Tuesday, February 19, 2019

Utilizing Renewable Methanol to Power Electric Commuter Aircraft

A Firefly ATR 72 (Credit: Wikipedia/Ken Fielding)

by Marcel F. Williams

Renewable methanol (methyl alcohol) is a hydrocarbon fuel that can be derived from the synthesis of carbon dioxide (CO2) and hydrogen. Methyl alcohol can also be synthesized from syngas derived from the pyrolysis of hydrocarbon waste. The production of renewable methanol from both methods can be powered by carbon neutral electricity from both nuclear and renewable energy resources.

CO2 can be extracted directly from the atmosphere or from the flu gases of a power plant using a renewable hydrocarbon fuel. Hydrogen can be produced from the electrolysis of freshwater, seawater, brine, or from desalinated water derived from seawater or brine.

Methanol can be synthesized from the syngas resulting from the pyrolysis of urban and rural biowaste and hydrocarbon waste of non-biological origin such as polymers.

Twenty million tonnes of methanol is produced annually, predominantly from fossil fuels, mostly as an industrial chemical precursor. But methanol has been used as a fuel or as a fuel additive for buses, automobiles, and even marine vessels. And methyl alcohol could also be used to power commuter passenger aircraft.

In 2018, a Department of Energy report from Grigorii Soloveichik suggested that commercial-- propeller air transports-- modified to use fuel cells, batteries, and sustainable fuels could reduce propeller airplane energy usage by 40 to 60%, emissions by 90%, and aircraft noise by 65%.

An ATR 72 propeller commuter aircraft, for example, has a cruise speed of 317 mph (510 km/h) and a range of 949 mi (1528 km) using kerosene derived fuels such as Jet A, A-1/JP8, JetB/JP4, and JP5/JP1.

The Department of Energy report determined that utilizing fuel cells and batteries to power the propellers of an ATR 72 could substantially increase the range of a modified aircraft if it used methanol, biodiesel, ethanol, dimethyl ether, or ammonia. Utilizing renewable methanol could give a modified ATR 72 a range of 1800 miles (2900 kilometers).

Fuel cell efficiency 55%, battery round trip efficiency 90%, energy consumption 4.6 kWh/mile for regional aircraft (Credit: Grigorii Soloveichik, DOE)

Because of mounting expenses and regional and political infighting, the governor of California's, Gavin Newsom, had no choice but to curtail the first component of California's high speed rail line to the San Joaquin Valley area, spanning between the small California cities of Merced, Madera, Fresno, Kings/Tulare, and Bakersfield.

With 12 to 25% of people in the US having some level of anxiety when it comes to flying, high speed rail could accommodate the regional transportation needs of up to 82 million Americans. And if the electric grid supplying the power is utilizing nuclear or renewable resources, high speed rail could accommodate regional transportation needs without adding excess greenhouse gasses to the atmosphere.

However, the utilization of carbon neutral renewable methanol in electric commuter aircraft could accommodate the regional transportation needs for the other 246 million residents of the United States. In California, commuter aircraft using renewable methanol could operate out of smaller airports throughout California, transporting commuters, for instance from Oakland Airport to Hollywood Burbank (Bob Hope) Airport in less than 90 minutes and to Lake Tahoe Airport in less than a half hour.

Notional Methanol Fuel Cell/Battery ATR 72 Regional Destinations from Oakland, CA Airport (510 km/hr cruise speed)

Less than 30 minutes:

Lake Tahoe, CA - 237 km

Fresno Yosemite Airport - 244 km

Less than one hour:

Reno, Nevada - 287 km

Mammoth Yosemite Airport - 297 km

Eureka, CA - 369 km

Bakersfield, CA - 397 km

Santa Barbara, CA - 442 km

Less than 90 minutes:

Burbank, CA - 522 km

Long Beach, CA - 567 km

Las Vegas, Nevada - 652 km

San Diego, CA - 716 km

Lockheed Martin airship (Credit: Lockheed Martin)

A new generation of airships using fuel cells, electric batteries, and renewable methanol could also play a role in regional transportation. Lockheed Martin is developing a diesel powered airship with a cruise speed of 69 miles per hour (111 km/h) and a range of 1616 miles (2,600 kilometers). Modifying the Lockheed Martin airship to use fuel cells, batteries, and renewable methanol could make such vessels carbon neutral while greatly expanding their range.

Notional Methanol Airship Destinations from Downtown San Francisco (111 km/hr cruise speed)

Less than 30 minutes

SFO (San Francisco International Airport) - 20 km

Oakland International Airport - 20 km

Vallejo, CA - 36 km

Less than 60 minutes:

San Jose, CA - 68 km

Santa Rosa, CA - 78 km

Santa Cruz, CA - 96 km

Stockton, CA - 101 km

Less than 90 minutes:

Sacramento, CA - 120 km

Modesto, CA - 126 km

Monterey, CA - 137 km

While renewable jet fuels are destined to replace jet fuel from petroleum, and renewable hydrogen will be essential for the coming generation of supersonic and hypersonic jet planes that will dramatically cut intercontinental flight times, renewable methanol could play a dominating role in the new age of airships and commuter airplanes.

Links and References

Electrified future of aviation:batteries or fuel cells?