DES-UNH POLLUTION PREVENTION PARTNERSHIP INTERNSHIP PROGRAM FINAL REPORT Project Title: Pollution Prevention at Nashua Corporation Intern: Wilburn M. Miller Home Phone: 603-654-2083 56 Robbins Road Wilton, NH 03086 Facility: Nashua Corporation 44 Franklin St. Nashua, NH 03061 Contact Person: Pete Walsh Project Engineer Phone: 603-880-2482 Advisors: Pete Walsh Daryl Secrist Lisa Grigg Dave Shea Executive Summary: Nashua Corporation wanted to reduce the amount of waste it generates and prepare for future environmental regulations. Nashua had three main projects: To obtain an alternate outlet for recovered solvent which can not be reused, investigate the production of waste in the developer manufacturing process and research the current technologies available to control the emissions from a particle coating process. Background: Nashua Corporation has been trying to reduce its production of waste solvent for several years. In the past they have qualified the re-use of solvent into the processes where possible and recently tried distillation in an attempt to purify the solvents so they could be re-used within the company. Unfortunately they were unable to achieve the needed quality to allow for re-use and the project was terminated. Nashua would like to continue trying to reduce the amount of solvent it ships as waste and would like to explore other options available. Nashua Corp has also been trying to reduce the amount of raw material which becomes waste. They have already set up a system to follow the production of toner. This allows Nashua to know the product yield and more accurately determine the cost of toner manufacturing. They would like to set up a similar system for the developer manufacturing group. It is important for Nashua Corporation to remain in compliance with all EPA and DES regulations. Currently Nashua does not operate any equipment which falls under EPA or DES VOC emission restrictions, but they do have one machine that could some day fall under such restrictions. If this equipment does fall under regulation, Nashua anticipates to be held to the industry standard of 95 percent emission reduction. With this in mind Nashua Corp. wanted to know the current technologies available that would meet the standard. Objective: It was the goal of this project to find ways to reduce the generation of waste at Nashua Corporation and help them prepare for future environmental regulations. Most of these projects could be accomplished using the pollution prevention methods of reduce, reuse and recycle. Approach: In order to reduce the amount of solvent waste generated it was necessary to track where in the plant the solvent was being used. Once the solvent usage was determined, tests were run on the recovered solvent in an attempt to determine the composition. Since the solvent is recovered from a batch process, the exact composition of each barrel of recovered solvent can not be determined unless it is tested, although it is hoped that the solvent will have a statistically representative composition. Once the general composition of the solvent is known. What to do with the solvent can be addressed. To track the generation of junk steel an understanding of the various process involved in developer manufacturing was needed as well as a history of the amount of junk steel produced. The history of the generation of junk steel should provide some information on where the waste is generated and if it has been increasing. Once the analysis of past junk generation has been done then certain parts of the process must be focused upon to generate a mass balance. If needed the entire process can evaluated using a mass balance. Researching the current technologies to control the emissions on the particle coating process involves knowing what is in the emissions. It is essential to know the composition of the exiting gas stream which is to be treated. When the composition, flow rate and temperature of the exit stream is known then the search for emission control can start. This is done through contacting the manufacturer of the fluid bed to get their input to solve the problem as well as other related vendors. Chemical Usage/Equipment Needs/Releases/Waste Generated: The solvents involved in the coating process are primarily MEK, Toluene and Xylene. They are used as resin carriers to deliver the resin coating to steel shot. Nashua uses two different coating machines. The first coater is a fluidized bed coater where the steel particles get fluidized in a stream of hot air. The coating is sprayed onto the fluidized particles then the carrier solvent is vaporized and released to the atmosphere. The second coater mixes the coating and steel together in a bath then vaporizes the solvent. The vaporized solvent is then recovered by condensing the vapors. The first coater is the machine that may fall under environmental regulations someday and is the subject of the emissions control technology research. The second coater is the source of the recovered solvent which becomes waste. This waste is then declared hazardous waste and is shipped to a fuel blending site for energy recovery. In the developer manufacturing process steel shot is put through many different steps. The amount of waste generated from each step is unknown but over all it has been estimated that some where between eight and twelve percent of the of the steel shot that enters the process becomes waste. Work Accomplished: The usage of solvent was reviewed throughout the plant. It turned out that there were only two places in the entire plant where solvent is used. The processes that use the solvent are the two coater machines which are part of the developer manufacturing process. In the developer coating process steel shot is covered with a coating. The coating is applied as a liquid with the aid of a carrier solvent and then the carrier solvent is vaporized leaving the resin on the shot. The first process that became of interest was one which was done on the coater that recovers the solvent. The process that was focused on used xylene as the resin carrier. The use of recovered xylene in other developer projects has not been qualified by Nashua Corp because the contaminants are feared to cause problems in other xylene based coatings. The other solvents that are used in this machine have been effectively reused on the fluidized bed coater. The only declared waste of these solvents are from cleaning and flushing operations. The process was studied and it was found that the main source of solvent was the resin which is purchased as a solution. The resin solution composition is 80% xylene which accounts for almost 80% of the total xylene used it the process. The other 20% of the xylene used in the process is virgin xylene which is used to flush the system clean. The flush xylene used in this process must be of very high quality to remove the catalyst from the system. Since the main source of xylene entering the facility is within the resin, which is a standard formulation from a chemical company, then it is not feasible for Nashua to try and recycle all of the xylene within the company. For this reason the choice was made to try and sell the xylene to a company who can use the xylene in its present state. The manufacturer of the resin was consulted to get more information on the contents of the recovered solvent and to see if they would buy back the recovered xylene. They do not participate in a solvent return program but they offered some help in determining the composition of the recovered xylene. The Pollution Prevention Division of the DES was then contacted for help to find a market for the waste xylene. The DES provided the names of several waste exchange organizations through which a solvent broker was contacted. The broker came up with a company who is interested in buying the recovered xylene. This company must be investigated and a statistical analysis of the impurities must be completed before the xylene can be sold. The other coating machine was the subject of the emission control search. This process is similar to the first coating machine except that the steel shot is fluidized in a stream of hot air. The fluidized steel shot is then sprayed with the coating and the solvent is vaporized leaving the coating on the steel. The vaporized carrier solvent is then vented to the atmosphere. This release of vaporized solvent is what could someday become restricted under environmental regulations. To prepare for this it is important to know what the composition of the exit stream is and to what the expected reduction standards are going to be. It is expected that the required reduction in emissions is going to be 95% which is the industry standard for VOC emission reduction. The theoretical composition of the exit stream was calculated for each product and the concentrations of the VOCs determined. Once the stream composition was known the DES pollution prevention center and various vendors were contacted to find out what the best equipment would be to achieve the needed VOC reduction. There are several choices available to reduce VOC emissions, they include: Condensation, Activated Carbon, and Oxidizers. The choices were narrowed down by using the conditions of the exiting gas stream. Condensation was not a viable choice because of the low VOC concentration. Activated Carbon was ruled out when it was considered that the carbon would be recovering many different kinds of solvent which would make the recovery of useful solvent impractical. A second thing to consider about activated carbon was if there happened to be any coating carry over from the coating process, the coating would cover the carbon and decrease its effectiveness. Oxidization (Incineration) became the most practical choice because of the conditions in the gas stream. There are two types of incineration, catalytic and non-catalytic. Catalytic incineration was ruled out because, as before with activated carbon, if there happened to be any coating in the gas stream, then the coating would cover the catalysis and proper incineration would not occur. For these reasons it was determined that the most practical technology available at this time was non-catalytic thermo-Oxidization. When this was done a collection of vender names, who manufactured incinerators, and contacts was compiled so that if needed the decision of whom should manufacture the incinerator can be quickly made. To analyze the generation of junk steel all the available records over the past few years on the production of developer and waste were used. The records showed that over the last three years there has been a 34,000 pound increase in junk steel generation. The records also showed that the manufacturing rate of developer over the past three years was declining. This means that the junk steel generated per pound of developer produced has increased. Once this was found an attempt was made at discerning where the increase in the generation of junk steel has come from using all the records. The data suggested that the increase came from the separation of over and under sized steel particles. A material balance is pending over the developer manufacturing process to try and locate exactly where the excess waste is produced. Project Benefits: These projects have numerous environmental and economic benefits. The recycling of the recovered solvent reduces the amount of money and effort involved in shipping and disposing of hazardous wastes. This practice also increases the life of the solvent, which reduces the amount that is used. This is an environmental benefit. The reduction in steel waste produced in the developer manufacturing will increase output and efficiency while reducing the amount of raw materials purchased. This could have substantial financial benefits because the cost of the raw materials and labor which is put into making developer. The goal of finding technology to reduce the emissions on the fluid bed coater will not result in a direct economic benefit but it will help keep Nashua Corp. in compliance with state and federal environmental regulations which will be environmentally and politically friendly.