Page 70 - Design of Simple and Robust Process Plants

54 Chapter 3 Design Philosophies
A striking example is the paint industry where, in order to reduce the number of
color compounds for distribution to the final customer, base colors and color con-
centrates are sent to the shops. When the customer arrives in the shop the required
color composition is prepared while he or she waits for their request to be carried
out.
In the process industry, several techniques are applied to implement the JIP con-
cept. In batch or campaign plants, only basic products are stored to a limited extent.
The additives for each customer are added either during loading into the transport
truck/system.
container/railcar, or at the customer's location, using a local dosing system. Loading
of material might be through a revolving manifold, and be automatically operated,
in order to minimize piping at the loading station. The ultimate option is to load the
product from the process directly into a transport container, without any storage
(see Figure 1.7 in Chapter 1).
Minimization of storage and operational cost is the main challenge of the supply
chain. Optimization should be carried out with respect to the transportation cargo
size, frequency and reliability of supply, processing reliabilities, storage volumes
and the customer delivery requirements, (Figure 3.4). The delivery requirements are
a trade-off between storage capacities transportation cost and the probability of capa-
city loss, due to unavailability of product. The methodology for optimization of stor-
age is based on probabilistic inputs of processing and transportation deliveries and
Monte Carlo simulations. The technique is known, and will be discussed in Chapter
7 (Storage optimization). The ultimate aim of JIP is to have a line between two
production facilities, without any storage. This may sound optimistic, but in the
case of gaseous feeds that is often a standard solution, especially in cases where
materials are highly toxic or flammable (e.g., chlorine, HCl, H 2 , CO), and also for
natural gas and hydrocarbons such as ethylene and propylene. The transport of liq-
uids through pipelines to processes in the neighborhood is being used increasingly.

Transport Storage Process Storage Transport Storage End product
Process
frequency? frequency?
cargo size? cargo size?
reliability reliability reliability reliability
Size? Production Size? Size? Process for
Process end product

Fig. 3.4. Optimization of a supply chain based on reliability and
availability data from transportation, production process, custo-
mer processes.