Competing in Goodness in Lowering the Earth's Temperature

Competing to lower the global temperature is a good thing. Competing in good deeds is highly encouraged in Islam. The negative impacts of global warming can be felt on land and at sea, and therefore must be minimized. This is why various parties involved in this effort should collaborate and synergize to achieve this goal. The business aspect of this activity should be a secondary priority, so that a spirit of good deeds, collaboration, and synergy will be fostered. Technically, strategic sectors that are the main causes of global warming are an important priority to address, although other, more pressing matters must also take precedence.

There is an excess concentration of carbon (CO2) in the atmosphere that causes the earth's temperature to rise due to the greenhouse gas effect, but on the other hand there are billions of hectares of land on earth that need carbon in the form of biochar to increase soil fertility as well as to absorb CO2 in the atmosphere with carbon sequestration / carbon sink. If these two things can be synchronized, it will be an effective solution to reduce the earth's temperature. In 2024, CO2 emissions from fossil fuels were recorded at around 36.3 giga tons (36.3 billion metric tons) and the latest CO2 concentration according to the Mauna Loa observatory in Hawaii reached 429.25 ppm (on June 24, 2025). Meanwhile, on the land side, globally an estimated 1.66 billion hectares of land have been degraded due to human activities such as deforestation, overgrazing, mismanaged irrigation, and excessive use of chemicals. 

Biomass fuel, produced by producing wood chips and wood pellets, or biofuel, is a carbon-neutral renewable fuel or source, thus complementing biochar. Wood chips and wood pellets, or biofuel, do not increase CO2 emissions, and biochar absorbs CO2, acting as a carbon sink (carbon sequestration), or carbon-negative. 

Maximizing the Rate of CO2 Absorption from the Atmosphere Based on Biomass

Maximizing the rate of CO2 absorption from the atmosphere is very important considering the rate of addition of CO2 concentration to the atmosphere is not comparable to the rate of CO2 absorption. This is what makes the CO2 concentration continue to increase. To balance this speed, a strategy is needed to increase the rate of CO2 absorption. The use of biomass will be very effective and provide multiple benefits for human life. 

CO2 from the atmosphere needs to be captured through biomass production through the process of photosynthesis in plants. Fast-growing species of plants that have high photosynthesis rates are needed for this. Furthermore, biomass, especially wood from fast-growing species of plants, is used as raw material for biochar. Furthermore, biochar is used to improve soil fertility (soil amendment) in various types of agricultural and forestry plants.

Biochar production with slow pyrolysis will also produce excess heat, syngas and biooil that can be used as energy sources. The benefits of biochar production will be obtained from the sale of biochar, the sale of carbon credits and the use of slow pyrolysis by-products. With conditions like this, efforts to increase the speed of CO2 absorption from the atmosphere should be increased. How fast and how much CO2 volume can be absorbed will depend on the type of fast growing species used, the area of ​​planting and the capacity of biochar production. 

Green Economy in the Cement Industry Part 6: Clinker Substitution in Cement Plants

Substituting clinker with additives or SCM (Supplementary Cementious Material) plays a major role in efforts to reduce CO2 emissions in cement plants. This clinker substitution is ranked second after carbon capture or CCS (Carbon Capture and Storage) in efforts to reduce CO2 emissions or decarbonization in the cement industry. This is because the largest CO2 emissions in cement plants are not from combustion or related to fuel but in the calcination process. CCS technology is still expensive so its implementation still faces many obstacles, but clinker substitution is easier to do, so many cement plants are already doing it. 

In the cement industry, all fuel use and around 60% of electricity use is used for clinker production starting from grinding raw materials, fuel preparation and cement kilns. The higher the clinker to cement ratio, the higher the electricity and fuel used for each ton of cement produced. The clinker to cement ratio can be reduced if less clinker is used in cement production or more additional materials or SCM are added to the clinker. This also means that substituting clinker with SCM can significantly reduce energy use (electricity and fuel) for each ton of cement produced. 

China currently has the lowest clinker to cement ratio in the world, namely 0.58, while a number of areas in other countries have the highest ratio, up to 0.9. It can also be understood that China uses the highest portion of SCM compared to countries in the world. The most commonly used SCMs today are fly ash, ground granulated blast-furnace slag (GGBFS) and ground limestone. Meanwhile, other SCMs such as pozzolan and calcined clay have the potential to be used in the future.

Fly ash comes from by-products or waste from coal-fired power plants. Decarbonization of coal power plants is also continuing to be carried out, namely by cofiring coal with biomass, but this is being done in stages so that fly ash production will still be large for a while. Fly ash from coal-fired power plant waste is very useful in cement production because it reduces the clinker to cement ratio, thereby reducing energy requirements for cement production or in other words reducing the carbon footprint of cement products. Meanwhile, GGBFS comes from iron and steel plant waste. Not all iron and steel plants produce GGBFS waste, this is because it depends on the type of furnace used. Only plants that use blast furnaces - basic oxygen furnaces (BF - BOF) can produce GGBFS, while those that use electric arc furnaces (EAF) cannot. Around 70% of iron and steel plants in the world currently use the BF – BOF process so as to produce quite a lot of GGBFS, even in China more than 90% use this BF – BOF process. Decarbonization in the iron and steel industry is marked by the switch from BF – BOF to EAF which results in the availability of GGBFS. However, the process is running slowly and gradually, so that for a while the amount of GGBFS will be available and can reduce the carbon footprint of cement production.

The use of fly ash in cement production is usually limited to 25-35% for technical performance reasons. Meanwhile, GGBFS can be used in larger portions than fly ash or other SCM. Even European standards allow the use of GGBFS up to 95% but in practice it is lower. Other SCMs commonly used are pozzolan and calcined clay. Pozzolan comes from mining, namely from deposits in nature. Pozzolan requires drying and grinding before being used in cement production. The electricity used for crushing (grinding) pozzolan is also almost the same as crushing clinker. Calcined clay can also be used as a substitute for clinker. The initial use of calcined clay with a higher portion causes a decrease in the compressive strength of the cement product produced. However, further developments using a combination or mixture of calcined clay with limestone powder have the potential to substitute up to 50% clinker without affecting the quality of the cement. Calcined clay is produced from the clay calcination process which requires energy, but the energy required is much less than the energy for clinker production. It is predicted that in 2050 by the IEA (International Energy Agency) / WBCSD (World Business Council for Sustainable Development) cement production with the above combination of materials will reach more than 25% worldwide.

It turns out that the use of SCM is not only a substitute for clinker in cement production but also in concrete production. The use of SCM in concrete production is also no less than a substitute for clinker, even in the United States SCM is mostly added during concrete production and not during cement production. A study in the United States estimated that only 5% of SCM was added to cement production and around 13% to concrete production. But basically the addition of SCM to both cement production and concrete production has reduced the carbon footprint or is in line with decarbonization. The problem is that the lack of education regarding the benefits of SCM, especially in concrete production, is a barrier to increasing the use of SCM. Other factors such as the availability of SCM, price and its relation to cement and building quality are also similar barriers. The creation of new standards and codes related to increasing the use of blended cement with SCM and concrete production needs to be developed to transform the current market.

Green Economy in the Cement Industry Part 5 : Increasing Production and Reducing Emissions

Increasing production capacity but simultaneously reducing CO2 emissions (carbon dioxide, the dominant greenhouse gas) sounds contradictory / paradoxical. It is indeed like that in passing. However, with a decarbonization or CO2 removal (CDR) program, efforts to reduce emissions can be done while increasing cement production. How big the target of reducing emissions and increasing cement production will depend on how much decarbonization efforts are made. The greater the reduction in emissions, the more expensive it will usually be. This is why efforts to reduce emissions while increasing production must also be carried out in stages with certain strategies.

Cement plant is an industry that contributes to an increase in CO2 of more than 6% globally. However, there is something unique about this cement industry, namely that most of the CO2 emissions produced do not come from fuel use, but from the calcination process. The percentage of CO2 produced from the calcination process reaches around 60%, while from fuel use it is only around 40%. The fossil fuels commonly used in cement industries are coal and petcoke, both of which are the two fossil fuels that pollute the air the most. In fact, in a number of areas cement plants are the largest coal users. Cement plants close to oil refineries will use more petcoke.

Decarbonization programs or efforts to reduce CO2 emissions that can be carried out in cement plants include increasing energy efficiency, using clinker substitute materials, using alternative/renewable energy, and using CCUS (Carbon Capture Utilization and Storage). With these characteristics, total decarbonization in the cement industry cannot be carried out by using only the best efficiency technology or by simply replacing the fuel. Meanwhile, the use of clinker substitutes and CCUS is very important among other technologies to achieve near-zero emissions in cement production.

The best scenario for increasing production and reducing emissions can be done by using much higher energy efficiency improvements using commercially available technology, using more aggressive fuels to low carbon or even carbon neutral fuels, using higher rates of clinker substitute materials. and adopting a higher portion of commercially available CCUS technologies.

And it's worth noting that all suggested improvements in these best-case scenarios can be achieved by implementing technologies that are already commercially available and most of them should also be cost-effective. As for CCUS, while the technology is commercially available, implementation requires large investments that demand higher financial incentives or carbon prices. However, on the other hand, CCUS has the largest contribution to CO2 reduction, followed by the use of clinker substitutes and the switch to low-carbon or even carbon-neutral fuels. And the use of efficiency-enhancing technology has the smallest contribution to reducing CO2 emissions. This is mainly because process-related emissions from calcination account for around 60% of total CO2 emissions and are not related to energy use.

Carbon Positive, Carbon Carbon Neutral or Negative?

Greenhouse gases from burning fossilfuels have caused the Earth's temperature to rise. Increasing the temperature of the earth or global warming causing numerous disasters due to climate change in a number of places on earth. When greenhouse gases not controlled then the result of damage to the environment of the earth will be more severe. Therefore, efforts were made to reduce greenhouse gases as the cause of environmental problems. In general, there are four common scenarios to prevent the global warming effect of CO2 in the atmosphere gradually, namely:

1.     increasing the efficiency so the fossil fuel consumption decreases,

2.     mix of renewable fuels with fossil fuels so that fossil fuel consumption has also decreased,

3.     substitution of fossil fuels with renewable fuels

4.     and the absorption of CO2 in the atmosphere so that the concentration of greenhouse gases can be reduced.

Here are some basic terms related to the above problems. Based on the origin and the effect that CO2 in the atmosphere then reviewed as follows:

A.    Carbon Positive

Fossil fuel or fuel mines are grouped into Carbon Positive fuel. This is because the burning of this fuel would make gas content in the atmosphere, especially CO2 will increase. Increased CO2 in the atmosphere is the source of global warming issues above.

Carbon Neutral cycle with biomass thermal route

Carbon Neutral Cycle with biomass densificaion (wood pellet) route

B.    Carbon Neutral

When CO2 gas in the atmosphere does not increase due to the generation of energy from an energy source it is said that energy sources Carbon Neutral.  Because it does not add to or reduce the balance of CO2 diatmosfer it is said to be environmentally friendly energy. Renewable energy sources such as biomass, wind, water and sun are Carbon Neutral. Material substitution of fossil fuels with renewable fuels included in the Carbon Neutral scenario.

C.    Carbon Negative

Currently the CO2 content in the atmosphere has exceeded the threshold limit. The latest report says has reached 390 ppm, this would need to be reduced concentration. Various technologies are developed in order to absorb CO2 from the atmosphere. Naturally the tree is able to absorb CO2 from the atmosphere, meaning that the more we plant a tree, the more CO2 diatmosfer reduced. Biochar or agricultural charcoal, the charcoal is used to fertilize the soil by placing it on the ground is a material that can absorb CO2 from the atmosphere as well as soil fertility, because its nutrient content and media for microbial breeding. Technology in the group Carbon Capture and Storage (CSS) is a Carbon Negative technology, although currently still very expensive investment.

Come be part of the solution to perform activities of Carbon Neutral and Carbon Negative, and minimize part of the problem with Carbon Positive activity.