{
    "title": "Coal Fuel Cell",
    "inventor_name": "John Zhu",
    "publication_year": 2009,
    "device_name": "Direct Carbon Fuel Cell (DCFC)",
    "goal": "Generate electricity from coal with twice the power efficiency while minimizing greenhouse gas emissions.",
    "problem_addressed": "Low efficiency and high CO_2 emissions of conventional coal-fired power plants.",
    "concept_summary": "A direct carbon fuel cell that uses a carbon (or carbon composite) anode, a metal-oxide cathode, and a low-medium temperature ceria-based electrolyte. Coal and air react electrochemically to produce electricity and pure CO_2 as a by-product.",
    "detailed_description": "The invention consists of a power-molded button cell with the electrolyte sandwiched between a carbon-based anode and a metal-oxide cathode. The electrolyte is a single or double-phase low-medium temperature ceria composite. Pressed sheets of anode and cathode are 1-2 mm thick. When operated at 600-650  deg C the cell delivers about 0.25 W cm^-^2, roughly twice the performance of comparable cells reported in the United States, and produces pure CO_2 that can be captured easily.",
    "category": "Fossil Energy Technologies",
    "principles": [
        "Electrochemical oxidation of carbon",
        "Fuel-cell operation",
        "High-temperature ceramic electrolyte ion transport"
    ],
    "scientific_domains": [
        "Chemical engineering",
        "Electrochemistry",
        "Materials science"
    ],
    "mechanisms_of_action": [
        "Carbon oxidation at the anode releases electrons",
        "Oxygen reduction at the cathode consumes electrons",
        "Oxygen ions migrate through the ceria electrolyte"
    ],
    "materials": [
        "Carbon (or carbon composite)",
        "Metal oxide (cathode)",
        "Ceria composite electrolyte"
    ],
    "energy_sources": [
        "Coal"
    ],
    "inputs": [
        "Coal (carbon)",
        "Air (oxygen)"
    ],
    "outputs": [
        "Electricity",
        "Carbon dioxide (CO_2)"
    ],
    "claimed_performance": "~=0.25 W cm^-^2 at 600-650  deg C, about twice the performance of similar fuel cells.",
    "experimental_evidence": "Prototype testing showed the cell delivering twice the power from coal and achieving 0.25 W cm^-^2 at 600-650  deg C.",
    "replication_status": "Prototype tested by the research team; no independent replication reported.",
    "keywords": [
        "direct carbon fuel cell",
        "coal",
        "high efficiency",
        "CO_2 capture",
        "ceria electrolyte"
    ],
    "related_technologies": [
        "Solid oxide fuel cell",
        "Carbon capture and storage"
    ],
    "controversy_level": "low",
    "confidence_score": 0.9,
    "practicability_score": 0.6,
    "fringe_score": 0.2,
    "evidence_strength": 0.5,
    "risk_score": 0.2,
    "trl_estimate": 5,
    "source_urls": [],
    "organizations": [
        "University of Queensland"
    ],
    "applications": [
        "Power generation",
        "Industrial electricity",
        "Carbon capture"
    ],
    "limitations": [
        "Requires high operating temperature (600-650  deg C)",
        "Scale-up and cost of ceramic electrolyte",
        "Dependence on coal supply"
    ],
    "open_questions": [
        "Long-term durability of the ceramic electrolyte",
        "Economic competitiveness versus conventional power plants",
        "Integration of captured CO_2 storage"
    ],
    "red_flags": [],
    "evidence_quotes": [
        "The very high-energy efficiency of the new technology will effectively halve the amount of coal required to create electricity.",
        "The DCFC produces pure carbon dioxide as a byproduct, making it much easier to manage.",
        "The invention can get the best performance about 0.25 watts per square centimeter under the temperature of 600 to 650 degrees centigrade, which is two times above the performance of such fuel cell according to a report from USA and has reached the international leading level."
    ]
}