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Technology & EvidenceWhat supports the proposition?
Oxy-fuel combustion is the component that makes a high-purity CO₂ stream available without a conventional capture plant. This page explains how it works, where the system boundary sits, what has been demonstrated by the technology owner, what remains to be integrated at a specific site — and how to read every number Valverde publishes.
Combustion in oxygen instead of air
Conventional gas-fired generation burns fuel in air. Air is 78% nitrogen, so the exhaust is a dilute mixture of nitrogen and about 4–8% CO₂ that is costly to separate. The oxy-fuel process removes the nitrogen before combustion rather than the CO₂ after it.
Oxygen supply
An air separation unit (ASU) on site, or an over-the-fence supplier, provides oxygen. Sizing the ASU and its power draw is one of the main economic variables of the project.
Oxy-fuel generator
Fuel gas is combusted in oxygen inside the CES Direct Steam Gas Generator — a design derived from rocket-engine combustion technology — with water injection to control temperature. The products are steam and CO₂ with very low NOx.
Turbine generator
The steam and CO₂ stream drives a turbine generator (CES’s OFT-900 class turbine in the reference design) to produce electricity for the facility and, where connected, the grid.
Condensing
The exhaust is condensed. Water is recovered — the process is a net producer of distilled water — and the remaining stream is CO₂ at high purity.
CO₂ compression
The CO₂ is compressed to pipeline or injection pressure. Compression power is an internal load that reduces net export and must be counted in any net-output statement.
Storage or use
Geological storage, delivery to a CO₂ pipeline or hub, or injection for enhanced oil recovery. These are different categories with different permanence, accounting and incentive treatment; we do not use them interchangeably.
Clean Energy Systems and the master licence
Clean Energy Systems (CES) of Rancho Cordova, California, holds the patents on the oxy-fuel combustor and has developed and tested oxy-fuel generation systems over roughly 25 years, including its ZEUS zero-emission power-station concept. CES employs about 25 professional engineers and is a minority shareholder in Valverde.
On 6 October 2021, Valverde and CES announced a definitive Master License Agreement granting Valverde the right to use the CES oxy-fuel combustion technology for an initial set of identified clean-power and carbon-capture projects in the United States, Canada and Mexico.
One description of the licence. Valverde’s public materials have described the licensed scope in different ways — “selected North American upstream and midstream applications” and “Canadian oil and gas applications”. The counsel-approved description of territory, field of use, exclusivity and duration will replace this note and be used consistently across all materials. verify
Equipment shown is the licensor’s reference design, not a Valverde installation.
How to read every claim on this site
For each family of statement, this register says what the number depends on and what basis Valverde can currently offer. Where the honest answer is “a target” or “not yet measured”, that is what it says.
| Claim family | What must be clear before it is stated | Current basis |
|---|---|---|
| Capture percentage e.g. “100% of combustion CO₂” | Denominator (combustion CO₂ only, or facility total); design vs measured; operating period; treatment of bypass, start-up and downtime | design basis Oxy-fuel combustion produces a CO₂/steam exhaust with no nitrogen, so the design intent is to capture all combustion CO₂. No measured Valverde project figure exists. Not a lifecycle result. |
| Electricity carbon intensity e.g. “zero-emission”, “carbon-free” | Net vs gross basis; included emissions; upstream fuel assumptions; storage permanence; auxiliary power (ASU, compression) | design target Applies to stack emissions of the oxy-fuel unit. Whole-life intensity requires a separate lifecycle assessment with an explicit accounting boundary. |
| Lower cost e.g. “lower CAPEX and OPEX” | Comparator technology; project scale; cost year and currency; operating assumptions; equipment and services included | company estimate Relative to post-combustion capture on a comparable gas plant, per Valverde and CES statements. Project-specific cost comparisons are made in feasibility, not in marketing. |
| Fuel flexibility e.g. “burns ~20% methane streams” | Tested composition range; contaminants; pretreatment; derating; materials and permit constraints | supplier data CES states the combustor handles a wide range of gas qualities including low-BTU and CO₂-rich streams. Site-specific composition is validated in feasibility. |
| Exclusive access e.g. “exclusive rights” | Territory; field of use; duration; exclusions; the actual rights holder | licence · 2021 Master License Agreement with CES, October 2021. Counsel-approved summary pending. verify |
| Completed or proven project | Responsible entity; development stage; test scale; run duration; independent verification | supplier data CES reports that all required systems have been tested at scale. Valverde has no commissioned project; see Projects for stage labels. |
| Dispatchable / dependable power | Availability, maintenance, outage plan, backup supply, gas security, grid interface | design basis Continuous generation is the design; availability guarantees are contractual matters set per project. |
| Incentive eligibility 45Q, CCUS ITC, LCFS, TIER | Jurisdiction; date of law; storage vs EOR treatment; ownership and monetisation route; stacking rules | professional review General overviews only; eligibility is determined per project by tax and legal advisers. Rules changed in Canada and the US during 2026. |
What is demonstrated, and what is integrated per site
Demonstrated by the technology owner
- Oxy-fuel combustor operation on natural gas at test scale (CES)
- Steam/CO₂ turbine generation in the reference design (CES)
- CO₂ pipeline transport, injection and EOR operations — decades of industry practice, including the leadership team’s Denbury experience
Integrated and validated for each project
- Oxygen supply configuration and its parasitic load
- Electrification of existing compression and generation
- Net output after ASU and CO₂ compression
- CO₂ specification at the storage or pipeline interface
- Outage, maintenance and backup-power plan
- Permitting, interconnection and incentive determinations
Valverde’s development work is the integration column. The technology column is the licensor’s.
The oxy-fuel plant in a wider energy system
Integrating several energy solutions is usually the most efficient way to deliver clean energy, and the oxy-fuel process can sit at the centre of a site’s system:
- Recovered water and electricity can feed hydrogen production by electrolysis; the oxygen from electrolysis can supplement the oxygen plant.
- The plant’s continuous output can firm intermittent renewable supply to the grid, and surplus renewable power can in turn support the ASU.
- Steam and boiler water are additional products where a host has a use for them.
These are configuration options, not features of any current Valverde project.
Plain-language terms
Oxy-fuel combustion
Burning a fuel in oxygen rather than air. Because there is no nitrogen, the exhaust is mainly steam and CO₂, which makes CO₂ separation a matter of condensing water rather than chemically scrubbing a dilute flue gas.
Direct Steam Gas Generator (DSGG)
Clean Energy Systems’ oxy-fuel combustor. Fuel and oxygen are burned at pressure with water injection, producing a high-temperature steam/CO₂ stream used to drive a turbine.
Air separation unit (ASU)
A plant that separates oxygen from air, typically by cryogenic distillation. It supplies the oxygen the combustor needs and consumes a meaningful share of the generated power.
Net vs gross output
Gross output is what the generator produces. Net output subtracts the plant’s own consumption — mainly the ASU and CO₂ compression. Only net output is available to the facility or the grid.
CCUS
Carbon capture, utilisation and storage. Capture separates the CO₂; storage places it permanently in a geological formation; utilisation uses it, for example in enhanced oil recovery. Each has different accounting and incentive rules.
Enhanced oil recovery (EOR)
Injecting CO₂ into an oil reservoir to recover additional oil. Some of the CO₂ remains in the formation; the accounting for that retention differs from dedicated geological storage.
Pre-FEED and FEED
Preliminary and full front-end engineering design: the study stages that define a project’s configuration, cost and schedule well enough for an investment decision. They precede detailed engineering and construction.
Dispatchable power
Generation that can run continuously or be scheduled on demand, as opposed to intermittent wind and solar output. Dispatchable design is not the same as a contractual availability guarantee.
45Q, CCUS ITC, LCFS, TIER
Section 45Q is the US federal tax credit for captured CO₂; the CCUS investment tax credit is Canada’s federal credit for eligible capture, transport and storage equipment; Low Carbon Fuel Standards are US state programmes; TIER is Alberta’s industrial emissions pricing system. All are subject to change and project-specific determination.
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