Agricultural Uses of By-Products and Wastes - American Chemical

Chapter 2

An Entrepreneurial View of the Future for the Use of Wastes and By-Products 1

Dale F. Galloway and John M . Walker

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Downloaded by COLUMBIA UNIV on September 8, 2012 | http://pubs.acs.org Publication Date: July 1, 1997 | doi: 10.1021/bk-1997-0668.ch002

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RDE, Inc., 101 North Virginia Street, Crystal Lake, IL 60014 Office of Wastewater Management, U.S. Environmental Protection Agency, 401 M Street Southwest, Washington, DC 20460

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Great opportunities exist for creative management of wastes and by-products that result from the centralization, concentration, and intensification of processing and production of animal and plant feedstocks. If these feedstocks are viewed holistically and if animals, humans, factories, and soils are viewed as organic matter and mineral processors, then greater opportunities exist to creatively benefit from the feedstocks at many different times during the various processing and reprocessing sequences.

I f s o c i e t a l wastes and by-products are considered h o l i s t i c a l l y / then the idea that these wastes and by-products are too valuable t o waste i s made paramount. The By-products and wastes l e f t a f t e r processing become feedstocks f o r other uses, some of which may involve recycling to land and some o f which may not. I t i s important t o think broadly. At the most basic l e v e l / the organic building blocks o f l i f e are also the by-products o f life, ( i . e . / oxygen i s the by-product o f plant photosynthesis and carbon dioxide i s the by-product o f both animal and plant r e s p i r a t i o n . Plants use oxygen and carbon dioxide t o produce food/ feed and f i b e r and animals use these plant products and oxygen t o sustain t h e i r l i f e . As we i n society learn t o make our l i f e more comfortable and pleasant/ we create more complex goods and generate more complex wastes o r as we should view them - feedstocks for other uses. The r e a l l i m i t a t i o n i s our a b i l i t y t o see and develop the opportunities f o r these other uses o f wastes and by-products. If we are able t o r e a l i z e these opportunities/ then the i n i t i a l feedstock users/ the "wastes" they generate/ the subsequent users of the wastes and by-product and the environment w i l l both p r o f i t and benefit. When l i f e was more simple/ the waste problem was more simple. The d r i v i n g force behind our current interest i n c r e a t i v e l y managing wastes and by-products i s c e n t r a l i z a t i o n and concentration o f animal

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© 1997 American Chemical Society

In Agricultural Uses of By-Products and Wastes; Rechcigl, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1997.


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Entrepreneurial View of the Future

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production and plant product processing i n confined areas - i n short the i n t e n s i f i c a t i o n o f i t a l l . V i s u a l i z e a picture that I have o f my grandmother and an uncle taken i n the e a r l y 1900's. This picture shows them d r i v i n g about 100 hogs 4 miles t o a r a i l siding f o r transport t o market. This was the largest batch o f hogs they had ever grown/ and they earned a reasonable p r o f i t from t h e i r s a l e . Today/ large-scale producers r a i s e 15/000 or more hogs a t a given l o c a t i o n - 150 times more than my grandmother grew. Think a l s o o f a 1970's soybean processing plant. This plant would t y p i c a l l y crush 200 tons of beans per day. Today/ a competitive plant must process or crush 10 times more beans o r 2000 tons per day. To supply the soybeans needed t o keep t h i s 1990's plant operating/ a l l soybeans grown i n a 55 mile radius would have t o be gathered. Now think about what a f r i e n d o f mine t o l d me who has been i n the tanning industry a l l o f h i s l i f e . He s a i d that an average tannery i n the e a r l y 1900's might tan 100 hides per day. Today an average tannery tans 6/500 hides per day o r 65 times greater volume. What once was a 5 g a l l o n per minute stream o f waste generated by the 1900's tannery i s now a 325 gallons per minute waste stream from the 1990 s tannery. (1) f

Research i s showing us more about how t o properly manage wastes and how improperly managed wastes can cause environmental problems. The i n t e n s i f i c a t i o n (confinement/ concentration/ and corporate l i k e structure) o f plant and animal production and management which I have b r i e f l y described magnifies the potential f o r environmental problems. Federal and state governments have enacted several rounds of environmental l e g i s l a t i o n t o help ensure the proper management o f the wastes and by-products from society's various enterprises. Hence/ the system f o r managing these wastes i s v a s t l y d i f f e r e n t than before i n t e n s i f i c a t i o n and regulation. Because o f large magnitude and concentration o f operations/ the large-scale hog producers and soybean processors have t o ship feedstocks i n from great distances t o supply t h e i r needs. And/ lakes o r mountains o f waste are created from these very confined production and processing f a c i l i t i e s . Before rules and regulations/ these wastes would often remain i n lagoons and p i l e s or be applied a t high rates on s o i l s . After regulation these options are being changed. The problems l i m i t i n g wise a g r i c u l t u r a l use i n accordance with these new r u l e s (both from a pollutant and nutrient management point-of-view) include odors and the high costs f o r transporting what currently are regarded as low value wastes. Hog producers would normally l i k e t o use the hog manure on nearby land. But the problems l i m i t i n g i t s use include/ but are not l i m i t e d to, odors/ excessive transportation costs and the need t o manage nutrients. Repeated and/or high rate applications o f manure on land have caused the b u i l d up o f nutrients i n excess o f crop needs and the q u a l i t y o f ground and surface waters can be degraded within watersheds. Degradation of watersheds from the excessive use of manures and the catastrophic accidents that can occur are adding considerable pressure and the need f o r better management and use of the by-products and wastes. A recent example o f such an occurrence was the recent accidental s p i l l a g e o f m i l l i o n s of gallons of waste into the waterways from hog waste storage lagoons i n North Carolina. Watershed degradation from by-products and wastes can be minimized i f we change our mind-set. In our e a r l i e r example/ think of hogs and soybean pressing f a c i l i t i e s as processors o f g r a i n . And/



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rather than viewing the s t u f f that comes out of the back door of soybean processing plants and the back side of the hogs as a f o u l refuse/ think of these wastes and by-products as recycling profit-making opportunities. In t h i s view of the opportunities f o r using these p a r t i a l l y processed feedstocks (by-products and wastes) as feedstocks f o r other than land recycling the organic matter and nutrients. I f a l t e r n a t i v e uses are not included/ the a b i l i t y to use them wisely and sustainably may not be possible. Minimization of waste i s being achieved. Sane industries l i k e the o i l r e f i n i n g industry have made great s t r i d e s i n converting most a l l of t h e i r feedstock into useful products. For example/ the o i l industry can extract more than 3/000 products from each b a r r e l of crude o i l (2) with e s s e n t i a l l y no waste. The o i l r e f i n i n g industry has had several great advantages/ ( i . e . / favorable economics and the need to avoid generation of wastes which can be environmentally t o x i c and c o s t l y to dispose. They a l s o have had very smart and creative people working t o f i n d new and better uses f o r each part of the crude o i l feedstock. On the other hand/ residues from the processing of animal and plant feedstocks have been viewed as major problems. Careful examinations of these co-products/ however/ reveals that they have many of the properties found i n the crude o i l feedstock. The task of using municipally generated wastes i s made somewhat easier because of subsidization. This subsidization helps make the use of municipal s o l i d waste (MSW) and b i o s o l i d s economically competitive with other feedstocks currently i n use f o r various practices. This subsidy i s often available from municipalities that generate by-products and wastes because they must pay f o r t h e i r d i s p o s i t i o n by some method anyway. For example with subsidization/ uses of MSW and b i o s o l i d s may have a competitive advantage over corn when used as a feedstock f o r ethanol production. A firm i s now designing a f u l l - s c a l e 600-ton per day f a c i l i t y f o r separating recycable p l a s t i c s / aluminum/ and ferrous components from MSW/ mixing i n biosolids/ and/ a f t e r a l s o mixing i n biosolids/ producing the ethanol. This process has been c a r e f u l l y researched and p i l o t e d and o f f e r s promise. Tipping fee and recycling revenue o f f s e t the $1.75 per g a l l o n cost of producing ethanol from MSW and b i o s o l i d s mixture and can compete with the $0.75 per g a l l o n cost of ethanol production from g r a i n . (3) Society i s w i l l i n g to pay t h i s much d i f f e r e n t i a l because i t i s equivalent to or greater than the amount that would have to be paid f o r d i s p o s i t i o n by other means. Most producers and processors of animal and plant feedstocks do not have the advantage of subsidization. As stated several times previously/ the challenge f o r these producers and processors of c a t t l e / hogs and swine and other foods i s to change t h e i r view to seeing the wastes and by-products as resources and not refuse. The current refuse mind-set stems from the corporate paradigm of focusing energy f i r s t and foremost on the production of core products. With such a focus/ the animal producer and food processor mind-set has been to get r i d of by-products i n the quickest and cheapest way possible. (4) In the future the corporate concept should be expanded t o include the i d e n t i f i c a t i o n and development of the use of l e f t over p a r t l y u t i l i z e d by-products and waste now considered as refuse. The current president of DuPont i s quoted i n a recent issue of Chemical Week (5) as saying/ "The goal of our Company i s to produce zero



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waste. Waste i s raw material we paid f o r that didn't make i t into the product we sell." This attitude w i l l probably have more influence on our r e a l i z i n g that great benefits e x i s t f o r future use of these "wastes and by-products" both inside and outside of agriculture. The following discussion i l l u s t r a t e s other opportunities f o r using by-products and wastes as feedstocks f o r other processes which i n turn y i e l d by-products and wastes that can be used as feedstocks f o r s t i l l other purposes. By t h i s s h i f t from narrowly focusing on core business there can be more p r o f i t as well as being environmental stewards and wasting the l e f t - o v e r by-product w i l l not be tolerated. Consider three examples: o One company I have worked with extracts pharmaceuticals from the l i n i n g of the small i n t e s t i n e s of swine. From a 20-ton truck load of t h i s l i n i n g they are currently able to harvest only about 8 pounds of the pharmaceutical. The 20-ton minus 8 pound balance of swine ingesting feedstock i s c e r t a i n l y not core business but i s now being used as a feed f o r baby pigs. o Paper companies extract c e l l u l o s e from wood t o make paper - t h e i r core business. Cellulose makes up only 50% of wood and as a r e s u l t the paper industry i s based on u t i l i z i n g only 50% of t h e i r feed stock. Over the years/ some improvement has been made i n converting a small part of t h i s 50% waste t o saleable products. The important d i s t i n c t i o n i s that the part of wood that i s not c e l l u l o s e can not be given the developmental muscle needed as long as the core business i s making paper. The press f o r e f f i c i e n c y w i l l not allow industries of the future to waste 50% of the feedstock going into a plant. This wastage w i l l continue u n t i l companies who make paper w i l l change t h e i r description of t h e i r core business to wood or f i b e r processors. o Animal a g r i c u l t u r e has existed f o r many years on the premise that i t s function was l i m i t e d to producing meat/ milk/ or eggs. The drive f o r ever increasing e f f i c i e n c y has driven animal production u n i t s to ever increasing s i z e s . Throughout the years animal producers have been aware that f r a n 50% to 80% of the feedstock that goes i n t o a u n i t i s not sold as a product. This large "waste" could e f f e c t i v e l y be used as crop food and a c t u a l l y was not a waste. The v a s t l y increasing s i z e of animal producing units i s eliminating the productive use f o r the wastes. This evolves as the s o i l i n the proximity of the animal u n i t reaches i t s capacity to carry minerals and n i t r a t e s . As a result/ these animal feeding units have moved towards hauling the manure t o ever remote areas or the use of lagoons. In either case/ the disposal of the waste has became a production cost. A s o l u t i o n f o r t h i s problem can be found by taking a broader view of feeding an animal. When a pound of feed i s ingested/ the digestive t r a c t makes a f r a c t i o n a t i o n . I t absorbs those nutrients which are r e a d i l y d i g e s t i b l e and r e j e c t s those which are not. This i s p r e c i s e l y what an o i l r e f i n e r y does i n each step of r e f i n i n g o i l ; except that the o i l engineers have c l e v e r l y devised a sequence o f extractions that allows them to s e l l p r a c t i c a l l y a l l of the feedstock going into a r e f i n e r y . I t seems l o j i c a l that we view the digestive t r a c t as being



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the f i r s t process i n r e f i n i n g g r a i n or feed generally. T h i s f i r s t step has extracted the more l a b i l e factions and necessarily has concentrated the l e s s l a b i l e . One demonstration o f t h i s i s found as we learned that the e a r l y s e t t l e r s found that b u f f a l o chips were a better f u e l than was the grass eaten by the b u f f a l o . The digestive t r a c t of the b u f f a l o had concentrated the carbon and i t became a better f u e l per u n i t of volume. If we adopt t h i s broader view/ we must answer the important question/ "What have we produced that someone can p r o f i t a b l y use?" We can not yet answer t h i s question because research on manure has l a r g e l y been focused on re-feeding manure to animals and these data are of l i t t l e use i n searching f o r i n d u s t r i a l uses f o r the component of manure. We see r a p i d l y increasing i n t e r e s t i n industry f o r proteins that can be used as adhesive r e s i n s f o r building materials and f o r foundry core binders. The carbohydrate f r a c t i o n shows promise of finding a home as a low cost adhesive i n industry to bind foundry dust/ coal f i n e s and limestone. Work has been done i n using the f i b e r f r a c t i o n i n making particleboard and hardboard The opportunity exists/ then, of turning a production cost into a p r o f i t center by making animals processing u n i t s . A generalized view of the properties of several animal manures are given i n Table I. Indication i s made of fractions that are p o s s i b i l i t i e s as feedstock products f o r i n d u s t r i a l uses. To repeat again/ i f we look a t animal agriculture h o l i s t i c a l l y as organic matter processors/ then we can begin t o look at manure as a p a r t i a l l y u t i l i z e d resource that should not be wasted. The witches' brew wastes that have been c h a r a c t e r i s t i c of the past may well disappear. Wastes and by-products w i l l become more uniform and suitable f o r other uses. There w i l l be l e s s burning/ l e s s dumping into the l a n d f i l l / and l e s s land a p p l i c a t i o n i n t h i s process. This does not mean that the opportunities f o r land use of these by-products w i l l disappear/ but these co-products w i l l become more refined and appropriate f o r other uses. As a r e s u l t of d i e t a r y design/ genetic engineering/ and other c r e a t i v e combinations and structuring of wastes and by-products/ p r o f i t a b i l i t y w i l l increase to the extent that wasting i s not economically f e a s i b l e .

TABLE I. Potentially Partitionable Fractions of Animal Manures (1)

Fractions

Types of Manure Poultry Cattle Swine % by dry weight

Protein

15-30

20-25

30-34

Ash

10-20

10-15

15--22

Ether Extract All

Other*

5-10

3-4

2--3

50-70

56-67

41--53

*Lignin/ Cellulose/ Hemicellulose


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Literature Cited Bliss, Earl. Private communication. L.H. Lincoln, Currwinsville, PA. Pampe, M. Petroleum. How It Is Found and Its' Uses p 47. 1996. Beneficial Use of Solid Waste and Sludge with the CES OxyNol Process. Masada Resource Group, LLC, Birmingham, AL. Galloway, D.F. 1995. Finding Uses For Industrial Wastes, p 4. Dorrance Publishing Co., 643 Smithfield St., Pittsburg, PA 15272 Roberts, M and Fairley, P. Sustainable Development Is A New Global Agenda. Chemical Week July 3/10, 1996 p 46.


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Agricultural Uses of By-Products and Wastes - American Chemical

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