Supervised by: Dr Semra Bakkaloğlu, Leonardo Centre, Imperial College London
Project Background
The chemical industry puts out around 8 percent of global CO₂ emissions, and ethylene is one of the most energy hungry things it makes. There are two ways to go after those emissions. Capture the CO₂ at the concentrated points, like hydrogen and ammonia production, or electrify the big heating systems, the steam crackers where ethylene actually gets made. People tend to back one or the other. Neither fixes the whole thing.
The part that gets skipped is where the carbon actually sits. Upstream extraction and refining are about 52 percent of the cradle to gate footprint. The cracker is about 39 percent. So you could remove every furnace emission and half the carbon would still be baked into the feedstock before the cracker even starts. That is why I don't think capture or electrify is the right question. The question is which one you use where, and in what order, once you account for cost, infrastructure, how mature the technology is, and the jobs tied up in these plants.
Research Question
What are the social, technical and economic trade offs between CCS and electrification for the chemical industry, and what framework can guide the order they get rolled out in European naphtha crackers?
Methodology
I'm comparing three systems: SMR hydrogen production with CCS, cracker furnace electrification, and cracker furnace with CCS. The functional unit is 1 kg of ethylene, cradle to gate, matched to the Plastics Europe eco-profile. Each system gets assessed against six metrics. Three are technical and economic: cost per tonne of CO₂ avoided, infrastructure change, and technical feasibility. The other three are about what happens on the ground: local health impact, employment and regional economy, and storage risk. Sources are peer reviewed LCAs, industry reports, policy briefs, and demonstrator data. I'm reporting everything as ranges, low to high with the study count behind each, because a spread is the honest answer here rather than one tidy figure. Then it comes together as four views: economic, environmental, technical, and social.
Objectives
Mostly I want to get past the binary. Both pathways do something useful, they just belong in different places. CCS earns its keep on the concentrated hydrogen stream, where capture runs roughly 25 to 50 dollars per tonne. The furnace is the hard case, a dilute stream that costs a lot more to capture from. Electrification is clean when the grid is clean, but it trades furnace emissions for exposure to power prices and imports. No pathway wins on its own. It comes down to timing, location, and how fast the grid decarbonises. Alongside the framework I'm building a working tool, the Industrial Decarbonisation Pathway Comparator, that I can bring into workshops with students, residents and workers so the human and economic side of these choices is actually in the room.
Significance
How Europe handles chemicals is going to set the pattern for the other hard sectors, steel, cement, refining. Treat CCS as the only option for the furnace when the economics don't support it, and money and policy lock onto the wrong path while electrification stalls. Push electrification before the grid can carry it, and you either export the emissions or build a fresh dependency. The jobs are not a footnote either. Chemical clusters in Germany, the Netherlands and the UK employ tens of thousands of people in exactly the processes this transition reshapes. What I want to add is the link between the technical pathways and those regional and social outcomes.