Oct 30, 2008

CO2 to fuels processes - II

Recently Carbon Sciences, featured in an earlier article on this blog revealed the source of hydrogen for their CO2 to fuels process.
"Dr. Naveed Aslam, inventor of the company's technology and chief technology advisor, commented: "Unlike other CO2 to fuel approaches, Carbon Sciences' technology does not use molecular hydrogen (H2) because the creation and reaction of H2 is very energy intensive. Rather, the company's approach is based on a low energy biocatalytic hydrolysis process where water molecules (H2O) are split into hydrogen atoms (H) and hydroxide ions (OH) using a biocatalyst. The hydrogen atoms (H) are immediately used in the production of hydrocarbons and the free electrons in OH are used to power the various biocatalytic processes." "Our technology is not based on photosynthetic plants where sun light is used to drive biofuel production reactions, such as in algae. Instead, it is based on natural organic chemistry processes that occur in all living organisms where carbon atoms, extracted from CO2, and hydrogen atoms extracted from H2O, are combined to create hydrocarbon molecules using biocatalysts and small amounts of energy. Our innovative technology allows this process to occur on a very large industrial scale through advance nano-engineering of the biocatalysts and highly efficient process design," concluded Dr. Aslam."
My opinions given below:
Understandably Carbon Sciences is justified in not fully revealing the details . However, the splitting of water to produce protons (H+) and hydroxide ions (OH-) still consumes energy. All the biocatalyst does is to speed up this transformation. It cannot influence the thermodynamics (feasibility) of this reaction. Judging by what the release says, I think that there is a sacrificial oxidant (something which gets oxidized, ex: simple sugars, providing the energy to drive the splitting of water) involved.

Related links:
Opinion: CO2 to fuels processes
Carbon Sciences Announces Prototype Plan for CO2-to-Fuel Technology

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Oct 22, 2008

PBS Frontline: Heat

Global Warming, can we roll it back?
Image courtesy of PBS.org

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Oct 21, 2008

Analysis: Algae for carbon dioxide (CO2) capture

Summary
This post describes a simplified economic analysis of an algal biofuel technology that converts carbon dioxide (CO2) from cement plants into (potentially) useful algal oil. I examined various key factors such as CO2 offset price, price of algal oil, and productivity that affect the profitability of such a process.

Based on my analysis I conclude that the single most important factor that affects the economics of CO2 capture is the algal biomass yield (mass produced/unit area). Doubling the productivity (and the CO2 offset) per hectare decreases the payback time by 50 % (15 years to 7 years).

Disclaimer: This is not a critique of the specific algal biofuels process proposed. CO2 mitigation using algae is one of the answers to our grand energy challenges, and we must continue to address these issues.

Assumptions:
The Holcim plant in Jerez likely produces a fraction of the total 5.1 million tonnes of cement per annum (5.1 MTPA). (A cement plant in India I worked at produced 2.6 MTPA, and it was the largest in Asia at that time. Not having first-hand data for this specific facility, lets assume that this plant is 1 MTPA, for the sake of comparison. The exact production does not alter the results significantly).

Cost of algal oil: 4 $/gal
Price of carbon offsets: 15 Euros/T CO2 (20 USD/T CO2)
(A high-cost scenario for algal oil and carbon offsets would be 6$/gal, 50 $/T CO2. This is also addressed in the analysis.)

Data:
Each lb of cement produces 1.0 lb of CO2 (U.S. average, pg.10).
Total CO2 to be mitigated annually by 2011: 50,000 T in 100 ha (0.05 MTPA
CO2 in 100 ha) .
Algal biofuel production: 1.3 million gallons/year

Calculations:
Total CO2 production: 1 MTPA
By 2011, the 100 ha. facility would mitigate 50,000 T of CO2 (0.05 MTPA CO2). This would be 5% of the CO2 emissions (if the Jarez facility production is 1 MTPA)
Average CO2 use of algae: 0.0005 MTPA/ha.
Revenues from algal biofuel: 5.2 million $/year
Revenues from carbon offsets: 1 million $/year
Total revenues: ~6 million $/year

Results
Capital cost of algal facility: $ 92 million/0.05 MTPA
CO2.
Area needed for 5% of the cement plant's CO2 output (assuming 1 MTPA production): 543 U.S. football fields (5.4 football fields = 1 ha.)

Payback on investment: 92/6 =~ 15 years. In comparison, typical payback for a new chemical plant is ~ 7 years.

Higher CO2 prices (50 $/T CO2), decrease the payback period by ~ 3 years. Higher algal oil prices (6 $/gal) and 20 $/T CO2 prices will result in a payback period of approximately 11 years.

Higher oil and higher CO2 prices will lower this period (11 yrs) by an additional ~2 years. However, doubling the productivity (and the CO2 offset) per hectare decreases the payback time by 50 % (15 years to 7 years).

The revenues from algal biodiesel + carbon offsets will be partly offset by the parasitic losses from the power plant to run the system. I don't have a feel for how much these utility costs would be. Any comments, anybody?

Bottomline The single most important factor that affects the economics is the productivity of algal biomass/unit area. Doubling the productivity (and the CO2 offset) per hectare decreases the payback time by 50 % (15 years to 7 years).

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Oct 17, 2008

Synfuels (CTL, OTL, GTL, BTL, XTL) Round-Up

Given below is a compilation of the latest news, analyses and resources on synthetic fuels from hydrocarbons (coal-to-liquids, biomass-to-liquids, gas-to-liquids, oil sands-to-liquids)
Analyses


The Impacts of Synfuels (CTL,GTL, BTL, OTL) on World Petroleum Supply

RAND Study Concludes Oil Sands Synthetic Crude Can Be Cost-Competitive with Conventional Petroleum Even Over a Wide Range of CO2 Prices

New Life-Cycle Analysis Concludes Neither GTL or CTL a “Reasonable Path” for Energy Security With Reduced GHG Emissions

Study Suggests “Flexible Carbon to Liquid” Fuel Process Could Displace 15-20% of Transportation Fuels in the US

The tale of two synthetic fuels & Using champagne to make beer

News

Australia:
Linc Energy Begins Producing GTL Liquids from Underground Gasification Syngas

South Africa:
Biofuels singled out as 'best option' for alternative fuels in SA

USA:
Synfuels Converts Natural Gas to Gasoline to Cash

New Route to Hydrocarbon Biofuels: A simple catalytic process converts plant sugars into gasoline, diesel, and jet fuel.

Synthesis Energy Systems Options Up to 15 Methanol-to-Gasoline Technology Licenses for Coal-to-Gasoline Projects

Researchers Propose Dual-Bed Configuration to Increase Efficiency and Reduce Emissions from Coal Gasification

China:
Shenhua Ningxia Coal Group boosts CTL project with Sasol

Is it the end of the line for coal-to-oil in China?

India:
Sasol mulls dlrs 8bn India CTL plant

UK:
Small Scale FT Contract with Thai National Oil Company

Resources:

Diesel Fuel from Bolivian Natural Gas by Fischer-Tropsch Synthesis using Nitrogen-rich Syngas

DOE Releases Feasibility Study for Small-Scale Conceptual Coal-to-Liquids Facility in Appalachian Basin : Technical and Economic Assessment of Small-Scale Fischer-Tropsch Liquids Facilities

An Engineering-Economic Analysis of Syngas Storage

Small-Scale Fischer-Tropsch

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Oct 15, 2008

News: Cleaner technologies for coal at Penn State

Structural representation of a South African intertinite-rich Highveld coal. Carbon atoms are green, oxygen atoms are red, and sulfur atoms yellow. Courtesy of Daniel van Niekirk / Jonathan Mathews

Research at Penn State (RPS) recently did an extensive article on current clean-coal research at Penn State. Featured were the following:
  • Direct liquefaction of coal to produce jet fuels (JP-900).
  • Better molecular models for coal, CO2 sequestration in coal seams.
  • Understanding coal reactions using femtochemistry.
  • Adapting existing refineries for coal conversion.
  • Making more comprehensive use of coal, producing value-added compounds.
  • Molecular-basket adsorbents to capture CO2 from flue gas streams.

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