Within-battery-limits costs

Functional unit methods are statistical methods for cost estimation. The production process is divided into functional units. Every chemical or physical treatment of the process flow is expressed as one functional unit. Each unit is weighted by a factor depending on the process intensity, material, and process conditions like pressure and temperature. The within-battery-limits (w.b.l.) costs, the outside-battery-limits (o.b.l.) costs, and the engineering costs are included. The w.b.l. are process equipment costs. The o.b.l. are the other facilities like storage, transportation, utilities and offices. The calculated investments have, within a 95% confidence level, an accuracy of 40%. 

Base equipment includes all equipment within the battery limits whose cost is as significant as the cost of a pump. For example, storage tanks, knockout drums, accumulators, heat exchangers, and pumps are classed as main-plant items (MPl). Early in the development of the process-flow diagram, it is advisable to increase the estimated (MPl) cost by 10 to 20 percent to allow for later additions. When the scope of the process has been well defined, (MPl) costs should be increased by 1 to 10 percent. 

Single-factor methods collect the various items of expenditure into one factor, which is usually used to multiply the total cost of delivered equipment X (Ce( )del lo give the fixed-capital cost for plant within the battery limits ... 

The cost of utilities is considered from their sources within the site to the battery limits of the chemical process served. 

Solve the problem given in Example 9-4 using the Miller method. Let us assume that 10 of the pumps and all the storage tanks are not within the battery limits. The total estimated F.O.B. price of the equipment in 1972 is then 1,105,000. The cost of it delivered, assuming a 5% freight charge (sales tax is not included), is... 

Classification of Estimates There are two broad classes of estimates grass roots and battery limits. Grass-roots estimates include the entire facility, starting with site preparation, buildings and structures, processing equipment, utilities, services, storage facilities, raihoad yards, docks, and plant roads. A battery-limits estimate is one in which an imaginary boundary is drawn around the proposed facihty to be estimated. It is assumed that all materials, utilities, and services are available in the quality and quantity required to manufacture a product. Only costs within the boundary are estimated. 

For control purposes it is advisable to estimate startup cost and time beforehand and then try to stay within the estimates. The general parameters which can be used to estimate startup cost Cso, which are usually between 2 and 20 percent of the battery-limit fixed-capital cost, are as follows ... 

The capital cost required for the provision of utilities and other plant services will depend on whether a new (green field) site is being developed, or if the plant is to be built on an existing site and will make use of some of the existing facilities. The term battery limits is used to define a contractor s responsibility. The main processing plant, within the battery limits, would normally be built by one contractor. The utilities and other ancillary equipment would often be the responsibility of other contractors and would be said to be outside the battery limits. They are often also referred to as off-sites . 

Before beginning an economic analysis to define the most convenient trade-oflF between evaporation and electrolysis cost, the upstream plants where sodium sulfate is generated should be inspected carefully to determine whether the dilute solutions are formed as such or are the result of mixing with other process wastewaters. Internal dilution is often a consequence of the old attitude toward by-product salt solutions, which were diluted as much as possible within the battery limits of the plants to reach the limit allowed for discharge. 

FOB X L-I-M ) -I- installed instruments -i- buildings required within the battery limits = L-I-M cost. 

It is obvious that only those battery recycling facilities which offer economical processing will remain viable in the long-term within a competitive market. Any primary battery recycling facility which concentrates on mercury removal at high cost has a very limited lifespan. 

Individual countries within the European Community handle the battery waste problem differently. For example, in Switzerland all used consumer batteries are considered hazardous waste and must be collected separately from ordinary household waste. Batteries must be recycled or stored in warehouses, not landfilled. A tax is collected on all new battery purchases to help defray the cost of recycling. In Italy, spent dry batteries are considered as hazardous waste and must be collected separately. In Sweden (10), the environmental issues relatii to waste batteries are addressed in the Control of Chemicals Bill and in the Decree on Environmentally Hazardous Batteries. All used batteries containing cadmium or mercury are collected separately under government control. The cadmium is then recycled. Regulations are in place for the manufacture of nickel/cadmium cells, limiting the exposure of workers and the emission of toxic materials. 

Wireless digital communication to and from the final control element is now commercially available. The advantage of a wireless field network is the potentially reduced cost vs. a wired installation. Hurdles for wireless transmissions include security from non-network sources, transmission reliability in the plant environment, limited bus speed, battery life, and the resistance of the process industry to change. Both point to point and mesh architectures are being commercialized at the device level. Mesh architectures utilize the other transmitting devices in the area to receive and then pass on any data transmission, thus re-routing communications around sources of interference. Multiple frequencies within the radio band are utilized to transmit data. 

---