Annette J. Kikta

A successful plant poilu- tion prevention (P2) pro- gram requires that manag- ers pay as much attention to the details of organiza- tion and execution as they do to the technical aspects of operational change. This article shows how one company used a six- step organizational frame- work to improve manufac- turing efficiency. reduce

To ESTABLISH A successful pollution prevention (P2) program in a plant requires that managers pay as much attention to the details of organization and execution as they do to the technical aspects of operational change. Critical management steps include

1. Setting the goals and scope of the program; 2. Mobilizing a P2 program management team; 3. Auditing to identify wastes and their sources; 4. Choosing improvement options; 5 . Applying information management tools to. track program

progress; and 6 . Conducting a follow-up evaluation.

costs, and improve enui- ronmental performance. This article shows how one company followed a similar organiza-

tional framework to implement a P2 program for two unique operat- ing units in a single facility.

Facility Process Descriptions

thetic fibers and hydrocarbon resins. The facility, which employs forty-six people, manufactures syn-

Synthetic fibers The older of the two process units produces polyolefin fibers. The

process, shown in Figure l, comprises the following steps. Raw materials, consisting of polyethylene and polypropylene fluff and hydrocarbon solvent, enter the plant and are unloaded to a storage area. Fiber production consists of mixing one polymer with the solvent, raising the slurry pressure to near 1500 psig., heating the slurry beyond the polymer melting point, and releasing the solution into a flash tank. The polymer is then reformed into fibers in the flash tank. The fibers are mixed with water treated with additives to impart hydrophilic properties to the fibers and for product preservation. In the flash tank, the majority of solvent is vaporized to an overhead

Annette J. Kikta is a staff engineer for the M. W. Kellogg Co., Environmental Engineering, in Houston, Texas. She was formerly employed by Hercules Chemical Co, LaPorte, Texas.

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Annette J. Klkta

Figure 1. The Fiber Process

4 VAPOR RECOVERY

I I PULP PROCESSING DISSOLVING

AND SPINNING POLYMER STORAGE

DEWATERING PACKAGING

EFFLUENT TREATMENT

refrigerated condenser for recovery and reuse. Hydrocarbon remaining in the fiber/water slurry is released

downstream during the mixing and fibrillation processing. The re- leased hydrocarbon is sent to the flare. From the last mixing vessel, the fiber slurry is sent to a dewateringmachine. The machine consists of a sheet-forming dewatering section, a press section, and a cutting and stacking section. The cutting and stacking section cuts the continuous web with high pressure water while it is held against a rotating vacuum. The vacuum drum rotates to a section where the vacuum is broken and drops the sheets onto palleted stacks that are wrapped and ready for sale. Water removed during the formation of the fibrous web is recycled for reuse in the flash tank.

Because water consumption in the additives makeup and sheet cutting exceeds the evaporative losses and water retained in the salable product, an effluent stream is discharged. The effluent stream flows over a screen used to remove gross fiber and then passes through a carbon bed before it is released.

Pollution prevention opportunities for the fiber unit lay in the three areas: (1) effluent discharge, (2) improved solvent reuse, and (3) solid and hazardous waste reduction.

Hydrocarbon resins The newer process (see Figure 2) blends an odorous heavy

hydrocarbon with additives, activators, and catalysts to produce reaction injection-molding resin monomers. The monomers, pro- duced one a t a time, use the same process equipment and react together to form a thermoset plastic upon mixing. Unreactive mono- mer, flushing solvent, and off-specification blends are diverted to an off-spec tank for disposal as hazardous waste. Key pollution preven-

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Case Study: Using a Six-Step Organizational Framework To Establish a Facilfty P2 Program

Figure 2. The Resin Process

ODORS HYDROCARBON

MONOMERS WASTE OFF SPEC TANK -

I CATALYST y / I \ u SOLVENTS RESIN A - Dnn'IUCT

1 1 I , l l V L . 1 ADDITIVES y

I I I . I RESIN B y PRODUCT

tion opportunities for this unit include minimization of hazardous waste and odor control.

Mobilizing a P2 Management Team and Selecting Goals Pollution prevention teams were selected for each unit. Each team

consisted ofpersonnel involved in the day-to-day operation of the unit: the unit supervisor, shift supervisor, and lab analyst. The facility maintenance supervisor, technical supervisor, laboratory analyst, and project engineer served on both teams.

The overriding goals of the program were to reduce pollution and lower the costs of production. The specific issues addressed by each team in identifying goals for their unit were as follows:

Inadvertent releases Public image Hazardous and nonhazardous waste streams RCRA permits Fugitive emissions Pollutant reductions at or below permitted levels Required return on investment Dealing with waste brokers

The fiber unit team then selected the following goals:

Elimination of uncontrolled releases to the air Reduction of wastewater pollutants Reduction of nonhazardous waste streams including disposal of unsalable product Reduction of the amount of product for recycling

Goals selected by the resin unit team were as follows:

Reducing the hazardous nature and cost of waste disposal

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Annette J . Kfkta

Avoiding a RCRA permit Eliminating the nuisance of an odorous chemical

Auditing To Identify Wastes and Their Sources Audits conducted by the two teams first focused on identifying the

waste streams and their sources. The resin team used hazardous waste manifests to determine the quantity and nature of the unit’s waste. Sources of waste were identified by evaluating operating procedures (e.g., start-up, shutdown, normal operations, and mainte- nance). Laboratory analysis of ambient air was used to detect the presence and source of odorous emissions.

The fiber unit team used effluent quality reports to identify the quantity and quality of the wastewater stream. Operating logs were used to determine the frequency of unplanned releases. Accounting inventories provided data to assess the quantity of unsalable product, solvent consumed, and the cost of packaging materials.

When the sources of wastes were known, each team developed strategies to reduce, eliminate, or reprocess the waste. Both teams explored the full range of the U.S. Environmental Protection Agency’s waste management hierarchy to be sure all P2 measures that met criteria for cost, ease d implementation, maintenance, and technical feasibility were considered.

Operating logs were used to determine the frequency of unplanned releases.

Choosing Improvement Options Prevention options for each waste stream were evaluated from

several perspectives. The form, shown in Figure 3, was used to docu- ment comments and project approvals from team members and plant management. First, potential changes were assessed against safety and cost criteria. Approvals for safety were based on compatibility with the facility‘s process safety management program. Additional information concerning the prevention measure was attached to the form. Capital and operational costs for each measure were then assessed.

Information Management Tools To Track Progress Databases were created to track progress. This information was

formatted to link goals with specific waste streams, potential solu- tions’ and the team member responsible for the waste stream and its solution investigation. The databases were frequently updated and used as a tool to communicate program progress to management. A sample database format used by the fiber unit is presented in Figure 4. ( See pages 203-207 for a detailed explanation of each prevention option.)

Implementing P2: The Fiber Plant After analysis of all potential prevention options was completed,

specific changes were targeted. A sampling of the P2 measures chosen by the fiber unit are presented here with a description of the problem and the solution that was implemented.

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Case Study: Using a Six-Step Organizational Framework To Establish a Facility P2 Program

Figure 3. Fiber Unit Pollution Prevention Process Change Form

Process Name Originator Date

Description of Waste Stream and Source of Generation:

Annual Volume Volume/Occurrence Cost per year $

Proposed Improvement: (attach Process Flow Diagram if applicable)

Benefits and Consequences of Improvement:

Annual Volume Reduction

Operability Concerns:

Safety Concerns:

Cost Implications:

Capital Cost of Improvement: Annual Operating Cost of Improvement: Annual Waste Reductions Savings:

Approvals:

Operations Laboratory Supv. Technical Project Engineer Maintenance Safety Engineer Plant Manager

Maintenance change lowered refrigerant releases The releases of refrigerant were found to occur duringpreparation

for maintenance. The refrigeration manufacturer was contacted to determine if the equipment could be pumped down to very low pressure without incurring damage. With the manufacturer’s ap- proval, this procedure was implemented prior to maintenance.

New flushing reduced storm sewer contamination The plant site drained to a stormwater basin owned by a neighbor-

ing company. Although the process sewer and storm sewer were segregated, flushout of pumps and tank gravity caused draining to the

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Annette J. Kikta

Figure 4. Database Example for the Fiber Unit

Goal

Eliminate releases

Reduce costs

Waste stream Source of generation

Refrigerant to air Refrigeration unit maintenance

Fiber in storm water Process upset & flushing operations

Hydrocarbon to flare Process design

Packaging Process design

Prevention options

Pump down

Improve reliability

Control releases

improve reliability

Direct flow to process sewer

Change procedures

Recover hydrocarbon

Recycle pallets

Redesign packaging

Responsibility

Project Engineer

Maintenance Supervisor

Technical

Project Engineer

Operations

Operations

Technical

Technical

Technical

storm sewer collection system. This resulted in additional costs to clean up the basin. The plant also received nuisance complaints associated with the contamination.

Procedures were modified, when feasible, to flush pumps through equipment to process vessels. Otherwise, hose connections were installed to allow flushing to the process sewer through these hoses. Drain pipes were piped from the drain connections of process vessels to the process sewer. Covers were obtained to seal the storm sewer from equipment flushing that could not easily be directed to the process sewer. Areas around equipment were also curbed to direct the drips and drains to the process sewer.

Disk strainer curbed fiber overload in downstream treatment

With the addition of the flow from flushing activities, fiber contamination in the process sewer increased. Gross fiber was re- moved in the process sewer treatment train by an inclined screen. When this screen overloaded, fibers were carried downstream to the carbon bed.

A disk strainer was installed in the treatment train downstream

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Case Study: Using a Six-Step Organizational Framework To Establish a Facility P 2 Program

of the inclined screen and upstream of the carbon bed. The disk strainer retained finer fibers than the inclined screen, thereby im- proving the effluent quality treated in the carbon bed. Fibers passing through the disk strainer also had a drier consistency, which reduced the volume and disposal costs for waste fiber.

Process and maintenance changes lowered oxygen demand in upstream efftuent

The carbon bed in the effluent treatment train was designed to remove wetting agents to achieve acceptable effluent discharge levels. Biological oxygen demand (BOD) and chemical oxygen demand (COD) levels in the process effluent were not comfortably lower than permit- ted limits, however. The wetting agents added to enhance the hydro- philic properties of the fibers were the sources of COD and BOD in the process effluent.

Two possible causes of high BOD and COD were considered. Either the concentration of wetting agents in the effluent exceeded the design conditions of the carbon bed, or the carbon bed efficiency to remove wetting agents did not meet the performance guarantees. The carbon bed’s efficiency was challenged and found to meet the manufacturer’s specifications. P2 efforts were then directed toward reducing the concentration of wetting agent in the effluent upstream of the carbon bed.

Frequently, the wetting agent concentration in the effluent was influenced by the addition of the wettingagent in the process. At other times, the concentration of wetting agent in the effluent was affected by leaking pump seals and discarded batches of spoiled wetting agent. The plant’s laboratory studied a simulation of the plant’s fiber process to determine how much wetting agent was required by the process to impart the proper fiber quality. The study enabled them to determine an optimum wetting agent addition rate that would maximize the fiber’s adsorption level. Based on the study, operating recipes were changed to reflect the optimum addition rate.

An intensive maintenance program was also undertaken to im- prove the wetting agent pump seals, and curbs were installed around the pumps to contain leaks. To avoid wetting agent spoilage, the temperature in the storage tanks was maintained just below boiling, and wetting agent makeup water was chlorinated.

The s&dy determfne an optfmum wetting agent addition rate.. .

them to

Hydrocarbon losses reduced by vapor recovery system The majority of solvent from the flash spinning process was

recovered by a solvent recovery refrigeration system. Residual sol- vent, trapped by the fiber, was released with further downstream processing and was vented to a neighboring company’s flare. Losses to the flare and charges for use of the flare inspired examination of a replacement technology.

Subsequently, a cryogenic vapor recovery system was installed, and vents to the flare were disconnected. The temperature of the

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Annette J. Kikta

recovery system vent was continually monitored to ensure that emissions of non-condensables met regulatory requirements.

Packaging waste reduction Nonreusable packaging was used to package the fiber bales.

Packaging wastes constituted 40 percent of the nonhazardous waste from the fiber unit, and packagingmaterials accounted for 15 percent of the product cost. A number of options were evaluated for reducing packaging waste and its cost.

A number of options were evaluated for reducing packaging waste and its cost.

First, in-plant pallet recycling was evaluated. Changing from disposable packaging to nondisposable packaging, which could be returned by the customer, was operationally acceptable with minor packaging line modifications. Some customers, however, were not comfortable with the change to returnable packaging, because it would also require package handling changes at their facilities. Thus, this option was implemented for selected customers.

To reduce the cost of packaging, packaging size was optimized according to the weight and height constraints of the existing pack- aginglines and safety requirements for the forklift operation. Alarger size was acceptable to most customers. Both initiatives significantly reduced disposal costs for nonhazardous waste.

New procedures reduced waste from mechanical failure Mechanical failure of the cutting section of the sheet-forming

dewatering machine resulted in product falling prematurely so that it missed the package stack. Often this product was contaminated, which meant that it was neither fit for sale nor recycling. Inadequate design and, in some instances, mishandling of the equipment by line operators was to blame.

An intensive reliability improvement program was launched to rectify both problems. The equipment manufacturer and corporate mechanical engineering experts provided input to address design issues. Additionally, operators of the sheet-forming machine were brought together to write procedures that would improve their ability to reliably operate the equipment.

Implementing P2: The Hydrocarbon Resins Unit As specified by the plant’s initial P2 goals for the resin unit,

solutions focused on two key problems-hazardous wastes and odor.

Reduced odor from emissions Odor from the hydrocarbon was detectable below ten parts per

billion. Emissions from tank vents and sampling activities were within permit limits, but were subject to regulatory scrutiny due to the odor. Proving that the odor limitations were continually met was difficult because of the technical limitations of available instrumen- tation.

As a temporary measure to minimize the odor, the pollution

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Case Study: Using a Six-Step Organizational framework To Establish a Facility P 2 Program

~~~~

Table 1. Results of Pollution Prevention Measures

Waste Stream Results of the Implemented Measure

Refrigerant releases Refrigerant losses were reduced by 90 percent.

Storm sewer contamination Complaints from the neighboring plant ceased.

Effluent treatment overload Installing the disk strainer reduced the fiber loading on the'carbon bed, resulting in easier changeout of the carbon. Disposal costs of the fiber were reduced.

EMuent quality

Hydrocarbon losses

Packaging waste

Waste generated due to mechanical failure

Odorous emissions

Waste disposal costs

BOD and COD of the effluent ceased to be a concern, life of the carbon bed more than tripled, and wetting agent costs were reduced.

Solvent losses were reduced around 70 percent.

Packaging and disposal costs were reduced.

Shipping costs for customers taking the larger packages were reduced.

Product costs were reduced for customers using returnable packaging. More attention was given to scheduling and inventory for package size.

Mechanical improvements were implemented resulting in an approximate 50 percent reduction in failure rate.

Product waste was reduced near 22 percent.

The measures implemented were accepted by the regulatory agency as the Best Available Control Technology.

Improvements resulted in reductions of approximately 40 percent of the waste generated due to off-specification quality.

The neutralized product was easier for disposal company to handle. Disposal costs were reduced.

prevention team elected to install carbon canisters on the vent lines. Additionally, open sample connections were changed to closed purge systems to eliminate emissions in sampling operations. The team also submitted a project proposal to install fixed carbon beds as a long- term solution to the odor problem.

Hazardous waste disposal costs reduced Waste disposal costs accounted for 10 percent of the product

manufacturing cost, To reduce this cost, measures to reduce the volume of the waste and neutralize its hazardous constituents were implemented.

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Annette J . Kikta

The success of this facility’s pollution preuention program is clearly tied to the organized step-by-step approach.. .

The waste consisted primarily of off-grade product that could not be recycled. Generation of some of the waste resulted from poor quality production runs. This tended to occur when product grades were changed in the blending system. Thus, procedural changes were made to require flushing of the system between product grades. Additionally, time delays were programmed into the blending se- quence to ensure that chemicals critical to the finished product were added well after the blend sequence began and well before the blend sequence was complete.

To address the hazardous nature of the waste, the prevention team developed a neutralization process for off-grade product to eliminate one of its hazardous characteristics. Because the product could not be sold before it was neutralized, regulatory authorities determined that the neutralization process required either a Re- source Conservation and Recovery Act (RCRA) permit, or the product could be de-inventoried every ninety days. The team elected to store the hazardous waste for less than ninety days as required by RCRA regulations.

Follow-up Evdua t ion An evaluation of the manufacturing process with the P2 measures

in place was conducted over a period of several months to ensure that each unit cycled through production of all product grades more than once. Results were reviewed and issued to management. Additionally, program results were summarized and presented to representatives from all locations of the parent company who attended the company’s annual environmental meeting. The results of the pollution preven- tion measures that were implemented are listed in Table 1.

Conclusion The success of this facility’s pollution prevention program is

clearly tied to the organized step-by-step approach, beginning with clear program goals that provided specific direction for the P2 teams. The program extended over three years for the fiber unit and one-and- a-half years for the resin unit. During these periods, innovative personnel on each team were able to solicit the support and coopera- tion of peers and management. Planning and communication main- tained the program integrity. The follow-up evaluation demonstrated success of the program. Sharing the plant’s experiences with other facilities in the company has spread the benefits and knowledge of pollution prevention. +

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