as well as a solution to climate problems. Even the utilization of by-products (excess heat and/or liquid products and gas products from pyrolysis) can also encourage the emergence of other environmentally friendly and renewable products.

In economic terms, the outline can be as follows, namely with an investment of 10 million US dollars, approximately 200,000 tons of biochar with more than 400,000 carbon credits will be produced over a period of 10 years. Or if with an investment of 100 million US dollars, almost 2 million tons of biochar and more than 4 million carbon credits will be produced over a period of 10 years. And for example, with a selling price of biochar of 100 dollars per ton and also a carbon credit of 100 dollars per unit (per ton of CO2), then within 10 years the investment has increased 6 times or it only takes about 1.7 years for the initial investment to return (payback period). Of course, when the price of biochar is higher and / or its carbon credits, of course the return on capital will be faster. And that does not include the utilization of liquid and gas products from pyrolysis and excess heat which also have economic potential that is no less interesting. The trend of the future business era will not only focus on financial profit but also provide solutions to environmental problems and climate problems, and of course solutions to social problems by creating jobs.

Energy Plantation: Wood Pellet or Wood Charcoal Production?

Energy plantations are starting to develop and large-capacity wood pellet production is emerging in line with the development of these energy plantations. It could be that now is the right momentum as predicted several years ago by the author in the following article. It is also possible that the Covid-19 era which has lasted for about 3 years has slowed down this momentum. The vast area of ​​industrial plantation forests (HTI) in Indonesia allows for the creation of energy plantations for large-capacity wood pellet production along with additional products such as animal feed and food (honey). The production of wood pellets as biomass fuel or carbon neutral fuel is mainly made or produced in the context of the energy transition towards the net zero emission era.

Viewed from the business side, the production of wood pellets is demand driven because efforts to achieve the net zero emission target require industries, especially coal-fired power plants, to carry out gradual decarbonization through cofiring biomass fuel (wood pellets) with coal. The target, which is getting closer in time, with various efforts that require planned programs and large costs, does require serious and sustainable efforts. Not only in the power generation industry, especially coal-fired power plants, but also other industries such as the iron and steel industry. Coal-fired power plants contribute 40% of CO2 concentration globally, while the iron and steel industry contributes 9% globally.

In the current power generation industry, more than a third of global electricity production still uses coal. That portion must drop to 4% by 2030 and 0% by 2040 if the world is to limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) and prevent the devastating impacts of the climate crisis. Developed countries should be able to reach zero coal faster because they have a stronger financial position than developing countries, most of which still rely on coal. The world has 6 years from now to reduce coal use in power generation to less than 4% by 2030, and a number of countries have taken rapid steps to eliminate coal use, which can be read here.

Meanwhile, in the decarbonization of the iron and steel industry, the fact is that currently it is still far from achieving this goal because the construction of blast furnaces - basic oxygen furnaces (BF -BOF) is still being carried out, which should be EAF (Electric Arc Furnace) or currently only around 30% globally the iron and steel industry uses this EAF. Even the International Energy Association (IEA) highlighted this critical issue to achieve the Paris Agreement's net-zero target by 2050. The CO2 intensity in this industry has only decreased slightly so that the use of renewable energy is becoming increasingly important and accelerated.

Currently, large energy plantations have begun to be created in the context of the energy transition. The main production of energy plantations is wood pellets which can be said to be carbon neutral fuel. Almost none of these energy plantations are designed for charcoal production, even though the need for charcoal is also projected to be very large. The difference is that wood pellets will be used in power plants while charcoal is for the iron and steel industry. The production process for wood pellets is biomass compaction / densification while charcoal is carbonized or pyrolysis. In the future, a number of these energy plantations could be designed for wood pellet production while other energy plantations are designed for wood charcoal production. Given that the agreed time target for net zero emissions is not long away, the creation and utilization of energy plantations for these things will automatically not be long away.

Decarbonization in the Steel Industry Part 2: Charcoal as Fuel and Reductant in Blast Furnace

Basically, the conditions in each steel industry vary so that the decarbonization process is also carried out using different and gradual routes to achieve net zero emission conditions. The conditions of each steel industry have a unique configuration of production technology, raw materials and energy sources, capacity and yield, regulatory requirements and so on. To achieve Net-zero by 2050, a number of things need to be done, such as efficient use of raw materials, increasing the portion of reuse and recycling, retrofit and advanced technology, and especially efforts to use renewable energy sources as fuel and reductant in the iron and steel industry. But the fact is that the construction of blast furnaces - basic oxygen furnaces (BF -BOF) is still being carried out, which should be EAF (Electric Arc Furnace) or currently only around 30% of the global iron and steel industry uses this EAF, but there are transition efforts that can be made as described below. The transition is influenced by market demand, policy interventions, and incentives given to producers to reduce emissions in steel production.

To create policies related to this transition, providing incentives to reduce emissions for producers and creating market demand for "green steel", a clear definition is needed between low emissions vs. almost zero emissions (near zero emissions) vs zero emissions (net-zero emissions). It is estimated that in 2021 CO2 gas emissions from this industry will be 3.8 Gt globally (this has not even taken into account methane emissions from coal mining). Meanwhile, for Net-zero 2050 conditions, direct CO2 emissions from the global iron and steel industry must be reduced to 1.8 Gt CO2 in 2030 and 0.2 Gt in 2050. It seems that a lot of hard work is still needed to achieve this target, even with the current conditions. Many people are pessimistic.

One use of biomass as a carbon neutral fuel in the iron and steel industry is the use of charcoal as a fuel and reductant. Biomass such as wood must be carbonized or pyrolyzed to become charcoal. The use of charcoal in blast furnaces not only reduces carbon dioxide (CO2) emissions, but also sulfur dioxide (SO2) emissions because the sulfur content of charcoal is very low (around 100 times lower) than coke. Likewise, the use of limestone will decrease so that slag production will also automatically decrease. Likewise, it makes the blast furnace operation acidic.

Apart from a number of advantages obtained as above, it turns out that there are drawbacks to using charcoal in blast furnaces, namely in large blast furnaces which causes operational problems because the strength of charcoal is usually lower than coke. As a solution, there are three methods of using charcoal in the blast furnace process. First, with pulverized charcoal injection (PCI). With this method the charcoal must be crushed into a powder and injected into the blast furnace. Second, with charcoal powder mixed with coke powder into pellets or briquettes called charcoke. By making this charcoke, its strength is sufficient for use in conventional blast furnaces. And third, by replacing coke with lump charcoal for small capacity blast furnaces (inner volume 60 – 550m3). In small capacity blast furnaces, the compression pressure on each charcoal particle is much smaller than in large capacity blast furnaces. Sintering and pelletisation are not required in this case.

Energy plantations or biomass plantations can be created specifically to supply raw materials for charcoal production. The energy plantation will also absorb carbon from the atmosphere (carbon sink) in a certain volume. The volume of carbon from the atmosphere can be maintained in such a way that its function as a carbon sink can be carried out, namely by the amount of wood harvested for charcoal production not exceeding the growth rate of the wood biomass. In this way, the energy plantation cannot be finished in one harvest but is sustainable while maintaining its volume or area.

With continuous pyrolysis technology, charcoal production can be optimized. With this continuous pyrolysis technology, apart from the large charcoal production capacity, multi-use by-products are also produced, such as gas products which can be used as an energy source as well as biooil. Biooil can also be used as a raw material in the chemical industry. Charcoal production of tens to hundreds of tons per day is also possible with continuous pyrolysis technology.

And especially in Indonesia, as the owner of the largest oil palm plantations in the world, which is estimated at more than 15 million hectares and with palm oil mills reaching around 1,000 units, there is a lot of palm oil waste that can be utilized, especially empty palm fruit bunches or EFB (empty fruit bunch). The potential for charcoal production from EFB is also very large. Apart from that, as the 5th largest coal producer in the world with production of around 570 million tons per year, coal also needs to be processed into coke. Charcoal from empty bunches or EFB can be made into powder for PCI or into charcoke by compacting it, namely making pellets or briquettes with coke.

Decarbonization in the Steel Industry

World steel production reached 1.9 billion tons in 2020, with China accounting for around half and followed by European Union countries. Germany, with annual production of around 42 million tonnes, is the largest steel producer in Europe or around a quarter of European steel production, while the other quarter is Italy and France, followed by Belgium, Poland and Spain. The steel industry contributes 8% of CO2 globally, each ton of steel production produces an average of 1.85 tons of CO2 emissions and compared to iron ore mining, iron and steel production contributes much more to CO2 emissions. Efforts to decarbonize the steel industry begin with the use of renewable energy for its smelters. Biomass-based fuel in the form of charcoal which has a high carbon value can replace the use of coke derived from coal. And the use of hydrogen from renewable energy sources is the ultimate target for decarbonization in the steel industry. 

Currently, the steel industry mostly uses coal as fuel using blast furnaces. To reduce carbon intensity, natural gas is used as fuel. The use of gas fuel in the form of natural gas is also a transition medium and basically because it comes from fossil fuels it is also a carbon positive fuel. Apart from that, the use of CNG in the form of natural gas is also a transition fuel before switching to hydrogen from renewable energy. The use of biomass-based carbon fuel in the form of charcoal has a better effect on the climate because it is a carbon neutral fuel. Apart from that, technically, because it is a solid fuel, the same as coal, practically there is not much or even no need for changes or modifications to the smelting furnace. The availability of high quality charcoal, large volumes and continuous supply are still the main obstacles.

The use of charcoal for metallurgy or steel making has actually become commonplace for some time. In the early 1900s, world charcoal production experienced its heyday with production of more than 500 thousand tons. In the 1940s, charcoal production decreased to almost half of what it was in the early 1900s, due to other carbon materials, namely coke from coal, replacing charcoal in the manufacture of metals.

With the current conditions of using coal as the main fuel in smelting furnaces or blast furnaces, slag will be produced. Slag or GGBFS (Grounded Granulated Blast Furnace Slag) from the steel plant is used in cement plants as a cement additive or SCM (supplementary cementious material) thereby reducing the portion of clinker in cement production. In the cement plant itself, the more slag or SCM used, the more clinker use is reduced, thereby also reducing CO2 emissions. In cement production, the clinker production section contributes the most to the CO2 emissions produced, so the use of slag or SCM is part of decarbonization in cement plants. It is estimated that around 70% of world steel production uses the blast furnace or BF-BOF process which produces quite a lot of GGBFS, even in China more than 90% of steel production uses the BF-BOF process. It is worth noting that the decarbonization of the steel sector is resulting in a shift away from blast furnaces, which will impact the availability of GGBFS worldwide in the coming decade. However, this change will occur slowly and gradually and, in the meantime, there are a number of GGBFS that will be available for use as SCM to reduce the carbon footprint of cement and concrete.

To be able to produce charcoal in large quantities, raw materials are also needed in large quantities. Raw materials in the form of biomass, especially wood, can be produced from energy plantations. Energy plantations from fast growing species and short rotation crops will be suitable to meet the need for raw materials because apart from the fast harvest period they also have high productivity. Apart from that, there is no need to replant every time it is harvested and it is easy to grow and easy to maintain. To produce steel per ton, an average of 6,000 MJ of energy is required (equivalent to 50 kg of hydrogen) or the equivalent of 200 kg of charcoal and requires around 600-800 kg of wood biomass as raw material. Apart from raw materials from energy plantation wood, raw materials from agricultural and plantation wastes can also be used.

The future palm oil industry could produce hydrogen from biogas. Each ton of steel will require 50 kg of hydrogen, while each palm oil mill with a capacity of 30 ffb/hour can produce 1 MWh of electricity, while the production of 1 kg of hydrogen requires 50 KWh, so that with the capacity of the palm oil mill it can produce 20 kg of hydrogen. Areas with a high concentration of palm oil mills such as Riau province could create a hydrogen pipeline network for environmentally friendly steel mills.

With higher prices for steel produced with renewable energy (green steel), market share is also limited. Currently, only certain uses, such as automotive, buy such premium or green steel. Decarbonization efforts in steel industries can also be carried out in stages, along with the development of renewable energy. With the increasing supply of renewable energy, the price will decrease so that environmentally friendly steel (green steel) will also become more competitive in price. New steel industries can be built close to these cheap renewable energy sources so that green steel production can become competitive.