An Economic, Environmental, and Technical Analysis of Biomass Sourced Jet Fuel.
The paper I'll discuss in this post is this one: Comprehensive Life Cycle Evaluation of Jet Fuel from Biomass Gasification and Fischer–Tropsch Synthesis Based on Environmental and Economic Performances (Xiao et al, Ind. Eng. Chem. Res. 2019, 58, 19179?19188)
I have very little use for Bill McKibben of 350.org because although he "cares" loudly about climate change, he is nothing more than a journalist, and a cowardly one at that, since it is increasingly obvious that his prescribed solution, so called "renewable energy" has clearly not worked, and is not working and won't work. McKibben is a journalist. I often joke that one can only get a degree in journalism these days if one has not passed a college level science course.
No one now living will ever see an atmospheric concentration of the dangerous fossil fuel waste carbon dioxide measuring under 400 ppm again, never mind "350." Next year I'm certain I'll be able to say - if still alive - "under 410 ppm again." The blind, and frankly ignorant faith is so called "renewable energy" is one reason why this is so. The more than 2 trillion dollars spent in the last ten years alone on this scheme has caused climate change to accelerate, not decline. We are now seeing increases at 2.4 ppm/year, an unprecedented rate.
I call McKibben a "coward" because it takes courage to say "I am wrong" or "I was wrong" and he clearly lacks this ability, since the only way to be serious about climate change is to embrace science and engineering, as opposed to driving one's Prius (or Tesla electric) car to protests chanting "We want 'renewable energy now!' and carrying signs that the bearers consider witty. Over the last several hours I've been studying lignins, a component of wood and the stalks of many plants, and as a result have been studying the environmentally dubious Kraft process for wood pulping, which is utilized to make paper for signs people can carry to their protests stating how much they care about the climate.
Bill McKibben lacks both the courage and the intellectual insight and education to be able to say the word "nuclear."
If one respects science, one considers how scientists work. We have theories or hypotheses which must be tested by experiment. If the experimental results invalidate the theory, the theory goes, not the experimental result. We don't make Trumpian scale excuses for the experimental result in order to save a precious theory, which by being precious translates into blind faith. The experimental results of the multitrillion dollar "renewable energy will save us" theory are in; climate change is accelerating, not being ameliorated. It's time for the theory to be rejected. Denial and excuses for the experimental result are meaningless. No one now living will ever see an atmospheric concentration of the dangerous fossil fuel waste carbon dioxide measuring under 400 ppm again. The so called "renewable energy" experiment did not work; it is not working; it won't work.
The purpose of this riff on McKibben, who I obviously hold in low regard, is a bit of "Gotcha," which has come to permeate our culture of anti-thinking, the age of twits posting twitter witticisms, all of which are making the world worse, not better.
To avoid "Gotcha" statements the young climate activist Greta Thunberg took a sailboat across the ocean to address the UN on climate change. She declined to fly, since flying requires the consumption of rather large amounts of fuels based on dangerous petroleum. This reminds me of a statement I heard attributed to Mahatma Gandhi in which he remarked that his advisers complained that was very expensive to be sure he was keeping his vow of poverty in place.
By the way, I have enormous respect for Greta Thunberg, because I think she is right to ask us "How DARE you?!!!" about what we in my generation have done to hers.
History will not forgive us; nor should it.
It's OK for Greta Thunberg to not know anything about engineering by the way; she's sixteen. (Bill McKibben is 58.)
Now.
In general, as I've just made clear, I am hostile to so called "renewable energy" not because its slightly better than dangerous petroleum, dangerous coal and dangerous natural gas, when it functions, but because it requires dangerous petroleum, dangerous coal and dangerous natural gas to back it up when it's not working, which is often. This is why it is not working and won't work, and why Germany and Denmark have the highest electricity prices in the OCED, because a system that requires redundancy is obviously more expensive than one that doesn't, and not only that it, it is worse from an environmental standpoint. (We hit 415 ppm of CO2 this year.)
Still, despite to my hostility to so called "renewable energy" I am flexible enough to be intrigued by what is, by far, the largest source of it, biomass. As practiced now, biomass is a health and environmental disaster: Slightly less than half of the world's 7 million air pollution deaths each year derive from it, and the Mississippi River Delta system, along with other bodies of water, has be destroyed by agricultural fertilizer run off to make corn ethanol, and the Indonesian and Malaysian rain forests are being rototilled to make biodiesel to meet German "renewable portfolio standards."
Nevertheless, biomass relatively efficiently captures carbon dioxide from the air, and this is a non-trivial task that we leave for Greta Thunberg's generation to accomplish with depleted resources and a degraded planet. Biomass, especially algae biomass, is fast growing, self replicating, and capable of covering the large surface area required to address the entropy of mixing that makes cleaning up the dangerous fossil fuel waste carbon dioxide. Thus it cannot be ignored.
This brings me to the paper at the outset. This is one way to make jet fuel so Greta Thurnberg can feel safe to fly someday, but there are others, one of my personal favorites being that proposed by the US Naval Scientist Heather Willauer , although in truth, it's less than perfectly idea since it requires an electricity intermediate and is thus thermodynamically questionable.
The best way to deal with biomass in my opinion is heat driven gasification, which what the paper cited at the opening of this post is about.
The cartoon graphic introducing the paper:
From the introduction:
The life cycle assessment (LCA) is a method for evaluating the environmental impact of a product throughout its life cycle. In order to compare the influence of different processes of biomass-based jet fuel on the environment and resources, some literature studies carried out a variety of life cycle evaluations of the abovementioned conversion processes. These studies mainly focused on the contribution of biomass-based liquid fuel to mitigate the greenhouse effect. Moreover, some comprehensive evaluations were based on the fuzzy mathematics method, such as the analytic hierarchy process (AHP).
Several researchers(7?9) performed the LCA of biomass-based jet fuel derived from hydrothermal liquefaction (HTL) of microalgae. Two HTL processes of algal jet fuel based on the different circumstances were analyzed, and Monte Carlo simulation and sensitivity analysis were completed. The results showed that the transportation of microalgae led to the increase in the life cycle climate change impacts, and compared to the process of petroleum-based jet fuel, greenhouse gas emissions could be reduced by 76.0% based on the optimized process of algal jet fuel.
Klein et al.(3,4) compared different routes for renewable jet fuel (RJF) production integrated with sugarcane biorefineries in Brazil based on the technoeconomic and environmental assessments. They concluded that hydroprocessed esters and fatty acids exhibited the highest production potential and FT synthesis showed the best economic performance among the studied scenarios of RJF. Moreover, all conversion technologies of RJF could reduce greenhouse gas emissions by more than 70% compared to the process of petroleum-based jet fuel...(10)
...Moreover, many researchers have integrated the AHP into LCA to evaluate the comprehensive performance of products.(14?16) Tao et al.(6) obtained a resource-environment-economic comprehensive performance evaluation model of biomass-based jet fuel from biomass gasification and FT synthesis based on AHP. They showed that the case of biomass-based jet fuel combined with waste heat for power generation exhibited a lower environmental impact than that combined with heat supply directly and the reduction of environmental impact indicators was in the range of 11.7–40.8%. Compared to petroleum-based jet fuel, the global warming potential (GWP) of biomass-based jet fuel reduced by 52.6–71.9% and the nonrenewable resource consumption reduced by 84.4–93.6%. Different environmental impact distribution methods, such as based on economic value distribution, energy distribution, and mass distribution, used in the biomass growth stage led to significant changes in the environmental evaluation, in particular, for GWP and eutrophication potential (EP). It could also be found that the comprehensive performance of biomass-based jet fuel is the most sensitive to feedstock consumption...
...The method of monetization is more objective and rational, which has the same criteria for weighting economic performance, resource performance, and environmental performance. Therefore, the comprehensive evaluation obtained is fairer to the entire society, and its decision-making meaning is more perfect. This study not only employed the monetization method to reflect economic benefits but also completed the comprehensive analysis through the monetization method on resource and environment, to avoid the subjective factors in comprehensive evaluation.
Some graphics from the text beginning with a process flow sheet diagram:
It is important to note that this analysis relies of combustion heat, and not nuclear heat, and therefore can be improved upon. Specifically in this diagram the heat is generated by the combustion of biomass, reducing the amount that can be recovered as a biofuel. However I very much like the FT approach and the heat exchange networks.
Two cases are considered:
Here is the grounds for the LCA analysis, note the presence of fertilizers and pesticides. These may not be necessary if the water utilized to grow the biomass is municipal waste water, or agricultural run-off water, since these are potential media for algae growth. The big problem with Algae growth is dewatering and transfer, both of which can be addressed to improve the process, dewatering by the use of waste heat, transport by direct flow into reactors. (This would also have the added advantage of recovering phosphorous, the depletion of which is another very, very, very, very serious matter we are dumping, with contempt, on Greta Thunberg's generation. How DARE we?)
An issue often ignored is the material costs of so called "renewable energy," which calls into question how "renewable" it is - this is a serious paper, not hand waving - is not not ignored here:
Table 2: from the paper:
Costs of this process, again analyzed in the absence of nuclear heat:
It is important to note that in the case of dangerous petroleum fuels, the economic costs of the destruction it causes, the costs of deaths and cost of disease from air pollution, and the cost of climate change - i.e. "external costs" - are not included. If they were, petroleum would be too expensive to use, inspiring idiots like Jim Kunstler to carry on how about we'll all die without oil, that "peak oil" nonsense. These external costs are not included although, they should be in an LCA paper in the analysis of the cost of petroleum jet fuel in table 4. I do not mean to criticize the authors or their fine work here, but they are buying into the fact that we blindly accept these enormous dangerous fossil fuel costs by habit while we all wait breathlessly for the grand renewable nirvana that never comes, and not because it is morally or intellectually justifiable.
Table 4:
For the next few graphics, there is a parameter called "ICP" for Indicator of Comprehensive Performance. There are also parameters associated with the weighting of these indicators, described in the text as follows:
The weighting factors utilized in the analysis of these are assigned in the graphic below, where the weighting factors are described thusly:
The next graphic on the sensitivity of benefits to the price of oil depends on the dubious assumption with which we all live that dangerous fossil fuels are allowed to dump the dangerous fossil fuel waste without charge.
A genuflection to this fact that dangerous fossil fuel wastes can be dumped without charges accruing to users and dangerous fossil fuel companies.
The next graphic refers to the price of stalks delivered to the plant; this is not an algae based process.
And the final figure refers to the influence of the cost of oil, which is subsidized by lung tissue, the destruction of habitats, and the destruction of the future of Greta Thunberg's generation and all generations after hers.
Some conclusions to the paper:
According to the sensitivity analysis, the comprehensive performance of the two processes is highly sensitive to the price of crude oil and stalk consumption and the Bio-FTJ-1 is highly sensitive to electricity consumption. The higher the price of crude oil is, the better the comprehensive performance of the Bio-FTJ is. The results of this study indicate that the comprehensive performance of Bio-FTJ can be improved significantly by the reduction of the consumption of stalks and external power input in the production.
I trust you're having a nice day.
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