Chemistry Reference
In-Depth Information
Table 13.1
Equipment characteristics.
Feature
Packed column
HiGee
Shell material
Carbon steel
Carbon steel
Shell dimensions
Diameter: 1.37m
Height: 13.7m
Diameter: 1300mm
Length: 2640mm
Random packing: stainless-steel 2
00
Pall rings (assumed)
Height of packing: 10m
(one bed)
Others particular
characteristics relevant
to equipment
Rotor dimensions:
Outer diameter:
660mm Inner diameter:
280mm Axial length:
250mm
Table 13.2
Equipment costs.
Packed column
HiGee
Present estimate
119 000 euro
80 000 euro
Bucklin et al.'s estimate [6]
165 000 USD
150 000 euro
where you are going, you are not likely to get there'. This case study is about how early phase
analysis of a process, including its economics, becomes a powerful tool in helping define
research targets. The approach used here is generally applicable to any project.
The very first step in a creative process is to define a focus: a target on which to
concentrate. There are several foci that more or less precipitate from this case study. Care
has to be taken in how to formulate them. They must not be so tightly defined as to hamper
the creative process, but too wide a definition would lead the process astray. Examples from
the case study are not limited to, but include:
How can the pressure drop be reduced to decrease the energy used by the fan?
How can the erected cost of the absorber be reduced?
How can hot and cold absorbent be heat exchanged more cheaply?
How can the energy needed for desorption be radically reduced?
The role of PI in this is to add the term 'radically' to the last question. Let us go back to the
description of PI as a way of reducing the size of equipment by two orders of magnitude. It
is clear that such a challenge would help set a very different agenda for creativity than if the
goal were simply to 'improve'. A different, but equally radical, angle would be to ask: Do
we need this piece of equipment, or could the function be taken care of by another item
already in the process? Or slightly differently: Could we combine two or more pieces of
equipment? As an example, it has previously been suggested that the reboiler could be
integrated with a rotating packed bed for distillation [9].
Many people working in research would argue that the type of analysis performed in this
case study would be impossible until considerable work had been done. This is not true.
Estimates, including the economics, can be made even if the idea is barely sketched. As is
generally taught in chemical engineering design classes, the first thing to check is whether
the product is more valuable than the raw materials. When an idea is first formulated and
Search WWH ::
Custom Search