Figure adapted by an ISO publication.
Typically, energy and cost savings are around 5% or more for many industrial applications of process control systems. These savings apply to plants without updated process control systems; many pulp and paper mills may already have modern process control systems in place to improve energy efficiency (Kramer, october 2009) . According to (Kramer, october 2009) increase energy savings further could be monetized by active energy monitoring teams and a through internal audit should be conducted by these teams. Specific energy savings and payback periods for overall adoption of energy monitoring and control systems vary greatly from plant to plant and company to company . A variety of process control systems are available for all kinds of industrial processes. Although energy management systems ideas are already widely spread in various industrial sectors, the performance of the systems can still be improved, which will help reduce costs.
The energy saving process for 50 GPM of reclaimed water would roughly require about 100 to 200 square feet of common production space. Utility requirements would be compressed air. The estimate for total connected horsepower for the entire process would range from 15 to 20 HP. The operating and maintenance costs for this process would consist of electric power costs along with chemical purchases and maintenance costs. The water recycle process would have to be connected with and electrical load in the range of 15 to 20 horsepower. Based upon the number of times water recycled associated power requirements an annual cost of $7,500 would be incurred according to (OConnor, October2006).
The chemical consumption rates estimated from the test run of this process were found to be very repetitive. The annual cost for chemicals is based upon the experimental operation expenses extrapolated to an annual consumption rate. These costs are based upon the specific coagulant and flocculants needed for the pilot testing. The annual cost is approximated at $16,000. If the fibre is recovered or dewatered further for disposal and the chemical treatment costs may be discounted as they are approximately same as to the chemical requirements for the treatment of the fibre and fillers needed for the waste treatment plant or the recovery of fibre through alternate technologies.
According to (OConnor, October2006) the maintenance costs for the equipment are very hard to estimate. Other miscellaneous repairs would be required for parts such as pumps, valves and instruments. For simplicity these cost are assumed to be annual maintenance cost of 2.5% of the capital equipment cost. This cost would be about $5,000. The process is designed to be fully automated. Daily tested by the mills lab staff to ensure proper operation. The chemical and operating cost should be lower as well. There should be a benefit in recovering the thickened stock from this stream for reusing in the mill and its value should clearly offset the reduction on thermal savings of the factory due to the implementation of water recycling process.
The most important raw materials used in a paper mill are pulp fibre, water, and thermal and electrical energy. Reduction in the use of any or all of these raw materials can have a significant, positive impact on the economics of paper production and a mills bottom line profitability. Numerous commercially available technologies are currently used throughout the paper industry for the recovery of fibre and clarified water from mill white water. (Romaro, september 2006). Heat recovery systems could also be utilized for minimizing thermal and electrical energy use. Nevertheless, all of these technologies are subject to a number of things such as performance, energy, efficiency, and reliability inadequacies.
It is considered impossible to produce economical high clarity, thermally rich water that may be substituted for fresh make-up water that typically requires heating to process-operating temperature (Romaro, september 2006) this means that you would have to incur additional cost to recycle water which in turn will make you economically inefficient . As a result, with these present technologies, paper mills waste large quantities of thermal and electrical energy and often lose their productivity due to lower than desired process operating temperatures, which they are unable to recover from significant portions of their process water, wastewater, and pulp fibre.
Companies all over the world are extremely conscious of their carbon footprints. More over European Union has aimed to stick to the Kyoto protocol. According to the burden-sharing agreement between EU Member States, Finland is committed under the Kyoto Protocol to bringing national average annual emissions down to their 1990 level in the 20082012 periods. (Ojala, 4 feburay 2011). Currently Motkamills has three production unit in Finland, for this to take place they need to be energy efficient as we know that fuel costs make up a larger proportion of the costs in any given factories, being energy efficient will not only bring down the operating costs for the year of the factory but also provide room for sustainable development.
Kramer, M. a. X., october 2009. Energy Efficiency Improvement and cost saving Opportunities for the pulp and the paper industry, s.l.: BERKELEY NATIONAL LABORATORY . OConnor, K., October2006. ENERGY EFFICIENT PAPER MILL PROCESS WATER AND WASTED PROCESS WATER FILTRATION FOR HIGH CLARITY WATER FOR REUSE
AND FIBER RECOVERY, s.l.: The New York State Energy Research and Development Authority (NYSERDA). Ojala, J. a. C., 4 feburay 2011. Finland is implementing, s.l.: Ministry of the Environment, Finland. Romaro, B., september 2006. PROCESS WATER FILTRATION FOR HIGH CLARITY WATER, s.l.: NEW YORK STATE ENERGY RESEARCH AND DEVELOPMENT AUTHORITY .