Biochar as a Diversified Carbon Dioxide Removal Pathway: Research and Technology Integration Update (2023–2025)

Dr. Abhilasha Tripathi , Research Coordinator, International Biochar Initiative

With the intensifying global urgency for climate change mitigation, achieving gigaton-scale carbon dioxide removal (CDR) alongside emissions reduction requires solutions that are scalable, durable, and scientifically validated. 

Biochar—pyrolyzed biomass rich in stable carbon—has rapidly emerged as one of the most promising CDR pathways due to its long-term carbon storage potential, multifunctional material properties, and real-world applicability across sectors extending its potential beyond carbon sequestration.

Between 2023 and 2025, the focus of biochar research has shifted from foundational “does it work?” to questions of “how broadly, reliably, and efficiently can it be deployed at scale?”. 

This reflects a maturing field transitioning into practical, market-ready solutions. Bibliometric analyses confirm exponential growth phase of interdisciplinary integration of biochar in publications and diversifying research foci from 2021 to the present due to global carbon market consolidation. 

Together, these trends highlight the rapid maturation of biochar from an experimental material into a multi-sector climate solution, supported by robust peer-reviewed evidence, formalized carbon registry frameworks, and an expanding portfolio of real-world deployment examples.  

Figure 1 illustrates the distribution of frequently used keywords in biochar research (2023–2025) derived from a bibliometric analysis, with dominant thematic clusters corresponding to soil application (green), water and wastewater treatment (blue), and pyrolysis processes (red). 

Figure 2 presents the country-wise co-occurrence network of biochar research studies, reflecting the global distribution and collaborative landscape of this rapidly evolving field. 

Building on these insights, this article examines the current status of global biochar research (esp. yr. 2023- 2025) alongside the emerging ventures that are translating scientific advancements into real-world applications.

Trends in Biochar Research (2023–2025)

Application-Wise Research Distribution

Soil-based applications continue to dominate biochar research outputs. This prominence is driven by well-documented outcomes such as:

Full-scale deployment of biochar for soil application is particularly prominent in the Global South, where it is increasingly used to restore degraded soils, enhance crop resilience, and deliver verifiable carbon removal—often through emerging biochar-based CDR ventures. Organizations such as MASH Makes (South Asia and Sub-Saharan Africa) and Exomad (Bolivia) are advancing multi-season, long-term soil application of biochar while generating valuable field-scale performance insights.

Several biochar producers are actively scaling projects across regions, including Varaha (India, Bangladesh, Nepal, and Kenya), Takachar, known for mobile pyrolysis systems (India, Canada, USA, and Kenya), Varhad Capital–Green Carbon collaboration (India), Longstraw Carbon (India), Sow and Reap Agro Private Limited (India), Tapovanam Biochar (India), Engrow (India), Ground Up (India), Alcom (India), Biochar Bytes (India), Bio-Logical (Kenya), Releaf Earth (Nigeria), PyroCCS (Namibia and India), Carboneers (Ghana), Biocare Biochar (Sri Lanka and Vietnam), Bukit Selar Carbon Station (Malaysia), Tera (Kenya), INNOVX–NetZero partnerships (Africa and Brazil), Solidaridad–Planboo (Zambia), and BIOSORRA (Kenya), among others.

Artisanal biochar production is being enabled through a growing ecosystem of ventures such as Varaha (India), Carboneers (India and Africa), Varhad Capital (India), Circonomy Pte. Ltd. (India, Malaysia, and Kenya), Equilibrium (India), Beetle Regen Solutions (India), KriShe Carbon (India), SunCarbon (India), Heartyculture (India), Sow and Reap Agro Private Limited (India), atmosfair gGmbH (India and Ghana), PyroCCS (India), Warm Heart Biochar (Thailand), Plant Village (Kenya), Planboo (Thailand and Sri Lanka), Wongphai (Thailand), and Biochar Life (Malawi), among others.

The sheer number and diversity of these ventures reflect the translation of decades of biochar research into real-world implementation, leveraging the agricultural sector to improve soil health while delivering climate impact at scale.

Water and Wastewater Treatment is the second-largest research cluster centres, reflecting global urgency around clean water scarcity. Currently evolving research areas include:

The advancement of biochar research toward full-scale application is increasingly associated with replacing conventional filter media and assessing its efficacy in removing heavy metals, nutrients, dyes, and other pollutants—thereby contributing to water security. Feedstock engineering and biochar modification further enable the translation of laboratory research into scalable and effective treatment solutions. US biochar producer Glanris launched based on research conducted by Professor Yu Lin at Christian Brothers University, Memphis, Tennessee. The company now holds patents for converting rice hulls into biocarbon filtration media for contaminant removal from water along with certified carbon removal credibility, exemplifying the successful translation of biochar research into scalable, real-world water treatment solutions.

Construction Materials and Infrastructure represent a rapidly growing area of biochar research, focusing on its incorporation into asphalt, concrete, polymer composites, and broader infrastructure applications. In this context, biochar acts as a durable carbon sink while delivering co-benefits such as reduced embodied carbon, improved mechanical and durability performance, and the development of low-carbon construction materials. Additionally, several emerging subtopics within this research area are worth highlighting, as outlined below:

Biochar ventures in the Global North are increasingly focused on applications in construction materials. Industrial research and scale-up efforts are being led by ecoLocked and NovoCarbo (Germany) and others, which leverage in-house laboratory capabilities to support the decarbonization of the construction sector. Verde Resources (Missouri, USA) is pioneering net-zero road construction through BioAsphalt and is actively engaged in R&D initiatives to enable the seamless integration of biochar into asphalt production. Other organizations, such as Carbo Culture (Europe), are utilizing high-stability biographites in concrete, and Climitra (India) working on decarbonizing cement. Beyond conventional infrastructure, innovative applications—such as biochar-based concrete blocks for coral reef restoration, developed through collaborations involving TCHAR, the Shin Kong Life Foundation, Blue Trend, and another initiative led by Holcim—further highlight biochar’s multifunctional role and its ecological co-benefits.

Anaerobic digestion (AD) is gaining increasing attention as a sustainable waste-to-energy technology, particularly with the incorporation of biochar to enhance reactor performance. Biochar addition improves reactor efficiency by increasing methane yield and substrate digestibility. These benefits arise from reduced volatile fatty acid (VFA) accumulation, ammonium adsorption, effective pH buffering due to biochar-induced alkalinity, and enhanced microbial diversity within the digester. Recent research trends increasingly focus on surface modified biochar, which further improves process efficacy through enhanced surface functionality and stronger microbial interactions. This progress creates strong opportunities for collaboration between biochar producers and anaerobic digester operators, enabling value creation through renewable energy generation and carbon sequestration. The resulting biochar-enriched digestate can also be applied as a soil fertilizer, supporting nutrient recycling and soil health.Pilot-scale efforts are actively exploring this synergy. A Penn State Extension field study, supported by the U.S. Forest Service, is optimizing farm-scale anaerobic digestion systems through observations and farmer feedback. Similarly, the Appalachian Energy Center has evaluated the anaerobic digestion of cheese whey with biochar under varying conditions. In the commercial space, CreChar by Carbogenics integrates scientific and industrial expertise to improve anaerobic digestion efficiency and accelerate the deployment of clean, green energy solutions.

With respect to other emerging and Advanced Applications, thegrowing research fields in biochar application include:

Biochar research is also extending into biomedical domains, with emerging applications including antimicrobial wound dressings, biosensors, controlled drug delivery systems, and Radiation dosimeter, among others. This interdisciplinary body of work underscores biochar’s expanding relevance across sectors, leveraging its high surface area, tunable porosity, and functional surface chemistry to enable diverse and high-value applications.

Biochar Permanence: From Hypothesis to Quantified Evidence

One of the most critical developments in recent years has been the growing body of evidence supporting biochar’s long-term stability and permanence as a carbon sink. Long-term incubation experiments and multi-climatic field trials consistently demonstrate that biochar can exhibit mean residence times ranging from hundreds to thousands of years, maintain high resistance to microbial degradation, and remain stable across a wide range of environmental conditions.

These findings highlight that biochar permanence is strongly influenced by key production and material parameters, including highest treatment temperature (HTT), heating rate and residence time, feedstock selection, and the proportion of aromatic carbon formed during pyrolysis.

More recently, advances in analytical and modelling approaches—such as random reflectance, inertinite benchmarking, radiocarbon dating, oxidative resistance testing, spectroscopic techniques (¹³C-NMR and FTIR), and multi-pool decay models—have enabled more conservative and scientifically robust estimates of biochar permanence. Another study shows, combining the H/C molar ratio with random reflectance (R₀) has been shown to provide more comprehensive and reliable permanence assessments than relying on the H/C molar ratio alone.

However, the article Biochar Permanence—A Policy Commentary highlights the complexity of biochar longevity in soils and outlines several key influencing factors, including soil type, microbial diversity, laboratory versus field conditions, and the physical and chemical properties of biochar. It also discusses biochar aging through photocatalytic and electromagnetic pathways, among other processes. Collectively, these perspectives underscore that biochar permanence is far more complex than often assumed and should be defined over decadal to centennial timescales, rather than millennial scales.

These research advances have a direct impact on registry integration and methodological development. Carbon registries are increasingly incorporating scientific insights on biochar permanence and linking them to clearly defined quality parameters. Cross-standard workshops have brought major registries—including Puro.earth, Verra, Isometric, and Carbon Standards International—together to align approaches to persistence quantification and transparency. 

In 2025, Puro.earth updated its biochar methodology to reflect recent advances in permanence science and expanded its durability classifications (e.g., CORC200+, indicating guaranteed carbon removal for several centuries, and CORC100+, guaranteeing removal for over a century). Isometric, meanwhile, has defined permanence across 200-year, 500-year, and 1,000-year durability scales. 

This evolving registry landscape is helping bridge the gap between scientific permanence metrics and market recognition, reducing reversal risk and strengthening confidence in biochar-based carbon removal credits.

Advances in Biochar Production and Processing

Biochar production research is increasingly focused on scalability, process efficiency, and emissions control. The following areas are witnessing particularly rapid diversification and innovation: 

Significant progress has also been made in bio-oil valorization, including, phase separation and solvent extraction using low-cost adsorbents, recovery of phenolics and aromatics for chemicals, pharmaceuticals, and nutraceuticals, catalytic upgrading to improve stability and calorific value, among others.

Moreover, research publications related to artisanal biochar systems collectively provide robust evidence supporting decentralized, low-cost biochar production; science- backed low emission verification encompassing emissions profiling; the debunking of myths around low tech methods; diverse feedstock utilization, and well-documented impacts on crop productivity.

Integration with Other CDR Pathways and other Research Topics

Lately, biochar research increasingly situates the material within hybrid CDR systems, pairing it with:

These synergies aim to enhance overall carbon removal efficiency and land-use effectiveness, though they also require complex MRV frameworks and regulatory alignment.

Several recent publications are particularly worth exploring, including studies on biochar-mediated nitrogen fixation, the soil “sponge” function of biochar under varying rainfall regimes, biochar aerosol generation from raindrop impact, and carbon sequestration coupled with yield optimization, among others.

To support practical implementation, analyses such as techno-economic assessment (TEA), life cycle assessment (LCA), reusability studies, carbon accounting, and toxicity impact evaluations are increasingly being incorporated, making research outcomes more actionable and decision-relevant. 

Conclusion

As research continues to mature, biochar is increasingly emerging not only as a multifunctional material but as a scientifically grounded and readily deployable carbon dioxide removal (CDR) pathway. 

The surge in research outputs between 2023 and 2025 reflects a clear shift in perception—from biochar as a niche soil amendment to a credible, durable, and diversified climate solution. Strengthening permanence science, expanding application domains, advancing production technologies, and the integration of rigorous MRV frameworks into carbon registries have collectively positioned biochar as one of the most operationally ready durable CDR options available today. This is further reflected in the high issuance and liquidity of biochar carbon removal certificates, with biochar contributing a significant share of market-verified durable carbon removals in recent years.

Importantly, this progress has tangible implications across the value chain and benefits multiple stakeholders: 

  • Innovators and researchers gain clearer mechanistic insights and improved methodologies to refine production and application pathways.
  • Biochar producers and project developers benefit from enhanced scientific validation and registry integration, which de-risk projects and strengthen carbon credit quality.
  • Carbon removal buyers and markets gain access to high-durability removal options backed by conservative permanence assessments and evolving credible standards.
  • Policy makers and climate strategists are better equipped to embed biochar within durable CDR frameworks, and nationally determined contribution goals recognizing its ability to deliver both climate mitigation and adaptation benefits.

By effectively bridging science, standards, and real-world deployment, biochar is no longer peripheral to climate action but is increasingly recognized as a core component of a scalable and affordable CDR portfolio.

Figure 3 Biochar bridging science, markets, and policy to enable full-scale deployment and deliver measurable climate impact. (Image created by: Tripathi, Abhilasha (2025), using tool: ChatGPT)

Acknowledgement: A special thanks to Kathleen Draper, who is always “Biocharming” me, for reviewing the article and offering critical perspectives that strengthened the analysis.