If you missed the fourth and last episode of the FlexSNG webinar series, or you would like to watch it again, the full recording is available here: https://youtu.be/1UbH6e2yRH4
The webinar welcomed more than 110 guests online and received many questions from an active audience.
A recap of all the questions and answers can be found here:
1. How much additional H₂, if any, is required for each of these operational modes?
Process can be operated without external H2. However, if low cost H2 is available maximized syngas mode can be boosted by H2. FlexSNG uses a CFB gasifier using a mixture of oxygen and steam as fluidising gases.
2. Could you elaborate on the assumptions used in the feedstock tranport costs? Loading/Unloading time, distance to rail head etc..
In tactical planning, we consider different vehicles for different assortments. For example, for fuel logs, we define log trucks; for chips, we define containers; and so on. Distance is the key factor in tactical planning. We have transportation costs x km x tonne for each vehicle, and the loading and unloading costs are also considered.
The details of this part, like Loading/Unloading time would be better answered at the Operational level.
In the technical project we have many supply points with the agricultural sites or forest sites. We don’t make an assumption on average distance because we actually use the real distances that the trucks are actually doing and the cost are based on typical agreements between different supplies and demand points. It has been used average cost for those transports and there are not really any assumptions on average cost but they are sort of computed within the model.
3. May I know which gas cleaning technology is being used in the FlexSNG?
Hot filtration and catalytic reforming is applied as raw gas cleaning method. The FlexSNG has a hot gas cleaning of the raw gasification glass that includes a hot gas filter and a catalytic reforming of tars. Afterwards there is some Innovative sulfur removal process which is on a dry basis and there is also the catalytic methanation.
4. Have you estimated the amount of fuel required by the trucks for feedstock collection and delivery? Specifically, how does the energy content of the fuel (HHV/LHV) compare to the energy produced in the FlexSNG using the same amount of feedstock?
What was presented here was comparison of the collaborative and non-collaborative scenario on a representative case to see how much reduction we can make by truck sharing at the operational level because truck transportation is inevitable means of transportation for biomass delivery, but train can also be used beside trucks. Our next step is to estimate the real cost at the operational level when thw real case is solved. In the example that Asudeh presented we assumed we use only trucks, but obviously the result on tactical level, train transportation result in a lot of benefits. So, the cost estimation will depend on train consideration as well.
The fuel consumption depends on truck configuration. Typical values of (bio-)diesel consumption for a loaded truck is typically in the range 0.3-0.5 l/km (also depending on road condition and characteristics). Average distances depends on combination of supply points (forest, agriculture, MSW) and biorefinery, and also on what level the biorefinery will run on. In Quebec, distances are typically longer than Europe so we can expect 60-100 km. However, the energy in a full load exceeds by far the energy needed for processes and transports. Not included in this project, it is also interesting to look at the use of electrical trucks which would reduce the use of diesel.
5. It will have a huge impact on your model, what are these assumptions?
The cost assumptions are based on actual and reported transport costs for different truck configurations. Please note that there is no assumption on on average distances as we use road databases to identify the real distances between (many) supply points and biorefinery (or terminals).
6. Has the project considered the carbon emissions or carbon removed for different types of biomass due to ILUC/LUC?
Yes. However this has been assessed by the FlexSNG project team @CERTH – and not addressed today.
7. Does the pre-treatment consider reducing the minerals/ash content of the biomass, especially from wheat straw and SRF?
Yes. As saw from Yasaman’s process configurations, various advanced pretreatment schemes have been (and continue to be) explored. If you have a suggestion for a particular innovative configuration, we would be interested.
8. What high prices for SNG in Quebec will probably/certainly not last for decades, however economics do not seem to be promising. what are in your opinion conditions to make the flex sng process attractive?
We looked at some great examples with industrial symbiosis, I feel that could maybe improve economics. As we can see there is a lot of low grade energy that is lost in the FlexSNG process that now is not valorized. So that could be an idea for input. Without policy there can’t be much of a project, so the government capital support for the risking projects is in my opinion necessary for these type of bioenergy projects
9. For energy as weel as benefits, did you consider 100% recovery? Because there is a lot of loss as well as contaminants (eg sulfur) that could decrease the benefits of biogas
I would say yes. That it’s been the Flexsng process has been modeled very carefully based on the results of VTT. It’s quantitative for the set of design conditions shown in the presentation.
10. In terms of availability, your calculation considerer all feedstock or you apply a factor? As there is a lot of challengers for agricultural as forestry biomass today (biochar, biogas, energy…)
We do agree with that. The challenge is in the gas cleanup, in the plastic and in the ash. But as said the wood is the easiest one and then the waste wood is the difficult one, especially if it contains some Plastics or other impurities. A big part part of the innovation is that FlexSNG has two modes of operation. And related to that is the production of biochar and then the reinjection of biochar, the mixing of it with some of the feed stocks. VTT showed that this really stabilized the operation to a good extent even with difficult feed stocks
