Junk or treasure? Looking at carbon monoxide and LanzaTech

October 15, 2014 |

Siemens und LanzaTech wollen Bioethanol aus Stahlwerksabgasen erzeugen / Siemens and LanzaTech partner to transform steel mill off-gases into bioethanolA blogger levels an explosive set of charges at LanzaTech: “Khosla’s latest gangrene venture”, “thermodynamic junk”, “gangrene fake company”.

Alleges that US Secretaries of Energy Moniz, Chu and Bodman were “bought out by special interests”. Why? What’s going on?

We lay out the complete story, and look at the data, as LanzaTech responds. 

In a note regarding LanzaTech circulated to several journalists and academics on October 11, blogger Lindsay Leveen wrote:

“I have a question besides the bull crap of the technology.  If the CO at the steel mill was combusted in a turbine to produce electricity at say 40% efficiency instead of going through the lonza BS process to become ethanol for cars surely less global C O 2 would result?  Much of the CO becomes CO2 in the bug process. By some accounts only one third of the carbon ends up as ethanol in the lanza bioreactor.  The gasoline engine using the ethanol may only be 19% efficient. Is it not time for Jim Lane to expose this Greenwashing??”

The following day, a blog post appeared, describing LanzaTech as “Khosla’s latest gangrene venture” and criticizing the presence of former Obama campaign manager Jim Messina on the company’s board of directors, describing Messina as a “big-time operative”, adding:

“In speaking to a highly qualified PhD Chemical Engineer, he…opined that the process uses as much energy as it creates and hence creates nothing of real green value from the carbon monoxide…The PhD Chemical Engineer opined that the LozaTech process basically wastes all the energy in the carbon monoxide.”

And the article added a number of specific charges relating to low process efficiency, adding:

“If all the moles of CO in a steel mill were run through a combustion turbine, much greater useful energy would be generated in the form of electricity and steam and much lower carbon emissions would be the overall result compared with the Rube Greenberg idea that LanzaTech is promoting, hyping, and greenwashing.”

The article asked:

“Why would we have a process with zero energy gain?”

In addition, the article alleged that:

“The only reason to do these wasteful projects and give our taxpayer dollars to companies that Khosla owns is that [former US Secretary of Energy] Dr. Bodman, [former US Secretary of Energy] Dr. Chu and [current US Secretary of Energy] Dr. Moniz were bought by the special interests that host presidents for fund raising dinners.”

The article described Bodman, Chu, and Moniz, as “a thermodynamic disgrace, plain and simple,” and demands that:

It is simply time for the green “press” and the department of entropy to tell us that the second law of thermodynamics gets the first and only award.  Then companies that obey this law will be the ones to be given taxpayer money, in the process describing LanzaTech as “thermodynamic junk”.

Later on October 12th, Leveen authored an email which was sent to dozens of political figures, primarily associated with Congressman Jared Huffman, a Democrat representing California’s 2nd district, in which:

“Mr. Huffman is hereby requested to commence an investigation how ARPA-E could give money to LanzaTech the gangrene fake green company exposed in my blog.  Note Mr. Messina joined the board of LanzaTech 5 days after ARPA E was giving it money for fake green science.   Is this a coincidence?????? We know a couple of years before that Dr. Chu wasted DOE money on this gangrene company….I look forward to your response.   If no response is forthcoming I have to assume you were a party to this extraction of tax payers’ money for the intended purpose of greenwashing.”

A hefty set of allegations. Let’s look at the data.

The company's facility at Freedom Pines.

The company’s facility at Freedom Pines.

Why don’t steel mills generate power for the grid — why make fuels instead of steam?

“The fact that many of these industrial facilities could be making electricity now, but are not, tells the story,” LanzaTech CEO Jennifer Holmgren told The Digest. “The question then, with respect to steel mill waste gas, is what provides the highest marginal value, financially/environmentally/socially. Our customers and partners have invested in us because they realize these three vectors (economics/environment/social good) are aligned in the LanzaTech process, where ethanol production provides a higher IRR, lower CO2 emissions, and lower SOx/NOx/particulate emissions when compared to electricity production. They also realize that ethanol is just one of many chemicals that we can produce.

Why not combust steel mill waste gas — or petroleum, for that matter? Isn’t the process simpler?

“The simplest chemical conversion is always combustion,” said Holmgren. “For example, refining petroleum into gasoline requires a greater energy input that combusting the petroleum into electricity. But there is a reason the refining industry exists, liquid fuels are needed.”

How does the IRR for liquid fuel production compare to power production?

“LanzaTech achieves a higher IRR,” Holmgren added, “because ethanol is more valuable than wholesale electricity and because the process efficiency is higher for ethanol production (up to 60%) than for electricity production (< 35%, and sometimes <<35%) as dilute gases combust very inefficiently, which is the cases for many industrial gas streams. LanzaTech is able to achieve a high process energy efficiency because our microbe is highly tolerant to ethanol so distillation energy requirements are quite low (<20% of the inherent energy in distilled ethanol product), and because our reactors are cooled by cooling towers which have extremely low energy input, and not chillers.

LanzaTech's strategy of diversification, illustrated

LanzaTech’s strategy of diversification, illustrated

 

Not all energy is created equal

“It is also worth noting that not all energy is created equal. When we integrate into an industrial site, the low-value waste heat that is used for distillation cannot be practically used for anything else, and therefore the energy required for distillation drops to 0-5%. Also, when considering this integration of these low temperature streams, the potential efficiency from electricity production drops even further. Additionally, China and India are experiencing rapid growth in liquid fuel demand. LanzaTech ethanol can be transported to these markets or globally, but the infrastructure is not there for selling electricity from these sites.

Sustainability

“While our fermenters release CO2 (similar to sugar fermentation) when using CO as a feedstock,” Holmgren noted, “there is net CO2 reduction when compared to business as usual, flaring or venting these gases. Further, as we react increasing amounts of H2 in our process (other industrial waste gases, MSW or biomass) our reactors become CO2 consuming, in addition to our process remaining net CO2 reducing. This is a consequence of thermodynamics; the process efficiency hasn’t changed, just the feedstock. Lastly, steel production is the 3rd largest stationary CO2 emitter (after electricity and cement), and LanzaTech’s solution has received a very positive response from this sector.

lanzatech

 

The health perspective

“From a human health perspective,” said Holmgren, “the local air quality is so bad worldwide that it caused 7 million deaths in 2012 (WHO). This is driven by SOx, NOx and particulate emissions. By converting these waste gases into ethanol, the LanzaTech process reduces each of SOx, NOx particulate emissions by > 90%. Unfortunately, further combustion of these waste gases into electricity would exacerbate these emissions. For our customers, they are keenly aware that the poor air quality locally poses a threat to business in some jurisdictions, and are doubly motivated to make a positive change.”

Let’s go specifically to items raised in the afore-mentioned articles and letters. We raised them individually in a Q&A with LanzaTech.

The claim-by-claim

The claim: “Why would we have a process with zero energy gain?”

LanzaTech reply: Energy cannot be gained in any process. Please refer to the laws of thermodynamics. Transforming energy from one form into another always results in a net loss of energy, by the 2nd law of thermodynamics. But the reason energy is transformed is to convert it into a form that has a higher value for society, in a more useable form, for reduced pollution, etc., at the expense of a loss of available energy.

The claim: “The reaction is 6CO + 3H2O = C2H5OH + 4CO2.  This reaction is exothermic and 729,120 BTUs go into the reaction and only 529,000 BTUs are yielded in the ethanol while the rest of the energy is lost as heat.”

LanzaTech reply: The reaction stoichiometry as written summarizes the bacterial conversion of carbon monoxide to ethanol. The standard enthalpy of this reaction is -330 kJ/reaction mole, and the standard Gibb’s free energy of this reaction is -216 kJ/reaction mole. Using the lower heating value of reactants and products at standard temperature and pressure, the energy efficiency of this reaction is calculated to be 73%. Also, the LanzaTech process has successfully produced ethanol in amounts much larger, and also much smaller, than 729,120 BTUs. The process is not confined to a single energy quantum.

The claim: “To remove this heat the bioreactor has to be chilled and this requires electricity for the chilling system.”

LanzaTech reply: No chilling is required. It is well documented in the literature that the optimal operating temperature of many microorganisms is significantly above the temperature of process water. As such, the exotherm released during microbial conversion is removed from the bioreactors using process water, and the heat is removed from the process water using cooling towers.

The claim: “Then the dilute ethanol has to be purified from the broth (water) and this requires energy.”

LanzaTech reply: According to the 2nd law of thermodynamics, all separation processes require energy to overcome the drop in entropy of the system. The ethanol is purified from broth using distillation. The LanzaTech process is integrated into industrial facilities where low-value waste heat, unsuitable for other purposes, supplies the energy for distillation. The energy required for distillation is much lower than might be assumed as the microorganism is very tolerant to ethanol.

The claim: “Now if all the moles of CO in a steel mill were run through a combustion turbine, much greater useful energy would be generated in the form of electricity and steam and much lower carbon emissions would be the overall result compared with the Rube Greenberg idea that LanzaTech is promoting, hyping, and greenwashing.”

LanzaTech reply: The CO containing gases are dilute and therefore do not combust efficiently, (~40% or much less) though testing has not been done on all waste gas streams. Further steel mills have little use for low grade heat and so co-gen is often not a good option. Regarding usefulness, one must ask, since electricity production is a well-known alternative, “why is electricity not being pursued?” In many jurisdictions, the local electricity demand is met, and also the distribution infrastructure is insufficient. Further, electricity production requires combustion of the gases which causes many negative externalities including an increase in local air pollution, specifically SOx, NOx and particulates. The LanzaTech process offers >90% emissions reduction of SOx, NOx and particulates.

The claim: “I found a 2007 article by Robert Rapier that was critical of LanzaTech.

LanzaTech reply: Unfortunately, the reference provides no calculations or justification to support its claims. It also makes poor process assumptions which leads to gross errors. In the absence of these, we assume poor assumptions around the LanzaTech process or a misunderstanding of the physical laws that govern it. The errors include:

• “Let’s say 340 BTUs of CO get fermented to 340 BTUs of ethanol”.

Since it is quite simple to calculate, there is no need to assume. As stated in the above mass balance, 340 BTUs of CO could be fermented to a maximum of 248 BTUs of ethanol, assuming no other energy inputs.

• “and then it takes 340 BTUs of natural gas to purify the ethanol. In effect, what we have is an input of 680 BTUs of CO plus natural gas to produce 340 BTUs of ethanol.”

As stated above, the distillation energy requirements are textbook calculations and easy to calculate. The distillation energy requirements are significantly lower than stated, and importantly, low value waste heat provides the energy source, not natural gas.

• “How about instead of this kind of system, we use the CO in a gas-phase reaction – keeping the product away from water – and then use the natural gas we saved in the distillation step to run a compressed natural gas vehicle?”

Natural gas is not used to provide the heat for distillation.

The claim: “The electron balance of the chemical reactions shows that the LanzaTech process will yield four molecules of Carbon Dioxide for each molecule of Ethanol.  Why in heavens name would we waste two thirds of the carbon and emit it as CO2 at the steel plant?”

LanzaTech reply: It is well known to those in the field that it is not possible to produce a more reduced fuel molecule from CO alone without producing a more oxidized molecule like CO2. Without supplying another energy carrier, these are the constraints of thermodynamics. Since waste gases are often flared or vented at these sites, 3rd party certification has shown the LanzaTech process represents a 50-70% CO2 reduction over conventional petroleum.

Further, as we react increasing amounts of H2 in our process (other industrial waste gases, MSW or biomass) our reactors become CO2 consuming, in addition to our process remaining net CO2 reducing. This is a consequence of thermodynamics; the process efficiency hasn’t changed, just the feedstock.

The claim:Why would use ethanol in an engine that is only 19% efficient when we could have used three times the carbon in the form of CO in a combustion turbine that is 40% efficient?”

LanzaTech reply: Combustion of dilute CO in a combustion turbine has an efficiency of less than 40%, and steel mills have little use for low grade heat, so co-gen is often not a good option. The laws of thermodynamics prevent a combustion turbine from achieving three times greater efficiency – all of the carbon cannot be used if there is not sufficient energy in the reactants. The value of a transportable liquid fuel must not be overlooked. Lastly, ethanol has many functions in addition to gasoline blending. It can be used to produce an array of chemicals where electricity does not substitute.

We’ll see

We’ll see if the process economics — and the general economic forces and choices at work on potential investors in the LanzaTech system — provide yields that result in a first commercial-scale plant for LanzaTech, and more to come.

We also will see if there are downstream uses for the CO2 released in fermentation systems that further improve the a) carbon footprint, b) economics and c) process efficiency. When it comes to monetizing CO2, there is no doubt that all fermentation technologies can get better at it. That’s one reason, for example, why ethanol producer Green Plains has invested in BioProcess Algae.

The good news is — if and when the company reaches scale — RSB has certified the 70-90% greenhouse gas emission reductions, compared to business as usual, for technology as it is today.

Economics vs efficiency

Based on process efficiency, it is more carbon-efficient to combust CO to make power.

By the same measure, it is more carbon-efficient to leave a tree in the ground instead of making paper from it. And it is certainly more process efficient to move wastewater back into homes and businesses without treating it.

So, why do we make paper? Why are trees felled? Why do we treat wastewater?

Here in Digestville we take the view that product demand as expressed in the economic value is the driver, rather than efficiency — economics trump efficiency as a measuring stick for investment and deployment. Higher value use cases will always trump lower-value use cases. Bottom line, people pay enough more for paper to compensate for the loss in yield compared to other uses (or the value of inaction).

It’s the reason that Farmer’s Markets exist, if you’ve ever visited one. It’s certainly less energy-efficient and process-efficient for farmers to individually schlepp goods into the city and runs tiny stands that sell directly to consumers. They do it because of the higher margins available in selling direct. That’s the power of economics vs the power of efficiency.

Something else to note: emissions reductions are a positive social and environmental factor that is real in China and will encourage investment, according to our reporting from that country across many years.

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