Carbon Capture/CO₂ Mitigation

V.K. KHANNA, Engineering Consultant, Gurugram, India 

Fossil fuels have several disadvantages: they are non-renewable; release high amounts of carbon dioxide (CO₂) into the atmosphere (67.8% of global fossil fuel CO₂ emissions come from China, India, EU27, the U.S., Russia and Japan);¹ contribute to global warming; and lead to soil, air and water pollution. They also cause irreparable damage to natural ecosystems by influencing the creation of potentially harmful elements that result in diseases affecting humans, flora and fauna. Therefore, technologies that promote decarbonization must continue to be adopted. 

The combination of hydrogen (H₂) production and carbon capture, utilization and storage (CCUS) can play a significant role in decarbonizing various sectors—especially those where electrification is challenging. H₂ (particularly low-carbon H₂) can be used as a fuel or feedstock in industries like heavy transport and steel production, while CCUS can capture CO₂ emissions from these industries and potentially repurpose them for other applications.

While the goal outlined above is achievable, tangible results have not yet materialized at the scale required to save the environment. Over the past two decades, the world has seen a surge of innovation in clean energy and emissions control technologies—from green H₂ projects powered by solar panels to sophisticated carbon capture units retrofitted onto industrial stacks. However, the sum total of these fragmented efforts has often failed to make a significant global impact. Why? Because innovation without coordination is like an orchestra without a conductor. 

The time has come for a systemic, universal framework—one that integrates affordability, adaptability and effectiveness across technologies and geographies. Technologies must not operate in silos, but rather as interoperable pieces of a unified global strategy. The fight against climate change requires both precision and collaboration. 

H₂ can be produced using renewable energy sources (e.g., solar, wind, hydro) through electrolysis, which splits water into H₂ and oxygen. H₂ can also be produced from fossil fuels (e.g., natural gas) using steam methane reforming, with carbon capture, often referred to as blue H₂.  

Green H₂ holds immense promise as a clean, storable and transportable energy carrier; however, its deployment faces significant challenges. A lack of standardized electrolyzer designs, supply chain coordination, safety protocols and efficiency metrics across countries have led to wide disparities. While countries such as Australia, Germany, Japan and India invest in developing their own H₂ ecosystems, there is limited collaboration or standard-setting that could ensure global synergy. 

What the sector needs is a modular, interoperable approach to H₂ technology—similar to the global standardization of internet protocols or electric vehicle charging ports. Such an approach will accelerate investment, de-risk projects and enable international H₂ trade.² 

CCUS can be applied to existing industrial facilities and power plants to capture CO₂ emissions from H₂-related processes, further reducing the carbon footprint. The captured CO₂ can be injected into oil reservoirs to improve oil extraction or serve as a feedstock for producing chemicals, fuels and other industrial products. If utilization is infeasible, the captured CO₂ can be stored in geological formations. 

In essence, H₂ and CCUS are complementary technologies that work together to achieve deep decarbonization in sectors where traditional methods are insufficient. For example, a steel plant might use H₂ as a fuel or feedstock, while CCUS captures the emissions generated during the process. 

Direct air capture (DAC) continues to receive media attention and funding but remains prohibitively expensive and inefficient.³ Capturing carbon from the atmosphere requires significant energy and massive infrastructure, with current costs ranging from $500/t–$1,000/t of CO₂. In contrast, point-source carbon capture—from refineries, cement kilns, steel plants and thermal power stations—is not only proven but also far more cost-effective at approximately $40/t–$60/t. 

These industrial sources offer concentrated CO₂ streams, making capture significantly more feasible. Technologies like amine scrubbing, oxy-fuel combustion and pre-combustion capture have already demonstrated success. Focusing immediate investment on capturing carbon at industrial sources offers the greatest near-term benefits. This approach can be scaled effectively and integrated with CO₂ utilization pathways or geological storage to support global climate goals. 

Waste-to-fuel: A circular economy opportunity. The energy transition must not overlook the vast potential of waste-to-fuel technologies. Organic waste, agricultural residue, plastic waste and even municipal solid waste can be converted into H₂, synthetic gas (syngas), methane and sustainable aviation fuel (SAF). 

Thermochemical pathways (e.g., pyrolysis and gasification), biological methods (e.g., anaerobic digestion) and chemical recycling (e.g., polymerization) are becoming increasingly viable. These technologies reduce the environmental burden of waste, minimize landfill use and contribute to local fuel production. Numerous innovations in this area are worth highlighting. 

Innovation in waste-to-fuel technologies focuses on improving efficiency, reducing emissions and expanding the range of waste materials that can be converted into usable fuels. This includes advanced gasification, plasma arc gasification and the development of new SAF sources. The key innovations in waste-to-fuel technologies include: 

• Advanced gasification: Uses high temperatures to convert various waste types [e.g., municipal solid waste (MSW), agricultural residues] into syngas, which can be used for electricity generation or as a chemical feedstock. Innovations target improved efficiency, lower emissions and adaptability to diverse waste streams.  

• Plasma arc gasification: Uses extremely high temperatures generated by a plasma torch to convert waste into syngas, which can then generate electricity. It also produces a valuable glass-like byproduct.  

• Refuse-derived fuel (RDF): Produced by processing and treating MSW to remove materials and increase energy content, making it suitable for energy generation.  

• Solid recovered fuel (SRF): A high-quality fuel made from sorted, refined and non-hazardous waste materials, also suitable for energy production.  

• SAF: Made from renewable sources like waste products and agricultural residues, significantly reducing carbon emissions.  

• Waste-to-SAF: Converts waste materials directly into SAF. 

• Anaerobic digestion: Breaks down organic waste in a controlled environment to produce biogas (primarily methane), which can be used as a renewable energy source.  

• Pyrolysis: Converts waste into high-quality fuels like diesel oil or dimethyl ether.  

• Intelligent systems: Used to automate and streamline waste processing operations, improving efficiency and reducing manual labor.  

• Custom process engineering: End-to-end engineering solutions are developed to convert agricultural waste into biofuels.  

• Waste processing machinery: Includes equipment for particle size reduction, sorting, drying and pelletizing, all essential for the operation of waste-to-fuel facilities.⁴ 

While substantial progress is underway, a well-organized and coordinated approach is essential to maximize outcomes. With the right structure, this sector could outperform others, both economically and environmentally. Governments and industries must collaborate to scale these solutions through standardized protocols, shared research and development investments, and incentives for decentralized energy generation. 

The need for a unified technological vision. Today, clean energy and climate mitigation technologies are evolving uncompetitive silos, shaped more by national interests and venture capital than by a collective global impact. However, climate change is a shared threat, requiring a shared response. 

A globally harmonized technological vision is essential—one that prioritizes open standards, supports cross-border interoperability and fosters multilateral collaboration. A proposed solution is the establishment of a "Framework Convention on Clean Technology Deployment," modeled after the Paris Agreement but focused specifically on technological infrastructure, the sharing of best practices and aligned industrial policy. This framework would encourage countries and companies to build toward common metrics, standards and goals—amplifying rather than fragmenting their impact. 

Takeaway. The fight against climate change cannot be won with fragmented solutions. A patchwork of regional experiments will never rival a globally unified response. The leading global players must come under one umbrella—collaborating, prioritizing environmental safety and adopting common, proven, acceptable and affordable technologies. 

We must capture carbon at its source, convert waste into fuels and align our innovation pathways within a shared framework. Only then can we ensure that technology becomes not merely a tool of progress but a pillar of planetary survival. H₂T

About the author 

VIJAY KHANNA has 26 yrs of experience in the oil and gas sector while working with Engineers India Ltd. (EIL) until March 2001 out of 50 yr in engineering projects. He worked for Engineering Review of the Jumbo LPG I plant for Sonatrach in Algeria, was the project engineer manager for the first hydrocracker plant in India and was the project manager for a grassroots refinery at Numaligarh, the BPCL refinery expansion at Mumbai and several revamps. Khanna has been published in leading international industry publications, including Hydrocarbon Processing in 2001 and H₂Tech in 2023. Khanna earned a B. Eng degree and a PGD in management. 

LITERATURE CITED 

¹ Crippa, M., D. Guizzardi, M. Banja, E. Solazzo M. Muntean, et al., “CO2 emissions of all world countries,” 2022, Publications Office of the European Union, 2022, online: https://data.europa.eu/doi/10.2760/07904 

² International Energy Agency (IEA), “Global hydrogen review 2023,” September 2023, online: https://www.iea.org/reports/global-hydrogen-review-2023 

³ Barnard, M., “Climeworks’ DAC and fiscal collapse and the brutal reality of pulling carbon from the sky,” May 2025, Clean Technica, online: https://cleantechnica.com/2025/05/15/climeworks-dac-fiscal-collapse-the-brutal-reality-of-pulling-carbon-from-the-sky/ 

⁴ World Bank, “Solid waste management deep dive,” December 2021, online: https://documents1.worldbank.org/curated/en/099351104212219950/pdf/P17574808b24e90a08f9c03ae4a856919a.pdf