Encapsulated iron nanoparticles

Advanced material · OPS

Zero-valent iron nanoparticles encapsulated in carbon

OPS are the result of an engineering process carried out with judgment: a zero-valent iron (Fe⁰) material protected within a graphitic matrix, produced with proprietary technology from olive-mill waste. An advanced material with known, consistent properties, batch to batch. The tool comes at the end of a technical line of reasoning, not at the beginning.

From the laboratory to plant control.

Fe⁰ CORE Carbon shell graphitic · conductive Zero-valent iron Fe⁰ reactive core · ZVI ≈ 350 nm · average particle size
Technical definition

What are OPS?

OPS are nanoparticles of zero-valent iron (Fe⁰) encapsulated in a graphitic carbon matrix. The semiconducting carbon shell protects the metallic core from immediate oxidation, keeping the Fe⁰ —the chemically active fraction— available under real process conditions.

They are produced with proprietary technology from olive-mill waste (alperujo), the residue from olive-oil extraction. Feedstock, product and by-products stay within a closed, traceable chain.

  • Zero-valent iron core as the reactive fraction.
  • Conductive graphitic carbon as the protective shell.
  • 100% waste-derived: valorization of olive-mill waste.
  • Characterized material, reproducible batch to batch.
Core–shell structure Fe⁰ Carbon shell Fe⁰ core (zero-valent) Reactive surface CONDUCTIVE The graphitic carbon conducts electrons.
Characterization

Verified values, not approximations.

Every batch is characterized before leaving the plant. These are the material's reference parameters; the full datasheet is provided on request.

16%
Total iron (Fe)
8%
Zero-valent iron Fe⁰ (ZVI) — reactive fraction
29%
Micronutrients
55%
Carbonaceous phase (graphitic shell)

Average size 350 nm · Magnetic (separable from the medium) · Pore volume 0.271 cm³/g, predominantly mesoporous · Non-toxic material, within a circular-economy framework.
Protected as a trade secret · Produced entirely in Spain, in Extremadura (Valdetorres, Badajoz).

The origin

From waste to a catalyst.

OPS are not a starting point: they are what you obtain after a valorization process carried out with judgment. Olive-mill waste goes in as a residue; it comes out as an advanced material with known, consistent properties.

Input

Olive-mill waste

Alperujo · olive residue

Process

Proprietary technology

Applied technical judgment

Output

OPS · Fe⁰

Advanced material · catalyst

Why zero-valent iron matters

The value is in the electron, not the gram.

In anaerobic digestion, cooperation between bacteria and archaea depends on how electrons are transferred. The graphitic shell of OPS is conductive: it enables Direct Interspecies Electron Transfer (DIET), a more stable route than the one mediated by hydrogen or formate. What we pursue is process robustness and control —not a promise of throughput.

Bacteria acidogenesis OPS conductive bridge Archaea methanogenesis e⁻ e⁻ e⁻ e⁻ DIRECT INTERSPECIES ELECTRON TRANSFER (DIET) OPS act as a conductive bridge: electrons pass from one microorganism to another.

The conductive shell of OPS shortens the electron-transfer route between microorganisms, sustaining methanogenic syntrophy even under load disturbances — the mechanism that explains why production stays stable when other processes collapse.

Fields of application

Where a conductive Fe⁰ makes sense.

OPS are a nanotechnological material with potential beyond biogas. These are the main areas where their chemistry is relevant —and, below, the properties that open new application and R&D lines.

Properties that open R&D lines

High specific surface area
Its reactive surface enables effective interaction with contaminants in remediation processes.
Chemical stability
The carbon shell protects the iron core from oxidation and extends its service life.
Magnetism
Their magnetic properties make separation from mixtures easier and support use in bioremediation.
Biocompatibility
Non-toxic to living cells: relevant for agricultural and biomedical applications.

Beyond biogas, OPS have potential in gas streams, water remediation, agronomic products, new materials (ceramics, textile fibers, electrodes for fuel cells), biomedicine and the energy transition. We provide material samples and collaborate with research centers and companies on developing new applications.

R&D&I projects
Technical questions

Iron nanoparticles: frequently asked questions.

What are carbon-encapsulated iron nanoparticles (OPS)?

They are a nanotechnological material made of a zero-valent iron (Fe⁰) core coated by a graphitic carbon shell. They are produced by valorizing olive-sector by-products. The shell protects the iron from oxidation and provides a conductive surface.

What is their composition and characterization?

On average: 16% total iron, 8% zero-valent iron (ZVI), 29% micronutrients and 55% carbonaceous phase. Average size 350 nm and pore volume 0.271 cm³/g, predominantly mesoporous. They are magnetic.

What is zero-valent iron (Fe⁰) and why does it matter?

It is unoxidized metallic iron able to donate electrons: the reactive fraction of the material. The carbon shell keeps it available in the medium and adds conductivity, opening routes such as direct interspecies electron transfer.

What applications can they be used in?

Biogas and biomethane, water treatment, gas-stream treatment, agronomic products, new materials and remediation processes. Their versatility makes them candidates for new research and development lines.

Do you offer samples or collaboration on R&D projects?

Yes. We provide samples and collaborate on research and development projects around OPS and their applications. See projects →

How do they differ from other iron sources?

The graphitic carbon encapsulation protects the Fe⁰ from oxidation, provides a conductive surface that favors electron transfer, and adds magnetic character (separable). It is not just about supplying iron: it is about supplying a route for electrons.

Let's connect

We turn technical knowledge into real operational control.

We develop nanotechnology solutions to improve the efficiency of converting waste into renewable energy, contributing to the decarbonization of the energy sector.