Carbon negative energy

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Andrew Lockley

Jan 16, 2016, 8:34:03 AM1/16/16
to geoengineering

January 15, 2016

Science Friday - Carbon negative energy

Giana Amador

Welcome back to Science Friday — our weekly blog post that links you to the most recent and relevant academic research on carbon removal. This week, we're focusing on the energy sector. Take a look at some of the research fresh from the new year and don't forget to let us know your thoughts in the comments! 

Nature Energy released their first issue and with it came two important pieces with thoughts on carbon removal.

First, this piece from Daniel L. Sanchez and Daniel M. Kammen explores a commercialization strategy for carbon-negative energy through the advancement of bioenergy with carbon capture and storage (BECCS). Citing the few BECCS facilities in existence today and the flexibility of thermochemical conversion of biomass, Sanchez and Kammen not only call upon government and industry to take action to develop and refine these technologies, but also give them a policy/technology roadmap to do so. This short piece is worth a read!

Next, David Reiner's research explores the world of CCS demonstration projects, outlining how far we have come and what work still needs to be done to meet global climate commitments. Reiner calls for a renewed commitment to CCS demonstration despite high costs, and emphasizes the need for a globally coordinated portfolio of demonstration projects that "learn through diversity." While not solely focused on carbon-negative CCS systems, Reiner's research could be important to the future of BECCS technology as the world begins to bring down costs of and de-risk CCS generally.

In Nature Climate Change, Pete Smith et. al,in "Biophysical and economic limits to negative CO2 emissions," lays out the needs for and limits to carbon removal systems generally. With some great graphics, Smith emphasizes the distinctive constraints between carbon removal technologies, particularly when it comes to the differences between BECCS and direct air capture systems. Read more about the water, economic, land use, energy, and nutrient tradeoffs in his article. 

Brian Cady

Jan 17, 2016, 1:35:07 PM1/17/16
to geoengineering
An example of carbon-negative energy sources becoming available:


Greg Rau

Jan 17, 2016, 2:10:52 PM1/17/16
to, geoengineering
More specifically, from the website:
"While today’s APL Power Pallets produce a relatively small amount of biochar byproduct (around 5% of input mass), it is still enough for modest carbon negativity in the fuel cycle. The round rule of thumb numbers are as follows:
1 tonne of dry biomass in produces about 1Mw/hr of electricity and 50kg of carbon byproduct.

50kg of raw carbon once recombined with O2 is the equivalent of 185kg of CO2 in the atmosphere. (mass C x 3.67 = mass CO2)

1 tonne of biomass input to the gasifier can soil-sequester the equivalent of 0.185 CO2 tonnes in the atmosphere.

Avoided CO2 emissions from not burning fossil fuel in the process are added to the wins above."

Question: How much of the nutrients in the biomass are returned to the soil and how much are sequestered/volatilized/lost, i.e is this sustainable?


From: Brian Cady <>
To: geoengineering <>
Sent: Sunday, January 17, 2016 4:34 AM
Subject: [geo] Re: Carbon negative energy

An example of carbon-negative energy sources becoming available:


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Peter Flynn

Jan 17, 2016, 5:27:42 PM1/17/16
to,, geoengineering

Nutrient balance is an important and interesting question, but not simple.


Imagine collecting straw or corn stover for power generation, vs. letting it rot on the field. If left, then of the three major nutrients, K, P and N: phosphorus can be expected to stay in place. However, many soils have an excess of phosphate, enough in some areas to pose a health issue if it impacts drinking water supply. Potassium may return to the soil, but might be transported in runoff, depending on local precipitation patterns and very local topography. Nitrates are subject to runoff, and can be reduced back to nitrogen by bacterial action on surface biomass, notably in the spring (which is why in some agricultural areas grass seed is aerially sprayed in the fall, to move the nitrate in the grass, above the soil level, until spring plowing buries the grass). Hence the loss of nutrients from biomass collection is subject to local analysis.


Biomass processing moves the nutrients away from the field. Ash can be recycled, at a cost, although not if char is buried (assuming the ash remains in the char). Nitrogen would have to be made up. If a dollar value is placed on carbon emission avoidance or negative carbon, it will overwhelm the cost of the incremental nitrogen requirement, since for agricultural crops there is already a fertilizer application, only the dosage is increased: the sole cost is the nitrogen itself.


Peter Flynn


Peter Flynn, P. Eng., Ph. D.

Emeritus Professor and Poole Chair in Management for Engineers

Department of Mechanical Engineering

University of Alberta

cell: 928 451 4455

Ronal W. Larson

Jan 17, 2016, 9:06:12 PM1/17/16
to Jim Mason, Geoengineering, RAU greg,,
Jim and list - with 3 ccs:

The following 3 e-mails all came in today to the “geo” list.  Could you add a little more on where you are with char production at All Power Lab (APL)?  I see a nice char-oriented write-up at the IBI site (,  but that is probably out-dated and your material at says that there is nothing char-oriented now available.  

Your news letter says you were at COP21 and, but I haven’t seen a wrap-up from you that would lend particular encouragement to this “geo” list about APL and CDR.

Also, Greg below talks of 5% char, but at, footnote 2 says 15%.  Yhat are your present best estimates on how you would design in this same 20 KW package - say if there was a $30/tonne CO2 credit ($100/tonne biochar)?

Peter Flynn below offers some thoughts on N, P, K issues for biochar.  Anything to report from APL on these topics?

To others - 

I first met Jim in Boulder in 2009 at the first US biochar conference - and we’ve visited at several other biochar conferences since.  I have been several times to his assembly facility in Berkeley - and am impressed on the steady growth of this small firm (that can be seen at many different other parts of the APL site).
APL has competitors.

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