PYROLYSIS OF AGRICULTURAL WASTE
Posted on: December 17, 2020
Pyrolysis of waste, and specifically of agricultural waste, is a well developed and commonly used technology that can recover the carbon in waste material as biochar for use as fuel. See for example:
Zanzi, Rolando, Krister Sjöström, and Emilia Björnbom. “Rapid pyrolysis of agricultural residues at high temperature.” Biomass and Bioenergy 23.5 (2002): 357-366.
Demirbas, Ayhan. “Effects of temperature and particle size on bio-char yield from pyrolysis of agricultural residues.” Journal of analytical and applied pyrolysis 72.2 (2004): 243-248.
Yanik, Jale, et al. “Fast pyrolysis of agricultural wastes: Characterization of pyrolysis products.” Fuel Processing Technology 88.10 (2007): 942-947.
Berruti, Franco, Cedric Briens, and Ronald Golden. “Apparatus and process for the pyrolysis of agricultural biomass.” U.S. Patent No. 7,943,014. 17 May 2011.
A typical study is Zanzi etal 2002 where they find: “This paper deals with rapid pyrolysis of agricultural residues such as olive waste and straw at high temperature (800–1000°C) in a free-fall reactor at pilot scale. The conditions are of interest for gasification in fluidized beds where rapid pyrolysis plays an important role as first stage. The objective of the work is to study the effect of the process conditions such as heating rate, temperature and particle size on the product distribution, gas composition and char reactivity. A higher temperature and smaller particles increase the heating rate resulting in a decreased char yield. The cracking of the hydrocarbons with an increase in the hydrogen content is favoured by a higher temperature and by using smaller particles. Wood gives more volatiles and less char than straw and olive waste. The higher ash content in agricultural residues favours the charring reactions. The higher lignin content in olive waste results in a higher char yield in comparison with straw. Chars from olive waste and straw are more reactive in gasification than chars from birch because of the higher ash content.”
The smart Indian chemical engineer Mr. Vidyut Mohan identified the utility of pyrolysis of agricultural waste as a way of saving New Delhi from the annual post harvest pollution event created by farmers in surrounding areas burning their agricultural waste. His amazing innovation was to buy agricultural waste from the farmers and then to use pyrolysis to convert agricultural waste into biochar that can be sold back to the farmers as fertilizer.
This innovation saves New Delhi from the annual post harvest pollution event but it has nothing to do with climate change. Anthropogenic Global Warming (AGW) and climate change is not a theory about how nature’s carbon cycle changes the climate. It is very specifically a theory about the impact of the industrial economy’s fossil fuel emissions as a perturbation of nature’s delicately balanced carbon cycle that causes atmospheric CO2 to rise and this rise in atmospheric CO2 concentration is thought to be the driver the observed warming since the end of the Little Ice Age.
The celebration of this innovation by the United Nations (UN) and by the United Nations Environment Program (UNEP) as a climate action innovation that will attenuate the rate of warming and save the planet {LINK: https://www.unenvironment.org/youngchampions/bio/2020/asia-and-pacific/vidyut-mohan } is inconsistent with the theory of AGW as explained by NASA climate scientist Dr. Peter Griffith in a related post on this site LINK: https://tambonthongchai.com/2020/06/19/vegandiet/ . What Dr Griffith explains there is an important feature of AGW climate change theory that is not well understood and/or often overlooked in the consideration of climate action policies. Anthropogenic global warming is specific to the impact of the industrial economy that dug up fossil fuels loaded with carbon from carbon cycles that are millions of years old. This is EXTERNAL CARBON. It is not part of the current account of the carbon cycle.
The essence of the theory of anthropogenic global warming (AGW) is that external carbon from very old carbon cycles in fossil fuel emissions cause warming by increasing atmospheric CO2 levels and that therefore the amount of warming can be attenuated by reducing fossil fuel emissions (Hansen, 1981) (Meinshausen, 2009) (Stocker, 2013) (Callendar, 1938) (Lacis, 2010) (Hansen, 2016) (IPCC, 2000) (IPCC, 2014). At the root of the proposed AGW causation chain is the ability of fossil fuel emissions to cause measurable changes in atmospheric CO2 levels in excess of natural variability because very old external carbon in fossil fuel emissions is a perturbation of the current account of the carbon cycle. This important detail has been overlooked by the UN and by the UNEP in their evaluation of the Indian pyrolysis innovation to save New Delhi from the annual harvest pollution event. The theory of anthropogenic global warming is specific to the industrial revolution and the industrial economy in terms of the combustion of fossil fuels.
An important feature of the carbon cycle is that the CO2 removed from the atmosphere by plant photosynthesis is returned to the atmosphere when the plant dies (or by animal respiration when the plant or its fruit is eaten). In the case of the New Delhi pollution issue, the return may have been hastened by burning agricultural waste instead of letting it rot on the ground but the issue there is not climate change but pollution. Another factor overlooked by the UN and the UNEP is that the biochar produced by pyrolysis of agricultural waste is not sequestered from the carbon cycle but put back into the soil where it acts as a fertilizer such that the biochar carbon eventually ends up back in the atmosphere but without the annual harvest pollution in New Delhi.
We conclude from this analysis that the smart Indian chemical engineer who came up with the pyrolysis idea to save New Delhi from pollution deserves to be recognized for this achievement but that the further interpretation of this event in terms of climate change by the UN and UNEP exposes a weakness in their understanding of an issue that plays an important role in their function as global climate action coordinator.
More about the UN: LINK: https://tambonthongchai.com/2020/03/18/the-eco-crisis-ambition-of-the-un/
8 Responses to "PYROLYSIS OF AGRICULTURAL WASTE"
December 18, 2020 at 3:25 pm
chaamjamal,
What explains the 284K in the last glaciation? And the multiple +/- 2k cycles of the Holocene?
Well, the mean surface temperature for Earth is:
Tmean.earth = [ Φ (1-a) So (β*N*cp)¹∕ ⁴ /4σ ]¹∕ ⁴
Tmean.earth = 287,74 Κ
And we compare it with the
Tsat.mean.earth = 288 K, measured by satellites.
These two temperatures, the calculated one, and the measured by satellites are almost identical.
The planet mean surface temperature is a year around average mean surface temperature. .
At present Perihelion occurs in the middle of the Southern Hemisphere summer.
In the summer Earth’s axis tilts toward sun. At Perihelion Earth receives 7% more intense sunlight than at the Aphelion.
This is because the Earth’s orbit is not circular but elliptical, with the Sun located in one of the foci of the ellipse.
When we apply Stefan-Boltzmann Law we come to conclusion that at present, when Perihelion occurs in the middle of the Southern Hemisphere summer, Earth absorbs more solar energy and that leads to orbital forced warming trend.
It happens because North and South Hemispheres have an unequal distribution of land and oceanic surfaces.
The Southern Hemisphere is mostly covered with oceans (water) and the Northern Hemisphere is crowded with continents (soil).
As a result there is a major difference in each Hemisphere surface qualities. The surface is what interacts with incoming solar flux.
cp. ocean = 1 cal /gr oC
cp. land = 0,19 cal /gr oC
Let’s apply the Rotating Planet Surface Solar Irradiation Absorbing-Emitting Universal Law:
Jemit = 4πr²σΤmean⁴/(β*N*cp)¹∕ ⁴ 
We can see now that when insolated, the land emits more intensively IR radiation back to space than the ocean does.
It is just happening that way at present. When Southern Oceans are tilted towards sun Earth is at Perihelion (at closest to sun position).
At present more intense insolation (+7%) falls on oceanic waters. That leads to orbital forced global warming trend.
It all happens according to Reversed Milankovitch Cycle.
And it happens according to Stefan-Boltzmann Law.
And of course the average global insolation remains reasonably constant.
And
Jabs = πr² Φ (1-a) So
What changes in the time is the Earth’s surface IR emission intensity. What changes in time is the intensity Earth gets rid from the incoming solar energy.
That is why I say there is an orbital forced Global Warming Trend.
It is the 21.170 years Milankovitch Cycle. Only the Milankovitch Cycle should be read Reversed.
Thus in the mean surface temperature equation
Tmean.earth = [ Φ (1-a) So (β*N*cp)¹∕ ⁴ /4σ ]¹∕ ⁴
there should be in the year around
cp (average surface specific heat) value some difference (cp less than 1) when planet’s axis is tilted the opposite way than now, when it is tilted towards Vega.
Also I think there would be more clouds over the Southern oceans in summer then, thus the year around average albedo would be higher than the present a = 0,306.
http://www.cristos-vournas.com
December 18, 2020 at 8:42 pm
Correction:
Instead of
“Also I think there would be more clouds over the Southern oceans in summer then, thus the year around average albedo would be higher than the present a = 0,306.”
It should be read as:
Also I think there would be more clouds over the Southern oceans in Southern Hemisphere’s warmer winters (since those Southern Hemisphere’s winters will occur in times closer to Perihelion then).
Thus the year around average albedo would be higher then, than the present a = 0,306.
http://www.cristos-vournas.com
December 18, 2020 at 9:10 pm
Thank you again very much for this very interesting analysis.
Thongchai Thailand 
December 18, 2020 at 4:01 am
1. Earth’s Without-Atmosphere Mean Surface Temperature calculation
Tmean.earth
So = 1.361 W/m² (So is the Solar constant)
S (W/m²) is the planet’s solar flux. For Earth S = So
Earth’s albedo: aearth = 0,306
Earth is a smooth rocky planet, Earth’s surface solar irradiation accepting factor Φearth = 0,47
(Accepted by a Smooth Hemisphere with radius r sunlight is S*Φ*π*r²(1-a), where Φ = 0,47)
β = 150 days*gr*oC/rotation*cal – is a Rotating Planet Surface Solar Irradiation Absorbing-Emitting Universal Law constant
N = 1 rotation /per day, is Earth’s axial spin
cp.earth = 1 cal/gr*oC, it is because Earth has a vast ocean. Generally speaking almost the whole Earth’s surface is wet. We can call Earth a Planet Ocean.
σ = 5,67*10⁻⁸ W/m²K⁴, the Stefan-Boltzmann constant
Earth’s Without-Atmosphere Mean Surface Temperature Equation Tmean.earth is:
Tmean.earth= [ Φ (1-a) So (β*N*cp)¹∕ ⁴ /4σ ]¹∕ ⁴
Τmean.earth = [ 0,47(1-0,306)1.361 W/m²(150 days*gr*oC/rotation*cal *1rotations/day*1 cal/gr*oC)¹∕ ⁴ /4*5,67*10⁻⁸ W/m²K⁴ ]¹∕ ⁴ =
Τmean.earth = [ 0,47(1-0,306)1.361 W/m²(150*1*1)¹∕ ⁴ /4*5,67*10⁻⁸ W/m²K⁴ ]¹∕ ⁴ =
Τmean.earth = ( 6.854.905.906,50 )¹∕ ⁴ = 287,74 K
Tmean.earth = 287,74 Κ
And we compare it with the
Tsat.mean.earth = 288 K, measured by satellites.
These two temperatures, the calculated one, and the measured by satellites are almost identical.
Conclusions:
The mean surface temperature equation
Tmean = [ Φ (1-a) S (β*N*cp)¹∕ ⁴ /4σ ]¹∕ ⁴
produces remarkable results.
The calculated planets temperatures are almost identical with the measured by satellites.
Planet………..Te…………Tmean….Tsat.mean
Mercury….439,6 K…….325,83 K…..340 K
Earth………255 K………287,74 K…..288 K
Moon……..270,4 Κ……..223,35 Κ…..220 Κ
Mars……209,91 K……..213,21 K…..210 K
The 288 K – 255 K = 33 oC difference does not exist in the real world.
There are only traces of greenhouse gasses.
The Earth’s atmosphere is very thin. There is not any measurable Greenhouse Gasses Warming effect on the Earth’s surface.
There is NO +33°C greenhouse enhancement on the Earth’s mean surface temperature.
Both the calculated by equation and the satellite measured Earth’s mean surface temperatures are almost identical:
Tmean.earth = 287,74K = 288 K
http://www.cristos-vournas.com
December 18, 2020 at 8:55 am
What explains the 280K in the last glaciation? And the multiple +/- 4k cycles of the Holocene?
December 18, 2020 at 9:07 am
Oops, i meant +/- 1k to 2k temperature cycles of the holocene. The 4k events happened in the Eemian
December 18, 2020 at 9:08 am
The 4k event happened in the eemian