Fit for Purpose – assumptions in MSW and WtE

End to end solution for treating Metropolitan Sewage and Waste (MSW) is a hot topic, and very much in the fore of forums for 2013. So enthusiastic are the players it is very difficult to differentiate the fact from the ideals. Look and you will see a lot of justification and more than adequate presentation of the material. What is more difficult is to get a clear indication of the capability and improvements over current practices.

The culprit may be assumptions, and they are widely used under management scenarios. If we define assumptions as a statement that is assumed to be true and from which a conclusion can be drawn. It might even be that as we rely more on big data an omission from the assumption can lead us to ignore the obvious. Take this example statement – Our machine can undercut all other in terms of power costs. Then if we find published a number of a competitors, but necessarily the same technology, we can quote that number and assume ours as similar or superior. Yet, as was said it is not the same technology.

Recently a post was read and it said in the US, under US Average Levelized Cost for Plants in the Annual Energy Outlook 2009 and 2010 and 2011, a typical generator running on Biomass has net requirement for a price of 11 c kWh to break even. Then came an assumption from the author that as these tables have no values for Advanced Plasma Conversion it is assumed a value of  $0.044/kwh is the value that you add for comparison. The difficulty is the published number for biomass is taken from experience and certain modeling under a list of data sources. The advanced plasma conversion unit was then part of a hypothetical assessment according to mathematical values that commence with an assumption, and will be correct until proven wrong. The fatal flaw in this is that facts are with the biomass and its testing included load scenarios and importantly it has a generator (that thing that produces electromotive force – electricity) attached. What is obscure is whether the Advanced Plasma Conversion unit is connected to a generator, or whether it needs one. For an investor this is a matter of concern, and for a professional in the industry it says embarrassing!

Another major issue is the maturity of the solutions put forward for you to make a project decision.  At program level you can take liberties and shuffle as you need to, at a project level on time and on budget can be you nemesis if you make the wrong assumptions – as said earlier – assumptions are a management scenario. CO2Land org assumes four scenarios are possible for waste handling solutions. It can be put forward to consider: Business as Usual, Gasification, and Pyrolysis, Plasma conversion.

  1. Business as usual (BAU) is an option fast running out, and in areas of rapid urbanization and rapid growing economies the time has already arrived that it cannot continue, not just because of the carbon issues but because it is an economic cost. This does not discount the importance of carbon, but indicated that developing countries needs the resource recovery as much as it is in need to develop.
  2. Gasification is an effective incineration tool, and innovations are proving to be effective in optimizing syngas recovery and returning additional products from the process for agriculture and raw material recovery.
  3. Pyrolysis is also an incineration tool, albeit at higher temperatures with the added benefit of being able to produce syncrude and chars to order. The process needs to be well managed to avoid the possibility of producing dioxins.
  4. Plasma conversion has been around for some years and has chequed history as an incineration method. Two particular issues have dogged the traditional designs. High and constant power requirement, and not being able to control temperature and ionizing across the plasma bed. Considerable claims are being made of advances in the technology. Confidence is continuing to grow on the refinement of the equipment and a number of sites across the world are being implemented.

The Cost benefit of each scenario indicates:

  • Point one is clear – the high cost of resource recovery weighs heavily when the budget is restricted for an authority and they would promote BAU until an incentive was put forward.
  • Point two and three are relevant and in more recent times the marrying of the two according to need is seeing this technology develop into a useful cost effective solution and should be the method of choice in most instances for the next 7 to 8 years.  By this it is meant it is the best technology to implement for most scenarios now and into the future in that time frame and it useful life for many more.  It also has an advantage of being complimentary to most commercial activities, and the ability to be scalable as required.  The strong point potential is to return a number of waste materials, especially plastics to virgin materials.
  • Point four will be the technology of the future; it has the potential (ideal) and the hopeful expect an almost unending product potential from this technology. The next generation is expected to be approved and producible in around 5 years. The scale of the projects required to cover the capital costs is the biggest limiting factor for future projects.

In more detail is this information the current Waste to Energy scenario suggests the difficulty is with the techno-commercial format. That comparing apples with apples may not be possible. An example is given by 
William G. Acker (http://www.ackerandassociates.com) where he looked for Advanced Plasma Conversion tables in the U.S. Annual Energy Outlook 2009 and 2010 and 2011. In these tables there are no values for Advanced Plasma Conversion. So he then said he must assume that what was claimed by another company representative was a value added to the values. He himself then assessed the closest estimate to which the technology is closest to be the figure for Biomass. This is not his definitive position, all he asks is someone to provide a value to share that is more accurate. However, in the mean time we make the assumption it must be correct until refuted

Then CO2Land org decides to ask a question in a forum on Waste to Energy (WtE): “Excuse the confusion, a lot of justification and adequate presentation of the material is provided. What is not clear is the capability from the production of an energy source to the actual electromagnetic force. In other words: what are the source, type and cost of the generator machine? Or, is your Plasma machine also a generator of electrical power in its own right without the need for other equipment?  The response: Good question!  The discussion then centres on whether matters were assumed or simply relayed on what was actually said on the capacity and nothing more.  Being that capability was not addressed is not the domain of the engineers for not giving you correct info, or how confidential agreement might stop you providing information. It may well be a simple case of the enquirers having no idea on what to ask. They do not ask because it was not obvious or lost in techno-commercial format of the communications.

In the quest for comparing apples to apples, and ignoring that baseline quotes may be flawed. To compare the possible in WtE from our view (to which we will assume you will be at odd. Information supplied illustrated:

A hearth gasifier with a reciprocating low Btu engine and conventional generator can be leased in Australia with an operating cost of 8.2cents per kilowatt-hours, with a 25,000 hours maintenance requirement. These costs are worked assuming a 1MW net unit and economies of scale suggest lower costs for larger units. If I combine the capability of the unit with a pyrolysis retort and produce syncrude and biochar, the offset pricing suggest a decrease in generation capacity will result, but the operating costs will settle at around 5 cents a kWh. The number will vary according to the feedstock quality.

Very recently an indicative quote that asked for capacity to handle MSW with1750 kcal as feedstock and input 300 tonnes per day for using advanced plasma conversion. What would be the project cost? The answer came back in the order of  $6.5m plus the cost of shredder activity and generator sets required – that is the cost to add capability is not in the cost mix.  The difficulty now is the assumption that must be made in the numbers.

In another example of a project where the project is not only proposed, is financed (and currently on hold to commence), is again supplied by William G Acker, of the MSW Plasma Gasification Facility for St. Lucie, Florida. This facility would use 686 ton per day of MSW and would produce 22 MW Gross and 18 MW Net of electricity. The installed cost came to $190,000,000. Amortized the project over 30 years with the Levelized Capital Cost alone (no maintenance cost, no labor cost etc.) comes to $0.0922 per kWh. If we add labor and maintenance costs the total may be ‘assumed’ to be around $0.14 per kWh. Then we must consider the money made for taking the waste off the hands of communities, or business that are paying to, landfill it we then could subtract around $0.03 per kWh from the operating cost resulting in $0.11 per kWh.

This results in CO2Land org asking: Will the actual plasma price to generate electricity please stand!  So we know without assumption forming the core costing criteria a project cost is capable of producing electricity for approximately 11 Cents per kWh, and the example hearth gasifier somewhere from 4.4 to 11 cents per kWh. Albeit other examples might swing wildly towards higher costs depending on the operating and technology vintage.  That said there is no doubt that given time and R&D plasma conversion in whatever form will be the way forward. In other examples plasma systems are doing OK for the job required, but academia and those in the industry say it is some way off being perfected and as efficient as it should be.

If we go back to the influence of assumptions the problem for the industry is that laboratory results and mathematical equations don’t often become reality, as not everything is scalable. In the mean time it is “danger danger, Will Robertson” as borrowed from ‘lost in space’ which was entertaining series a little while back. We also need to be fully aware of the smoke and mirrors approach that do a wonderful job with customers who are not normally that knowledgeable.

Another factor of our times is that despite each supplier wanting to win each job, they are fighting for funds within an economy where funds requiring $50M or more are highly competitive. In these instances those projects where the technology is still to be proven it will take second place to those known to do the job.

Evidence of uncertainty in the accuracy of a useful lifecycle may lead you to consider that you might want to lease the plant, it could be a lower risk in these times. The more popular in these circumstances are suggested as those that offer an operational lease rather than a financial risk.

We trust that has covered off on the choices – if you feel too much assumption is made or if you know better – please show yourself!

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