MISSISSIPPI'S WOOD PRODUCTS MANUFACTURING INDUSTRIES:

AN OVERVIEW REPORT ON WOOD RESIDUE DISPOSAL

Submitted To:

Jack Kennedy, Industrial Representative Mississippi Power Company Hattiesburg, Mississippi

Submitted By:

Paul H. Short, Ph.D. Wood Products Specialist Food & Fiber Center Mississippi Cooperative Extension Service Mississippi State University

February 19, 1993MISSISSIPPI'S WOOD PRODUCTS MANUFACTURING INDUSTRIES:

AN OVERVIEW REPORT ON WOOD RESIDUE DISPOSAL

Mississippi's wood products manufacturing industries consist of both primary and secondary manufacturing. The Mississippi Forestry Commission defines primary forest products industries as those which purchase logs and bolts as they come from the woodlands and convert them into rough, unfinished products which can be remanufactured into finished or semi-finished products. They further define secondary forest products industries as industries which purchase rough, unfinished products from primary industries and finished or semi-finished products from other secondary industries and remanufacture them into finished or semi-finished products.

As with all manufacturing operations, the primary and secondary wood products manufacturing industries generate residues. These residues may be defined as either hazardous or non-hazardous. For example, wood and bark are normally considered non-hazardous materials. During the finishing operation some wood products are finished with organic solvent-based materials, which may be classified as hazardous materials. The combination of wood and finish may be classified as a hazardous material. However, the majority of Mississippi's manufactured wood products are not finished. Thus, this report will address only non-hazardous wood residues generated during the primary and secondary wood manufacturing operations. This wood residue will be defined as a non-hazardous, industrial processing by-product, and represents an economic opportunity for the state of Mississippi.

It is to be noted that the furniture manufacturing industry, a secondary manufacturing industry, is the largest and fastest growing manufacturing industry in Mississippi, contributing over a billion dollars annually to the state's economy. Decisions concerning its wood residue disposal will affect the future of the state's furniture industry.

This report will first briefly describe the wood residue being generated in Mississippi. Next, it will describe some of the many economic opportunities that exist for this residue. And lastly, it will describe some strategies for maximizing the benefits from the material.

For clarification, an Appendix contains calculations associated with examples of value-added, wood residue products discussed. It must be noted that considered costs during the discussion are for capital investments and do not include any other costs, e.g., operating costs. Where assumptions where made, values were chosen which would minimize the returns on the investments.

2The By-Products

Approximately 56 percent of Mississippi's land area, or 17 million acres, is currently forested with both softwoods and hardwoods. Although the harvesting of timber during a logging operation generates wood residues in the form of tree tops, sawdust and broken timber, this biomass does not present any substantial disposal problem. Thus, this particular type of residue will not be discussed in this report.

During the sawing of logs at a sawmill, bark, chippable material, and sawdust residues are generated. The factors that can be used for estimating the tonnage of wood and bark residue generated per thousand board feet of lumber produced by both softwood and hardwood sawmills are found in Table 1. As an example: (Appendix A-l) A circular headsaw sawmill sawing oak logs with 2 inch tops, and annually producing 1 million board feet of oak lumber, would generate: 720 tons green bark 1,530 tons green chippable material 1,340 tons green sawdust

Although, the yield from a typical sawmill is approximately 50 percent of the initial log volume, it was estimated that in 1984 4.9 million oven-dry tons, or 8.2 million green tons, of wood residue were generated by sawmills in Mississippi. Approximately 50 percent of the sawmill wood residues were used for boiler fuel in 1984.

Focusing attention on the hardwood residue being generated by the Mississippi furniture manufacturing industry, it is estimated that the average furniture plant utilizes approximately 60 percent of the lumber it processes. If oak lumber has an average price of $800 per thousand board feet (MBF), a 1 percent increase in manufacturing efficiency would save $218,500 per year for the average plant processing 10 million board feet (MMBF) per year. It needs to be emphasized that source reduction should be the major method of minimizing waste (Appendix A-2). Note that a board foot is a unit of measure; it represents a board 1 foot square and 1 inch thick. Thus, 1 BF contains 144 cubic inches of wood.

Table 2 is a list of factors for estimating tons of wood and bark residue generated per thousand board feet of wood used to produce various wood products. Information published by TVA indicates that the wood residue from the upholstered furniture manufacturing industry consists of 49 percent shavings, 42 percent chippable, and 9 percent fine material or sawdust. It is estimated that for each MBF of high density hardwood, e.g., oak, that is processed approximately 0.74 tons of hardwood residue is generated. Processing a low density hardwood, e.g., yellow poplar, generates approximately 0.53 tons of residue per MBF. A typical manufacturer

3of upholstered furniture employing 250 people will process

approximately 10 MMBF per year. Thus, this manufacturer would generate approximately 7,400 tons of oak residue per year (Appendix A-3). It has been estimated that for the year 1989, 200 MMBF of lumber was processed by the furniture industry generating 148,000 tons of wood residue. This is enough residue to fill 15,000 tractor-trailer trucks which bumper-to-bumper would reach from Tupelo, Mississippi, to beyond Memphis, Tennessee.

One plant manager of a upholstered furniture plant in Mississippi is paying transportation costs plus $14 per ton tipping fee to dispose of his wood residue at a municipal landfill. If this is typical, the estimated 148,000 tons of wood residue generated annually by the whole furniture industry would represent a cost of $2,000,000 to the industry considering only the tipping fees.

It interestingto note that this same 148,000 tons of wood residue has a BTU value equivalent to approximately 65,000 tons of coal (Appendix A-4)! A South Carolina electric utility is burning wood residue along with coal and saving an estimated $80 per hour in fuel costs.

Approximately 75 percent of the Mississippi Furniture
manufacturers are located in northeast Mississippi. It is estimated that over 110,000 tons of hardwood residue generated each year comes from this 20-county area.

Due to the high cost of disposal and the trend for these costs to increase dramatically over the next few years, a major concern for any wood products manufacturing plant manager is the availability of an economical efficient method of disposal of his wood residue. It would appear to be an attractive promotional and marketing tool for economic development if prospective manufacturers could be ensured that Mississippi has an economic and safe means of either utilizing the wood residue in an innovative, value-added product, or disposing of it.

Economic Opportunities For Wood Residue

It is believed that many furniture manufacturers are currently disposing of their wood waste by utilizing local landfills and/or rubbish dumps. Considering that some manufacturers are paying tipping fees as high as $14 per ton, and that new EPA regulations will make a large number of these landfills cost prohibitive, manufacturers may be forced to curtail plant expansions and many

may even consider closing operations. Critical decisions concerning wood residue disposal need to be made in a very timely

manner.

There are several alternative uses for wood residue besides landfilling. These value-added uses need to be engineered to specific plant sites, but should be given serious consideration.The discussion of these alternative uses considers only the initial

capital investment costs, and does not consider any operating

costs.

Wood incineration system. Although wood incineration systems are a means of disposing of wood residue, they do not directly increase value added to the manufacturing plants economy. There are many EPA approved incineration systems currently operating, especially in the northern part of the United States. It is estimated that an incinerator burning 1,800 pounds of wood residue per hour, 50 percent moisture content, would cost $40,000 and generate over 5 million BTUs per hour. For reference, it is estimated that a 20,000 pound per hour incinerator would cost $120,000 and generate over 57 million BTUs per hour. It may be reasonable to include the installation of commercial non-hazardous incineration systems with all new regional landfill proposals to dispose of residue from local industrial plants. These incineration systems could be purchased jointly between counties, manufacturing plants, etc.. This approach to wood residue disposal would provide an immediate solution the current problem.

Wood-fired boiler system. The next logical step in the sequence of wood incineration is the use of wood residue as a fuel for boilers which could supply thermal energy for plant heating, lumber drying and/or processing steam. There are over 90 installations of this type in Mississippi. An example of the potential economic advantages of using a wood-fired boiler system to dry green lumber is presented. To dry 1 MBF of green lumber from 50 to 6 percent moisture content requires an estimated 4 million BTUs of energy. A 150 HP boiler produces approximately 45 billion BTUs of energy per year and costs approximately $150,000. Natural gas as a fuel produces approximately 1 million BTUs of energy per 1 MCF at an estimated cost of $3.50 per MCF. Assume that a typical furniture plant processes 10 MMBF of lumber per year. To dry this amount of lumber would require 40 billion BTUs per year. This would require 40,000 MCF of natural gas per year with a fuel cost of $140,000. Thus, if the plant manager would use a wood-fired boiler system, he would realize a substantial savings in energy costs (Appendix A-5).

Fuel for a cogeneration system. Cogeneration will be defined as the process of producing both thermal and electrical energy with a wood-fired boiler/turbine system. There are over 10 cogeneration systems of this type operating in Mississippi. An example of the economic potential of a cogeneration system is given. A 200 HP wood-fired boiler system is the minimum size required for cogeneration at an estimated installation cost of $1,000 per KWH of electricity produced. A 200 HP boiler system would produce approximately 420 KWH of electricity at an estimated cost of $495,000. Operating at 50 percent annual capacity this system would produce 210 KWH of electricity. Public electric utilities

7charge approximately $0.06 per KWH. For a minimum cogeneration system of 210 KWH

, the average savings in only electrical operating costs would be approximately $110,000 per year (Appendix A-6).

Wood residue as finger jointing raw material. Currently, there are some manufacturers finger jointing the chippable portion, or larger pieces

, of their wood residue to augment plant production. Other potential markets would include molding, stair rails, door and window framing, etc.

The capital investment for a finger jointing machine operating at 80 feet per minute is estimated at $225,000. If it is assumed that a furniture plant processing 10 MMBF per year could produce and utilize 336 MBF of finger-jointed product per year, a potential savings of $134,000 per year in lumber cost could be realized. This assumes a value of $400 per MBF for the finger-jointed product

(Appendix A-7).

Wood residue as raw material for particleboard manufacturing. It is feasible for certain particleboard manufacturers to use a maximum of 10 percent of hardwood shavings as raw material in combination with softwood shavings. The shavings portion of classified wood residue from a furniture manufacturing plant would be suitable for particleboard manufacturing.

An average size particleboard plant could utilize approximately 27,000 tons of hardwood shavings per year. A furniture manufacturer processing 10 MMBF of oak per year would produce approximately 3,600 tons per year of suitable hardwood shavings for particleboard manufacturing (Table 2). Most particleboard manufacturers desire oak for the hardwood portion of their raw material mix due to the acidic nature of oak.

Furniture manufacturers would receive approximately $10 per ton for oak shavings delivered to the particleboard plant. Transportation costs are estimated at $1.50 per

mile. No further processing of the hardwood shavings is necessary, thus, no major capital investment would be required. For a 10 MMBF per year furniture plant an estimated $36,000 per year could be expected from the sale of hardwood shavings delivered to a particleboard plant. Mississippi has only one particleboard plant which utilizes hardwood shavings (Appendix A-8).

Wood residue pelletized for woodfuel. The technology for pelletized wood residue or modified wood residue with additives, e.g., urea, has been developed. Considering the increasing market for pelletized wood for fuel in stoves, especially east of the Mississippi River

, stricter EPA emissions regulations for burning, and the increasing gas and oil prices

, demand for pelletized wood

8fuel is dramatically increasing. Pelletizing equipment is

estimated at $600,000 for a capacity of 7,000 tons per year. Pelletized wood fuel is selling for $62.00 per ton, bulk, and $91.00, bagged.

A 10 MMBF per year furniture plant produces a minimum of approximately 7,000 tons of suitable wood residue for pelletizing into wood fuel (Table 2). Thus, with an initial capital investment of $600,000, it would be possible to realize an annual return of $434,000 for bulk pellets, $637,000 for bagged pellets (Appendix A-9). This return considers only capital investment costs and does not include operating costs, or any other associated

costs.

Another pelletized wood residue product is compressed wood fire place logs. The latest technology allows these logs to be made of hardwood and/or softwood particles using only high temperature and pressure to form the logs. The market for this type of fire place log is increasing, especially, in the larger metropolitan areas.

Woodresidue as livestock bedding material. Due to the limited suppliers, there is a growing demand for livestock bedding. Softwood shavings are considered to be ideal. A suitable baling operation would require a capital investment of approximately $26,000. An estimated selling price for a bale of wood shavings is $3.00 per 60 pound bale with manufacturing costs of $1.50 per bale. A 10 MMBF per year furniture plant processing poplar, a low density hardwood, would produce an estimated 2,600 tons of suitable shavings per year (Table 2). Producing 2,600 tons of shavings per

year a furniture manufacturer may be able to sell 87,000 bales per year with an estimated gross profit of approximately $130,000 per year (Appendix A-10). This gross profit does not consider operating costs and any other expenses.

It is interesting to note that with Mississippi's large poultry production requiring extensive amounts of bedding material, a ready market is available for wood residue shavings. The spent bedding from the poultry houses would be very suitable for soil additives requiring a high nitrogen content.

There are other possibilities for utilizing wood residue in value-added products, e.g., landscape and mulch, floor sweep, charcoal, etc. Further processing of the larger wood residues could generate additional amounts of smaller sized materials. For example, grinding chippable material could produce finer, sawdust material.

Open dumping and burning of wood residue is not an option. If a manufacturer needs to dispose of wood residue, but does not have the ability to utilize an existing landfill, it is possible to establish a private wood residue dump site.

9Private wood residue dumping site. Open burning and/or dumping is

not an acceptable method of disposing of wood residue. An acceptable method is to use or operate a private landfill. It is not normally required that the operator of a rubbish disposal landfill obtain a permit. However, there is an application process in order to make that determination. To initiate this application

process, a letter of application should be filed with the Mississippi Department of Environmental Quality (DEQ), including the following information about the proposed operation:

1. The type, description, and characteristics of the wastes to be accepted at the landfill and the anticipated sources of the wastes.

2. A legal description of the site and a map showing the boundaries, roads, designated disposal area, buffer distances, and other physical characteristics of the site. In addition, a property owner's map indicating the surrounding immediately adjacent property owners to the site.

3. The name and address of the landowner, if different from the site operator, and written confirmation that the landowner concurs with the use of the subject property as a solid waste disposal facility.

4. A letter from the County Administrator or County Board of Supervisors stating that there are no zoning ordinances, laws or regulations which restrict or prohibit the siting of this facility at the proposed location.

5. A plan of operation including details regarding site maintenance, cover frequency, equipment available, and any other pertinent information.

6. Plan to prohibit unauthorized wastes from the landfill, e.g., household garbage, putrescible wastes, hazardous wastes.

7. Closure plan, e.g., final cover, grading and sloping intentions.

Upon review of the submitted information, DEQ will conduct an inspection of the site to determine if there are any special characteristics or conditions that would make the site unusable or would require a permit. Following this inspection, DEQ will provide written authorization or denial of the rubbish landfill operation.

According to the State Of Mississippi, Nonhazardous Waste Management Regulations, Regulation N. PC/S-l, July 6, 1988, Section

10E--Rubbish Disposal Facility:

A rubbish disposal facility is one which receives materials.

e.g. brush, tree limbs, stumps, leaves, construction and demolition debris, and other inert materials. A permit shall not normally be required for a rubbish disposal facility...

However, the following minimum requirements shall apply to all rubbish disposal sites:

1. Aminimum separation distance of 150 feet shall be maintained between the disposal operation and the site boundary.

2. Rubbish shall not be disposed in such a manner that may result in washout.

3. Rubbish materials shall be managed in a manner that it shall not become windblown or harbor insects or rodents.

4. Open burning of rubbish shall be prohibited.

5. An adequate supply of water under pressure at the site or an adequate stockpile of earth reasonably close to the disposal area shall be provided, or there shall be a nearby organized fire department providing service when called.

6. Garbage, liquids, sludges, paints, solvents, asbestos, putrescribes, and toxic wastes and other wastes determined to have a possible adverse effect on the environment shall not be disposed at a rubbish site.

7. Unloading and disposal of rubbish shall be confined to as small an area as practical.

8 . Adequate security at the site shall be established and maintained in order to prevent uncontrolled access and dumping.

11A-l. From Table 1, circular headsaw, 2-inch top, hard hardwood,

g (green): 0.72 tons/MBF bark 1.53 tons/MBF chippable 1.34 tons/MBF sawdust

Calculation: (0.72 tons/MBF) x (1 MMBF) = 720 tons green bark (1.53 tons/MBF) x (1 MMBF) = 1,530 tons green chippable (1.34 tons/MBF) x (1 MMBF) = 1,340 tons green sawdust

A-2. Savings associated with an increase in yield from 60 to 61 percent for the initial breakdown of oak lumber priced at $800 per MBF. Example is for a typical furniture plant processing 10 MMBF per year.

Calculation: Value of lumber processed at 60% efficiency: ($8OO/MBF) / (0.60) = $1,333.33/MBF

Value of lumber processed at 61% efficiency: ($8OO/MBF) / (0.61) = $1,311.48/MBF

Annual savings: ($1,333.33/MBF - $1,311.48/MBF) x 10 MMBF = $218,500

A-3 : From Table 2, either wooden furniture frame or an upholstered furniture plant, hard hardwood: 0.31 tons/MBF chippable material 0.36 tons/MBF shavings 0.07 tons/MBF fine (sawdust)

0.74 total tons/MBF wood residue

Calculation: (0.74 tons/MBF) x (10 MMBF/year) = 7,400 tons/year

12A-4 : Fuel required for equivalent heat: Bituminous coal (80% net boiler efficiency) = 0.034 tons Wood & bark, 30% MC (76.08% efficiency) = 0.077 tons

Calculations: ( Coal ) / (0.034 tons) = (148,000 tons) / (0.077 tons) Equivalent coal = 65,351 tons

A-5 : Estimation: To dry 1 MBF of lumber from 50 to 6% moisture content requires approximately 4 million BTUs; Natural gas produces approximately 1 million BTUs/MCF at a estimated cost of $3.50/MCF.

Calculation: Energy to dry 10 MMBF/year from 50 to 6% moisture
content: (4 MMBTU/MBF) x (10 MMBF/year) = 40 MMMBTU/year

Natural gas required: (40 MMMBTU/year) x (1 MCF/l MMBTU) = 40 MMCF

Annual fuel cost for natural gas: (40MMCF)x($3.50/MCF) = $140,000

A-6: Estimation: Public utilities charge $O.O6/KWH; a plant requires an average of 210 KWH per hour for 24 hours a day.

Calculation: (210 KHW) x ($O.O6/KWH) = $12.60/hour (365 days/year) x (24 hours/day) = 8,750 hours/year (8,750 hours/year) x ($12.60/hour) = $l10,376/year

13A-7: Estimation: The yield efficiency for processing lumber is

approximately 60% (40% wood residue is generated); approximately 42% of the wood residue generated would be suitable for finger jointing; the manufacturing plant utilizes only 20% of the finger-jointed material; plant processes 10 MMBF of lumber annually.

Calculation: (10 MMBF/year) x (0.40) = 4 MMBF/year (4 MMBF/year) x (0.42) = 1.68 MMBF/year (1.68 MMBF/year) x (0.20) = 336 MBF/year (336 MBF/year) x ($4OO/MBF) = $134,40O/year

A-0 : From Table 2, upholstered furniture plant generates 0.36 tons/MBF shavings; furniture plant processes 10 MMBF/year; particleboard plant could utilize 27,000 tons/year shavings paying $lO/ton FOB plant.

Calculation: (0.36 tons/MBF) x (10 MMBF/year) = 3,600 tons/year (3,600 tons/year) x ($lO/ton) = $36,00O/year

A-9: From Table 2, upholstered furniture plant generates 0.07 tons/MBF sawdust; furniture plant processes 10 MMBF/year; bulked pellets sell for $62/tan; bagged pellets sell for $9l/ton.

Calculation: (0.07 tons/MBF) x (10 MMBF/year) = 7,000 tons/year (7,000 tons/year) x ($62/tan) = $434,00O/year, bulk (7,000 tons/year) x ($9l/ton) = $637,00O/year, bagged

A-10:From Table 2, upholstered furniture plant, soft hardwood (poplar) generates 0.26 tons/MBF shavings; furniture plant processes 10 MMBF/year; $1.50/60 lbs bale profit.

Calculation: (0.26 tons/MBF) x (10 MMBF/year) = 2,600 tons/year (2,600 tons/year) x (2,000 lbs/ton) = 5,200,000 lbs/year (5,200,OOO lbs/year) / (60 lbs/bale) = 86,667 bales/year (86,667 bales/year) x ($1.50/hale) = $130,000/year

14