Knowledge Base

Proposed Chosen Technology

Draft Medium Vision 3,421 words Created Mar 3, 2026

Proposed Chosen Technology

We looked at seven different ways to destroy ocean plastic. We chose one. This page explains what it is, why we picked it, and what a realistic deployment looks like -- with honest numbers on cost, size, energy, and what we still don't know.

The Choice: Plasma Gasification

We Evaluated Seven Technologies

Before landing on plasma gasification, we studied every credible technology for thermally destroying plastic waste:

1. Plasma gasification -- superheating waste with an electric plasma arc at 5,000-15,000 degC 2. Pyrolysis -- cooking waste in the absence of oxygen at 300-700 degC 3. Conventional gasification -- partial combustion at 700-1,500 degC 4. Mass burn incineration -- straight burning at 850-1,100 degC 5. Microwave pyrolysis -- using microwave radiation to heat waste internally 6. Hydrothermal liquefaction -- using superheated pressurized water to break down plastic 7. Cement kiln co-processing -- burning plastic as fuel in cement factories

Each has strengths. Several work well on land with sorted, clean waste. But ocean plastic is none of those things. It is mixed, wet, salt-encrusted, tangled with fishing nets, encrusted with barnacles, and contaminated with toxic chemicals that have been absorbing into it for decades. We needed a technology that could handle the worst-case feedstock on earth -- and do it on a floating platform in the middle of the Pacific Ocean.

Why Plasma Gasification Won

Four reasons:

  • It eats anything. Mixed plastics, fishing nets, rope, bottles, foam, film -- all at once, no sorting required. Pyrolysis needs clean, sorted, dry input. Conventional gasification struggles with mixed polymers. Plasma doesn't care. Throw it all in.
  • It destroys everything. At 5,000 degC and above, every molecule is ripped apart into individual atoms. Every toxic chemical -- PCBs, dioxins, persistent organic pollutants -- is completely destroyed. InEnTec, one of the leading plasma companies, has verified 99.99999999% destruction of PCBs (that is ten nines). Nothing survives those temperatures.
  • It produces useful energy. The process doesn't just destroy waste -- it converts it into syngas, a fuel gas made mostly of hydrogen and carbon monoxide. That syngas can be burned in generators to produce electricity, which powers the entire system. More on this below.
  • It is already proven at sea. This is the clincher. The US Navy's PAWDS system (Plasma Arc Waste Destruction System) runs on the USS Gerald R. Ford, the most advanced aircraft carrier ever built. It has been operational at sea since October 2022. A different system, Terragon's MAGS, has been running on Canada's MV Asterix since December 2017. These are not concepts or prototypes -- they are working systems on moving warships.

What Goes In, What Comes Out

What Goes In

Ocean plastic -- exactly as collected. Tangled fishing nets, crushed bottles, film fragments, microplastic-laden debris, all mixed with salt, seawater, barnacles, and algae. The only preparation needed is shredding it into roughly fist-sized pieces and squeezing out the bulk seawater. No sorting by plastic type. No cleaning.

What Comes Out

  • Syngas -- a fuel gas made primarily of hydrogen (~44%) and carbon monoxide (~31%). This is the energy product. It gets burned in gas engines or turbines to produce electricity that powers the entire system. Plastic-derived syngas is roughly 36% richer than syngas from wood or biomass, because plastic is chemically very close to oil.
  • Vitrified slag -- a dark, glassy, rock-like solid similar to obsidian. This is what happens to the non-organic material (salt residues, sand, mineral deposits, pigments). It accounts for roughly 5-10% of input weight and is completely inert. Heavy metals are chemically locked inside the glass matrix at the molecular level. Independent testing consistently shows leachate concentrations 10-100x below hazardous thresholds. This slag could be used as construction aggregate, artificial reef material, or simply stockpiled for shore delivery.
  • Clean flue gas -- after multi-stage scrubbing (water quench, alkaline scrubbers, activated carbon filters), the exhaust is dramatically cleaner than incineration. Dioxin emissions at Japan's Utashinai plant measured approximately 100x lower than comparable incinerators.
  • Scrubber water -- moderate amounts of treatable wastewater containing dissolved salts and trace metals. Far less problematic than incinerator wastewater.

What Does NOT Come Out

  • No toxic ash (incineration produces two toxic ash streams -- plasma produces zero)
  • No dioxins or furans at meaningful levels
  • No microplastics -- everything is dissociated at the atomic level

How Much Can It Process?

The Sweet Spot: 25-50 Tonnes Per Day

Based on the track record of every plasma gasification plant ever built, we know that 25-50 TPD (tonnes per day) is the reliable operating range. To put that in everyday terms, that is roughly 1-2 shipping containers worth of compressed plastic per day.

Real-world reference points:

  • Yoshii, Japan -- 25 TPD, operational since 1999. One of the longest-running plasma gasification plants in the world.
  • Mihama-Mikata, Japan -- 25 TPD, commissioned in 2002. Built by Hitachi Metals using Westinghouse plasma torches.
  • Utashinai, Japan -- designed for 200-220 TPD, peaked at about 300 TPD. This is the largest plasma gasification plant ever built. It worked, but it was at the very edge of what the technology can reliably do.
The honest lesson from history: plants at 25-40 TPD work. Plants above 150 TPD have historically struggled or failed commercially. The Utashinai plant closed in 2013 not because the technology broke, but because Japan's improving recycling rates starved it of feedstock. The technology worked -- the business case changed.

What That Means for the Garbage Patch

The Great Pacific Garbage Patch contains an estimated 80,000 tonnes of surface plastic. At 50 TPD continuous processing, that is roughly 4.4 years of operation. But the GPGP also receives an estimated 1.15-2.41 million tonnes of new plastic inflow annually, so a single station would be fighting an uphill battle. The long-term vision requires multiple platforms or vessels.

Still, even one station processing 50 TPD would remove more plastic per year (about 18,000 tonnes) than any ocean cleanup operation currently in existence.

Energy: Does It Power Itself?

This is the most important question. If the energy loop closes -- if the system produces more electricity than it consumes -- then we have a self-sustaining ocean cleanup machine that never needs fuel deliveries. If it doesn't close, we need diesel generators or some other external power source running forever.

The Short Answer

Yes, the loop closes. And it is not even close.

The Long Answer

The plasma torch -- the part that generates the superhot plasma -- needs electricity to run. At small scale (10 TPD), it consumes about 800-1,100 kWh per tonne of waste. That is a lot of electricity. But here is the thing: ocean plastic is incredibly energy-dense.

Think of it this way. Plastic is made from oil. Chemically, polyethylene and polypropylene (which make up 55-65% of ocean plastic by mass) have an energy content of about 46 MJ/kg. Crude oil is about 42-47 MJ/kg. Ocean plastic is essentially solid petroleum. Ordinary household trash, by contrast, is only about 10-15 MJ/kg.

When you run this energy-dense feedstock through plasma gasification, the syngas produced contains far more energy than the torch consumes. The Utashinai plant in Japan -- the best real-world data point we have -- generated 7.9 MW of electricity and consumed only 3.6 MW internally. It exported the remaining 4.3 MW (54% of total generation) to the Japanese power grid. And that was running on ordinary household trash and car shredder waste, which has far less energy than ocean plastic.

A peer-reviewed study published in PNAS by researchers from Worcester Polytechnic Institute, Woods Hole Oceanographic Institution, and Harvard University calculated that in high-concentration zones of the GPGP, the energy surplus from processing collected plastic is 480% -- nearly five times more energy produced than consumed by the entire collection and processing operation.

Our own modeled scenarios for The Claw show:

ScaleDaily GenerationDaily ConsumptionSurplus
Prototype (5 TPD)~13,800 kWh~8,200 kWh+68% surplus
Full scale (100 TPD)~275,700 kWh~67,700 kWh+307% surplus
Pessimistic (100 TPD with 35% ocean penalty)~179,200 kWh~67,700 kWh+165% surplus
Even in our worst-case scenario -- where we assume a 35% energy penalty for wet, salty, biofouled feedstock -- the system still produces 165% more electricity than it needs. The surplus can power ship systems, water desalination, crew quarters, communications, navigation, and collection equipment.

What We Don't Know Yet

We have not tested this specific energy loop with actual ocean plastic feedstock. All the numbers above are modeled from real plant data and published research. The prototype phase exists specifically to answer this question with certainty. But the math is strongly in our favor -- the energy margin is so wide that even significant real-world losses would not close the gap.

How Big Is It?

One of plasma gasification's advantages is its compact footprint. The reactor itself is surprisingly small relative to what it can do.

The Reactor

The MAGS unit built by Terragon -- which processes 17-50 kg/hr and has been running on the MV Asterix since 2017 -- measures just 2.8m x 1.8m x 2m and weighs 4,400 kg. That is roughly the size of a large SUV. It processes up to one tonne per day in that footprint.

PAWDS, the plasma system on the USS Gerald R. Ford, is described by PyroGenesis as being 75-80% smaller than a conventional marine incinerator -- approximately five times more compact -- while processing 200 kg/hr. It was designed specifically to fit within the tight confines of a warship.

PyroGenesis also built a transportable 10.5 TPD plasma waste system (the PRRS) for the US Air Force at Hurlburt Field, Florida. This system was mounted on standard shipping containers (ISO containers), making it modular and transportable.

The Complete System

The reactor is only one piece. A full processing facility also needs:

  • Feed preparation -- shredders, dewatering equipment, conveyors
  • Gas cleanup train -- quench tower, scrubbers, filters, activated carbon beds
  • Power generation -- gas engines or turbines, electrical switchgear
  • Control room -- monitoring and automation systems
  • Storage -- slag collection, consumables (NaOH for scrubbers, activated carbon)
For a 5-10 TPD system, the gas cleanup train fits within a 20-40 foot equipment skid. The complete facility -- reactor plus gas cleanup plus power generation plus control room -- would occupy roughly the area of a tennis court to a basketball court (approximately 250-500 square meters of deck space). That is well within the deck area of even a modest commercial vessel.

For a 25-50 TPD system, the footprint grows proportionally but remains manageable. A complete 25 TPD facility, including all support systems, would likely require 500-1,000 square meters -- roughly the floor area of a large house or a small supermarket. Plasma gasification plants are notably more compact than conventional incineration or gasification facilities because the extreme temperatures allow smaller reactor volumes and produce less gas volume to clean.

What Would the Platform Look Like?

We have evaluated three main options for the physical platform. Each has real advantages and real drawbacks.

Option 1: Converted FPSO Vessel (Most Practical)

An FPSO (Floating Production, Storage and Offloading) vessel is a ship designed to process oil and gas at sea. These are floating factories with industrial processing equipment, power generation, chemical handling, crew quarters, and helidecks already built in. Hundreds exist, and many are being decommissioned as oil fields deplete.

Why it works: The fundamental engineering challenges (stability, power distribution, chemical handling, safety) are already solved. Self-propelled, large deck space, crew accommodation, and existing regulatory frameworks (ABS, Lloyd's, DNV-GL).

What it costs: Standard FPSO oil and gas conversions run $150-700 million, but our processing equipment is far simpler than oil and gas topside modules. Our estimate: $50-150 million total (hull acquisition plus conversion). This is probably our most practical path.

Option 2: Purpose-Built Vessel

The best example is The Manta by The SeaCleaners -- a 56.5-meter catamaran designed from scratch to collect and process ocean plastic, budgeted at approximately 35 million euros. Every system is optimized for the mission, but it is the most expensive option, the longest timeline (3-5 years minimum), and the highest risk since nothing is proven in combination until sea trials. We would consider this for Phase 3 or later.

Option 3: Converted Oil Platform or Rig

Thousands of offshore platforms are being decommissioned worldwide (the Gulf of Mexico alone faces a $38-40 billion decommissioning bill). These offer massive deck space (2,000+ square meters), robust structural capacity, and could be acquired cheaply -- potentially at a fraction of replacement value, since owners face expensive removal obligations. Converting an existing platform could cost as little as 10% of building equivalent new infrastructure.

The problem: not self-propelled (towing to the GPGP would cost millions), cannot reposition to follow plastic concentrations, and mooring in deep open ocean presents significant engineering challenges. This option makes more sense if the GPGP has a sufficiently dense, stable concentration zone that a fixed station can work. That is an open question.

What Does It Cost?

Capital Costs

Plasma reactor system: Industry data suggests capital costs of approximately $130,000-390,000 per TPD of capacity. So:

  • A 5 TPD prototype reactor: $650,000 - $2 million
  • A 25 TPD system: $3.25 million - $9.75 million
  • A 50 TPD system: $6.5 million - $19.5 million
These figures are for the reactor and plasma torches only. The complete facility -- including gas cleanup, power generation, feed preparation, controls, and integration -- roughly doubles the reactor cost.

Complete processing facility estimates:

  • 5 TPD prototype: $5-10 million
  • 25 TPD demonstration: $15-30 million
  • 50 TPD full scale: $25-50 million
Platform costs (vessel or structure, separate from processing equipment):
  • Converted FPSO: $50-150 million total (hull plus conversion)
  • Purpose-built vessel: $35-80 million (based on Manta-class estimates)
  • Converted oil platform: highly variable, potentially $10-50 million plus towing

Operating Costs

Electrode replacement is a significant ongoing cost. Cathodes last approximately 1,000 hours and anodes approximately 500 hours. PyroGenesis charges about $700,000-741,000 for replacement torch components (based on their US Navy after-sales contracts). Annual torch maintenance for a 25 TPD system would likely run $1-2 million.

Other operating costs include consumables (NaOH for scrubbers, activated carbon), crew, maintenance, and vessel operations. Total operating costs are estimated at $50-150 per tonne processed, depending on scale. This is comparable to incineration costs in developed countries ($69/tonne average in the US, $200-300/tonne in Japan and Europe).

Context: What Others Are Spending

  • The Ocean Cleanup has raised over $100 million and collected approximately 500 tonnes from the GPGP. That is collection only -- no processing. The plastic is shipped to shore for recycling.
  • The Manta (SeaCleaners) is budgeted at approximately 35 million euros for a purpose-built vessel with pyrolysis processing.
  • Gaia First has been seeking 750,000 euros for initial R&D for over five years, with no hardware built.
  • The US Navy paid $11.5 million for PAWDS systems on two aircraft carriers (CVN-80 and CVN-81).

Revenue Streams

This is not purely a cost center. Potential revenue includes:

  • Carbon credits -- destroying ocean plastic that would otherwise degrade into microplastics and release methane has a measurable carbon impact
  • Plastic credits -- an emerging market for verified plastic removal
  • ESG corporate partnerships -- companies with ocean plastic reduction goals
  • Slag sales -- vitrified slag as construction aggregate (modest but real)
  • Surplus electricity -- if co-located with other marine operations
  • Hydrogen production -- syngas can be converted to hydrogen via water-gas shift reaction and pressure swing adsorption. This is a Phase 3+ possibility, not a near-term revenue source.

Phased Approach

We are not proposing to build a $100 million platform on day one. The realistic path is phased.

Phase 1 -- Prototype (1-5 TPD) | ~$5-15 million

Goal: Prove the energy loop closes with actual ocean plastic feedstock.

This is the critical experiment. We know plasma gasification works on municipal waste. We know it works at sea on warships. We know ocean plastic has higher energy content than municipal waste. What we have not proven is the specific combination: plasma gasification of wet, salty, mixed ocean plastic in a marine environment, running self-sufficiently on its own syngas output.

Phase 1 could be done on land (coastal facility processing collected ocean plastic) or on a small vessel. A containerized system like PyroGenesis's transportable 10.5 TPD design -- which mounts on standard ISO shipping containers -- could be adapted for this purpose. Timeline: 12-18 months from funding to operational data.

Phase 2 -- Demonstration (10-25 TPD) | ~$20-60 million

Goal: Full vessel deployment, six to twelve months of continuous operation in or near the GPGP. A converted vessel carrying a complete plasma gasification system with gas cleanup, power generation, and collection equipment. Phase 2 proves the logistics: crew rotation, resupply, equipment maintenance at sea, weather downtime. It also generates the data needed for regulatory approval and investor confidence.

Phase 3 -- Full Scale (50-100+ TPD) | ~$80-200 million

Goal: Actual cleanup at scale -- removing 18,000-36,000 tonnes of plastic per year. Multiple 25-50 TPD vessels or a single large platform at 100+ TPD. At this scale, advanced options become viable: Fischer-Tropsch synthesis (converting syngas to diesel), hydrogen production, and combined cycle power generation.

What Has Already Been Proven

We are not starting from zero. Significant pieces of this puzzle have already been demonstrated in the real world, on real vessels, under real operating conditions.

  • PAWDS on aircraft carriers -- PyroGenesis's Plasma Arc Waste Destruction System has been operational on the USS Gerald R. Ford since October 2022. It processes 200 kg/hr of mixed waste at 5,000-10,000 degC with virtually zero visible emissions. The US Navy has committed to PAWDS on all four Ford-class carriers. After-sales orders in 2023 and 2024 confirm it is actively used and maintained. This is not a demo -- it is operational military hardware on a moving warship.
  • MAGS on naval and cruise vessels -- Terragon's Micro Auto Gasification System has run on Canada's MV Asterix since December 2017 -- over eight years of proven naval operation. It processes up to one tonne per day and is energy self-sustaining (produces ~2,400 kWh/day from waste). Also deployed on Princess Cruises and Seabourn ships. Critically, Terragon created the IMO regulatory category for shipboard gasification (approved May 2015). That framework now exists for any future system, including ours.
  • InEnTec -- 13 systems worldwide -- their Plasma Enhanced Melter technology has operated for 20+ years, with a verified 99.99999999% destruction rate for PCBs. The gold standard for toxic waste destruction.
  • Japanese municipal plants -- Yoshii (25 TPD, since 1999), Mihama-Mikata (25 TPD, since 2002), and Utashinai (200-220 TPD, 2003-2013) provide years of reliable operational data and the best published energy balance figures.
  • Hurlburt Field (US Air Force) -- PyroGenesis's transportable 10.5 TPD system, mounted on shipping containers, has operated since 2011 generating 420 kW from syngas.

What We Still Don't Know

Honesty about gaps matters. Here is what the prototype phase is designed to answer:

  • Actual syngas yield from real ocean plastic -- wet, salty, biofouled, mixed polymer feedstock has not been tested in a plasma gasification system. The modeled numbers are favorable, but models are not data.
  • Salt's effect on electrodes -- marine air and salt-contaminated feedstock may accelerate electrode erosion. We don't know how much.
  • Optimal dewatering method -- how much energy does it take to get ocean plastic from dripping-wet to reactor-ready? We have estimates. We need measurements.
  • Fishing net shredding -- tangled nylon nets are mechanically difficult. Shredder design and energy consumption need real-world testing.
  • Marine biofouling impact -- barnacles, algae, and microorganisms on the plastic add a small biomass fraction. This probably helps (biomass gasifies readily) but has not been quantified.
  • Full system integration at sea -- collection, processing, and power generation have all been proven individually. Integrating all three on one platform in open ocean has not.
These unknowns are exactly why we propose a phased approach. Phase 1 exists to convert these question marks into data points.

Sources