As the issue of carbon emissions becomes increasingly severe, reducing carbon footprint has been a focal point of global attention. Among the measures to reduce carbon emissions, biochar has attracted considerable interest as a sustainable solution. Read on to learn formation principle of a carbon footprint and how biochar plays a crucial role in reducing carbon footprint.
What is Carbon Footprint?
Carbon footprint is a measure of the total greenhouse gas (GHG) emissions generated directly or indirectly by an individual, organization, product, service or activity during its life cycle. These emissions are usually expressed in carbon dioxide equivalents (CO₂e). It covers greenhouse gases such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). The calculation of a carbon footprint helps quantify the impact of human activities on climate change. It is the basis for developing emission reduction strategies and achieving carbon neutrality goals.
Division of Corporate Carbon Footprint
According to the Greenhouse Gas Protocol (GHG Protocol), carbon emissions are divided into three scopes (Scope 1, Scope 2 and Scope 3) to help companies identify and manage greenhouse gas emissions from different sources.
Scope 1: Direct Emissions
- Combustion Emissions: Boilers, vehicles and other equipment used in the industrial chain burn fossil fuels (such as natural gas, coal, and oil) generate CO₂.
- Process Emissions: Chemical reactions in specific industrial processes release greenhouse gases. For example, calcination and decomposition of limestone in cement production generates CO₂.
- Fugitive Emissions: Leakage of refrigerants, fire extinguishers and other chemicals. And GHG fugitive emissions in oil and gas extraction and waste treatment.
Scope 2: Indirect Emissions-Owned
- Electricity: When an enterprise obtains electricity from the public grid, the GHG emissions such as CO₂ generated during the production of this part of electricity belong to the enterprise’s Scope 2 emissions.
- Heat and Steam: Similar to electricity, if the company uses heat or steam provided by an external supplier, the emissions during its production and transportation are also included in Scope 2.
Scope 3: Indirect Emissions – Not Owned
- Upstream Activities: including emissions generated by activities such as the extraction and processing of raw materials, the transportation of products to the enterprise’s premises, and waste treatment.
- Downstream Activities: Emissions generated by the transportation of finished products to customers, the use phase of products, and the disposal of products after their life cycle.
The following will make a detailed analysis of the carbon footprint of some key industries.
Formation of Agricultural Carbon Footprint
Source1: Soil-related Production Activities
CO₂ Emissions
- Soil Respiration: Soil organic matter decomposes under microbial action, releasing CO₂. The higher the organic matter content, the greater the respiration intensity and CO₂ emissions.
- Stubble Burning: Burning stubble in the field directly releases CO₂ and accelerates the oxidation of soil organic matter, indirectly increasing CO₂ emissions.
- Machinery Operation: Tractors and harvesters burn fossil fuels, directly emitting CO₂. Studies show that fuel consumption in machinery accounts for approximately 30%–40% of the total agricultural carbon footprint.
CH₄ Emissions
- Flooded Rice Fields: In flooded fields like rice paddies, anaerobic conditions promote methane-producing microorganisms (methanogens), resulting in significant methane emissions. Methane escapes into the atmosphere through soil pores or water, with a greenhouse effect approximately 25 times greater than CO₂.
- Composting Process: Organic fertilizers (such as animal manure and straw) can generate methane if oxygen supply is insufficient, creating local anaerobic conditions that encourage methane production. Poor management (e.g., overly moist or poorly ventilated compost) can significantly increase methane emissions.
N₂O Emissions
- Nitrogen Fertilizer Application: When synthetic nitrogen fertilizers (e.g., urea, ammonium nitrate) are applied to soil, ammonium (NH₄⁺) undergoes nitrification under aerobic conditions, forming nitrate (NO₃⁻). Nitrate then undergoes denitrification in localized anaerobic environments, releasing N₂O.
- Composting Process: Microorganisms first mineralize organic nitrogen into NH₄⁺ and nitrify it into NO₃⁻. In localized anaerobic zones of the compost pile, incomplete denitrification occurs, releasing N₂O. Excessive moisture, poor aeration, or an imbalanced C/N ratio can exacerbate this emission.
Source2: Agriculture Input Production
Fertilizers & Pesticides
The synthesis of nitrogen fertilizers requires high temperatures and pressures, consuming large amounts of fossil fuels, with emissions of 2.2–2.5 tons of CO₂ per ton of ammonia. Pesticide production involves complex organic synthesis and the use of solvents and catalysts, emitting 1.5–2.0 kg of CO₂ equivalent per kilogram produced.
Plastic Agricultural Film
Polyethylene (HDPE/LDPE) agricultural films made from petrochemical materials (e.g., ethylene) have a carbon footprint of 2.6–2.9 kg CO₂e per kilogram during production, from raw material extraction to factory manufacturing. After disposal (e.g., burning, landfilling, or natural degradation), these films also release CO₂.
Source3: Land Use Change
Deforestation
Forest soils and vegetation store approximately 123–243 tons of carbon per hectare. However, when converted to farmland, the average carbon loss is around 100–135 tons per hectare (equivalent to 367–496 tons of CO₂ per hectare). Additionally, the area loses the ability to sequester 2.2 tons of CO₂ per hectare annually.
Wetland Conversion
Draining and cultivating organic soil in wetlands (such as peatlands) causes the organic matter to decompose, releasing large amounts of CO₂ and N₂O. In 2021, this process alone produced about 0.8 Gt CO₂e in emissions, accounting for nearly 20% of global land-use change emissions.
Soil Degradation
Intensive farming, over-fertilization, and soil erosion lead to soil degradation and structural damage. As a result, approximately 124 million tons of organic carbon (equivalent to about 455 million tons of CO₂) are lost globally each year. Soil degradation severely diminishes the soil’s carbon sequestration potential and productivity.
Formation of Forest Carbon Footprint
Source1: Wood Harvesting Activities
Logging
The fuel consumption of logging machinery (e.g., harvesters, chainsaws) and timber transportation equipment (e.g., forwarders, tractors) directly produces CO₂ emissions. Additionally, the complexity of forest terrain (e.g., steep slopes, wetlands) increases the difficulty of mechanical operations, leading to higher energy consumption and emissions per unit of work.
Transportation
Fuel emissions from vehicles used to transport roundwood or wood chips by road or rail are the largest single source of forestry carbon footprint. Short-distance transport from the logging site to temporary storage areas relies on trains, heavy diesel trucks, and tractors, all of which are heavily dependent on fossil fuels.
Waste Disposal
Open burning of logging residues (branches, bark) directly releases CO₂ and CH₄, with approximately 2–5 tons of CO₂ equivalent emitted per hectare. Landfilling these residues generates greenhouse gases through microbial decomposition. If forestry waste is left to accumulate, it poses a fire risk, potentially becoming a carbon source.
Source2: Loss of Forest Carbon Sink Capacity
Forest Degradation
In recent years, excessive logging, the conversion of natural forests to plantations, and the conversion of forest land to construction areas have caused significant damage to forest structure and function. This has led to the loss of carbon stored in the original vegetation, resulting in a net decrease in forest carbon stocks and a significant increase in the forest carbon footprint.
Impact of Natural Disasters
Since the 21st century, forest fire carbon emissions have exceeded 100 billion tons. Forest fires release 50–100 tons of CO₂ per hectare of burned area. After a fire, burned trees decompose or rot, continuing to release carbon. Vegetation recovery in burned areas is slow, and the carbon sequestration capacity is reduced for decades.
Formation of Livestock Carbon Footprint
Source1: Livestock Farming
Enteric Fermentation
Ruminant animals produce and release CH₄ through the fermentation process in their stomachs, particularly due to the action of methane-producing archaea. On average, a single dairy cow emits 70–120 kg of CH₄ annually. It is estimated that global enteric fermentation from livestock produces about 4 billion tons of CO₂ equivalent each year.
Manure Management
Under anaerobic conditions, manure storage and handling release CH₄ and N₂O. Liquid manure management systems (e.g., biogas pits, septic tanks) are the largest sources of CH₄ emissions, while solid composting systems primarily emit N₂O. Global manure management in livestock farming accounts for approximately 2 billion tons of CO₂ equivalent in annual emissions.
Source2: Farm Management
Feed Processing
This process involves steps such as harvesting, grinding, silage making, drying, mixing, and pelleting of feed crops. These operations require diesel and electricity, leading to direct or indirect CO₂ emissions.
Facility Operation
Operations at livestock farms include heating, ventilation, lighting, milking machines, and automatic feeding systems. These activities generate indirect emissions from fuel combustion and electricity consumption.
Source3: Land Use Change
Feed Crop Farming
Growing feed crops converts natural ecosystems into farmland for crops like soybeans and alfalfa. This type of land use change reduces the carbon sequestration capacity of ecosystems. For instance, intensive farming practices can lead to a 0.5%–1% annual decrease in soil carbon storage.
Overgrazing
High grazing density reduces vegetation cover on grasslands, causing soil organic carbon loss and increasing the risk of wind and water erosion. Overgrazing results in approximately 500 million tons of CO₂ equivalent emissions annually, reducing the carbon sequestration capacity of grazing systems by 30%–50%.
Formation of Construction Industry Carbon Footprint
Source1: Cement Production
Limestone Calcination
In cement production, limestone (mainly composed of CaCO₃) is heated at high temperatures to decompose into CaO and CO₂. This process directly contributes about 60% of the carbon emissions from the cement industry. With global cement production continuing to rise (reaching 340 million tons in 2011), total emissions have also increased due to larger scale production.
Rotary Kiln Combustion
The fuel (e.g., coal, biomass) burned in rotary kilns to heat raw materials generates CO₂, accounting for 40% of total cement production emissions. Modern high-efficiency kilns have reduced energy consumption by 50% compared to traditional wet kilns, but dependence on fossil fuels in cement production persists.
Source2: Steel Production
Steel Smelting
The steel production relies on the blast furnace-basic oxygen furnace process. In this process, coke is used as a reductant to react with iron ore (Fe₂O₃) to produce pig iron, releasing large amounts of CO₂. Steel smelting is responsible for about 2.6 billion tons of CO₂ annually, accounting for 7% of global energy-related emissions.
Steel Transportation
Since steel production facilities are often located far from consumer markets, transportation logistics play a significant role. Global steel logistics are primarily powered by diesel (over 60% of road transportation). The transportation of steel contributes 3%–5% of the annual carbon emissions in the steel industry (approximately 7.8–13 million tons of CO₂).
Source3: Construction Activities
Construction Equipment Consumption
Heavy machinery such as bulldozers and cranes relies on diesel fuel. Each liter of diesel burned produces 2.68 kg of CO₂. According to the U.S. Environmental Protection Agency (EPA), large construction sites consume over 5,000 liters of fuel daily, resulting in annual emissions of 50 tons of CO₂.
Waste Landfilling
Wood, plastic, and other organic waste generated during demolition or new construction are sent to landfills, where they decompose anaerobically, releasing CH₄. Each ton of mixed construction waste landfilled releases about 0.5 tons of CO₂ equivalent. This process results in a global loss of about 120 million tons of carbon sequestration capacity annually.
Industry Drivers of Reducing Carbon Footprint
Policy Regulatory Pressure
As global attention to climate change grows, governments and international organizations are implementing stricter environmental policies and goals. For example, the Paris Agreement calls for nations to take action to limit global warming and promote green, low-carbon development. Many countries have already implemented carbon pricing mechanisms, such as carbon taxes or emissions trading systems, which directly impact business operating costs. To comply with these regulations and avoid potential fines, enterprises must find ways to reduce their carbon footprint.
Supply Chain Demands
Reducing the carbon footprint often means improving resource efficiency and reducing energy consumption, which can directly translate into cost savings. For instance, optimizing production processes, using renewable energy, and improving logistics efficiency can lower operational costs. In terms of supply chain management, more companies are beginning to demand low-carbon products and services from their suppliers. This means that enterprises effectively managing their carbon footprint will have a competitive edge in the market.
Brand Image & Consumer Trends
Modern consumers are increasingly concerned with environmental protection and social responsibility, preferring to choose brands that embrace sustainability. Therefore, actively taking steps to reduce carbon footprints not only enhances a brand’s image but also attracts environmentally-conscious consumers. Moreover, a strong brand reputation can help companies gain investor trust and support, especially as ESG investing becomes more popular. In other words, reducing carbon footprint is the key to a enterprise’s sustainable transformation.
Understand Biomass & Biochar
Carbon Footprint in Biomass
It is estimated that plants globally absorb approximately 600 billion tons of carbon annually through photosynthesis, of which 10% can be converted into waste biomass. Biomass, once detached from its growth environment, typically undergoes natural decomposition. This means that each year, about 60 billion tons of carbon are in an unstable state. Moreover, human activities such as burning or composting accelerate the decomposition process of biomass. Some carbon elements in biomass are converted into carbon dioxide (CO2) or methane (CH4). This leads to an increase in carbon footprint. The following is a schematic diagram illustrating the carbon footprint of biomass.
Biochar Production Process
Biochar is produced by the pyrolysis of biomass under high temperatures and low oxygen conditions. In the biochar machine, moisture and volatile organic compounds in the biomass are removed, leaving behind stable carbonaceous residue. The production of biochar converts unstable biomass into recalcitrant carbon. It can persist in the environment over centuries. High-quality biochar has the following characteristics：
- High Porosity: Biochar possesses abundant micro and mesopores. These pores typically range in size from nanometers to micrometers, providing a large surface area for gas molecule adsorption.
- Chemical Inertness: Biochar exhibits a highly resilient carbon structure. This structure is resistant to biological degradation or chemical oxidation, making it a stable carbon storage medium.
How Biochar Reduces Carbon Footprint
In recent years, biochar has become a representative of efficient carbon emission reduction tools. Its stable solid carbon structure can store biomass carbon for a long time. In addition, its porous properties can inhibit the production of potent GHGs in anaerobic environments. At the same time, as a low-carbon alternative, biochar can reduce dependence on industrial raw materials and agricultural inputs in high-carbon emission industries. It achieves a full-cycle carbon footprint reduction effect through the synergistic mechanism of “carbon fixation – emission suppression – substitution”. The following details how biochar can reduce carbon footprint for several typical industries:
Agricultural Carbon Footprint Reduction
Increasing Soil Carbon Storage
- Carbon Sequestration: Biochar’s high porous structure adsorbs soil organic matter, slowing down microbial decomposition. This extends carbon retention time for up to hundreds of years.
- Soil Improvement: Biochar promotes soil aggregation, enhancing water retention and nutrient holding capacity, indirectly supporting plant photosynthesis and root carbon input.
Reducing Burning and Composting
- Burning Substitution: Pyrolysis technology transforms agricultural waste into biochar, preventing direct CO₂ emissions from burning and indirect emissions from accelerating soil organic matter decomposition.
- Composting Optimization: Biochar improves compost aeration, inhibiting CH₄ formation in anaerobic conditions. It also adsorbs nitrogen, reducing N₂O emissions.
Reducing Fertilizer Use
- Nitrogen Adsorption: Biochar adsorbs NH₄⁺ and adjusts soil pH, suppressing nitrification-denitrification processes, which leads to a 20%-30% reduction in N₂O emissions.
- Fertilizer Addition: Biochar-based composite fertilizers reduce chemical fertilizer usage by 25%-30%, indirectly lowering high-energy consumption emissions during fertilizer production.
Forestry Carbon Footprint Reduction
Waste Resource Utilization
- Reduced Burning & Landfilling: Branches, bark, and other waste can be pyrolyzed into biochar, preventing CO₂ emissions from open burning and CH₄ from landfilling.
- Reduced Transport Energy Consumption: Biochar production facilities located near forests reduce diesel consumption for long-distance transport of timber/wood chips.
Promoting Forest Carbon Sink
- Improving Soil Conditions: Biochar enhances soil fertility and water retention in reforestation areas, speeding up tree growth and increasing carbon absorption per unit area.
- Ecosystem Restoration: Biochar accelerates vegetation recovery on degraded or post-disaster areas, compensating for carbon loss from over-harvesting or forest fires.
Preventing Forest Fire Impact
- Reducing Fuel Load: Biochar is produced from clearing dead branches and waste, lowering the likelihood of wildfires. This reduces direct fire emissions and long-term carbon loss after a disaster.
- Fire Retardant & Protection: Biochar covering the soil can suppress the spread of fire. After a fire, applying biochar helps reduce soil erosion, preserving carbon stocks in unburned vegetation.
Livestock Carbon Footprint Reduction
Suppressing Methane Production
- Enteric Fermentation Regulation: Biochar can be added to animal feed to adsorb substrates for methane-producing archaea in the rumen, reducing CH₄ emissions.
- Microbial Community Optimization: Biochar alters rumen fermentation patterns, lowering the acetic acid/propionic acid ratio, thus reducing methane generation pathways.
Optimizing Manure Management
- Inhibiting Anaerobic Emissions: Biochar suppresses anaerobic microbial activity. As bedding or an additive, it lowers CH₄ emissions from liquid manure and N₂O emissions from solid composting.
- Nutrient Recycling: Biochar adsorbs ammonia (NH₃) and phosphorus in manure, converting it into slow-release organic fertilizer. This indirectly reduces carbon emissions in fertilizer production.
Improving Feed Efficiency
- Reducing Feed Demand: Biochar improves feed absorption efficiency. This reduces feed demand and feed-related direct emissions. This also indirectly reduces emissions from the feed growing process.
- Shortening Growth Cycles: Higher feed conversion rates promote faster animal growth and shorten breeding cycles. Thus, it reduces cumulative emissions per unit weight.
Construction Industry Carbon Footprint Reduction
Replacing Cement Clinker
- Cement Additive: Biochar can replace part of the cement used in production, directly reducing the demand for limestone calcination, which accounts for 60% of cement emissions.
- Cement Modification: Biochar improves concrete workability, allowing for a lower water-to-cement ratio and reducing the amount of cement needed for the same strength, thus lowering CO₂ emissions.
Substituting for Calcination Fuel
- Biomass Co-generation: Pyrolysis produces biochar and combustible gases that can replace coal in cement kiln heating, reducing fossil fuel consumption.
- Emission Synergy: The sulfur and nitrogen content of biochar raw materials is much lower than that of fossil fuels, so using it as fuel reduces not only CO₂ but also pollutants such as SO₂ and NOₓ.
Replacing Smelting Reductants
- Blast Furnace Ironmaking: Biochar can replace 5%-10% of coke in the carbon reduction reaction (C + Fe₂O₃ → Fe + CO₂), reducing fossil carbon consumption.
- Low-Carbon Metallurgy Potential: The porous structure of biochar increases the reaction surface area, improving reduction efficiency. It also avoids high-temperature coking emissions from coke production.
Get Your Exclusive Solution from Beston Group
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