Support from experts on hardware

3.6.1. Plant engineering and operation

When implementing the new process at an existing plant site, cooperation

between the process developing team and the senior technical staff of the plant should be established early. This will be beneficial to both sides. Admit- tedly, such cooperation may often cause personal problems, mostly due to the differences in priorities, point of view, and style of communication between the two groups (i.e., what do they know about runninga plant and about R&D science?). Here, the personality of the project manager should bridge these differences, and it is always better to address and solve them calmly and in a timely manner than under decision-making pressure. The plant’s management also can contribute some very good ideas and propose effective and practical design solutions from their point of view, and should be given credit

for that. This cooperation can become critical anyway if it is decided to install and run a pilot plant at the plant’s site and connect it with “live” streams.

On the other hand, several cases have been known of new processes that have been developed “in secret” in the corporate R&D facilities and that were later bluntly opposed and rejected by the plant’s operating manage- ment who felt that it was forced on them without their consultation.

Whenever possible, the process developing team should get a clearand earlypicture of the eventual implementation conditions of the new process in connection with an existing facility, including its infrastructure, existing services, and waste disposal possibilities. These specific conditions can pose

objective limitations that have to be taken into account in the early stage of development, rather than making changes later. For example, the design temperature of the cooling water supply depends on the average climatic conditions in the area and can be critical when designing an installation for evaporation/condensation under high vacuum.

3.6.2 Equipment design

In many cases, the design of a novel process section can be critically linked to one particular piece of equipment or specific technology. Thus, the process’ results will depend not only on the process chemistry, but also on a particular combination of equipment design factors and operating conditions.

Furthermore, it may be that this particular piece of equipment or specific technology can be supplied only by a very small number of specialized com- panies, each of them with their particular know-how, or at least their claims of such know-how. For example, this situation can apply to industrial crys- tallizers, special dryers for hygroscopic solids, industrial plasma heat torch, and the like. The process developing team may be feeling “cornered” if they are operating in a corporation committed to the “purchase-by-bid-only” procedure, since such formal link with a specialized supplier may cause the following problems.

• From the beginning, in order to get enough information from any would-be supplier for evaluation and preselection, a mutually bind- ing secrecy agreement should be negotiated. This is not a simple proposition, but requires at least that the novel process has already passed the patent application stage and that the equipment supplier is not already signed up with competing corporations.

• The pilot tests should be done with one particular supplier in mind (most probably with his pilot equipment) and the cooperation of his staff after a basic commercial framework has been established. • This procedure would give the selected equipment supplier a clear

advantage in the final price negotiations, which would include some remuneration for his know-how and past experience, and for his guarantees and assistance in start-up.

• It would be logical to include the engineering company staff at this stage of “prepilot” equipment survey and contract negotiations, and use their experience and services also in the pilot testing. However, this participation would need to advance the decision on the contract bid for the choice of the engineering company more than it would be generally anticipated.

3.6.3 Corrosion in construction materials

In many cases, the novel chemical process conditions can introduce unknown

corrosion aspects, which have to be clarified as early as possible. These aspects relate to the reliability of the materials of construction that will be used for the equipment and for the piping. This reliability bears first on safety considerations deriving from a possible accidental failure (particularly in pres- surized and/or high-temperature systems), but also on theestimate of the lifetime, supply cost, maintenance schedule of each piece of equipment, or the possibility of contamination of the product with metallic traces.

The orderly and reliable testing of the corrosion rate for each combination

of one particular choice of construction material and one particular set of process conditions is a relatively long procedure of many months, starting with obtaining reliable samples of unusual materials of construction. Furthermore, the exact and final conditions for such a corrosion test might be known only after the process development has firmed up (compositions, additions, temper- atures, etc.). Therefore, the tendency is to be safe and to test the worse possible conditions. But this choice can also lead to an expensive overshooting. Even if the choice of just-in-case better/safer materials is available, it may result in a sig- nificant increase in investment costs and reduce the calculated profitability.

The presence of certain “trace elements” impurities in certain streams can affect seriously the corrosion properties. A classical example is the pres- ence of copper cations in a solution, which can “cement” on a steel surface, create a corrosion cell, and (quite surely) a hole. When such possibility is defined and confirmed, the need for certain pretreatments or a side-stream treatment becomes an essential part of the process or, in certain cases, the need for bleed streams to avoid accumulation of such impurities.

This is a highly specialized field, and it is advisable to engage, from an early stage, the support of an expert consultant with relevant industrial experience, who can recommend the options and procedures to arrive in time

at the optimum specifications for materials of construction. Furthermore, the public authorities and the insurance company representatives often insist on receiving written recommendations from an expert, at least in relation to the risks and damages that could result from a possible accidental failure.

3.6.4 Operation and process control

Nowadays, automatic process operation and control are taken for granted for nearly every new chemical plant. The design techniques and the hard- ware selection are well advanced; however, the correct design is critically dependant on the input of process experts with industrial experience on the following issues.

• What are the more efficient procedures for starting and stopping of the plant? These transient procedures are not obvious, and they are not always well covered in the basic designs. They have to be care-

fully thought out for every new process and for every installation in particular, as they determine the internal inventories of the buffering tanks, or the need for recycling certain streams, or for reprocessing some bulky intermediate streams. These transient procedures are based mostly on kinetic response data, which may have to be measured experimentally, or inferred from previous reliable industrial experi- ence in similar situations.

• How to assure a safe response to any possible failure of some equip- ment or a possible error in the action of an operator, limiting the risks and damages.

• What is the better choice for reliable probes and instruments in direct contact with the process streams, which are made of suitable materials and can be available and supplied off-the-shelf?