Abstract
This paper introduces the advanced technology NanoActive® Sulphur Scavenger (NASS), a Zinc Oxide (ZnO) based nanostructured material, and examines its applications across a range of problems faced by the petroleum industry. Principally, the neutralization of hydrogen sulphide (H2S) from crude oil and gas phases, resulting in the reduction of operational risks, environmental impact and pollution, and increased productivity and profitability.
NASS is a non-toxic, non-hazardous, non-dangerous substance. It is manufactured using advanced chemistry nanotechnology processes, creating unique properties (such as increased surface areas, large porosities, unique morphology, additional surface functional groups) causing enhanced chemical reactivity and increased chemical selectivity. The inherent chemical reactivity centers on a high surface area. Due to their exceptional porosity, NanoActive® materials have demonstrated the ability to destructively adsorb a wide range of harmful chemicals and odor causing compounds.
NASS’ two-step decomposition mechanism (adsorption by physisorption, followed by nonreversible chemical decomposition) substantially enhances its detoxification abilities because decomposition is less dependent on temperature. Use of NanoActive® technology improves scavenger efficacy between 4 and 6 times, depending on feed composition.
Currently, the range at which NASS stand-alone systems are economical is up to 10,000 ppm H2S in liquid streams, and 1,000 ppm H2S at 320 m3/hr to 10,000 ppm H2S at 30 m3/hr in gas streams. At these levels, NASS reduces H2S to 0 ppm. For higher concentrations, NASS is used in combination with existing removal technologies.
Containment. Chemicals and vapors are taken up by adsorption into the large, porous surface of the NASS molecule.
Adsorption. Chemicals and vapors bind to the surface of the NASS molecule.
Neutralization. Chemical reaction occurs to change the toxin to non-hazardous.
NASS solutions can be applied to a wide range of challenges:
Danger to personnel
Environmental release to atmosphere
Sour crude and sour gas streams
Tank vapor space, tank cleaning
Unrecoverable or wasted hydrocarbon
The earlier in the process NASS is deployed (for example, near the wellhead), the better for the process overall, with many downstream problems eliminated altogether.
Removal or reduction of H2S in upstream production improves safety, and reduces corrosion and byproducts, thereby reducing flaring and disposal, and producing sweet gas for power.
Reacted NASS is transformed into zinc sulphide (ZnS), which, along with any surfactant and inorganic materials, is non-toxic and does not require hazardous waste disposal, except where mandated by local legislation.
With the adoption of this technology, the current philosophy of H2S "containment and control" changes to "elimination by neutralization". It delivers significant HSE benefits, and reduces operational risk. It is today's Best Available Technology Not Entailing Excessive Cost (BATNEC). It allows development where currently there are technical, regulatory or economic barriers.
