Research and Development

       The chemical process industries spend more money on research and development than do most other industries. As a result, we now use many kinds of products unheard of a few years ago. Countless items in our daily lives are different from those our parents used, because of this innovation. Much of our clothing is now made of synthetic fibres instead of natural materials such as wool or cotton. The toys our children play with are often made of plastics that replace wood or metal. And many of us drink instant coffee rather than brewing the beverage from ground coffee beans.
       These kinds of products have come about through research and development in research laboratories (Fig. 2.1). These laboratories are usually staffed by chemists who do their experimentation in the usual laboratory glassware. For example, when two materials must be mixed together, the chemist may do it with a glass rod or by merely shaking the container. The mixture can be heated by placing the container over a small gas burner or cooled by setting it in cold water. But many of the things that seem so easy in the laboratory are much harder to do in the plant. Even making the same product in the same way, but on a larger scale, presents many problems.

       Let us look at a very simple process as the chemist does it and as I might be done in a chemical process plant. He or she (many chemists are women) takes a bottle of Chemical A from a shelf and dumped into a flask and a second liquid, Chemical B, is measured and added in the same way. Chemical C, a powder, is weighed on a small laboratory scale and added to the two liquids. The chemist mixes the chemicals together by shaking the flask and heats the mixture over a small gas flame, with constant shaking. Finally, the mixture is rapidly cooled by placing the flask into a container of crushed ice. The chemist may have made a total quantity of a half-litre or less of product. 

       Now consider the same process carried out in a plant in batches of a thousand gallons (Most chemical plants in English-speaking countries still use the old units such as pounds, feet, and gallons). Instead of a glass flask, the container will be a thousand-gallon metal tank. Chemical A will not be in a bottle on a shelf – it will be in a storage tank. The proper amount of Chemical A will be added by pumping it from the storage tank through a flow meter into the processing tank. Flow meters usually show flow in gallons per minute, so five-hundred gallons might be added at 50 gal/min for ten minutes. Chemical B will be pumped from its storage tank in the same way (The operator will probably pump both liquids into the processing tank at the same time unless there is a danger in mixing them this way). Adding Chemical C – the powder – is not as easy. If only a small amount is needed, it might be weighed into a container and dumped by hand into a mixture. If larger quantities are required, Chemical C will probably be stored in a hopper over the processing tank; the hopper will have some sort of measuring (usually weighing) device to ensure adding the proper amount. 

       Mixing a thousand-gallon tank cannot be done with a glass rod so the engineers will have provided a mechanical mixer, something like a ship’s propeller, driven by a an electric motor. The tank will probably be heated by steam supplied to a steam jacket surrounding the tank. The mixture in the tank is stirred throughout the heating period to make sure it is heated uniformly. To cool the mixture, the steam will be shut off and cold water pumped into the jacket. Water cannot be cooled below 32oF (0oC) without turning to ice, but colder temperatures can be achieved by using a solution of salt water called brine. Finally, the mixture will have to be pumped into another tank for storage or the next stage of the process. 

       What has just been described is an example of a batch process in which a given amount of chemicals is processed in some way to yield a quantity of product. Batch processes are commonly used when relatively small quantities of materials are handled and are particularly common when the materials are expensive. For example, batch processes are very often employed in the manufacture of drugs, dyes, and foods. 

       Another widely used way of handling materials is the continuous process in which materials are constantly fed into one end of the equipment and finished product comes continuously out of the other end. All petroleum refining, for example, is done by continuous processes. In a refinery, crude petroleum is pumped into one end of the plant and a continuous stream of gasoline, kerosene, and fuel oil pours out of the other end. Let us look at the simple process we have been describing (mixing quantities of Chemicals A, B, and C, heating, and cooling) and see how it might be done as a continuous process. 

       The two liquid chemicals are pumped by a proportioning pump into a small mixing tank, where Chemical C is continuously drawn off the bottom of the mixer and passed through a heat exchanger where they are steam heated. They then pass into another heat exchanger where they are chilled by cold water or brine. The products flow out of the end of the cold heat exchanger. 

       Because chemical plant equipment is so different from that used in the laboratory, one of the major jobs of R&D engineers is to decide what kinds of equipment must be used to carry out a commercial chemical process. They also determine the sizes of equipment needed – how big must the pumps be, how much power must the mixer have? Before designing the full-sized plant, the R&D engineer usually constructs a pilot plant – actually a small model of the final plant, containing small versions of the equipment (Fig. 2.2). Pilot plants are particularly useful when designing continuous process plants which are so different from the research laboratory (It is usually impossible to run a continuous process in the standard laboratory glassware available to the chemist). 

       A continuous process pilot plant will usually run twenty-four hours a day with three or four groups of operators and engineers, each group working for eight hours. This is called shift work, and each group is called a shift. Most often, shifts work from 8 a.m. to 4 p.m., 4 p.m. to midnight, and 15 

midnight to 8 a.m. A fourth shift is needed if the plant is to run during weekends, although many pilot plants shut down at that time. Usually there is a group leader in charge of each shift. The group leader may be a chemical engineer, a chemist, or a specially trained operator. This arrangement makes pilot plant experimentation unattractive to many chemical engineers who prefer to work during the day and leave the evening and night shifts to specially trained operators. However, a pilot plant is often so complicated that engineers are required on all shifts.

       Since the basic purpose of the pilot plant is to gather information, there are frequent changes of flow rates, pressures, and temperatures. R&D engineers are always looking for that combination of conditions that will enable them to produce the maximum amount of product at the minimum price. As information is gathered, it is passed along to the company’s management. This may be done by memoranda and telephone calls but in most companies, once a month; the R&D engineers write all they have learned during the past month in a progress report. These become their main record of accomplishment. The purpose of R&D is to gather information; since a company’s management judges R&D engineers by the reports they submit, a great deal of work goes into the reports’ preparation. When the research and development project is completed, information in the various progress reports is consolidated into a final report that details everything learned during the research. This final report is invaluable to the process design engineers who will design the full-scale plant. 

       There is one thing about R&D that many engineers find frustrating: a project is seldom finished. As with all research, there are always more ideas than time or manpower. Eventually, the work must end, even if the best possible design has not been reached. Otherwise no process would ever get into full-scale production. The decision to end a project is usually made by the head of the research laboratories in consultation with the executives of the company.

Special Terms 

Laboratory: A place especially equipped for experimentation, testing, and/or analysis in a particular field of science or technology. 

Flow meter: An instrument used for measuring the flow of fluids (liquids of gases). Many different types are available. 

Hopper: A container, usually funnel-shaped, for storing and delivering powdered or granular material. It is filled from the top, and the bottom is often equipped with a device for delivering measured quantities of the material. 

Steam Jacket: A shell fashioned around a tank or other vessel. Steam is introduced into the space between the vessel and the shell, thereby heating the vessel and its contents. 

Batch Process: A way of manufacturing chemical products. Measured quantities of materials are carried through a series of operations, step-by-step, to produce the final product. 

Continuous Process: A way of manufacturing chemical products in large quantities. Raw materials are fed continuously into one end of the processing plant, flow through various operations, and emerge as the desired product. Continuous processes may run for months or years without stopping. 

Proportioning Pump: A device usually consisting of several interconnected pumps. They are designed so that their outputs are adjustable, thereby permitting the ratios of materials discharged to be changed. 

Heat Exchanger: A device for heating or cooling fluids. Steam is usually used for heating and cold water for cooling. 

Pilot Plant: A miniature plant used for experimentation.

Shift Work: A way of staffing a plant or laboratory continuously for long periods of time. The workers are divided into groups; each group works at a different time. 

Group Leader: The person in charge of a group of people. In experimental work, the leader is usually an engineer or scientist. 

Progress Report: A description of the work of a group of researchers. Generally, a progress report is written each month.

What Chemical Engineers do

       Most chemical engineers work in the chemical process industries. These include the plants that manufacture such things as food products, plastics, paper, fertilizers, petroleum products (gasoline, kerosene, fuel oil), synthetic (manmade) fibres such as nylon, and the basic chemicals used by 3 many industries, such as acids, alkalis, and dyes. These are all industries in which raw materials are separated or changed into useful products.
        Almost all chemical engineers are college-trained in mathematics and physics, with particular emphasis on chemistry. However, the basis of chemical engineering is the study of unit operations.
Before the First World War (1914 to 1918), all chemical process plants were designed and operated by chemists. (Even today, in some countries such as Germany, this work is done by specially trained chemists.) However, shortly after the war, three American college professors – Walker, Lewis, and McAdams – published a book based on principles common to all chemical process plants. They noted that in all plants materials were mixed together, heated, cooled, moved from place to place, and wanted materials were separated from wastes. Each of these steps was termed a unit operation, and the student was taught both the engineering principles that underlie each one, and the procedures used to design or select equipment for each operation.
        Every chemical process consists of a number of sequential unit operations (Fig. 1.1). Much of this book consists of descriptions of unit operations, so they will not be further discussed at this time.

       How does a chemical process plant come into being? It starts with an idea – an idea for a completely new product, for improvement of an existing product, or for a way of producing an existing product at a lower cost. Ideas for completely new products usually come from a company’s research laboratories but improvements on existing products may occur to almost anyone. 

Once the executives of a company have become interested in the idea of building a new plant, their first step is usually to call for a feasibility study. Such a study involves estimating production costs for the product as well as its potential market. Since essential engineering information is usually lacking, these estimates may contain major uncertainties. 

       If it appears that the plant will make a reasonable profit, the next step is to develop the engineering data that will be needed in designing it. This is the job of the research and development engineer. The R&D engineers who work for a CPI company are generally chemical engineers, although in large companies some mechanical, electrical, and civil engineers may also be employed. 

       R&D engineers do part of their work in the library with books and articles. They often work with other specialists, most often chemists, who are expert in some aspect of the problem. And they may do or direct some laboratory work themselves. But there is a great deal of difference between making a product in a laboratory and making it in a chemical plant. For example, penicillin was developed by growing a mould on a nutrient solution in a flask. The first commercial production was the result of doing the same thing in thousands of flasks. 

       When chemical engineers were called in to work on the problem, they devised a method of growing the mould in thousand-gallon tanks. Large quantities of sterile air were bubbled through the tanks to provide the oxygen the mould needed for growth. (The air had to be sterile so that no bacteria would grow in the solution.) In the flasks, the mould grew only on the surface where it could get oxygen from the air. But in the tanks, there was sufficient air so that the mould could grow beneath the surface as well. Within a short time production was so high – and the price so low – that the drug was widely available.5 

       Because commercial production can be different from the laboratory process, the R&D engineer will often build and operate a model of the proposed plant in order to find out what kinds of problems may develop and how to solve them. When the research and development work is completed, enough information is available so that the original cost estimate can be refined to a fairly exact figure. Again, the company management has to decide whether to go ahead with the plant or to cancel the project. 

       If the company decides to go ahead, the next step is process design. In this stage, the chemical engineer decides what kinds of equipment will be needed for each unit operation and calculates the size of each item. He or she must also select the material that each equipment item is to be made of – usually metal, plastic, or glass – and contact various equipment manufacturers about prices. 

       One of the tools with which the process design engineer organizes all this information is the flow sheet (Fig. 1.2). This is a diagram that shows what happens from the time a raw material comes into the plant to the time it emerges as the desired product. The R&D engineer will probably have made a simple flow sheet to help him or her understand the process, but the one made by the process design engineer will be much more complete. It will show all the pieces of equipment in the plant and how they are connected. The flow sheet will indicate the temperatures, pressures, and flows at each step of the process, and other things as well. One of these other things is the instrumentation that will be needed for operating the plant. Most processes in a CPI plant take place inside the equipment and it is only by using instruments that the operators can tell what is happening. If something might lead to a dangerous condition, the instrumentation designer will generally provide flashing lights or ringing bells to call the operators’ attention to the developing problem. If it cannot be solved immediately, the entire plant may have to be shut down. 

       In many plants, instruments not only indicate what is happening but also run the process automatically. A person walking through a modern chemical process plant for the first time is often surprised at how few people are working there. It is possible to run a very large plant with only a 6 

few operators and maintenance people because the instrumentation does so much of the work. 

       After the process design has been completed, the design engineer often supervises the building of the plant. Chemical process plant is usually built by specialized construction companies accustomed to working closely with process design engineers. When the plant is finished, chemical engineers are placed in charge of it to ensure its proper operation. They are known as plant operation engineers and are usually executives who spend most of their time at desks. Many people work under them: operators who run the plant on a day-to-day basis; maintenance personnel who keep the equipment operating; material handling personnel who move materials from place to place in the plant; cleaners, clerks, and others. Supervising equipment maintenance is an important part of the plant engineers’ work. 

       They must be sure that both spare parts and trained maintenance personnel are always available to prevent shutdown of the plant. The main priority is to anticipate and prevent machinery problems. Repairing equipment before it breaks down is called preventive maintenance. Sometimes instruments are installed to indicate if equipment is running hot or vibrating excessively. But more often, elaborate records are kept on critically important machines – records that show how long each part is expected to last so that new parts can be installed before the previous ones fail. Another responsibility of the plant operation engineer is to keep a supply of raw materials on hand, although some raw materials, like natural gas, are brought into the plant by pipeline and are always available. Another term for raw material is feedstock. 

       It is not uncommon for a CPI plant to run continuously for a year without a break. But some pieces of equipment, such as high speed pump, cannot be expected to run that long without being stopped for maintenance. In such cases, a spare piece of equipment will be installed permanently, with piping arranged so that either one can be used. Then, if the item must be repaired, the spare can be put into service to handle the load. 

       Although most chemical engineers work either in R&D, process design, or plant operation, some follow other careers. They may become college teachers to train new engineers or they may become salesmen of chemical-process equipment. An engineer who has become well known as an expert in some phase of chemical engineering may work as a consultant, charging high fees for solving problems too difficult for the average engineer. (College professors often earn extra money by working as consultants.) And recently, more and more engineers are taking jobs with government. These usually involve enforcing laws that relate to health of safety.

Special Terms 

Chemical Process Industries (CPI): A large group of industries that use chemical and engineering principles to separate or change materials into salable products. 

Raw Material: The material that comes into a plant, where it is processed to produce a salable product. Petroleum is the raw material for the manufacture of gasoline. Sulphur is the raw material for the manufacture of sulphuric acid (H2SO4). 

Unit Operation: One of the processing steps that materials undergo in a chemical process plant. Mixing and drying are examples of unit operations. 

Feasibility Study: An analysis of a project to see if can be carried out successfully. This is a common preliminary step in the planning of a new plant. 

Research and Development (R&D): The gathering of the basic information needed for the design of a plant. Some of the information may be found in the library or learned from experts; the rest must be discovered in the laboratory. 

Process Design: Making the decision on equipment to be used and developing all the information needed for building a chemical process plant. 

Flow sheet: A diagram that shows the equipment used and the steps by which a raw material is changed into a finished product. All process design is based on the flow sheet. 

Instrumentation: The devices used for measuring or controlling a property such as temperature or pressure. The individual devices are called instruments. In an automobile, for example, the instrumentation includes the speedometer, the gasoline-level indicator, and the water-temperature indicator.

Plant Operation Engineer: The engineer in charge of a process plant after it is built. He or she may be the plant manager or may report directly to the plant manager. 

Preventive Maintenance: The job of maintaining equipment in working order before it breaks down. In a chemical process plant the breakdown of an important piece of equipment may force the entire plant to be shut down, which can be very expensive in terms of lost production. 

Consultant: An expert in some field who sells specialized knowledge to persons who need it.

What Chemical Engineering Tools are

       Chemical Engineering Tools for people other than chemical engineering people may only be 6 words that can be heard in everyday life, does not give much meaning. But for us chemical engineering Chemical Engineering Tools is like PANCASILA for Indonesians, yes ... Guidelines for living in the world of chemical engineering. Of course your friends already know and understand what Chemical Engineering Tools are, but it's a good idea to revew up a little here:

1. Mass Balance
       Mass Balance is the most basic thing in Chemical Engineering Tools, we first learned in ATK lessons, it can be said simply that the total mass entering a system will be the same as the discharge mass even though the types of compounds are different, the system here is a tool or factory overall . The mass balance can also be detailed into an elemental balance sheet that if there are compounds consisting of elements eg C, H, O then the mass of element C enters = the mass of element C out, as well as the elements H and O.

2. Hot Balance
       Hot balance study about energy, we learn a lot in the lessons of heat transfer and thermodynamics. in principle: total energy enters + energy generated - total energy out-energy changes shape = energy accumulation. Energy can be generated from chemical compounds such as combustion or other chemical reactions. Energy in a system can be detected through the system temperature. Energy may change form from heat to motion, from electricity to heat, but the end result will remain the same.

3. Balance
       Balance is one of God's grace in the world, there is day and night, there is good, there is bad, there is pleasure, there is sadness ... Balance in chemical engineering refers to the point that is as if it would be static, but not static! balance is if the mass / heat transfer rate of the two systems has the same speed, the sum of the two balanced systems does not have to be the same ... Balance can be in the form of a reaction balance, phase balance, etc.

4. Rate Process
       Rate Process (Transfer process) is a guideline for studying and analyzing the speed process in mass transfer or heat transfer. We have learned in the Transfer Process lesson and to be honest this is the most difficult to learn in Chemical Engineering. In this Chemical Manufacturing Design project the task will not be used too much, maybe in the next level of education will be widely studied.

5. Economy
       In matters of world life, we must fully pay attention to economic aspects, specifically in the field of chemical engineering whatever we design, we produce must always take into account economic aspects. Chemical engineering is a science that is open minded or the knowledge that to solve a problem can be done in various ways, staying optimized which is the most easy and economically beneficial. For what is it difficult for us to design if it is clear we clearly know the loss ???

6. Humanity
       Humanity requires us as chemical engineering people to always consider the environment and social aspects in carrying out our profession, must be responsible for the social and environmental risks to whatever we do. If there is a chemical engineering scholar who is scheduled to patrol or not ... well not a chemical engineering graduate he he he

What Chemical Engineering is

Chemical engineering is a discipline influencing numerous areas of technology. In broad terms, chemical engineers conceive and design processes to produce, transform and transport materials — beginning with experimentation in the laboratory followed by implementation of the technology in full-scale production.

Chemical engineers are in great demand because of the large number of industries that depend on the synthesis and processing of chemicals and materials. In addition to traditional careers in the chemical, energy and oil industries, chemical engineers enjoy increasing opportunities in biotechnology, pharmaceuticals, electronic device fabrication and environmental engineering. The unique training of the chemical engineer becomes essential in these areas when processes involve the chemical or physical transformation of matter.

For example, chemical engineers working in the chemical industry investigate the creation of new polymeric materials with important electrical, optical or mechanical properties. This requires attention not only to the synthesis of the polymer, but also to the flow and forming processes necessary to create a final product. In biotechnology, chemical engineers help design production facilities that use microorganisms and enzymes to synthesize new drugs. Problems in environmental engineering that engage chemical engineers include the development of processes (catalytic converters, effluent treatment facilities) to minimize the release of or deactivate products harmful to the environment.

To do these jobs, the chemical engineer must have a complete and quantitative understanding of both the engineering and scientific principles underlying these technological processes. This is reflected in the curriculum of the Chemical Engineering Department, which includes the study of applied mathematics, material and energy balances, thermodynamics, fluid mechanics, energy and mass transfer, separations technologies, chemical reaction kinetics and reactor design, and process design. These courses are built on a foundation in the sciences of chemistry, physics and biology.

Source: cheme.stanford.edu