Biological Hydrogen Production: A Sustainable Future Fuel

[Music] [Music] hello my friends now we are going to

discuss about the high drain production from the biological process so in our past four lectures we have discussed

about the productions of the hydrogen by different process like electrolysis process by fossil fuels or by some other

means in this particular case we are going to discuss about the hydrogen production from the biological process

itself so in introductions we can say that hydrogen is the fuel of the future

because now so many companies like Toyota or maybe in some kind of space shuttles basically people or maybe

scientists are trying to use the hydrogen gas as a fuel so this can be used in a future fuel because as the

petroleum products or maybe the fossil fuels are going to be finished within some couple of years so basically then

in that particular case we have to totally depend upon the renewable energy and this kind of renewable energy the

hydrogen productions and used hydrogen as a fuel will be the most efficient one so basically hydrogen is the fuel of the

future as I told already mainly due to its high conversion efficiency recyclability and non polluting nature

about half of all the hydrogen currently produced is obtained from thermo catalytic and the gasification process

using the natural gas as a starting materials but in this case also there is the same problem persist that we are

using the natural gas so natural gas also the limited one so maybe after certain time we have to work on

something like that which can be directly coming from the nature as a waste product like sunlight or maybe

some kind of energy or maybe some kind of electrolysis of the hydrogen so electrolysis of the water by which we

can produce the hydrogen gas so large quantum of waste generated from diverse sources specially food industry and

agricultural practices seems to be a viable feedstock for biological hydrogen production biological hydrogen

production process are found to be more environment friendly and less energy intensive as compared to thermo chemical

and electrochemical process so basically what we are talking about we are talking about some kind of bacteria some kind of

virus some kind of algae those basically are generating the hydrogen gas if we are able to capture that hydrogen gas

and stir it so automatically that generation hydrogen generation is the waste one directly it is going into the

environment so we are not able to collect it so now the scientists are thinking to collect those hydrogen gas

as a future fuel so basically we are having certain kind of bio reactors or maybe we are having that fuel cells so

basically by sunlight that photo bioreactor it is producing the hydrogen gas or may be the breaking of the water

into the hydrogen and the oxygen we can collect the hydrogen gas so they are producing certain kind of hydrogen gas

over there and another beauty of this particular technology is that simultaneously they are absorbing some

kind of toxic gases like carbon dioxide carbon monoxide into the systems so one way they are reducing the pollutions

from the environment as well as they are keeping the hydrogen gas so what we are trying to store in some for the future

applications so now if we talk about the history so you can see in the year of 1939 hand Gaffin discovered that algae

can switch between producing oxygen and hydrogen then in the later in the year of 1997 professor Anastasios Mally's

discovered that deprivation of sulfur will cause the algae to switch from producing hydrogen he found that enzyme

hydro genese's responsible for these particular reactions then we have come to in the

year of 2006 researchers as University of bill felt genetically changed the single-cell elamite ominous rain hardy

tea in such a way that it produces an large amount of hydrogen so this is one kind of biological product

in the 2007 professor again professor Anna's statius Molly's studying solar to chemical energy conversion efficiency in

tax X mutants op chalindo Damas rain hardy tea achieved as 15% efficiency so now you can understand that how the

scientists are working to produce the hydrogen from the biological product so biological hydrogen production process

in short basically we are calling it as a bhp so bhp from renewable source like biomass water and organic wastes either

biologically or photo biologically is called the bio hydrogen biological production of hydrogen as a by-product

of microorganisms metabolism is an exciting new area of technology development that offers the potential

production of usable hydrogen from a variety of renewable sources bhp at ambient physiological conditions is the

most obvious and viable approach over energy intensive conventional chemical or maybe the electrochemical processes a

successful biological conversion of biomass to hydrogen depends strongly on the processing of raw materials to

produce pit stock which can be fermented by the microorganisms bhp can be realized by inner beak and

photosynthetic microorganisms using carbohydrate reach and non-toxic raw materials now you are not thinking that

we can produce or maybe we can be able to produce the hydrogen from these particular bio organisms or maybe the

from these particular micro organisms so now people are tending their research towards this pill so basically they are

trying to make certain kind of microorganisms which can produce the hydrogen gas and that hydrogen gassing

for future applications we can store now what is the classifications of biological hydrogen productions so

basically it has been divided into five parts first one is called the bio photolysis then second

one is called the fermentations third one is called the biological what are gas shift reactions fourth one is the

microbial electrolysis cell and the fifth one is called the major enzymes then if we go into little bit deeper of

the bio photolysis it has also divided into two parts so direct bio photolysis and another one is called the indirect

bio photolysis if we talk about the fermentations it has also been divided into two parts one is called the photo

fermentations another one is called the dark fermentations so this is the whole classifications of the biological

hydrogen production now we are going to discuss one by one so first is called the bio photolysis so first we are going

to discuss about that direct bio photolysis then second one we are going to discuss about the indirect one so

biological hydrogen can be generated from plants by bio photolysis of water using the microalgae green algae and the

cyanobacteria fermentation of organic compounds and photo decomposition of organic compounds by the photosynthetic

bacteria itself so photosynthetic production of hydrogen from water is a biological process that can convert

sunlight into useful stored chemical energy by the following general reactions simple the water is breaking

in the presence of sunlight or maybe the light energy into two hydrogen and the oxygen that means into the hydrogen gas

and oxygen gas simple splitting is taking care by this particular plant or maybe by the plant itself in the

presence of sunlight so the light energy is absorbed by the pigments at photosystem one ps1 and photosystem two

pH two or both so in this case this is the ps1 and ps2 both so which raises the energy level of electrons from water

oxidation when they are transferred from ps1 Piatt ps2 to ferredoxin FD the hydro genese's

accepts the electrons from a to produce the hydrogen itself so in this particular case it is ps1 and ps2

systems directly solar energy is coming and then we are using this ferredoxin so over there or maybe it is already

present over there by these hydro genese's is taking place by which we are getting the hydrogen gas and in this

particular case the oxygen is coming throughout it the concept of direct bio photolysis envisions light driven

simultaneous oxygen evaluations on the oxidizing side of ps2 and hydrogen productions on the reducing site of ps1

with a maximum h2 o2 ratio of 2 is to 1 such a reactions with green algae could start to provide clean renewable and

economically viable hydrogen fuel since hydro genese's is sensitive to oxygen green algae see rain hardy is used to

maintain the oxygen content at a low level under 0.1 percent so that hydrogen production can be sustained for a longer

time now we are going to discuss about the indirect bio photolysis so cyanobacteria can also synthesize and

evolve hydrogen through photosynthesis process via the following process like 12 h2o plus 6 co2 simple it is preparing

the glucose c6h12o6 plus oxygen then this c6h12o6 glucose additions with the water 12 molecule of water then it add

light energy on may be the in presence of sunlight it is producing the hydrogen gas and the carbon monoxide gas indirect

bio fertilizes therefore consists of two stages in series one is called the photosynthesis for carbohydrate

accumulations this is the number one and number two is the dark confrontations of the carbon reserve for the hydrogen

production that is the number two so basically in direct bio photolysis process involves separations of the

hydrogen and oxygen evaluation reactions in two separate stages coupled through the carbon dioxide

evaluation the cells takes up carbon dioxide first to produce the cellular substances which are subsequently used

for hydrogen production so this is about the indirect bio photo lysis process now we

are going to discuss about the second one that is called the fermentations that also divided into two parts one is

called the photo fermentations another one is called the dark fermentations so in photo fermentations basically the

photosynthetic bacteria evolve molecular hydrogen catalyzed by nitrogenous under nitrogen deficient conditions using

light energy and reduce the compounds itself so the overall reaction of hydrogen production can be given as same

it's like glucose then we are adding the water and in the presence of sunlight or maybe the light energy it is producing

the hydrogen gas with carbon dioxide gas many studies have demonstrated that photo commentation by photosynthetic

bacteria can convert small molecular fatty acids into hydrogen and carbon dioxide with high efficiency so

basically we can do by these methods it's called the sugar cane suppose we can we are taking and then we are doing

that meaning so meaning the extract basically it is known as the buggers or maybe the bagasse fiber then after

milling we are doing the photo fermentations so in one case we are using the anaerobic digester and we are

able to produce the methane gas in other case we are using the pressure swing adsorption techniques by which we are

able to produce the hydrogen gas now the next one is called the dark fermentations so basically the dark

fermentations mainly differs from photo fermentations in which it works without the presence of light so that means we

can do it into the lab or Nevada into the inside the room so dieppe employs diverse group of faculty type and

anaerobic bacteria such as e---coli e Cloquet and coal stratum SP for the efficient conversion of wide range of

organic substrates deep technology has the simpler reactor design and less energy requirement when compared to

other hydrant production technology so the most dominant hydrogen produced root for the DF can be achieved with the

acetate mediated fermented pathways with the generation of four moles of molecular hydrogen with one mole of HEC

souls as shown in equation so in this particular case what we are trying to do so we are basically trying to do the

fermentative substrate such as biomass or maybe the agricultural products or maybe other organic wastes we are

collecting then we are doing certain kind of pretreatment over there pretty different in terms of some kind of

cleaning some kind of pre heat treatment kind of things then we are doing the fermentations and through fermentations

simple we are getting the two gas that is the hydrogen and the carbon dioxide and simple we are separating the

hydrogen gas and the carbon dioxide gas by the gas separation process by which we are able to produce the hydrogen gas

so this is the overall thing about the dark fermentations now we are going to the third part which is called the

biological water gas shift reaction so hydrogen is produced via water gas shift reaction by the photo heterotrophic

bacteria so while carbon monoxide is oxidized to carbon dioxide in the presence of anaerobic bacteria hydrogen

is released from the water gas shift reaction shown in this particular part so carbon monoxide in the gaseous state

h2o into the liquid form it is forming the carbon dioxide as a gas and hydrogen as a gas so in these particular case

organisms growing at the expense of this process at the gram-negative bacteria such as Rodo Spira Liam

rub rub and rub prefix gala to nuances and the gram positive bacteria such as carbon oxide do thermos hydrogen

formance so basically these all are the names of different bacteria so basically bacteria is divided into two parts one

is called the gram positive and gram negative bacteria so basically in this case with the help

of this kind of bacteria we are trying to develop the hydrogen gas from the biological water gas shift reaction x'

next the fourth one is called the microbial electrolysis cell so in short basically we are calling it as a M EC so

Amy C is a noble bio electrochemical tool for hydrogen productions that employs domestic and industrial wastes

as fuel source and used electrochemically active bacteria EAB as a bio catalyst with the presence of

electric current so simple in this particular case what is there we are having two electrodes one is known as

the anode another one is not known as the cathode in between that we are using the separator membrane so basically we

are using some kind of polymeric membrane over there and one side we are giving the electro chemically active

bacteria so this is basically the electro chemically active bacteria and it is attaching with the anode materials

and then after that what is happening MSE consists of anode cathode membrane electro chemically active bacteria as an

electric power supply so this is the external road that by which we are giving the potential difference in

between the two electrode over there now hydrogen production efficiencies of a meeseeks generally 80 to 100 percent are

significantly higher than that of the DA process that is 33 percent and the water electrolysis of 65 percent now you can

understand that what is the efficiency we are achieving by this microbial electrolysis cell so basically what is

happening we are able to achieve almost eighty two hundred percent efficiency for the hydrogen production next is

called the major enzymes there are three fundamentally different hydrogen producing and metabolizing enzymes found

in algae and the cyanobacteria first one is called that the reversible or classical hydrogenases second one is

called the the membrane bound optic hydro genese's and the third one is called the

nitrogenous enzymes so first we are going to discuss about the reversible or maybe the classical hydro genese's

these oxides ferredoxin or other low redox electron carriers both natural and artificial in a readily reversible

reaction the hydrogen evolution reaction in green algae is due to the reversible hydro genese's

so that means they are doing the back reactions over there then second one is called the mem

brain bound optic hydro genese's these are able to take up hydrogen at low partial pressures reducing a relatively

high potential electron acceptor but producing little or maybe no measurable hydrogen means the hydrogen production

quantity is very very low in this particular case then the third one is called the nitrogenous s enzymes these

normally reduces Nightrain to ammonia but can also evolve hydrogen particularly in the absence of nitrogen

gas so reduce reduction of nitrogen to ammonia that's why it is called the nitrogenous basically among the algae

only the blue-green algae which is known as the cyanobacteria have these enzymes or maybe have being these kind of

particular properties the presence of nitrogen ASUS and hydro genese's have been found in photo systems and the

fermentation bacteria respectively then this one is called the potential hydrogen producing microorganisms so in

this particular case we have discussed detailed about the different types of microorganisms then what are the

scientific name of these microorganisms and what are the advantages and disadvantages so if we talk about the

green algae so basically the advantage is called the hydrogen production from water and high Sun energy conversions if

we talk about the disadvantages also it is having light requirement for hydrogen productions because every time it

requires sunlight and then sensitive to the oxygen presence then if we talk about the cyanobacteria so this is the

scientific name or maybe the microorganism names so it is also having certain advantages like hydrogen

production from water by nitrogenous enzyme nitrogen fixation and of course there are certain disadvantages too so

first it is called the inhibitory of oxygen for nitrogen is's second one is the presence of oxygen and carbon

dioxide in the product gas and third is that sunlight requirement if we talk about the photosynthetic bacteria so

this is the scientific name of that particular microorganisms it is also having certain advantages like can use

differ and substrate for hydrogen production and second one use a wide range of light

for hydrogen productions these advantages light requirement for hydrogen productions water pollution

problem by fermented growth presence of carbon dioxide in product gas and the fourth one is called the fermentative

bacteria that is ferment to vector arrow genes or maybe a clock a so these are not the scientific names so it is also

having certain advantages producing hydrogen without light demand the that is the biggest advantage over there

second is can use a wide variety of substrates as carbon source of course it is having certain disadvantages to that

water pollution problem by fermented broth and the presence of carbon dioxide in product gas now we are going to

discuss about the purifications of the hydrogen gas so the gas is produced by biological process mostly contain the

hydrogen sixty to ninety volume and impurities like carbon dioxide oxygen and small portions of moisture are

present in the gas mixture so there are some kind of byproducts are already added with the hydrogen gas now how we

are going to get the one hundred percent pure hydrogen gas scrubbers can be used to separate carbon dioxide 50 percent W

by V weight by volume potassium hydroxide solutions is a good carbon dioxide absorbent so it can be used for

carbon dioxide removal then alkaline pyro Galal solution can be used for the removal of oxygen from the gas mixture

presence of moisture in the gas mixture must be reduced otherwise the heating value of the fuel will be decreased this

can be achieved by passing the mixture through either a dryer or a chilling unit by condensing out of the vapor in

the form of water and then after that we are going to get the 100 percent pure hydrogen over there now what are the

criteria to choose the nanomaterials for biological hydrogen productions so it should be photo condom

if it should be hi catalytic properties it should be non corrosive and it should have high specific surface area now what

are the influence of the nanoparticles on bio hydrogen productions till now we are discussing about different types of

microorganisms algae bacteria kind of things now how the nanoparticle will be able to produce the hydrogen gas or

maybe help to produce the hydrogen gas in more volume concentrations or maybe in a lesser time and efficiency of that

particular system can be increased the use of nanoparticles has been increasing significantly for applications such as

protein in mobilizations biosensors biofuels and microbial metabolic activity for hydrogen production does a

positive effect of various NPS including silver gold copper iron nickel palladium silica titanium activated carbon carbon

nanotubes and composites were absorbed on PHP these nanoparticles must be stimulating bhp by their surface and

quantum size effect nanoparticles has a larger specific surface area which enables strong ability to adsorb the

electrons the extent of the quantum size is directly correlated with the rate of electron transfer between nanoparticles

and enzyme molecules such as hydro genese's which is known to catalyze the

conversion of hydrogen to proton and YC versa now what are the advantages so it is the effective waste management system

because we are taking all the waste products over there like algae some kind of microorganism some kind of sunlight

some kind of other energy sources prevents the environmental pollution hydrogen can be produced with and

without light in few methods of course it is having certain disadvantages need extra efforts to remove the impurities

like oxygen carbon dioxide and the moistures from the system need more research for bringing this technology

from lab to the industrial scale that means the commercialization of this particular technology needs

or attention for the future hydrogen production point of view now we have come to the last slide of this

particular lecture so in summary we can say that in this particular lecture we have discussed about the biological

hydrogen production process which has been found to be more environment friendly and less energy intensive as

compared to thermo chemical and electrochemical process in indirect bio photolysis the cells take up carbon

dioxide fast you produce cellular substances which are subsequently used for hydrogen production that

fermentation technology has the simpler reactor design and less energy requirement when compared to other

hydrogen production technology hydrant production efficiencies of a meeseeks is up to 82 hundred percent are

significantly higher than that of the DA process means dark fermentation process of about 33 percent and water

electrolysis process of about 65 percent thank you [Music]