TL;DR: Alberta's heavy oil has earned a "dirty oil" reputation because extracting and upgrading it often requires extra energy-intensive steps that conventional oil doesn't need. Carbon capture technology can significantly reduce these emissions—but successful integration depends on properly engineered combustion control and burner management systems (BMS). MICA Controls has developed a steady-state constraint control approach that stabilizes reformer operations during carbon capture retrofits, helping operators accommodate changes in process fuel composition without triggering reformer instability or box pressure trips.
If you operate heavy oil infrastructure in Alberta, you've heard the label more times than you'd like: dirty oil. It's not a fair characterization of the people doing the work, but it's rooted in a real technical reality that's worth unpacking honestly.
Alberta's oil often carries a higher production carbon footprint than conventional crude for a straightforward reason: getting it out of the ground and turning it into usable product can require more energy-intensive processing steps.
Much of Alberta's in-situ bitumen is produced using steam-assisted gravity drainage (SAGD), a process that relies on steam generators to produce the steam injected underground to heat and mobilize the oil. Those steam generators emit CO₂. From there, because the oil itself is heavy, it may need to be upgraded—its hydrocarbon chains shortened through processes such as coking or hydrocracking. Hydrocracking depends on hydrogen, and that hydrogen is commonly manufactured using steam methane reformers, which are heated by burners and produce additional CO₂ in the process.
Compared to a typical light oil refinery, heavy oil upgrading can require additional equipment: vacuum distillation capacity, sulphur recovery furnaces, additional hydrotreating heaters, larger hydrocracking units, and in some cases fluid coking or delayed coking equipment. Many of these systems require additional fired heating or other energy inputs, creating further sources of emissions.
This is the chain of extra steps that gives Alberta's oil its carbon-intensive reputation. It's also exactly the chain that carbon capture technology can help address.
Here's a distinction that gets lost in broader conversations about carbon capture: one of the most effective opportunities is capturing CO₂ from the reformer's process stream itself, rather than from the combustion gases used to heat the reformer.
When a reformer generates hydrogen, it reacts natural gas with steam to produce hydrogen and carbon monoxide. A subsequent water-gas shift reaction converts carbon monoxide and steam into additional hydrogen and CO₂. The resulting process gas contains hydrogen, water vapour, CO₂, and smaller quantities of other gases.
Historically, operators would separate the hydrogen for use in hydrotreating, while the leftover "off gas" or "purge gas"—which can contain significant concentrations of CO₂, hydrogen, carbon monoxide and methane—was often sent back into the burners as fuel.
Carbon capture changes that. Depending on the process configuration, CO₂ can be removed from the process gas before hydrogen separation or from an appropriate downstream gas stream. Where CO₂ is removed from the gas returned to the burners, the remaining fuel becomes more concentrated in combustible components such as hydrogen.
When you change how a steam methane reformer fires, you can change the fuel composition and flow characteristics the burner management system was designed around. That requires a review of the combustion control system and applicable code compliance requirements, including CSA B149.3.
This is where a lot of carbon capture projects can run into trouble. Reformers have "wild flows"—like purge gas—that can't necessarily be throttled with a control valve without affecting the upstream process. Block that flow and you risk backing up the process. Natural gas flow, on the other hand, can be controlled with pressure and valves. Any BMS and combustion control strategy that doesn't account for this difference is setting the facility up for instability.
MICA Controls has implemented what it calls constraint control across eight reformers to date. Rather than applying a conventional boiler-style control philosophy—where air is increased before fuel during increasing demand to maintain adequate combustion air—constraint control leaves air flow under full operator control via a remote set point, established in engineering units. The system only intervenes on the supplemental natural gas side, pulling back fuel if the available combustion air can't support it, based on the required air-to-fuel ratio and the combustion-air demand of the process fuel. Wild flows like purge gas are left alone by the combustion control system. Their availability is governed by upstream process conditions rather than furnace heat demand.
This distinction matters because reformer fireboxes are large and can be sensitive to pressure swings. Boiler-style logic that moves air dynamically, without properly accounting for reformer process conditions and furnace draft control, can destabilize box pressure and potentially send a reformer into a box pressure trip—a problem MICA Controls has seen firsthand when reviewing control functions originally commissioned by large EPCs. In more than one case, those legacy combustion control functions had been sitting in manual since startup, never actually functioning as designed.
Constraint control maintains the intended combustion operating envelope, while the BMS retains its independent protective functions, including combustion-air, fuel-pressure, flame and furnace-pressure protection.
Getting this right isn't optional. Following code language without understanding reformer behavior can leave a facility with an unstable, trip-prone unit. The code tells you what's required; it doesn't tell you how to implement it in a way that holds up operationally.
Carbon capture, implemented with the right combustion control and BMS strategy, can significantly reduce the carbon intensity associated with heavy oil upgrading. By capturing CO₂ directly from the reformer process stream, Alberta's heavy oil can substantially reduce the emissions associated with hydrogen production, narrowing the carbon-intensity gap with conventional oil production.
This is a significant shift. The technology has advanced to the point where Alberta's heavy oil has a practical pathway to a substantially lower production carbon footprint. Achieving carbon intensity comparable to other oil sources will also depend on reducing emissions from extraction, steam generation and other upgrading operations. The "dirty oil" label reflects historical emissions performance—not necessarily what the industry is capable of achieving with modern technology.
If your facility is planning a carbon capture retrofit on a reformer, upgrader, or refinery, the BMS and combustion control strategy aren't details to work out later—they're foundational to the project succeeding. Talk to MICA Controls about what a properly engineered constraint control approach looks like for your operation.