Clean Coal

Currently there are efforts underway to mitigate the emissions from coal firing plants by growing algae biomass which is then converted into fuel on sight or harvested and then exported to refineries.  This has been going on for a few years now and this is a great idea and a currently proven and working model, except the fact that some of the originators of this business model failed to make the fuel production from the biomass cost competitive with petroleum extraction and processing. It makes sense because fossil fuels like coal and petroleum are decomposed plant and animal life that have undergone extreme geological processes over a long period of time.  In other words nature has already done the work of packing all that energy into a tighter space. So instead of allocating extracting and processing the fossil fuels we have to grow, harvest and then process the fuel from live organisms.  Both types require roughly the same in transportation cost but the removal of large amounts of water form biomass is far more energy intensive than mining or drilling on a large scale not to mention the hydrocarbon separation processes require extra energy intensive steps as well. Even though some of these algae producers are using the waste heat that is generated by coal firing to dry the algae, they are still focusing too much on converting their biomass into various products and byproducts, which is a great thing for many applications and other business models, but not for the coal/biomass cogeneration model. Since the problem is that this model calls for the energy intensive methods for harvesting, drying, separation, extraction, processing, refining, and transportation all while continuing to burn coal and rubber, it is no wonder why algae based fuels are not yet cost competitive with petroleum fuels. However, due to the differences in the nature of the two resources (dead plant matter compared to live plant matter) I see that we may have a rare opportunity here to supplement the remaining stores of coal and rubber with the algae “press cake” or “algae crude” that is harvested from the bioreactors on sight. So instead of converting the wet biomass into products that need to be separated, processed and/or exported we just dry the algae into a press cake and then burn it for electricity generation.  I just conceived this idea so I welcome anyone to help me “refine” the idea.  Because burning algae biomass will produce carbon emissions as well as coal does.  It takes two units of CO2 to grow one unit of algae biomass, give or take depending on the alga species and its resistance to acidic conditions.  Water next to the coal firing plant is used to create steam pressure when it is heated by the burning of coal and sometimes rubber.  I see the existing infrastructure of coal plants being easily retrofitted to burn algae paste as well. However, instead of just heating the water to generate steam from the coal firing, we generate steam from algae as it is dried by the heated water and waste heat that that is being used to dry the algae already. By heating a pool of water tightly contained inside a conducive reservoir capped with a clear mylar sheeting, we can contain the heat energy inside the water.  Then by depositing a wet substrate (such as wet algae biomass) straight out of the bioreactor via clear mylar conveyor belt, we can force the heat energy through the algae via convection to allow the heat to escape upward. This will create steam and dry the algae at the same time.  Then the relatively dried algae (based on heat energy requirements) can be directed from the mylar conveyor into a depository where it is then stored for artificial decomposition until it is needed for energy generation where it is then fired upon.  The heat generated from firing of the dry algae press cake will be used to heat the water in addition to the supplemented coal and rubber heat sources. This may be done altogether but I suggest building separate entities that grow dry and fire the algae for isolated power generation.  Several of these algae power plants can be constructed on the flood plains behind the coal plants in a circular arrangement around the facility, instead of inside of it, which will allow for more energy generation.  The emissions from the coal firing plant as well as the algae firing plant can both feed the bioreactors. The first bioreactor will feed off of the coal plant and then each algae plant thereafter will feed of its neighbor. The excess heat from coal firing could be fed to the algae drying process as a supplement to the algae firing heat energy.  The electrical generation of each algae power plant can also feed power to the grid. And just like the coal plant the excess steam can be recycled back into the bioreactors of each algae plant. This I propose will be a closed system like that in nature and can be scaled up as needed so to not to compete directly with coal but make it a clean renewable product. I say clean because I suppose by the time I break ground with my designs there will be a cost effective process that converts the algae paste into coal while extracting the oil to make it pure carbon.  This can be done to the stored excess of algae biomass over a long period of time so when coal eventually runs out of the coal mines or preferably beforehand we will have a process that generates coal to be burned on sight as well. http://www.cleantick.com/users/donmichael/blogs/clean-coal