From: Rich Blinne (richblinne@hotmail.com)
Date: Wed Sep 04 2002 - 12:27:25 EDT
----Original Message Follows----
From: "Glenn Morton" <glenn.morton@btinternet.com>
To: "Rich Blinne" <richblinne@hotmail.com>,<hoss_radbourne@hotmail.com>
CC: <asa@calvin.edu>
Subject: RE: Biomass Hydrogen Paper in 29 August Nature
Date: Wed, 4 Sep 2002 06:15:52 -0700
Rich Blinne September 03, 2002 4:16 PM
>What I don't see in the article or the review is any mention of how much
>energy must be spent to get that hydrogen. The only energy balance they
>mention is that you get 1 kW per liter volume of the reactor. What is
>needed before this becomes an energy SOURCE is how much energy is spent per
>liter volume of the reactor in operating it plus the fixed cost of building
>the darn thing (steel manufacture, transporation energy, construction
>energy etc). I can't see that this process would be more efficent than
>other uses of biomatter. If it takes more energy to manufacture the
>hydrogen than that which you get out of the process, it is not useful for
>an energy source.
Yes, the nasty word endothermic is in the paper. Now there is no
calculations that I can find to back it up but the paper does say this
concerning energy balance:
>Reforming reactions between hydrocarbons and water to generate hydrogen are
>endothermic, and conventional steam-reforming of petroleum thus depends on
>the combustion of additional hydrocarbons to provide the heat needed to
>drive the reforming reaction. In contrast, the energy required for the
>aqueous-phase reforming of oxygenated hydrocarbons may be produced
>internally, by allowing a fraction of the oxygenated compound to form
>alkanes through exothermic reaction pathways. In this respect, the
>formation of a mixture of hydrogen and alkanes from aqueous-phase
>reforming of glucose, as accomplished in the present study, is
>**essentially neutral energetically**, and little additional energy is
>required to drive the reaction. In fact, the energy contained in these
>alkanes could be used as a feed to an internal combustion engine or
>suitable fuel cell; this would allow the use of biomass-derived energy to
>drive the aqueous-phase reforming of glucose (and biomass more generally)
>with high yields to renewable energy. [emphasis mine]
>From what I can glean from both the paper and the review article that while
prograss has been made but we are not quite there yet, both from a monetary
and energy balance perspective. Nevertheless, I find the results
encouraging.
As for your ethanol example, I lived in Iowa in the '80s. It was pretty
much an open secret that the ethanol programs was a payoff for the farm vote
and Archers Daniels Midland.
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