Emissions reduction
This article is part of our special series "The Tough Stuff: Decarbonizing steel, cement and chemicals." Read more.
This key chemical is super dirty to make. Can an electric furnace help?
These high-profile pilots are using electricity to slash CO2 emissions from making ethylene — the building block of materials from plastic to PVC.
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Chemelot is a vast industrial park of petrochemical plants and research labs in the Netherlands. Inside one of its facilities, a group of companies is working to solve a thorny problem vexing the global chemicals industry: how to make one of the world’s most important compounds — ethylene — without pumping copious amounts of carbon dioxide into the atmosphere.
Ethylene is a key building block for many of the chemicals that go into everyday items, including diapers and detergent, fabrics and foams, mattresses and milk jugs, plastic bags, PVC pipes and even airplane wings. It is the most-used primary petrochemical in the world, accounting for about one-third of the industry’s global consumption.
Today, making ethylene involves “cracking” apart the molecules in ethane or other hydrocarbons, which is done by burning huge amounts of fossil gas to heat giant furnaces to scorching temperatures. This step alone is responsible for 90 percent of the CO2 emissions associated with ethylene plants.
At Chemelot, near the city of Geleen, the engineering firm Coolbrook is piloting a new kind of technology — one that uses only electricity to crack ethane. The European company recently began testing its electric-driven ethylene reactor, as part of a broader 12-million-euro ($12.7 million) initiative for decarbonizing industrial emissions. In September, Coolbrook successfully completed its first phase of large-scale testing at the site, using an electric heater that makes high-temperature process heat for chemical, cement and steel manufacturing.
“We think this [electrified] technology can be one of the big game-changers in industrial decarbonization, especially in the sectors that have been considered ‘hard-to-abate,’” Joonas Rauramo, CEO of Coolbrook, told Canary Media.
He said the company plans to connect its first “commercial demonstration” ethylene reactors to existing chemical plants in 2025, and to deliver its first industrial-scale heaters starting late next year.
Coolbrook's pilot "e-cracker" technology is housed in this complex structure at the Dutch industrial park Chemelot. (Coolbrook)
Globally, ethylene production totals around 160 million metric tons per year, resulting in more than 260 million metric tons of annual CO2 emissions. That’s roughly the climate equivalent of operating 70 U.S. coal-fired power plants for one year.
Coolbrook’s electric “cracker” plant is among several high-profile initiatives that are seeking to clean up the most emissions-intensive part of ethylene production.
Shell and Dow, two major chemical manufacturers, are developing their own experimental unit to electrically heat steam-cracker furnaces. In June 2022, the companies announced they had begun operating their “e-cracking” furnace at a research campus in the heart of Amsterdam. Meanwhile, another chemical consortium — Linde, BASF and Sabic — is close to completing construction on a large-scale demonstration plant in Ludwigshafen, Germany.
In the United States, Houston-based LyondellBasell recently announced its plans to give e-crackers a try. In June, the chemical company signed an agreement with Chevron Phillips Chemical and Technip Energies to “potentially design, construct and operate” an electric-furnace demonstration unit, possibly at LyondellBasell’s Channelview site in Texas.
The companies behind all of these projects promise to deliver significant emissions reductions. If powered only by carbon-free energy, and lots of it, electric crackers could all but eliminate the carbon pollution that comes from burning gas to heat conventional furnaces.
Manufacturers are likely still years away from operating full-scale electric crackers. Switching to electricity will require spending significant sums not only to develop and prove out cutting-edge technologies but also to upgrade grid infrastructure and expand clean energy capacity in places where these facilities operate. Other approaches — such as installing carbon-capture equipment on conventional plants or burning clean hydrogen in lieu of gas to heat crackers — might prove to be more feasible in some cases, though both of those options are saddled with their own complications.
Despite the hurdles, the e-cracker concept is steadily gaining traction within the $5 trillion global chemical industry. As companies face growing regulatory and public pressure to achieve net-zero emissions — and as clean electricity becomes increasingly cheap in many places — electrifying steam crackers is emerging as one of the promising pathways for decarbonizing chemicals.
“A few years ago, if you talked about electrification in a chemical-industry setting, pretty much nobody would’ve taken you seriously,” said Dharik Mallapragada, a principal research scientist at the MIT Energy Initiative in Cambridge, Massachusetts.
“But I think that’s changed,” he added. “There’s been, if not an evolution, then an incremental appreciation toward electrification.”
A step in the right direction
The push to electrify ethylene production is a critical step toward reducing the climate impacts of chemical manufacturing, which accounts for about 15 percent of global industrial CO2 emissions every year. But e-crackers can’t address the inconvenient reality that, in its current form, ethylene is fundamentally problematic for the environment.
First, ethane is primarily derived from fossil gas extraction or as a byproduct of petroleum refining. The fossil-based feedstock accounts for about one-third of ethylene’s total life-cycle emissions when measured from the point of raw material extraction to the stage when ethylene leaves the production plant, according to a 2020 analysis commissioned by the American Chemistry Council.
Second, in addition to generating CO2 emissions, the process of cracking ethane gas releases significant amounts of cancer-causing air pollutants, including benzene, butadiene and naphthalene. A 2021 ProPublica investigation found that, across the United States, emissions from two dozen BASF-owned ethylene plants exposed an estimated 1.5 million Americans to elevated cancer risks.
Pollution-reduction equipment, routine emissions monitoring and active government oversight can help reduce the risks that crackers pose to public health — assuming companies and regulators adopt such measures. When it comes to feedstocks, it’s also possible to replace fossil fuels with alternatives, such as biomass waste, algae or “pyrolysis oil” made from recycled plastic.
Yet even if ethylene crackers were equipped to the hilt with pollution controls and were only made using non-fossil feedstocks, that still wouldn’t solve the third and perhaps biggest problem associated with the chemical’s production: Plastics made from ethylene and other ingredients are clogging the world’s waterways at unprecedented levels. Toxic chemicals from plastics are increasingly entering water supplies and our bloodstreams. Unless countries drastically curb consumption, annual plastic use is projected to nearly double by 2050.
Experts say these key underlying issues don’t necessarily undermine the case for electrifying ethylene production — especially if it means slashing emissions from existing facilities, many of which still have decades of operating life left. But they do illustrate the multilayered challenge of tackling an industry that’s both highly polluting and integral to modern society.
“There’s no simple trick” for cleaning up ethylene, said Matteo Gazzani, an associate professor at the Copernicus Institute of Sustainable Development in Utrecht, the Netherlands.
Three big projects aiming to electrify ethylene
An ethylene plant can, at first glance, resemble a dystopian version of the Wizard of Oz’s Emerald City, with rows of tall, skinny towers reaching up to the sky.
Ethane gas flows into each towering structure and moves through a tube, where it’s diluted with steam and pushed through a massive furnace. Temperatures can reach as high as 1,650 degrees Fahrenheit (900°C), achieved by burning fossil fuels. The heat instantly cracks apart the molecular bonds in ethane to produce ethylene gas, which is then separated from co-products and piped into narrow distillation columns, where the ethylene is processed into resins for making plastics.
In the Netherlands, Coolbrook is working to replace this entire setup with its own design, which it calls a RotoDynamic Reactor.
Using this equipment, ethane or other gaseous feedstocks are first mixed with steam inside a “turbomachine,” a type of technology also used in jet engines and gas turbines. By spinning a rotor shaft at supersonic velocity, then slowing it down, Coolbrook’s machine converts electrical energy into mechanical energy, then into thermal energy, which directly heats gas inside the reactor — reaching temperatures above 1,830°F (1,000°C). This creates the conditions needed to crack molecules to make ethylene.
The concept dates back to at least the 1990s, when a team of rocket engineers began exploring using turbomachines to generate high-temperature process heat for making petrochemicals. Coolbrook was formed in 2011 with the goal of developing an early prototype device into commercial-scale technology. The company is simultaneously working on the reactor and its RotoDynamic Heater, which uses a similar electricity-driven process to produce carbon-free high-temperature heat for industrial processes. Its partners in the projects include industrial heavyweights such as ABB, Linde Engineering, Shell, Cemex and ArcelorMittal.
Coolbrook claims its ethylene reactor can yield up to 20 percent more of the chemical when compared to traditional crackers that burn fossil gas to generate heat.
Rauramo, the company’s CEO, said he predicts that efforts to electrify heavy industries will mirror the trajectory of renewable energy development: years of modest growth followed by a sharp and widespread increase in global adoption.
“It may look slow in the beginning,” he said. “But when clean technologies are brought to the market, and people see that they actually operate and are reliable, that uptake will be much quicker than we anticipate today.”
Elsewhere in the Netherlands, at the research campus in Amsterdam, Dow and Shell are testing a “theoretical electrification model” for retrofitting gas-fired ethylene crackers. In 2021, the companies received a 3.5-million-euro ($3.7 million) grant from the Netherlands government for a four-year research project, which also involves the Institute for Sustainable Process Technology and TNO, a Dutch nonprofit research organization.
The partners have two stated goals — to electrify Dow and Shell’s existing cracking furnaces, and to develop “new breakthrough technologies” for electric cracking — though they haven’t yet discussed many of the details publicly (and declined to speak for this story). The chemical companies have said they’re evaluating the construction of a multi-megawatt pilot plant that could start operations in 2025, should they secure enough “investment support.”
Meanwhile, in Germany, BASF, Sabic and Linde are nearly finished building a first-of-a-kind demonstration plant for a large-scale, electrically heated steam-cracker furnace. The facility at BASF’s Verbund site is expected to process around 4 metric tons of hydrocarbons per hour and will require a total of 6 megawatts of renewable energy. Several thousand amps of electrical currents will flow through each of the nine new transformers, according to the companies.
The e-furnace project received 14.8 million euros ($15.6 million) from a German government program for decarbonizing heavy industries. The companies say they’ll test two different heating concepts: direct and indirect heating. The former involves applying an electric current directly to process tubes inside the ethylene reactors; the latter involves applying currents to heating elements, which in turn warm the process tubes via radiative heat transfer.
“This is a milestone towards electrifying one of the most energy-intensive production processes in the chemical industry,” BASF said about the project’s progress in a September news release.
Ramping up renewables to power e-crackers
As engineers work to make industrial-scale e-crackers a reality, renewable energy developers and grid operators must begin building gigawatts’ worth of new capacity and shoring up grid transmission systems to handle the influx of supplies and outside demand.
A typical ethylene plant produces around 1 million metric tons of the chemical every year. At that scale, an electric ethylene cracker’s rate of average energy consumption would be as much as 350 to 400 megawatts, said Mallapragada of the MIT Energy Initiative.
Electric ethylene crackers may wind up being more energy-intensive to operate than gas-burning counterparts, even if they generate far fewer emissions overall. One reason is that conventional crackers recycle the co-products of ethylene production — hydrogen and methane — back into the facility to generate heat used to power manufacturing processes. Electric plants produce the same co-products but can’t harness their energy; instead, companies will have to capture and potentially sell the hydrogen and methane to other industries.
A final conundrum for e-cracker developers is that today’s cracking furnaces generally operate around the clock. They often do so at maximum capacity, owing to the high investment costs of building crackers and the complexity of the ethylene production process. Wind and solar power, by contrast, are notably intermittent resources.
Chemical companies and grid operators could potentially decide to balance supply and demand by investing in energy storage solutions, such as batteries. However, installing enough storage capacity to meet the energy needs of steam crackers likely won’t be technically or economically feasible, at least in the short term. Another idea is to operate electric crackers more flexibly, meaning that plant operators would ramp up their production at times when renewable electricity is most available and prices are relatively cheap.
Julia Tiggeloven, a doctoral student at Copernicus Institute of Sustainable Development, is using computer models to study how this more flexible approach could allow ethylene producers to benefit from variations in electricity prices, as well as avoid “oversizing” renewable power sources in their efforts to maintain the same yearly production of ethylene. This also has the added advantage of lessening the strain on the broader electrical system.
Routinely ramping ethylene plants up and down is technically complicated and isn’t normally done. Still, e-cracker operators might be able to achieve greater emissions reductions and secure significant cost savings by operating facilities flexibly instead of constantly, said Tiggeloven, who was the lead author of a recent analysis published in the scientific journal Industrial & Engineering Chemistry Research.
Mallapragada noted that future generations of technology — like those using electrochemical or plasma-driven processes — could make it possible to produce ethylene from various feedstocks at lower temperatures and use less energy, in turn enabling companies to operate plants more efficiently and flexibly. In the meantime, some companies are considering a “hybrid electrification” approach: gradually electrifying some steam-cracking furnaces while leaving other gas-fired systems in place until the grid can meet demand.
While electrifying ethylene involves a host of unique complications, it shares one key challenge with other heavy industries seeking to achieve net-zero emissions: the currently limited availability of renewables, Coolbrook’s Rauramo observed.
“When we talk seriously about the decarbonization of heavy industry, a great deal of investment needs to happen, regardless of the path that you choose,” he said.
Maria Gallucci is a senior reporter at Canary Media. She covers emerging clean energy technologies and efforts to electrify transportation and decarbonize heavy industry.
