Importance of creativity and elements of creativity: Creativity is the most important aspect of R & D when you are doing something new. For this you need some basic instincts:
- Common Sense: It is most uncommon to have a good common sense. You can develop it by your day to day activities. You can solve many problems using common sense.
- Observation: There are many products around us. We do not even notice them or know what is the use of the product, how it is manufactured, who are the probable users. Some products are traditional of that area, while some can be traditional for neighboring areas or neighboring cultures. Many of these ideas can be obtained from magazines, TV education programs, catalogs of supermarkets, etc.
- Imagination: Once you observe one product, imagination is required to understand as to how it is manufactured, and how it can be sold. Reverse engineering, scale up and other techniques can be applied to understand the manufacture of these products.
- Basic sciences: Basic knowledge of sciences and art used for the manufacture of a prototype or a sample material. For manufacture of a chemical, you should know the unit operations and unit processes, methods of analysis and requirements of storage and handling. For this knowledge of Chemistry, Physics, Mathematics as well as Engineering is required.
Requirement of R & D Personnel: The most important requirement of R & D personnel is patience. Lot of efforts are required in getting successful product and developing a process that can be feasible, safe and make more profit as compared to many other routes for the same product.
Team for Bench Scale Process Development
Failure and waste in R & D: Till a useful and profitable process is developed, all the other processes can be considered as failure. The amount of money, and time spent on failed product is considered as waste. But, it is the price of development of a correct product. If reasons for failure are analyzed better techniques can be developed in future.
These failed processes or chemicals may provide products for other processes. Removable self adhesive tags was a failed product as it did not give a permanent adhesion. It was imagination, that made a failed product a big business.
Process Development on Bench Scale Study
- Role of Organic Chemist:
- Study and monitor the reaction cycle
- Look for better reactions, producing same product
- Look for better reactions, producing other products
- Role of Chemical Engineers:
- Provide technical assistance to related departments.
- Establish and monitor manufacturing and processing procedures
- Review and approve equipment and facilities
- Smooth running of all equipment
- Role of Analytical Chemist:
- Determine adequacy and quality of raw materials
- Measure degree of control during processing
- Measure finish product according to the prescribed standards of important parameters
- Role of Catalyst Expert:
- Check suitability and life of catalyst used in process
- Look for new efficient catalyst in place of older one
- Develop new processes based on new catalyst
Design and Analysis of Bench Scale Study
- Literature Survey: Chemistry is the basic science on which the chemical industry rests. Literature survey is done in a library or on internet. The starting point is Encyclopedia of Chemical Engineering by Kirk and Othmer. The index volume gives reference to the volume in which these can be found. Most of the topics are arranged alphabetically. However, the same product can have different names. Cross-references of names can give complete information. These volumes give good information about the products, their properties, and the old and new manufacturing processes. There are different encyclopedia for reactions, testing, handling, hazards etc. Many references are given for each product which can be books, research papers etc. Chemical Abstracts also give similar information, but these are for very deep study. Merck Index and some other dictionaries can also give most of the preliminary information. Many articles, company catalogs and personal communications are also available on world wide web.
- Identification and criterion for choosing process for bench scale development: Once preliminary literature survey is done, some processes can be identified based on the available raw materials. The chemical engineer should apply the chemistry of a particular process through the use of coordinated scientific and engineering principles. The materials of construction required for fabrication of equipment should be available. The availability of equipment fabricated locally or imported from abroad should be investigated. Special care is required for processes involving high temperature and high pressure. The bench scale study is generally done in glass vessels or in vessels of same material as actual one, but having a smaller size. Generally size used is 1 liter initially and up to 100 liters for higher size pilot plant. The shape of the vessel is generally simple and may not be same as the actual one likely to be used. As far as possible the shape of vessel should be similar.
- Exploratory work : Many books and articles have an outline of the process carried out on bench scale. These can be tried directly on Bench scale to check the accuracy of the processes given in literature. If the process is not tried and reported, we have to select proper method which has similar raw materials. Based on the data given for this process, trials can be done to check whether same thing applies to the process under investigation.
- Parameters to be studied in laboratory for process development: Many things can be responsible for process. Some of these are Temperature and Pressure of reaction mixture. Also proper mixing, heat transfer, mass transfer can play a major role in the completion time and degree of conversion of raw materials to the final product, with very less amounts of by products.
- Design of Experiments, Factorial and Sequential: To set up a plant effectively, the engineer must develop research laboratory results of chemist into an economical chemical process. The most important single factor is yield, which must be carefully differentiated from conversion. Yield is that fraction of raw material recovered as the main (or desired) product. Conversion is also used to indicate the amount changed by a single pass through an apparatus when multiple passes are used. For example in the synthesis of ammonia, the yield is frequently above 98%, whereas the conversion is limited by equilibrium to about 14% (per pass), which means that 86% of the raw material does not react and must be recirculated.
- Statistical Methods in Design of Experiment: Adequate and flexible initial design is essential. The process engineer should be a specialist in current aspects of chemical process design. Practical experience is necessary if the senior design engineer is to be able to foresee and solve the problems of a less obvious nature, such as maintenance, safety, and confirmation of governmental, environmental and statutory controls.
- Data Collection: The operating pressure and temperature play a very important role in the yields and conversion. Higher pressure and temperature sometimes give better yield and conversion but operating and equipment costs increase. Increased reaction time can give better conversion and yield but this requires larger and more expensive equipment. Catalysis is another important factor in reaction and improved catalysts can shorten reaction time, but equilibrium remains unaffected.
- Significant Tests on various parameters: The goal should be to have the conversion equal to yield, which means all the raw material is converted to useful product and the production of by-products is minimum. The plant size goes up as the conversion rate is low. The cost of plant due to expensive materials of construction can lead to higher product cost.
- Data validation: Thermodynamics is widely used for providing useful data on all phases of technical reactions. Data validation is done using flowcharts, which are of many types and are used for many purposes. Simple blocks often show only the material and energy flows and operating conditions. More elaborate ones show everything in the process and become extremely complicated. Specialized ones show such details as fire fighting lines, instrument and control systems, air lines, drains etc. Most coordinate the sequence of unit operation and unit processes. They indicate the point of entrance of raw materials and any necessary energy, points of removal of product and the byproducts. Many flow sheets are made to illustrate proposed alteration as a design proceeds. No other description of a chemical process is as concise or as revealing regarding equipment, operating details, and general reactions as that presented by a skillfully drawn flowchart, which would include data covering not only materials, but labor and utilities as well.
- Analysis of Variance: Batch processes are good for smaller rate of production verses continuous processes which are economical if rate of production is high. Continuous processes require far smaller, less expensive equipment and have much less material in process. Due to this there are less chances of production of bad products and have more uniform operating conditions and products than batch process. Continuous processes require more accurate process control of flows, temperature, pressure etc., and it is possible only due to very high quality computer control.
Small quantities of chemicals are usually made by batch operations, but when markets enlarge, it is changed over to continuous process. The reduction in plant cost, per unit of production is often the major force behind the change. Where batch processing is either impossible or undesirable, continuous plants are favored.
- Data reconciliation by Material Balance: Since the costs are most strongly affected by material use and distribution, material balance is very important. It shows the origin and ultimate disposition of all materials used. Energy use and distribution is also important, and much effort is currently being spent on reducing use of energy. In future, energy saving will be more important than it is now. This is the reason why most of the processes depend more and more on catalysts that make it possible to carry out processes at lower temperature.
- Working safely in Laboratory: Since most of the laboratories are small and crowded with tables and racks, one has to be careful. Corners of tables can cause injuries. If you dash against a table, it might shake the table and racks on it and all the articles on it might fall and cause problem. Loose cloths might get stuck somewhere and can lead to accident.
- Safety Attitude: The working attitude must be co-operative. All pointed objects should be avoided and hot and cold lines should be insulated for personal protection. Most of tables and chairs should be sturdy and capable of absorbing shocks. Its corners must be smooth.
- Nature of Hazards: There are different types of hazards. The most common are:
Accident Prevention: Alertness and caution should be followed all the time.
- Fire: Many organic chemicals can catch fire if sufficient quantity of vapors of these are mixed in air. A flame can ignite such a mixture and can cause a small fire, which can then get converted into a large fire.
- Splashing: Many acids can damage face, hands or other parts of body if these splash on them. It can cause greater damage if these are hot and concentrated. Most of these are stored in glass bottles and are handled in glass equipment. Special care should be taken in handling glass equipment.
- Drinking: While sucking some acids or other chemicals in pipettes and burettes, these might get sucked in the mouth and may pass further. These can damage some of the organs of body either for some time or permanently.
- Inhalation: Vapors of many chemicals are present in the laboratory. Some of them might irritate eyes, nose etc. Some may make you lose conscience. Some of these can be poisonous. This might lead a person to collapse.
Working on Safety Aspects in Laboratory: When working in laboratory you should not work alone. Sufficient supporting staff should be present after the office hours.
- Fire: Proper ventilation of the place of work can avoid formation of explosive mixtures in the air. Flame-proof electrical equipment, which do not give out sparks, is very important as most fires get ignited due to small sparks. All electrical fittings and switches must also be flame-proof and have a closed enclosure. No open flame should be used.
- Splashing: Proper protective suits, like face mask, goggles should be used. The chemicals should not be transferred under pressure.
- Drinking: Vacuum creating bellows should be used for filling pipettes and burettes. Do not check any chemical by tasting with tongue.
- Inhalation: Well ventilated hoods should be used for dangerous and poisonous chemicals.
Need for study: Even if a process is completely explained in a book or in a research paper, it is necessary to try and confirm it on laboratory scale to check for yield and conversion. The product produced, can be used for testing the properties of the product. Since it is done on very small scale, it is easy to handle and experimental apparatus can be set up with very small cost in a very small time.
Tools available for study: Conventional methods are more reliable in study of these processes. However, new techniques like computer simulation are also available for studies. Simulation techniques can be used as a next step for study after the conventional method. Different types of glass equipment, which are quite similar to the equipment in actual plant are available. Reactors, agitators, distillation columns, condensers, reflux mechanisms made of glass are available. Autoclaves of steel, titanium and other metals can be used. Readymade setups for a particular unit process or unit operation are also available.
Runaway reactions: Due to wrong process conditions, localized heating or failure of cooling can lead to runaway reaction. Constant watch should be kept on proper functioning of all the equipment. The process parameters should be carefully monitored to check runaway reactions.
Corrosion testing in Laboratory: Corrosion can not be prevented, it can only be minimized. Advances in material science have provided many corrosion resistant materials, like rubber-lined steel, resin bonded carbon, stainless steels, titanium, even bricks, cast iron, steel, wood, cement. Corrosion testing should be done in pilot plant using commercial chemicals rather than using pure laboratory chemicals, since it frequently happens that a small amount of contamination is there in a commercial raw material.
Classification of Tests: These can be to test the quality of product. Density, viscosity, boiling range can give purity of the product. Thin film or gas chromatography can give the purity to a very high accuracy. However, this test is expensive and should be done at the end. pH of the product can give the acid content of the product. Flash point test can give the flammability criteria for the product.
Objectives of Tests: Most important objective is to check whether the product that is produced is really the one we have intended. The purity of the product is also important.
- Fire: Sufficient open space should be provided around the experimental set-up. Escape doors and ladders should be there, for all the floors.
- Splashing: Safety shower for full body as well for eyes should be within walking distance.
- Drinking: Wash basins to clean face and mouth should be provided in case of sucking of any chemicals.
- Inhalation: Exhaust fans and ventilators should be present very 10 meters. Breathing equipment should be kept ready nearby. A compressed air line should be there to give extra air for breathing.
Methods of Testing: These are physical and chemical methods. Only instruments are used for physical testing, while other chemicals are used for chemical testing.