Is the Sarvel technique intended only for agricultural crops containing little or no lignin?
Lignin percentage makes no difference for our technology. The technology applies to all kinds of biomass and waste materials.
For trees, do we add in the Sarvel Process before or after the dryer? Do we even need to use it for forest wood?
The process will be used while the wood is still wet. Our mechanical de-watering process will bring the moisture down to around 20% before further processing. After that, to produce the bio-coal no further drying is required with the technology our partner has fortorrefaction if necessary for the client.
Will it add to the already high cost of drying?
No extra drying is required (see the answers above). We have tried the system in small scale and it works. We are developing mechanical de-watering as part of the technology together with the leaching baths. The cost for the mechanical de-watering is not going to be a significant part of the total cost of the Sarvel equipment.
Is the process aggressive enough to be applied to take out sodium chloride and related seasalts from wood? Would “de-salting” produce a new wood product in its own right?
Yes, that is what the technology does. It removes any kind of alkalies, sulfur, phosphorus, chlorine and other in-organics. The new product is categorized as clean biomass feedstock.
Bio-coal from trees is expensive already and produces a marginally profitable commodity product, albeit a high quality product. Does Sarvel add to the production costs?
The final cost is actually negative as the outputs will be able to be used in combustion and gasification processes with much higher efficiency and without ash, tar and emissions related problems.
What do you mean by “clean bio-coal”? Doesn’t Torrefaction clean the wood already? How does removing inorganic content prevent subsequent organic content tar formation?
Biomass contains inorganic elements such as alkali metals, chlorine, sulfur, phosphorus, etc., that are creating ash-related problems such as deposition, corrosion, agglomeration as well as air emissions during combustion and gasification processes.
Removing the inorganics before the biomass is used as feedstock for combustion,gasification and pyrolysis processes improves the process efficiency and economics. You don't need just to remove a few impurities but rather all. Otherwise the problems will knock on your door sooner than you think.
What torrefaction does is altering the chemistry of biomass and make it more brittle so it can be milled easier during the conversion in pf boilers. It does not clean anything from the biomass. It does not remove contaminates. It actually condenses them. Torrefaction is a densification technique used to prepare biomass for shipping over long distances. Torrefaction is required if you are going to feed the fuel into a pf boiler and/or if you plan to store the fuel for long time in relatively humid conditions and/or to ship it in long distances. If these are not the cases then you don't really have to do it.All this will result in net gaining from the process. If your biomass is forest residues orwhatever wood including bark, then you have to apply this process to be able to have aproduct that can compete with coal. We are working with a company that develops torrefaction technology endorsed by EPRI. When you combine the two systems (torrefaction+Sarvel) you save on man power as well as equipment which are duplicates, such as the milling, the drying, the storage. The actual cost of the leaching plant goes down by 30-50% compared to when stand alone
How does removing inorganic content prevent subsequent organic content tar formation?
Inorganics removed during the Sarvel process play a very significant role in tar formation. We just finalized a gasification testing with EPRI where the tars were reduced by more than 50% and up to 90% in volume with the use of the Sarvel process. Because leaching will allow the use of higher temperatures in the gasifier without ash related problems, the conversion of the tars inside the reactor will be much higher also. It's expected that with 1000C in the reactor and the Sarvel process we will remove the tars by 99% without applying any gas cleaning method. Furthermore, if you don't remove the inorganics, you will have to keep the temperature low to avoid ash related problems. As a result your efficiency will be low and the final profit low.