How to Deal with Carbon Emissions Using Holistic Process Engineering Principles

How to Deal with Carbon Emissions Using Holistic Process Engineering Principles A framework for following carbon, energy, and consequences across the whole system 1. Start with the fundamental physical reality Carbon is matter. In ordinary industrial chemical processes, carbon atoms are neither created nor destroyed. They are transformed from one chemical form to another and transferred from one location or reservoir to another. Combustion illustrates this clearly: CH₄ + 2O₂ → CO₂ + 2H₂O The carbon contained in methane has not disappeared. It has simply moved into CO₂. Methanation demonstrates another transformation: CO₂ + 4H₂ → CH₄ + 2H₂O Again, the carbon remains. Carbon does not disappear when it crosses an engineering, corporate, geographical or regulatory boundary. We must continue following it. 2. The system boundary is necessary - but it can also mislead us Engineers need boundaries. Without them, mass balances, energy balances and process calculations would be impossible. But nature does not recognise the boundaries we draw on process-flow diagrams. A power station may reduce its stack emissions by capturing CO₂. From the plant boundary, this appears to solve the emissions problem. Holistic Process Engineering asks the next question: Where did the carbon go? If it was compressed, transported, and injected underground, the carbon has not disappeared. Its location and physical state have changed. Properly designed geological storage is intended to retain CO₂ for very long periods, and monitoring technologies exist to evaluate containment. The holistic point is that moving a material beyond the visible boundary of one process cannot, by itself, be considered the end of our responsibility for that material. 3. Follow the Carbon rather than only Follow the Emission Instead of asking only, “How much CO₂ came out of the stack?”, ask: “Where did the carbon originate, where is it now, and where will it ultimately reside?” Conventional fossil-energy pathway: Geological carbon → extraction → processing → fuel → combustion → CO₂ → atmosphere/ocean/biosphere The climate problem arises fundamentally from continually transferring carbon from a geological reservoir into the active carbon cycle. Reducing emissions is necessary, but the deeper destination should be defossilisation: progressively ending the requirement for continual extraction of additional geological carbon. 4. CCS changes the destination, but does not eliminate the carbon Conventional CCS creates another pathway: Geological carbon → extraction → fuel → combustion → CO₂ capture → conditioning → compression → transport → geological injection → long-term geological inventory This can substantially reduce atmospheric emissions when it operates successfully. Holistic Process Engineering, however, requires assessment of the entire chain: capture efficiency, energy penalty, compression, transportation, injection, reservoir behaviour, monitoring, leakage risk and long-term responsibility. Design performance should never be confused with demonstrated sustained operating performance. A FEED study specifying a high capture percentage is an engineering design objective; it is not equivalent to a facility demonstrating that performance continuously for 10 or 20 years. The same standard must ultimately apply to CRT. 5. History tells us that the carbon question is not new The scientific foundations extend back well over a century. Eunice Newton Foote demonstrated the heat-retaining behaviour of CO₂-rich air in 1856. Svante Arrhenius quantitatively investigated the relationship between atmospheric CO₂ and temperature in 1896. In 1912, the now-famous “Coal Consumption Affecting Climate” item publicly explained that burning enormous quantities of coal was adding CO₂ to the atmosphere and could increase Earth's temperature. In 1985, Carl Sagan testified before the United States Senate about fossil-fuel CO₂ and greenhouse warming. The important lesson is not that humanity suddenly discovered the carbon problem recently. Our understanding has progressively strengthened over more than a century. The engineering question now is: What are we going to do differently with the carbon? 6. Separation is useful - but separation does not terminate responsibility Process engineering depends on separation. We separate CO₂ from flue gas, hydrogen from mixtures, water from process streams, and contaminants from products. There is nothing inherently wrong with separation. The problem arises when separation is mistaken for resolution. Separation can be a process operation, but it cannot be the boundary of our responsibility. What we separate conceptually remains connected physically. 7. There is another possible carbon pathway: circulation Methanation itself is not a new experimental chemistry. Industrial methanation and synthetic natural gas production have decades of experience, including large coal-to-SNG installations. A simplified coal-to-SNG pathway is: Coal → gasification → syngas → gas treatment → methanation → SNG The fundamental carbon issue remains the continuing introduction of new geological carbon and the eventual release or disposal of carbon from the process. This raises a logical engineering question: If CO₂ can be captured, and captured carbon can be converted with hydrogen into methane, why must disposal necessarily be the final destination of the captured carbon? 8. CRT changes carbon from a waste stream into a circulating inventory Conceptually, the proposed Carbon Recycling Technology (CRT) pathway is: Managed carbon inventory → RSNG → power + heat → CO₂ → capture → conditioning → methanation + H₂ → RSNG → repeat The intention is not to destroy carbon. Instead, the objective is to manage carbon as an inventory. Once the circulating inventory has been established, additional carbon should ideally be required primarily to replace measurable carbon losses rather than continually supplying the gross quantity circulating through the system. 9. CRT must be subjected to exactly the same standard Holistic thinking cannot be used to criticise CCS while giving CRT an exemption from rigorous measurement. If CEWT claims high carbon circulation, a demonstration plant must prove it through a whole-system carbon balance: Carbon input = Carbon products + Carbon emissions + Carbon waste + Change in carbon inventory Every significant pathway should be instrumented. The system should measure carbon entering, carbon converted, carbon combusted, carbon captured, carbon recycled, carbon lost and carbon make-up required. A Carbon Recirculation Ratio may ultimately become an important CRT performance indicator, but its precise definition should be established rigorously during engineering and demonstration. 10. Technology readiness must distinguish components from architecture The relevant question is not simply, “Has CRT operated commercially for 20 years?” It has not. Instead, each element should be assessed independently. Methanation, syngas production, hydrogen production, CO₂ separation, CO₂ compression, gas turbines or engines, and heat recovery are established industrial operations at varying levels of commercial maturity. The novel element is primarily the integration of these operations into sustained carbon recirculation, carbon-inventory management, and dynamic plant operation. A technically defensible description is: CRT is a novel system architecture integrating predominantly established industrial unit operations, with sustained closed-loop carbon recirculation and integrated system performance requiring demonstration. 11. Data, logic, intuition and engineering each have a role Data tells us what has happened. Logic asks whether our explanation is internally consistent. Scientific knowledge establishes the governing physical laws. Engineering determines whether an alternative can actually operate. Within Holistic Process Engineering, spiritual intuition provides another perspective: intuition sees the whole before we divide it into individual analytical pieces. These do not have to compete. A holistic engineering process can move through: Intuition → question → logic → scientific analysis → engineering → measurement → demonstration The intuition may originate the idea. Ultimately, nature determines whether the engineering works. 12. Follow both carbon and energy Carbon cannot be considered independently of energy. Converting CO₂ back into methane requires hydrogen and therefore substantial energy. Consequently, circulating carbon is environmentally meaningful only if the energy required to maintain that circulation is simultaneously accounted for. This leads to the broader principle: Follow the Carbon and Follow the Energy simultaneously. A solution that closes one material loop while creating an unsustainable energy requirement somewhere outside the selected boundary would not satisfy Holistic Process Engineering. The central proposition We create boundaries to understand nature. Nature does not obey the boundaries we create. Carbon does not know whether it has crossed a power-station fence. It does not recognise corporate ownership or national borders. It does not disappear because it has moved beyond human sight. Dealing with carbon emissions holistically therefore means continuing to follow the carbon - and the energy associated with it - until the consequences across the whole system are understood. This provides the philosophical and scientific foundation for Follow the Carbon, defossilisation, and the continuing development and demonstration of CRT.