Waste-to-Energy Project Planned by Energos

"advanced thermal conversion" is ambiguous so I went to the web site. It doesn't explicitly say 'fluidized bed' but that is what I suspect it is.

The other technology (at least that I am aware of) is plasma. Both result in gasification.

There must be a commercial/technical reason why we don't hear more about plasma gasification.

Why don't we hear more news on "Thermal Depolymerization" plants. Supposedly they produce a light oil ideal for diesel fuel.

Part of the reason you don't hear much about gasification as a solution for waste is that the media is dominated by the lobbyists pushing for large-scale plants (which almost certainly means incineration + steam turbines). The gasifier route provides smaller, decentralised solutions, but are not considered big enough in capex terms to be of interest to the big players. Plasma gasification is great for conversion of hazardous wastes but comparatively expensive in terms of operating expense when using it for "normal" wastes.

One of the other "problems" is that the sector is still suffering from the hangover of technology short-comings of earlier designs (which blocked the banks' ability to approve project finance structures), so that industrial/commercial sized demonstration plants are only now being built and commissioned.

The producer (or "syngas") gas generated by a single stage gasifier (or a two-stage pyrolysis and gasification) plant will allow you to do many things with the gas, including production of syndiesel (hats off to messrs Fischer and Tropf). Much depends on what the input feedstock contains. Whether or not this delivers an economically-viable end-product is very much market-driven - the safest bet at the moment is to use the gas in a CHP application, ideally with gas IC engines (comparatively high efficiency) or (if you haven't solved the gas clean-up issues) boiler and ST configuration (comparatively low).

Chris,

Referring to small scale local/decentralized plants - how small can they be and still provide a positive cost/benefit scenario? Can something be done with a 1 to two ton/day wet food waste (with some waste cardboard and paper) feedstock?

We're looking at a prison feeding 3000 persons/day that also has a 12,000 SF 'food factory'. Consider that the labor would be almost free, except for some inmate supervision. Existing costs are tipping fees at a pretty low basis of $35 to $70/ton.

The cost aspect would be compared, in a scenario of 1 year to max 10 year equalization or improvement of costs. It is recognized that government and private grants, energy rebates might be available but we don't want to count on those for the cost analysis.

Milt, yes the company I represent here in the UK & Eire, KIV based in Slovenia, can make these reliable, proven and bankable WID Compliant plants at a small size from 1MWth to 25MWth input, see www.kiv-uk.com or www.kiv.si Just so long as the net CV is >8.0 MJ/kg and the moisture content is <60% - then we can combust it and give you your energy back in heat and /or power (depends on scale of plant).