Methodologies for Sustainable Consumption and Production Dr. Naeem-uz-Zaman email@example.com
Presentation Sequence • Aims of SCP • Methodologies for SCP • Documentation of consumption • Use of indicators and controls • Substitution of raw materials and auxiliary materials • Increase of useful life of auxiliary materials and process liquids • Improved control and automation • Reuse of waste
Aims of SCP • Sustainable production is a preventive, company-specific environmental protection initiative. • It is intended to minimize waste and emissions and maximize product output. • By analyzing the flow of materials and energy in a company, one tries to identify options to minimize waste and emissions out of industrial processes through reduction at source strategies. • To help in reduction of usage of materials and energy, and to avoid waste, waste water generation, gaseous emissions, waste heat and noise by improvement in organization and technology
SCP is Industry Specific • An installation is generally product specific. Which means each industrial installation uses specific types of raw material to produce specific end products. • At present, millions of goods are being manufactured in different facilities. These facilities are created for specific items to be produced. • For example there are large size single product installation such as cement and sugar mills and there are installations which take variety of feeds and produce variety of products such as chemical processing, textile processing, petrochemicals manufacturing etc.
Methodologies for SCP • Documentation of consumption • Use of indicators and controls • Substitution of raw materials and auxiliary materials • Increase of useful life of auxiliary materials and process liquids • Improved control and automation • Reuse of waste
Documentation of Consumption • Basic analysis of material and energy flows • How to Document • Shanky Diagram • Graphical Representation of Consumption
Importance of Documentation: Case of Boiler • Usually boiler operator does not know how much steam he is producing per hour as there is no flow meter indicating or recording on the steam line. There is no flow meter available on water feed side thus it is virtually impossible to know how much water is being pumped, how much steam is being produced and how much water is lost by blow down. • The raw water was analyzed when the plant was installed, and a matching softening plant was installed. During the course of time, the analysis of subsoil water (TDS) might have changed. However, no water analysis has been carried out periodically. Thus the quality of feed water is not known, resulting in inefficient boiler operation.
Importance of Documentation: Case of Boiler • The same is true for the fuel side. How much fuel is being consumed to produce one ton of steam. Since no flow meters are installed on fuel side, therefore there is no way to specify the cost of fuel per ton of steam produced. • Even in the absence of online instruments, relatively efficient documentation can be maintained to determine steam produced per hour and it’s cost. For example by installing a level indicator on the boiler water feed tank and reading its value every time the feed water pump start and stops one can have an idea of water feed to the boiler per unit time that is per hour, per day and per year. By measuring the blow down quantity and time interval one can easily determine the total water drained through the blow down . The balance can safely be assumed as the steam produced. Thus by carrying out very simple documentation, one can determine the quantity of steam being produced by the boiler.
Importance of Documentation: Case of Boiler • In case of gas fired boilers, a specific gas flow meter can be installed close to the boiler and quantity of the gas being consumed per unit time can be measured. • In some installation where gas is used exclusively for steam purposes, the reading of the billing meter can give a clear indication of the gas being consumed. • It is only by documentation of hourly and daily fuel consumption that the cost of steam produced can be determined. • Besides this, the efficiency of the boiler depends on the combustion conditions which are determined by analysis of the flue gases. • Instead of purchasing the instrument, services of companies can be hired to determine the combustion conditions by flue gas analysis. • By carrying out documentation of flue gases periodically, the losses can be controlled. • This goes for the consumption of other process inputs as well.
Chemical Consumption • The observation is that at the end of year, the quantity of all the chemicals consumed, is collected and the cost of production is based on this information. If there is leakage of chemicals from store, it is difficult to monitor, unless a daily record of consumption of chemicals is maintained. Water Consumption • Now water is not a free commodity, and all industries need to monitor the water consumption per unit of goods produced. This can easily be done by installing water meters and documenting water consumption.
Use of Indicators and Controls • To identify losses from • poor planning • poor education and training • Mistakes • Desired process conditions at different steps should be identified and displayed in graphic form in the working area. So the operator is always aware of the conditions that are required to be maintained and if he deviates from these said conditions, he would know of the losses.
Planning • For any operation to be successful, it is essential that proper planning is carried out before actually starting the process. • In planning, we determine the total inputs, times at which these inputs are required, quality of the inputs, and last but not the least, properly trained man power to run the operation. • Proper planning must be identified and documented so that every person involved knows his responsibilities as well as limitations.
Training • The operators must be properly trained in their respective fields, so that they can easily identify the variations from the said conditions and take remedial measure well in time. • For example, if a boiler is set to operate at 10 bar, it must be specified in the indicators. If by any chance, the pressure starts increasing above the set limits, the operator must know what to do to stop this trend before the boiler or steam lines are damaged by steam pressure.
Substitution of raw materials and auxiliary material • Industrial production on large scale started after industrial revolution. • Raw materials as well as operating conditions are identified at the time of design of a plant. • With the development of technology and research, new and alternate methods of production have been developed which are less polluting and more efficient.
Case of Sulfuric Acid Manufacturing • Initially, chamber process was developed which was inefficient. • By the beginning of the 20th century, catalytic oxidation of sulfur dioxide to sulfur trioxide was developed. • Within few years most of the chamber process became obsolete. And all new plants are based on contact process. This process consumed 98% sulfur to produce sulfuric acid and 2% sulfur was lost as sulfur dioxide in the atmosphere. • This was being tolerated for many year. • However with the realization of pollution effects, it was desired to eliminate this loss. • During the last two decades, two stage oxidation method has matured which reduces the SO2 emissions to less than 0.1 percent. • In developed countries, all new sulfuric acid plant are being designed on this technology.
Improved Control • The operation of a processing plant, without instrumentation is like driving a car blindfolded. • Initially operating conditions like temp, pressure etc were monitored periodically. • With the arrival of recording instruments, these operating conditions are not only monitored but recorded round the clock so that any variation in the end product can be traced down to time and area of the deviation. • With the arrival of online instrumentation, the operating conditions such as pH, TDS etc which were used to be determined in laboratory, are measured and recorded constantly. This helps in minimizing the losses and maintaining the quality of the product.
Automation • It means that process conditions are not only monitored but corrected without the intervention of human beings. • For example, in case of boiler operation, an instrument may indicate, increase or decrease in boiler pressure, but would require human intervention, to rectify the problem. With automation, the instruments will rectify the condition and may even record the reasons for variation in pressure and the rectifying measures taken . • In many processes such as refinery etc. the time lag for rectification is very short, and proper control is possible not only with instrumentation but also automation. • In processes like tanning, where time intervals are large, SCADA helps in maintaining the quality and minimizing the losses of raw materials. • Instrumentation is expensive in Pakistan and automation is more expensive, however in many case it is inevitable and the pay back period may be in months not years.
Reuse of Waste • Internal • Design/ Process Optimization • Counter Current Washing • Recycling e.g. chrome, salt, caustic, size • Water pinch technology • Waste Heat Utilization
Reuse of Waste • External • Waste to Energy • Leather cuttings can be turned into glue • Use of waste cotton • Cellulose Acetate Fiber • Cellulose Nitrate Plastic/ Licqor/ Explosive • High Grade Paper • Cotton available in used jeans is being shredded and turned into fill material in blankets. • All Metals are recycled after use and non metals such as plastics and paper are also being recycled.