Environmental Engineering Reference
In-Depth Information
of epichlorohydrin from glycerol using the Epicerol TM [13] process and Bio-
Methanol Chemie uses glycerol to produce synthesis gas which is reformed to
methanol [14]. Archer Daniels Midland also plan to use this feedstock to pro-
duce glycols [15], and others are investigating its use to produce (on pilot scale)
1,3-PDO using Klebsiella pneumoniae [3]. A review by van Haveren et al. in 2008
describes the potential to produce a wide number of chemicals from various biomass
components including glycerol [16].
3 An Approach
If one considers the enthalpy changes involved in the petrochemical industry, the
conversion of oil to other hydrocarbons are carried out with no major changes in the
enthalpy of the raw materials and the products formed and also production is car-
ried out with very efficient use of energy. However when hydrocarbons are used as
the raw materials to produce chemicals functionalised with amine, carboxylic acid
functionalities and the like, the resultant product has a lower calorific value than
the original raw material. Allied with this large amounts of energy are expended in
the production process itself and auxiliary energy is required for the production of
co-reagents e.g. chlorine, ammonia, in order to introduce the required functionality.
Renewable raw materials consist of a number of major components: oils, carbo-
hydrates, lignin and protein, as well as a small amount of other compounds. Thus
renewable raw materials contain functionality and indeed in some cases require the
removal of some functionality in order to transform them to compounds similar to
(or the same as) those currently produced in the chemical industry. This is opposed
to the approach used with oil (or gas). It is conceivable to consider using biomass to
make one common intermediate, for example conversion to synthesis gas (CO and
hydrogen) and using this to prepare base chemicals which can be rebuilt to make
the desired compounds. However this appears to be “using bonbons to make bars
of chocolate” and does not take advantage of the functional groups present in the
renewable raw material.
To achieve the best use of renewable raw materials (or biomass), and to be able
to generate a respectable net income from a crop, it is desirable to utilise (all)
components for application (in the broadest terms: food, heat, fuel, chemicals) by
employing an efficient bio-refinery process [17]. In terms of raw material value per
GJ of biomass produced by the farmer, if it is used only for its calorific value, then
returns are low, too low to cover costs. However returns would increase if higher
value applications such as fuels could be achieved and this should cover costs. For
“high end value” applications such as functional chemicals, the returns would be
high and the result very profitable. However it is unrealistic that all components
could be used for such an application and that it is more likely different fractions
(obtained from bio-refinery) for several applications could be achieved thus still giv-
ing rise to a good return. The fractions obtained should then be used for the most
suitable application or transformation. For example, it would be more advantageous
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