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Re: level of effort for mass balance?



Materials (resource) accounting (according to the National Academy of 
Engineering report which predates both the Massachusetts and New Jersey 
legislation) is performed with available information and estimates.  It is 
not a mass balance.  The numbers do not have to "balance."  They can be 
approximate.  Burt used the term, mass balance.  One has to be careful not 
to use these terms interchangeably.

The points Melinda raises are excellent.  However, there can be some 
problems with using industry-accepted and other "engineering" estimates as 
the basis for materials (resource) accounting.  The API estimate that I 
referred to in my last note was a widely accepted value used the entire 
industry for DAF treatment.  It turns out that the estimate was taken from 
a single flux chamber reading in the sixties at a single refinery.  The 
real situation for benzene emissions at the Amoco Yorktown refinery was 
750% lower when measured.  Is this pollution prevention?

Information on the Material and Flow Cost Accounting (Eco-Effizienz) 
methods gaining rapid acceptance in Europe and Japan can be found at 
http://www.imu-augsburg.de  I have been using some of these principles in 
some of my recent work with great success.  These methods link directly 
into the management information systems (e.g., enterprise resources 
planning software like Oracle or SAP) to get information on resource use 
and cost.  This substantially lowers the cost of data gathering and makes 
the results more "believable" to management - since you are using their 
numbers.

Hope this helps.

BOB Pojasek

>Bob et al,
>Please differentiate between a detailed chemical mass balance (which is
>what the Nat'l Academy of Sciences did) and the much more commonly used
>materials accounting process. Materials accounting is straightforward
>chemical engineering and while it does take some time and effort (not
>unlike the estimates per chemical from Burt below), it has been shown to
>be well worth the effort in NJ and Mass. Here in NJ, for every dollar
>spent to do P2 Planning (including process level materials accounting),
>facilities found 3-8 dollars in savings. The other 2 big bonuses: 20-80%
>of all environmental releases were "discovered" and had gone
>unpermitted, and of course, production managers had a chemical use
>efficiency measure that they could track as frequently as they wished.
>I would never recommend a chemical mass balance unless a facility had
>no idea of what chemical tranformations took place in their processes.
>Melinda Dower
>Research Scientist
>NJ Dept. of Environmental Protection


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