Sustainable Resource Management - bioeconomy.lodzkie.pl fileReductive Pentose Phosphate cycle RPP gives the key product for obtaining carboxylic acids - acid three carbon atoms, plants

Sustainable Resource Management

Prof. of PIMOT Krzysztof BIERNAT Ph.D.(Mech.Eng.)

Process of photosynthesis

CO2 + H2O → {CH2O} + O2; ΔGº=477kJ

Empirical formula of biomass:

C1H1,45O0,7

Necessary components:

water + soil (nutrients)

During the growth phase, possible assimilation of almost

the same amount of carbon dioxide as its release during

combustion:

{CH2O} + O2 → CO2 + H2O; ΔH=-440kJ

1 Mg of dry feedstock → 1,5·10¹º J energy

Bioeconomy Congress EBCL 2018; Łódź, Poland, 24 Sept. 2018. 2

Estimated biomass consumption

❑ Poor countries, about 40% of energy comes

from biomass;

❑ Rich countries, about 1% of energy comes

from biomass;

❑ The global average is about 14%, which

roughly amounts to 50 EJ per year.


Analysis of sources

❑ 46% of solar energy can be absorbed by the

Earth's surface;

❑ 43% of this value available for use in the

process of photosynthesis in the spectral (400

... 700) nm, „photosynthetically active

radiation” PAR in the photosynthesis.


Transformation processes (1)

❑ Reductive Pentose Phosphate cycle RPP gives

the key product for obtaining carboxylic acids

- acid three carbon atoms, plants C3.

❑ Plants C4, together with the RPP cycle,

incorporates a molecule of carbon dioxide in

the acid molecule with four carbon atoms.



C3 plants (temperate climate):

wheat, rice, soybeans, tomatoes, potatoes and

sugar beet.

C4 plants (tropical areas):

sorghum, maize, sugar cane, desert grass.

C4 – transpiration 500 moles of water for each

mole of the built CO2

C3 – 1000 and more moles of water lost per mole

of related molecules CO2



Smaller rate of net photosynthesis in C3 plants in bright sunlight → synthesised material is lost

by re-oxidation to CO2.

This process does not occur in C4 plants (more efficient process).

At 2 times the amount of CO2 in the atmosphere for C3 plants obtained biomass

increased by (20 ... 40)%.


Maximum capacity of the photosynthesis

process (1)

To bind 1 molecule of CO2 need 8 quanta PAR, hence the energy:

E=nNhc/λ = 1660 kJ/mol, at λ=575 nm;

Since the value of the standard free enthalpy = 477 kJ, the efficiency of

photosynthesis is: 477/1660·100% = 29 %;

Having only a portion of radiation absorbed by the Earth (43%), the efficiency

of photosynthesis will be: 0.43 · 29% = 12%;

This represents a theoretical yield, because plant respiration as a reaction to

the reverse process of photosynthesis decreases biomass productivity by

(20 ... 80)%, without taking into account microbial degradation as a further

source of loss, hence the seasonal maximum growth rate:

for C4- 22 g/m²·d, which is equivalent to 3,8 GJ/ha·d;

for C3- 13 g/m²·d, which is equivalent to 2,2 GJ/ha·d;


Maximum capacity of the photosynthesis

process (2)Since the average total amount of energy absorbed by the Earth

is 16 GJ/ha·d, so the actual maximum output transformation is:

▪ for C3 – 1,4 %

▪ for C4 – 2,4 %

Even taking into account good agricultural practice, the actual

efficiency of the production of maize grain with the stem is

0.6% and for wheat grain with straw - 0.3%.

Hence, the actual global average – about 0.25%

Attempts of sunless biomass synthesis ("Solazyme" USA) - Biofuel production

technology, through sunless breeding of algae from agricultural sludge, grasses

and waste substances.


Definitions (for reminder)

Standard free enthalpy (Gibbs function, thermodynamic potential, chemical potential) -free enthalpy related to the standard conditions

(p,T);

Gibbs free-enthalpy (from "entalpsis" which means "the heat" - this part of the energy, the

way heat (enthalpy), which can be used, because:

ΔH= ΔG + TΔS;

TΔS – entropy factor, lossy - energy irreversibly dissipated.


Releases of carbon dioxide

❑ Combustion of coal - 112 kg CO2 per GJ of

energy produced;

❑ This value is equivalent to burning 100 kg of

biomass;

❑ Emission cost-effectiveness of lignocellulosic

biomass (wood), the growth period not

longer than 10 years - the maximum

accumulation of carbon


Biomass transport directions


Products from biomass processing


•Thank you for your

attention.

Perspective solutions

1. Biomass gasification and further processing

of synthesis gas to obtain value-added

products (biochemicals, bio-plastics, food,

feed, energy carriers, including fuels)

2. Technologies of separating value-added

products, gasification (liquefaction) of

residues. Further processing as above.


Synthesis gas as a raw material


Synthesis gas

CO2 + H2GasificationBiomass

Compression

Raw

material for

industrial

aplication

ElectricityAlcoholic fermentation

Salvage

Bioethanol

Hydrocarbons

Hydrocarbons C2-C5

DME

synthesisDME

Methanol

synhesisMethanol

F-T (GtL)

synthesis

Motor

gasoline

Diesel oils

C2: ethanol, ethanoic (acetic) acid

C3: isopropanol, dimethyl ketone (acetone)

C4: 2,3-butanediol, butane, isobutane, 1,4-butanedioic (succinic) acid

C5: isoprene

Synthesis gas as a

universal energy carrier

Furfural route


Synthesis gas production (CalTech)


www.pimot.org.pl

ul. Jagiellońska 55

03-301 Warszawa

[email protected]

recepcja : 22 7777-000

sekretariat: 22 7777-015

fax.: 22 7777-020

Thank you for your attention.

Krzysztof Biernat

[email protected]

22 777 72 11

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Sustainable Resource Management - bioeconomy.lodzkie.pl fileReductive Pentose Phosphate cycle RPP gives the key product for obtaining carboxylic acids - acid three carbon atoms, plants