1. Lecture 3. Plant Location and Layout Selection of Site/Plant Location The selection of plant site is very important to ensure that it has all the support required to make the venture a feasible and profitable. There are many factors that must be considered when selecting a suitable site. The principal factors to consider are: Location, with respect to the marketing area. Raw material supply. Transport facilities. Availability of labour. Availability of utilities: water, fuel, power. Availability of suitable land. Environmental impact, and effluent disposal. Local community considerations. Climate. Political and strategic considerations.

2. 1. Location, with respect to the marketing area The selection of location with respect to the above criteria depends on the cost of production versus the cost of transportation. Most chemical/petrochemical process plant has significantly higher production cost compared to the cost for bulk transportation if the distance is within certain range. Therefore, most of the time the location selected is near to the transportation hub particularly sea port. This will enable the delivery of the finished products to customer as quickly and as cheaply possible. However, there are products that are produced in bulk quantities; such as cement, mineral acids, and fertilisers, where the cost of the product per tonne is relatively low compared to the cost of transportation which forms a significant fraction of the sales price. In such cases, the plant should be located close to the primary market. All the above consideration may not apply or less important for low volume production, high-priced products; such as pharmaceuticals.

3. 2. Raw material supply. The supply of raw materials is one of the most important factors especially when large quantities are involved. It lead to savings in the storage facilities as well as transports. Thus the availability and price of suitable raw materials will often determine the site location. eg . Proximity of steelworks to the major coalfields in the UK, major petrochemical complexes around Kertih where supply of natural gas from offshore Terengganu. Plants producing bulk chemicals are best located close to the source of the major raw material; where this is also close to the marketing area.

4. 3. Transport Facilities The transport of materials and products to and from the plant will be an overriding consideration in site selection.If practicable, a site should be selected that is close to at least two major forms of transport i.e., road, rail, waterway (canal or river), or a sea port. Land transport such as road transport is being increasingly used, and is suitable for local distribution from a central warehouse.Rail transport will be cheaper for the long-distance transport of bulk chemicals. Air transport is convenient and efficient for the movement of personnel and essential equipment and supplies, and the proximity of the site to a major airport should be considered.

5. 4. Availability of labour. Although the general trend is for increased automation, many processes would still require a reasonably large labour force. Labour will be needed for construction of the plant and its operation. Skilled construction workers will usually be brought in from outside the site area, but there should be an adequate pool of unskilled labour available locally; and labour suitable for training to operate the plant. Skilled tradesmen will be needed for plant maintenance. Local trade union customs and restrictive practices will have to be considered when assessing the availability and suitability of the local labour for recruitment and training. In addition, the local pay rates, competing industries and turnover rates need to be also considered.

6. 5. Availability of utilities: water, fuel, power Chemical processes invariably require large quantities of water for cooling and general process use, and the plant must be located near a source of water of suitable quality.Process water may be drawn from a river, from wells, or purchased from a local authority.At some sites, the cooling water required can be taken from a river or lake, or from the sea; at other locations cooling towers will be needed. Electrical power will be needed at all sites. Electrochemical processes is an example of a process which require large quantities of power. A competitively priced fuel must be available on site for steam and power generation.

7. 6. Availability of suitable land. Suitable land area with reasonable land rates (for hire or purchase) has to be identified and selected. May require approaching the local council office to explore the possibilities. 7. Environmental impact, and effluent disposal. In a building chemical process plant, the environmental impact has to be assessed. The assessment should be done to ascertain the impact of the surrounding as a result of building the plant. Normally, an environmental impact assessment study will be conducted prior to project approval by the local council.

8. 8. Local community considerations. The local community in terms of facilities and support that could be provided. 9. Climate. Climate can have an important bearing on the economic operation of the process. Either a hot or cold severe climate, the cost of protective buildings, facilities for personnel and utilities must be considered especially when performing the economics. 10 Political and strategic considerations. Stable country and political situation where there are not much possible public disturbance Financial incentives provided by the government and the tax policy Financial facilities provided by the local businesses.

10. Hazardous processes must be located at a safe distance from other buildings. Consideration must also be given to the future expansion of the site.

11. The ancillary buildings and services required on a site, in addition to the main processing units (buildings), will include; Storages for raw materials and products, tank farms and warehouses. Maintenance workshops. Stores, for maintenance and operating supplies. Laboratories for process control.

13. An example of a site/plant layout

18. Equipments requiring large cranes for services should be located at the perimeter of the rectangular set up, adjacent to a main roadway.

21. Valves, sample points, and instruments should be located at convenient positions and heights.

22. Heat exchangers need to be sited so that the tube bundles can be easily withdrawn for cleaning and tube replacement.

23. Vessels that require frequent replacement of catalyst or packing should be located on the outside of buildings.

24. Equipment that requires dismantling for maintenance, such as compressors and large pumps, should be placed under cover.

25. Blast walls may be needed to isolate potentially hazardous equipment, and confine the effects of an explosion.

26. Equipment should be located so that it can be conveniently tied in with any future expansion of the process.

28. Relief devices that can vent inflammable and noxious fumes in an emergency should be located down wind of the administrative facility.

29. Storage areas should be positioned for ease of access from public roads and railways and remote from hazardous areas.

30. Facilities for generation and distribution of services (power supply, steam & water supply) should be located in a completely safe area.

33. the design of site layout which takes into account of operation and maintenance requirementAbove all, there is no clear / systematic guidelines or procedures for designing site layout other than leveraging on ‘some common sense rules’ thus making it more of an art rather than scientific approach.

34. Lecture 4. Plant Utility System Many processes operate with a common utility system generated and located centrally. Emission BOILER FEEDWATER TREATMENT & DE-AERATOR VHP Fuel BOILER /USING FUEL OR GAS TURBINE EXHAUST POWER Boiler Blowdown BACK PRESSURE TURBINE Condensate Return HP POWER POWER LET DOWN VALVE BACK PRESSURE TURBINE BACK PRESSURE TURBINE MP Steam Mains to Process POWER LET DOWN VALVE CONDENSING TURBINE LP CW

35. The centralised utility system supplies steam, power and cooling water to the processes. It can also supply compressed air and refrigeration. Cooling water cycle Steam Supply PROCESS 1 Condensate Return Steam Supply PROCESS 2 CENTRALISED UTILITY SYSTEM Condensate Return Steam Supply PROCESS 3 Condensate Return POWER

37. Steam tracing for pipes and storage tanks

38. Direct heating through live steam injection

39. Vacuum creation through steam ejectors

40. Mass and heat exchange by live steam injection in distillation

41. Reduction of partial pressure in gas phase reactors

42. Combustion processes to atomise fuel oil

43. Injection into combustion process to lower NO2 emissions

45. A convenient way of transferring energy around

46. Has a high heat content as well as wide range of operating temperature

47. Non toxic and losses could be easily replaced

49. 2. Steam Boilers Fire tube boiler. A fire-tube boiler is a type of boiler in which hot gases from a fire pass through one or more tubes running through a sealed container of water. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating the water and ultimately creating steam.

50. Water tube boiler. A water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. They are used for high-pressure boilers. Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes. In smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely on the water-filled tubes that make up the walls of the furnace to generate steam. The heated water then rises into the steam drum. Here, saturated steam is drawn off the top of the drum. In some services, the steam will reenter the furnace through a super heater to become superheated.

51. 3. Steam Turbines A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. It has almost completely replaced the reciprocating piston steam engine primarily because of its greater thermal efficiency and higher power-to-weight ratio. Because the turbine generates rotary motion, it is particularly suited to be used to drive an electrical generator – about 80% of all electricity generation in the world is by use of steam turbines. The steam turbine is a form of heat engine that derives much of its improvement in thermodynamic efficiency through the use of multiple stages in the expansion of the steam, which results in a closer approach to the ideal reversible process. HP LP

52. 4. Gas Turbines A gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between. Energy is added to the gas stream in the combustor, where fuel is mixed with air and ignited. In the high pressure environment of the combustor, combustion of the fuel increases the temperature. The products of the combustion are forced into the turbine section. There, the high velocity and volume of the gas flow is directed through a nozzle over the turbine's blades, spinning the turbine which powers the compressor and, for some turbines, drives their mechanical output. The energy given up to the turbine comes from the reduction in the temperature and pressure of the exhaust gas. GE H series power generation gas turbine: in combined cycle configuration, this 480-megawatt unit has a rated thermal efficiency of 60%.

54. Higher latent heat content in the steam for the steam heater

55. Lower capital cost heat transfer equipment due to lower pressure.Steam system typically has 3 levels of steam pressure namely HP, MP and LP. For larger sites, a higher level namely very high pressure (VHP) steam is generated for power production. The let down steam from the turbine is then channeled into the steam system. At times, the steam is expanded to lower pressure using expansion valve. Flow control, or metering, of the expanded fluid is accomplished by use of a temperature sensing bulb filled with a similar gas as in the system that causes the valve to open against the spring pressure in the valve body as the temperature on the bulb increases.

57. Have a negligible steam consumption.

59. Natural and forced-draft cooling towers are generally used to provide the cooling water required on a site; unless water can be drawn from a convenient river or lake in sufficient quantity.

60. Sea water, or brackish water, can be used at coastal sites, but if used directly will necessitate the use of more expensive materials of construction for heat exchangers.

62. Dry Cooling Towers operate by heat transfer through a surface that separates the working fluid from ambient air, such as in a tube to air heat exchanger, utilizing convective heat transfer.

65. 6. Refrigeration (Vapour Compression Cycle) Vapor-compression refrigeration[1] is one of the many refrigeration cycles available for use. Oil refineries, petrochemical and chemical processing plants, and natural gas processing plants are among the many types of industrial plants that often utilize large vapor-compression refrigeration systems.

67. Steam boiler

68. Steam Turbine

69. Gas Turbine

70. Steam System Configuration

71. Cooling water

72. Refrigeration (only for plant with sub ambient temperature operation)Together, they form the main and important support for ensuring successful plant operation.