8. Wood Syngas Allam Cycle BECCS Power Plant
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Wood Syngas Allam Cycle BECCS Power Plant
(Shown with already developed coal syngasifier as a possible beginning prototype to build off) 
(The largest biomass gasifiers seem to be 1,000 ton-per-day wet MSW (Metropolitan Solid Waste [domestic garbage]) plasma torch gasifiers for providing gas to sub-100 megaWatt electricity generating turbines.)
(Over 100 mW we find boatloads of U.S. wood pellets recently replacing pulverized coal in European power plant boiler installations.)
(At the moment, it looks like I would have to use several 1,000 ton-per-day plasma units for base load and supplement them with natural gas for peaks.)
Midwest Regional Carbon Sequestration Partnership: 

(NOTE: "LHV" means lower heating value, "HHV" means higher heating value. Coal and lignite might come out this way because of their different starting heat values.)

Allam cycle is natural gas-only. Solid fuels such as wood need a solid-to-gas gasification module. 

(If we can figure out how to make money at it.)

Reference: REPORT ON CONVERSION EFFICIENCY OF BIOMASS - VER #2 - JULY 2015 - Intelligent Energy Europe Programme of the European Union (2.883.02)
Reference: Biomass Energy sheet from Georgia Forestry Commission. (2.201.01)

Major CO2 questions are:

1. "How many tons of trees will it take for Allam Cycle electricity generating stations to remove sufficient Climate Changing CO2 from the air to roll back the CO2 level from today's 415 ppm to a far safer 350 ppm?

2.  Assuming zero future CO2 emissions, how long might that take?

3. "How many tons of trees will it take to keep the CO2 ppm figure stationary at today's rate of CO2 emissions?


General items about biomass thermal energy and biomass energy economics.

12,000 green tons/year/megawatt ($2,220,000 ) required for biomass-to-electricity or 3,600,000 green tons/year ($666,000,000 pellets) for a 300 megaWatt plant. ($185 /ton, densified pellets, retail, delivered by truck, in purchaser's storage bin.)
At a typical wholesale price for electricity of $50 per megaWatt hour that's $1,200 a day. For a 300 megaWatt plant that would be = $360,000 /day times 365 days/year = $131,400,000 /year.

Green Wood chips are 4,300 btu/pound or 8,600,000 green ton.

BTUs or British thermal units measure the energy in natural gas. One BTU equals the heat required to raise the temperature of one pound of water 1 degree Fahrenheit.
The amount of heat in a burning wooden match is roughly equal to one BTU. A cubic foot of natural gas has 1,015 BTUs
1 megaWatt-hour of electricity = 3,409,510 Btu.

An Allam Cycle engine running on natural gas is claimed to be 60% efficient - meaning a megaWatt-hour of electricity, which contains 3,409,510 Btu, would consume 3,409,510 Btu/.60 efficient or
 5,682,165 Btu / 1,015 Btu per cubic foot or 5,598
ft3 of natural gas per megaWatt-hour of electricity.

Biomass electricity power plants built in Europe over the last 5 years have a thermal efficiency averaging 30%.

Converting a solid fuel such as coal or lignite to synthetic natural gas appears to reduce the efficiency of the Allam Cycle engine from 60% for natural gas to 50% for coal or lignite.

Converting wet wood pellets to synthetic natural gas may cause a similar reduction in efficiency or 3,409,510 Btu / .50 efficient  or 6,819,020 Btu / 1,015 Btu per cubic foot or 6,718 ft3 of synthetic natural gas per megaWatt-hour.


The Toshiba Allam Cycle power plant will be rated at 300 megaWatts, a substantially large electricity power plant unit. Running on wet wood pellets, it might consume 300 mW-h x 6,718 ft3 or 2,015,400 ft3 of synthetic natural gas per hour running at full output.

The cost of wood pellet fuel is usually given in dollars per ton; the average price of the fuel is typically around $250 per ton.  Quality wood pellets at 5-10% moisture content have a heating value of about 16,500,000 British Thermal Units (BTUs)/ton.

The Georgia Forestry Commission says 7,750 Btu per lb for wood pellets, 4,300 Btu per lb for green wood, and 9,000 Btu per lb for oven dried wood.

An 80-foot hardwood tree with a 24-inch diameter can weigh as much as 20,000 pounds [50 trees/hr?], a 50-foot pine tree with a 12-inch diameter will only weigh as much as 2,000 pounds [400 trees/hr?].

Please take a look at the youtube video presentations listed below. You can't get easier-to-understand presentations faster. And very few commercials.

     The company:     
     Articles About:             supercritical carbon dioxide (sCO2) cycles
     This website's pages:  3a Natural Gas or Oil Allam Cycle CCS Power Plant          3b Coal or Lignite Allam Cycle CCS Power Plant          Similar Technologies

This new type of power plant, located over a CO2 disposal region, would burn trees originally planted to remove Climate Change CO2 from the air, store their CO2 underground, and sell the electricity.




The basic Natural Gas burning Allam cycle module.
"ASU" means "Air Separation Unit". The ASU contributes oxygen from the air to the CO2 working fluid for combusting the natural gas in CO2 (1). First time I've encountered this.
To me, it's basically a rocket engine connected directly to a single stage steam turbine. The CO2 and steam water are then separated in (4), the water separator.
Most of the exhaust of a rocket is steam - recall all the white?

For details of proposed coal processing components see pdf 2.301.02

A leading chemical engineer, Rodney Allam, has invented a new fossil-fuel powered thermodynamic cycle for power plants. It has been named the "Allam Cycle".  It's emissions are sequestration grade and pressure CO2, potable water, industrial grade argon gas, and industrial grade nitrogen gas - each coming out of their individual exhaust pipes.  A 1/10th size pilot plant has been constructed in LaPorte, Texas (near Houston) and has been connected to the Texas electrical grid, providing 25 megaWatts of electricity since last October. As far as I know, so far, so good.

This new technology has the potential of economically powering the reduction of fossil fuel greenhouse gas emissions to net-zero by 2050 by powering the manufacture of biomass-based net-zero replacements for fossil fuels such as gasoline, diesel, jet fuel, and natural gas. Since fossil fuel is available everywhere, these fuel factories can be located anywhere both biomass and CO2 sequestration strata exist. Mankind can then consume the world's remaining fossil fuel by using it to power the manufacture of net-zero fossil fuel substitutes.

Dubbed the "Allam Cycle", it exploits the thermal and pressure characteristics of supercritical liquid carbon dioxide and water - instead of pure steam, air, or helium - as its working fluid. Relatively simple and 59% efficient, it uses an external rocket-engine-like oxygen+methane combustor instead of a water boiler. The combustor directly drives a simple high-temperature gas turbine-generator with a blast of CO2 gas and steam. It can be powered by any methane-gasified fossil fuel, i.e., natural gas, oil, coal, lignite. The only emissions are pure high pressure liquid CO2 ready for underground disposal and pure liquid fresh water, industrial grade nitrogen gas, and industrial grade argon gas, each coming out of the Allam engine contained in it's own pipe. If renewable fuels are used and sequestered, the Allam engine would produce carbon-negative CO2 emissions.

It should be noted that the super-clean, fossil fuel versatile, Allam Cycle 30 mW(e) grid-connected pilot plant - a new form of Oxy-fuel carbon capture - is performing well and appears economically competitive all the way down to non-CCS Lignite.

The first mass production Allam cycle power plant will be a 300 mW(e) single turbine version made by Toshiba, possibly as soon as 2021. "While the challenges remain significant and require a focused research effort, there donít appear to be any show stopping problems to commercialization of this technology." - P.A. Strakey, et al., 2014. 

Toshiba will manufacture the 300 megaWatt full size version. In addition to the 300 megaWatts of grid electricity, it might produce as much as 1 million gallons of potable water per day and 5% CO2 by volume. The Allam's oxyfuel combustor is pretty close to a rocket engine. Think of the massive white plume of steam coming out of a oxyfuel rocket engine as it lifts off.

Perhaps Toshiba could license their design to the world's top power plant companies to ultimately make 10 to 20 thousand 300 mW copies in the next 10 to 20 years. The coal and lignite versions would need an additional gasification module. Shutting down all the world's conventional coal plants would really pull the rug out from under Climate Change.

To this author, this achievement may open the door to halting the 100 million tons of CO2 the world adds to the air every day via unconfined fossil fuel burning and perhaps also halt most of the current plans for building over 1,600 new large conventional coal power plants in 62 countries    [Urgewald's tally], replacing conventional air polluting coal power plant plans with plans for environmentally safe Allam cycle gasified coal power plants instead. (Recall pre-WWII "Town Gas" made from coal?)

Once fossil fuel CO2 addition to the air is halted by substituting the use of environmentally safe carbon-neutral renewable fuels instead of fossil fuels, CO2 subtraction from the air can begin with the goal of eventually restoring the air to the way it was before the beginning of the first fossil fuel age.   




I've been aware of what power plant steam turbines should look like since 1956. This is the fattest turbine I've ever seen. Supercritical carbon dioxide must pack a heck of a wallop.
Look at all those bolts holding it together.

A typical power plant turbine has three-stages of pressure: High, Medium, and Low. This unit has only a single stage and it's way small for the power it is putting out. Conventional is the size of a school bus, this is the size of an SUV.






Below: Close, but no cigar!  


Around 2010, there were several supercritical CO2 engines in various stages of development out there in the Kimberlina, California, sand and bushes.
The Allam cycle engine appears to have captured both the technical and market leadership at this time (2018).


This image appeared on this website several years ago when Nancy Pelosi was previously speaker of the House.  At the time, a couple of gas-fired combined heat and power units were being proposed to replace the coal boilers in the Capital Complex Boiler House and I was suggesting to the world we add a carbon capture unit to make the U.S. Capitol the world's first carbon-neutral Capitol.

This is a good example of a current state-of-the-art "Post-combustion Carbon Capture" application.
At 90% carbon capture for 130% capital, fuel and power output loss, that amount of parasitic burden is about as good as can be expected for non-Allam technology BUT it can be installed anywhere and everywhere and used on existing equipment to clean up environmentally dirty sites.



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(The image above is from a different web site and will eventually be corrected.)