PROCESS DESIGN DEVELOPMENT Plant Design 3 Plantdesign-1

Principal responsibility of chemical engineer Design Construction Operation of chemical plants Information must be available : recent publication, operation on existing process plants, laboratory and pilot plant data Plantdesign-1

Design project procedure The development of design project always start with initial idea or plan. The initial idea must be stated as clearly and concisely as possible in order to define the scope of the project. General specification and pertinent laboratory or chemical engineering data should be presented along with the initial idea Plantdesign-1

Types of Designs Preliminary or quick-estimate designs The designis based on approximate process methods, and rough cost estimates are prepared. Detailed-estimate designs In this type of design, the cost-and-profit potential of an established process is determined by detailed analyses and calculation. Plantdesign-1

Firm process design or detailed design Complete specification are presented for all component of the plant, and acurate costs based on quoted process are obtained. The firm process design included s blueprints and sufficient information to permit immediate development of the final plans for constructing the plant. Plantdesign-1

Feasibility Survey Before any detailed work is done on the design, the technical and economic factors of the proposed process should be examined. The various reactions and physical processes involved must be considered, along with the existing and potential market conditions for the particular product. Plantdesign-1

List of item that should be considered in making a feasibility survey Raw material (availability, quantity, quality and cost) Thermodinamics and kinetics of chemical reaction involved (equilibrium, yield, rates, and optimum conditions) Facilities and equipment available at present. Facilities and equipment which must be purchased Estimation of production costs and total investment Plantdesign-1

Materials of construction Safety consideration Profits (probable and optimum, per pound of product and per year, return on investment) Materials of construction Safety consideration Market (present and future supply and demand, present uses, new uses, present buying habits, price range for products and by-products, character, location, and number of possible consumers) Competition (overall production statistics, comparison of various manufacturing processes, product specification of competitors) Plantdesign-1

Shipping restrictions and containers. Plant location Properties of products (chemical and physical properties, spesifications, impurities, effect of storage). Sales and sales service (method of selling and distributing, advertising required, technical service required) Shipping restrictions and containers. Plant location Patent situation and legal restrictions. Plantdesign-1

PROCESS DEVELOPMENT In many cases the preliminary feasibility survey indicated that additional research, laboratory, or pilot-plant data are necessary, and a program to obtain this information may be initiated. Process development on pilot-plant or semi works scale is usually desirable in order to obtain accurate design data. Plantdes-2

Valuable information on : Material and energy balances can be obtained, and Process conditions can be examined to supply data on temperature and pressure variation, Yieds, Rates, Grades of raw materials and products, Batch versus continuous Material of construction Operating characteristics, and Other pertinent design variables. Plantdes-2

Design If sufficient information is available, a preliminary design may be developed in conjunction with preliminary feasibility design. Quite a number of alternative processes or methods may be available to manufacture the same product. Plantdes-2

The step in preliminary design 1). Establish the bases for design Specification of products and availability of raw material, Item will be affect to design : temperature of cooling water, available of steam pressure, fuel used, and value of by-products. 2). Preparing the simplified flow diagram Qualitative flow diagram Quantitative flow diagram Combined detail. Plantdes-2

Qualitative Flow Diagram for the manufacture of Nitric Acid Plantdes-2

Quantitative Flow Diagram for the manufacture of Nitric Acid Plantdes-2

3). Unit process involved in production system Equipment specification are generally summariz-ed in the form of tables and included with the final design report. Columns distillation. In addition to the number of plates and operating conditions it is also necessary to specify column diameter, materials of construction, plate lay out, etc. Vessels. In addition to size, which is often dictated by the holdup time desired, materials of construction and any packing of baffing should be specified. Plantdes-2

C. Reactors. Catalyst type and size, bed diameter and thickness, heat interchange facilities, cycle and regeneration arrangements, material of construction, etc. must be specified. D. Heat exchangers and furnaces. Manufacturers are ussualy supplied with the duty, correected log mean-temperature difference, percent vaporized, pressure drop desired, and material of construction. Plantdes-2

E. Pumps and Compressors. Specify type, power requirement, pressure difference, gravities, viscosities, and working pressure. F. Instruments. Designate the function and any particular require-ment. G. Special equipment. Specification for mechanical separators, mixers, driers, etc. Plantdes-2

4). Preparing typical process design Involved writing the report which will present their result of the design work. It is important that the preliminary design can be carried out as soon as sufficient data are available from the feasibility survey or the process-development step. Plantdes-2

Manufacturing process Material and energy balance The preliminary design and the process develop-ment work give the results necessary for detailed-estimated design. The following factors should be established before a detailed-estimate design is developed : Manufacturing process Material and energy balance Temperature and pressure ranges Yield, reaction rates, and time cycles. Plantdes-2

Material and construction Utilities requirements Plant site Plantdes-2