How to Calculate Carbon Capture Mineralization Capacity Factor
Carbon mineralization converts captured CO2 into stable carbonates by reacting it with alkaline feedstocks. Investors and regulators scrutinise the capacity factor of these plants to judge whether contracted removal volumes will be delivered. This walkthrough explains how to combine throughput data, uptime records, and purity penalties into a transparent metric, building on the delivery assurance framework in the carbon removal delivery confidence guide.
By grounding the calculation in operational telemetry, facility teams can reconcile reported capacity factors with the material balances used in life-cycle assessments and MRV (measurement, reporting, verification) packages. The embedded calculator mirrors the steps below and standardises how updates flow into sustainability reporting systems.
Purpose of the mineralization capacity factor
Capacity factor expresses the ratio of effective throughput to design capability. For mineralization, “effective” must account for both physical uptime and the fraction of feedstock that actually converts into durable carbonate. A high capacity factor indicates that reactors, curing lines, and downstream logistics are working smoothly; a low factor points to bottlenecks or quality issues that jeopardise removal commitments.
Tracking the metric also supports downstream utilisation, such as blending carbonated aggregates into concrete. If capacity factors drop, supply agreements should be adjusted accordingly—similar to how binder ratios are tuned in the carbon-negative concrete binder ratio walkthrough.
Variables and measurement
Gather the following values for the reporting period (daily, weekly, or monthly):
- Cdesign – Nameplate mineralization capacity (tonnes/day). Derived from engineering design.
- Mavg – Average processed mass while the plant is online (tonnes/day).
- u – Operational uptime (percent). Share of the period when reactors and material handling were available.
- p – Purity penalty (percent). Accounts for contaminants or incomplete carbonation that reduce the effective mass.
Uptime should reflect the entire end-to-end system, including feedstock preparation, reactor operation, curing, and loading infrastructure. Purity penalties come from lab assays or carbon-accounting reconciliations that compare input CO2 with sequestered carbon.
Formulas for effective throughput and capacity
Convert the inputs into a capacity factor with the following steps:
Effective throughput: Meff = Mavg × (u ÷ 100) × (1 − p ÷ 100)
Capacity factor: CF = Meff ÷ Cdesign
The calculation assumes linear relationships between uptime, purity, and throughput. If reactor performance degrades at partial loads, adjust Mavg to reflect actual operating conditions. When CF exceeds 1, the plant is outperforming nameplate—common during short overdrive campaigns. Cap reported values at a defined threshold (for example 5×) to flag anomalies without distorting dashboards.
Step-by-step analytical workflow
Step 1: Validate input data
Reconcile throughput measurements from belt scales, weighbridges, or batch records. Align them with MRV documentation so auditors can trace how Mavg was derived. Remove outliers caused by commissioning hiccups unless reporting a commissioning period.
Step 2: Calculate uptime
Use historian logs to measure the fraction of time reactors were available. Include downtime for maintenance, feedstock shortages, or curing bottlenecks. Express the result as u.
Step 3: Quantify purity penalties
Analyse carbonate samples for unreacted oxides, moisture, or impurities. Convert assay results into a percentage reduction p that represents non-durable mass. Update the penalty when feedstock quality changes.
Step 4: Compute Meff and CF
Apply the formulas to determine effective throughput and capacity factor. The embedded calculator presents the values in plain language, ready for inclusion in stakeholder reports.
Step 5: Contextualise results
Compare CF against contractual obligations. If the factor remains below target for multiple periods, investigate root causes—feedstock logistics, reactor fouling, or labour constraints—and implement corrective actions.
Validation, monitoring, and reporting
Validate capacity factors by reconciling them with carbon accounting ledgers. The tonne of carbonate sequestered should match MRV-certified removal credits. If discrepancies occur, revisit measurement instrumentation or purity assumptions. Track CF on rolling averages to separate structural issues from short-term noise.
Pair the metric with forward-looking indicators such as sorbent productivity from the direct air capture sorbent productivity guide. Combined dashboards help investors and offtakers assess whether future delivery targets remain achievable.
Limitations and edge cases
Capacity factor alone does not capture carbon intensity per tonne, energy usage, or financial performance. Supplement the analysis with lifecycle assessments and cost curves. When new reactor trains are commissioned mid-period, recalculate Cdesign to avoid artificially low factors.
Some mineralization processes co-produce valuable materials whose market demand caps throughput. In those cases, adjust targets so the capacity factor reflects intentional throttling rather than operational underperformance.
Embed: Carbon capture mineralization capacity factor calculator
Provide design capacity, average processed mass, uptime, and optional purity penalties. The calculator outputs effective throughput and the resulting capacity factor.