At this moment in places like my country, the main problem is the technology associated to these systems. We do not have enough knowledge or technical support to implement them. Therefore, these systems are expensive and out of most people around the world.

And sustainable biofuels need to be more accessible if we want them to have a better future.

I am very doubtful that algae-based biofuels will be important in the future. As we explain in our chapter 'Biorefinery Design from an Earth Systems Perspective' (see attached pdf) suggests reasons why the energy return on energy invested may be too low for feasibility in large-scale systems.

Thanks Saad -

It all depends on the price of fossil fuels, the main competition. If that stays at less than $100/barrel, then algae biofuels cannot be competitive. However, if fossil fuels get expensive because of a carbon tax or international conflicts, then algae biofuels have a good chance. In any case, it is important to have the kinks worked out, so that when algae biofuels are becoming economically feasible at larger scale, we do not need to develop the stuff from (almost) scratch.

Thanks @wim vermaas for your answer but in my opinion the fossil fuel are limited stocks, with time duration the price will go higher as compared to present scenario, in that case algae will be the only option for fuel.

With improved extraction technologies (fracking, etc.), there are fossil fuels to last at least a number of decades; coal may even last a century or more. I think that rising CO2 levels and their global effects will be more of a reason for policy decisions to curb CO2 emissions than a lack of fossil fuels.

1.Dear @wim vermaas I agree that new technologies explored the new fossil reserves but it is also true that price is continuously increasing https://changethrutime.com/2017/01/18/155-years-of-crude-oil-prices/

2.Fracking is strongly opposed by the environmentalist and US citizens I think now it banned in US

3. I think to achieve the sustainable development goals algae based and other clean environment friendly fuel source play significant role. If we will focus on the building the technological infrastructure for the algal biofuels it will be feasible option for future energy source.

A major issue here is that the global (fossil) fuel demand is in the same order of magnitude as is the total biomass production on the planet (HANPP, see Article Engineering photosynthesis: a necessary tool to protect the ...

The world as approaching rapidly the limits to growth! If we do not get this growth under control, the world will probably not be able to solve the energy and climate problems.

The main controlling key for all these is the market price of fossil fuels. Till now there are so many reasons which control the market price of them. But market price does not increase the availability of fossil fuels. Therefore, we have to be dependent on renewable fuels in near future and biofuel is the most renewable thing on earth for the capacity of their resource to reproduce. Now, algae is is one of the most promising resource for fuel production for its high oil content, less requirement etc. But till now the price of algae based fuels are high because of technical reasons. But it is a matter of fact that the price of these algae based fuels have been reduced to many folds after good researches on it throughout the world. Dr. Mayfer from UC, San Diego, who demands that the fossil fuels are the derivatives of algae actually, has done wonderful job in this field. Several Indian industries too have done good job. I have done my doctorate on unused algal biodiesel and I am providing the links of my papers below from where you can get good ideas. Finally, I must say again very soon we have to be dependent on renewable fuels and for existing engines, biofuels are the most prominent alternatives and algae based fuels are one of the bests among them. It is just a matter of time and algal fuel is going to be in the market very soon.

Link: https://www.researchgate.net/publication/321755355_Production_of_biodiesel_from_unused_algal_biomass_in_Punjab_India

Article Fuel properties and emission characteristics of biodiesel pr...

Thanks for elaborated answer @ranchan karmakar I will surely go through your papers.

Dear @Rachan karmakar I have gone through your papers and you have stated that the Nox is comparatively high in biodiesel when compared with petro-diesel. As per my understanding NOx is a serious pollutants so how can we reduce NOx percentage in biodiesel?? If you have some data about related to NOx percentage in biodiesel please share with us.

Well because of the inbuilt oxygen and higher cetane number of biodiesel, more NOx is produced for the combustion of most of the biodiesel. Algal biodiesel produced in my experiment is no exception of that. In my paper I mentioned that use of de-NOx catalyzer or NOx reducing additives will solve the problem.

Thanks @rachan for your answer.

Dear Ravindra,

your questions seems very interesting. There are expert opinion presented already by some colleagues. i think , Yes, its feasible to have such a green product from green gold. As for as economic concern , we should kept in mind that algal based biomass has a diverse options to be utilized for various valuable side streams. while on the other hand fossil fuels are decreasing rapidly and take million of years to form their reserves. while algal biomass has no such kind of challenge. moreover, if we think for larger scale scenario then algal biomass industry has more worth. its not only associated to energy sector only but to health, cosmetic, textile and food industry as well. If we talk about available technology, yes its true that some efforts are needed to move for larger scale setup. Its my personal opinion that in future it might e possible that its cost could be lower than other resources. However, to attain this goal a serious and well balanced approach is needed to be executed.

Thanks @muhammad amin for your opinion.

Maybe.

Dr Kamath Madhusudhana