United States
 Environmental Protection
 Agency
            Office of Pollution
            Prevention and Toxics
            7408
EPA745-K-95-008
November 1995
 EPA's 33/50 Program
 Company Profile
    Monsanto
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               EPA's 33/50 PROGRAM
                 COMPANY PROFILES
                               1? PMOKHY CHEMICALS mm CYAN JD-ES
                                      METHYL ISOBUTYLJTQNE
                                              XYJJ3NES-
                                    * Also referred to as jnethylene tjhlaridfe^ ,
 This Company Profile is part of a series of reports
 being developed by EPA to highlight the.accom-
 plishments of companies participating in the 33/50
• Program. The 33/50 Program is an EPA voluntary
 pollution reduction initiative that promotes reduc-
 tions in direct environmental releases and offsite
 transfers of17'high-priority-toxic chemicals. The
 program derives its name from its overall goals —
 an interim goal of a 33% reduction by 1992 and
 an ultimate goal of a 50% reduction by 1995. The
 program uses 1988 Toxics Release Inventory (TRI)
 reporting as a baseline. In February, 1991, EPA
 began contacting the parent companies of TRI
 facilities that reported using 33/50 Program
 chemicals since 1988 to request their participation
 in the 33/50 Program. As of November,  1995,
 nearly 1,300 companies had elected to participate
. in the Program, pledging to reduce emissions of
 the 17 target chemicals by more than 380 million
 pounds by 1995. Companies set their own reduc-
 tion targets,  which may vary from the Program's
 national 33% and 50% reduction goals.

 Industry exceeded the 33/50 Program's interim 33%
 reduction goal by more than 100 million pounds in
 1992. National emissions of Program chemicals
 were reduced by an additional 100 million pounds
 in 1993, bringing total reductions since 1988 to
 more than 685 million pounds (46%). Facilities' TRI projections suggest that the Program's ultimate 50%
 reduction goal will be observed to have been achieved or exceeded in the 1994 TRI data, a full year ahead
 of schedule.  The 1,300 companies enrolled  in the 33/50 Program have accounted for most of the Progra-
 m's pollution reductions. Representing just 15% of eligible companies, and owning only a third of the facil-
 ities reporting Program chemicals to TRI, participants are responsible for 78% of the reductions since
 1988 and 98% of the 100 million pounds reduced in 1993.

 EPA  is committed  to recognizing companies for their participation in the 33/50 Program and for the
 emissions reductions  they achieve.  The Program issues periodic Progress Reports, in which participat-
 ing companies are listed and highlighted: In addition, Company Profiles, such .as this one, are being
 prepared to provide more detailed information about how companies have achieved their emissions
 reductions. Information presented in these profiles is drawn from a number of sources, including the
 company's written communications to the 33/50 Program, extensive interviews with company representa-
 tives, the annual TRI reports submitted by the company's facilities (including Pollution Prevention Act
 data  reported to TJRI in Section 8 of Form R), and, in many cases, site visits to one or more of the com-
 •pany's facilities. Mention of trade names, products,  or services in this document does not convey, and
 should not be interpreted to convey, official EPA approval, endorsement, or recommendation.

 Copies of other 33/50 Program Company Profiles, as well as Reductions Highlights documents-
 summarizing all of these Profiles, may be obtained by contacting the Program as'specified in the box
 below.  In addition, all written company communications to EPA regarding the 33/50 Program are avail-
' able to the public upon request.                             ,
     . For ttf&rfttattdn m the 33/5Q Prdgrmif cvtttaai
     * Program stgjfiiiKctty by phone
      Preventi&k 'ftatt
                          TSCA -Matlmg M \20Z) 554-1404 4r contact 3^/SQ *
                               mail at,&s% Code 740$ *&jjice ef Pollutfan ,
                         f Vtodfagton, #
.. 33/50 PROGRAM COMPANY PROFILE:  MONSANTO COMPANY

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    SUMMARY

             Monsanto Company joined the 33/50
             °rogram in May 1991 with a goal
             jf reducing on-site releases of 33/50
 • ,  Program chemicals from U.S. facilities by 50
    percent by 1995, using 1988 as a baseline.
    Since then, Monsanto  reduced releases of
    33/50 Program chemicals by 66 percent from
  .  2,567,783 pounds in 1988 to 865,629 pounds
    in 1993. Monsanto also reduced off-site trans-
    fers of 33/50 Program chemicals by 71 percent
    from 2,781,569 pounds in 1988 to 817,466
    pounds in 1993.  .

    In addition, Monsanto's Air Emissions Reduction
    Program aims at reducing air emissions ofTRI
    chemicals from all facilities worldwide by 90

 COMPANY  BACKGROUND
• percent by the end of 1992, using 1987 as the
 baseline. This effort was successfully completed
 by the end of 1992, when a 90 percent reduction
 in air emissions was achieved.  The Company-
 also continues in a parallel  effort to reduce
 multi-media releases and transfers of toxic
 chemicals from 338 million pounds in the 1990
 base year to less than 100 million pounds by the
 end of 1995..  This  case study provides an
 overview of Monsanto's efforts to implement the
 33/50 Program at  its facilities  in the U.S.  It
 also highlights two projects — the reduction of
 xylene emissions through equipment upgrades
 and process redesign, and the reduction of
 toluene emissions using vapor  balancing 'and
 steam stripping!
         Monsanto, a Fortune 100 Company based in St. Louis, Missouri, is the fourth
         largest chemical company in the United States. Founded in 1901 when
         Monsanto Chemical Works was established to manufacture saccharin, the
. Company now employs nearly 30,000 individuals worldwide at 33 major manufacturing
 locations. Monsanto manufactures and markets agricultural products, prescription
 Pharmaceuticals, food ingredients, industrial chemicals, and performance chemicals used
 in consumer products.  At the end of 1994, the Company was organized into the fol-
 lowing four operating units or subsidiaries:

    • The Chemical Group manufactures a range of high-performance materials
      including fibers, Saflex™ plastic interlayer, phosphorus and its derivatives,
      rubber and process chemicals, and plastics used to make consumer, household,
      automotive, and industrial products.
                              Monsanto
           33/50 PROGRAM COMPANY PROFILE: MONSANIP COMPANY

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         Monsanto manufac-   I
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                                           Group manufactures herbicides, lawn-and-garden products,
                                       enhariceci by Kiotechnolbgy to improve food production and pre-
                           serve environmefital quality in agricultural, industrial and residential markets.

                           Searle, a wholly owned subsidiary of Monsanto,  develops and markets pre-
                           scription pharmaceuticals,  including  medications, to treat infections, arthritis
                           pain, high blood pressure, the formation of ulcers, and insomnia.
                                                                                                                ,,j   i

                                                                                                               L:i	jit	:
ifc
           tares and markets
                             	i
            ucts, prescription
            "'" i '„ |I!!|lji|O, 	I,, j,'1 ii|lli!li : «•	,',i,',,,i? »i	'i"ii.illlll}ii,i. '»	''4 -(
            Pharmaceuticals,   ;
            'foqdjfjgredients,
            ""	IBd'tfiltr".^	, i : rv,, !W'Jmllll	'*, ' Ml1!
            industrial chemi-
       	I1'
       ll.	
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     Tn'consumer	
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    §iii.	!;>'.•,.:&!	i'W/y	WiE  ;«•}
    ^^ products.
   'd*	>v';	:JV'-'W'	«»
                                       The NutraSweet Company is also a wholly owned subsidiary of Monsanto and man-
                                       ufactures and markets sweeteners and other food ingredients, including NutraSweet™
                                       sweetener, Equal™ and NutraSweet Spoonful™ brand tabletop sweeteners.
                                 In addition to those mentioned above, some of Monsanto's well known brands include
                                 Roundjip™ and Lasso™ herbicides, Ortho™ lawn-and-garden products, Wear-Dated™ carpet,
                                 aid"Q3ah™.calcium channel blocker. In 1993, Monsanto reported net sales of $7.9 billion.
                                                                              illllll|ll|lll,iiill|l||,lillllli'l ',,1,,,1,1'liil	ililill ,'liallljnll	Ill llhilLli'iiii'iJn all. " „ i||i|ilil|,,i||i;i
                                           iilllll :|' i', ill|iMI||l!l|l|i I il	'i»	IHlHiFiiillll'illllllnii'	llliilllI'lMlllllllll.'lllllllliKIHII I'llllii 'I	'Slim 'il	lil,iilili;,,,|i,,,ill|lliA	IWhili: I i
                                                                                                 illlllll'iiiii	pill	'Ji ,1 'i l;|||l,,li:i|i||l,,'	i'lKliN'ill'ifilllllilllliiilip,,, *ill|||lllll||||llill,i.
                ij/gg programs
                	
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Board of Directors
*• Chief Executive Officer
^ Corporate Social
Responsibility Committee
A
^

  I
 Environmental Policy
     Committee
     9 S
Corporate Environmental
 Safety and Health Dept.
                                          Monsanto Pledge
                                                                  Responsible Care
                                                                     Principles
                                                                 Business Charter for
                                                                Sustainable Development
Chief Environmental
  ...  Officer
> Vice Chairman
                 Operating Units
               ES&H Departments
                           Monsanto Operations
                              Worldwide
                    Internal Reporting
             > Board of Directors
             ^•Environmental Policy Committee
             ^ Management
             v^ Employees
   «  §
                                                 External Reporting -•
                                            >• Environmental Annual Review
                                            >• Financial Reports
                                            ^ Communities
                                           . *"• Government
                                        Employee Recognition
                                        ^•Awards
                                        ^•Rewards
                                        ^ Communications
 of environmental, safety and health performance. The Corporate Environmental, Safety
. arid Health Department oversees issues at Monsanto relating to regulatory management,
 safety, toxicology, occupational medicine, quality assurance, and industrial hygiene. The
 department is responsible for conducting oroverseeing periodic environmental, safety, and
 health audits to ensure compliance with company policy and procedures. Results of these
 evaluations are reported to corporate, operating unit, and subsidiary management. To oversee
 the implementation of Monsanto's environmental programs, each of the Company's four
 operating units and subsidiaries appoints individuals to accept primary responsibility for
 coordinating environmental operations. Monsanto has more than 1,100 employees at the
 corporate, operating group, and plant levels worldwide whose primary responsibility-is
 work on environmental, safety, and health issues.
                                                                                         Exhibit 1
                                                                            Monsanto's
                                                                            Environmental
                                                                            Management System
            -33/50 PROGRAM COMPANY PROFILE: MONSANTO COMPANY


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      Illinois:  First Annual Environmental Citizenship Award, received in 1991.

      Michigan: The 1993 Environmental Quality Award from the Michigan Chamber
      of Commerce.           •    .'•

      Florida:  Take Pride in Florida Award, for sponsorship of "Environmental
      Classroom" in 1992.

Monsanto's expenditures in 1993 were approximately $53 million for environmental capital
projects and approximately $233 million for management of environmental programs,
including the operation and maintenance of facilities for environmental control. Monsanto
estimates that during 1994 and 1995  approximately $40 to $70 million per year will be
spent on additional capital projects for environmental protection.

OVERVIEW OF 33/50  AND TRI CHEMICAL

RELEASES AND TRANSFERS

In 1988, Monsanto reported releases  and transfers of thirteen 33/50 Program chemicals
from 27 manufacturing facilities in the U.S. In that year, Monsanto reported a total of
295,0'62,815 pounds of releases and transfers of all TRI  chemicals.  Of this total,
5,349,352 pounds were 33/50 Program chemicals. Monsanto's releases and transfers
of 33/50 Program chemicals for 1988  and 1993 are shown in Exhibit 2.  Additional detail
is provided in Appendices A through D. The following is a list of 33/50 chemicals used
at Monsanto's facilities arid their source of emissions:               '
MONSANTO'S RELEASES AND TRANSFERS
OF TRI

33/50 Chemicals (1.000 Ibs.)
Benzene
Cadmium & Compounds ;
Chloroform
Dichloromethane
• Hydrogen Cyanide
Methyl Ethyl Ketone
Methyl Isobufyl Ketone
Nickel & Compounds
Tetrachloroethylene
Toluene
1,1,1-Trichloroethane
Trichloroethylene
Xylene
33/50 Subtotal*
Other TRI Chemicals
Total*
NR = Not reported, use below reporting threshold
,.* Columns may not sum to total due to rounding
CHEMICALS

1988 • . '
-800
,26
<1
128
81
75
557
11
530
843
135
237
1,925
- 5.349
289,713
295,063




1993
139
23
NR
321
181
219
74
9
NR
314
NR
.2
402 ,
1.683
. 81,223
82,906



Exhibit 2

Releases and
Transfers of
TRI Chemicals
(1,000 pounds)

: • - f












'

Monsanto estimates
that during 1994 and
1995 approximately
$40 to $70 million
per year will be
spent on additional
capital projects
for environmental
protection.
          33/50 PROGRAM COMPANY PROFILE: MONSANTO COMPANY

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S:S:=SBii-!Kr'$T?r--mi*
                                                                                     Transfers Off-site for
                                                                                     Treatment/ Disposal/
                                                                                          Other
                                                                                         28.77%
'i'&m.-t
J '  ,	""I"",'!."', '",'1 , ,  ]'i
           ::  I"1!
          *.-
                           Benzene is primarily used as a building block chemical in several processes. Almost.
                           half of the chemical releases and off-site transfers were transfers to a POTW with
                           large amounts also released as air emissions.' Small quantities of benzene were also
                           injected underground or released to land.
                                  11 •             i             *              •    '  i  i       i     ,  <
                           Cadmium & cadmium compounds are used in metal plating processes to increase
                           resistivity and provide resistance against corrosion. They were primarily transferred
                           off-site for treatment or disposal.
                                                         1    	'',	j    *	'.;	
                           Chloroform was used as a solvent and was released as air emissions and transfers
                           to a POTW.

                           Dichloromethane is used as a solvent.  Large quantities  of the chemical were
                           injected underground, with the remainder released as air emissions.

                           Hydrogen cyanide is used as a building block chemical in the production of several
                           chemical iritermediates. The majority Is Injected underground, and small quantities
                           are released as air emissions.
                           Methyl ethyl ketone (MEK) is primarily used as a solvent in several processes. Large
                           quantities are transferred to a POTW, with small amounts transferred off-site, and
                           the remainder released through underground injection and air emissions.
                           Methyl isobutyl ketone (MlK) is also used as a solvent in several processes. Large
                           quantities of the chemical were transferred off-site, with smaller quantities transferred
                        ";^7tp	^'"pQTW	released	as	au^nuslronsj	anJInjected underground. _
                        	,lii'Ti|RV	Klviiiiin                                           ii in I illnli III i ii null Inn IIP i in I  n 111 nil in    11 n n
                        •      '  '  :.',        '    '    .. , " •'• -     ' ; ' !."   ," .,  r;     "   I  '                .
                         -•Nickel & nickel compounds are present in metal alloys  and are used in plating
                           processes"to provide resistance against corrosion. Most nickel is injected underground,
                           '"'    ;veFsrnall quantities are discharged to surface water or released to land. Nickel
                                       were	release9	to	land"	—JBiscfiarged1 to' surface water.
                                                                                              Ill	llllillil  nil III  ill nililii
                                                   	•-
                                                                                                L"	|l	I	I	|'»
                                   oroetkylene was used as a solvent, and was primarily released as air emissions,
                                   	~	an'3	3ie~reraalndertfansiened'	to	a POTW.
                                                                              i	
                                                                           ^'o COMPANY'

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        Trichloroethylei
            4.44%
      Dichloromethane	__
         2.38%
  Xylene
  35.99%
  Hydrogen Cyanii
      1.51%
    Tetrachloroethylene
        9.91%
                                                             Methyl Isobutyl Ketone
                                                               '  10.41%
  	Methyl Ethyl Ketone
—  '  .    1.41%
                                                     1,1,1-Trichloroethane
                                                          2.53%
             'Other Cadmium Compounds (0.49%), Chloroform (0.01%), Nickel Compounds (Q.21%)
   Toluene is used as a solvent and,as an extractant to remove impurities from chem-
-   ical manufacturing processes.  Toluene-is primarily transferred off-site, with large
 ,  quantities also released as air emissions.  Small quantities were discharged to surface
   water and transferred to a PQTW.

   1,1,1-Trichloroethane (TCA) was used as a solvent, and, the majority of releases of
   .the chemical were to the air, with small quantities transferred off-site.

..   Trichloroethylene was also used as a solvent, and was primarily released as air emis-
   sions, with small amounts transferred off-site.

   Xylene is used as a carrier solvent in the, production of rubber chemicals.  It is pri-
   marily released as air emissions, with large quantities of the chemical also transferred
   to a POTW, and/theTernamderJransferred off-site.

Exhibits 3 and 4 illustrate 1988 releases and transfers of 33/50 Program chemicals by
release media and by chemical, respectively. In 1988, of the total air emissions of 33/50
chemicals, xylene emissions accounted for 35 percent, tetrachlbroethylene accounted
for 19 percent, and toluene made up 15 percent.  Of total off-site transfers, 19 percent
were methyl isobutyl ketone, 17 percent were toluene, and 40 percent were xylene.
• _    .      *'           .,'•-'     .„•''.-.'      .    '   '   -             .>.•-• x
33/5O PROGRAM  GOALS  AND  REDUCTION
PROJECTS

Monsanto joiried the 33/50 Program in May 1991, at which time the company set a goal
of reducing on-site releases of 33/50 Program chemicals from U.S. facilities by 50 percent
by ,1995, using  1988 as a baseline.  Since 1988 releases of 33/50 chemicals were.
2,567,783 pounds, this translates to a targeted reduction of 1,283,891 pounds by 1995.
Monsanto limited its 33/50 Program goal to on-site releases because of the uncertainty
of the impact of RCRA waste combustion rules, which  imposed requirements that
could cause the Company to switch from on-site combustion to dff-site combustion and
disposal of wastes. The remainder of this section.describes two projects that resulted
in significant reductions of on-site releases of 33/50 Program chemicals:
                                                                                Exhibit 4
Percentage Breakdown
of 33/50 Program  "
Chemical Releases
and Transfers for 1988
(by Chemical)
                           Monsanto limited
                           its 33/50 Program
                           goal to on-site
                           releases because of
                           the uncertainty of
                           the impact of RCRA
                           waste combustion
                           rules, which
                           imposed require-
                           ments that could
                           cause the Company
                           to switch from on-
                           site combustion
                           to off-site combus-
                           tion and disposal
                           of wastes.
           33/50 PROGRAM COMPANY PROFILE: MONSANTO COMPANY

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                 I	!	RiHS	P	"•	"i	1	a	fti
                                      i	ifj!'i •'i'1"'!1' ff"':';,
                                      Vf;ji. i." * Tf.1 u ;i;:;y|;!fl«	jWS; [ *':••
j Project #1:   Krummrich
I Reduction Program

 The W.G. Krummrich Plant, located in Sauget, Illinois, is one of the largest Monsanto
 manufacturing sites supporting the Chemical Group. It produces a variety of chemical
 lnt6ftai§iatesl]ncluding: paradichlorobenzene, a component of mothballs and bathroom
 phosphorus pentasulfide, used in motor oils to prevent corrosion; moriochlorobenzene,
 Iclganers ;	rubbCTcherrucalSj	used	in	the production of tires and other rubber products;'
                  USed inEasso™ herbicide; and orthonitroaniline, which is used in Monsanto's Saflex™
                  l||	Uliill	I	qnran	I	I	Hill	ill!	I	IF	I	SiSSii	SUSi!	if	,	Si-	-i.	,	liliil	I'll.!:*	Ill	Hi	  	    	
                   |lass coating.
                                              	It	'ill	I	liSii!::.	
                                                                  	in!	j	,•.	i*.	•'	!	I	!	j	I!	Illlll!	illi	I	I	'ill
                       ,'itif-, ,!?•,!>;
                                                                                "i1-1'1' fi1-!!:-' viifc"1) i!
 Jn 1§88, Monsantq made a voluntary pledge to reduce its JLRl-reported air emissions
 |)y 90 perceni by the end of 199:2 from aT^^baseiuie!This pledge, coupled^ with the
 SOmpaly's participation in the 33/50 Program beginning in 1991, led engineers at the
 I!"!'""'"1"'1	"	i	'""i	S	I	3	;	 :	""«	i	P'	t	'*	ii'	"	F	"—fm"	'"'	"'"	———	——	—	——u———	- -	
 ,]@mmric| plant to'assess methods' bFiredTlcinglFeleases	oFx^ene, among 5their chem-
   '''•''>  'j'i' "•, '	inn	 '	H	i.Yiv.ilr	 in'iL",	n: ' , , ur ,11	' :. < > v >" «,'

       Nitrogen system upgrades—The 4NDPA Department maintains approximately
       30 nitrogen blanketing systems that were installed at various times over the last
       few decades. In order to reduce xylene emissions from these systems, old units
       were replaced and the new systems were installed in such a way as to allow for
       easier troubleshooting, 'identification of leaks, and repairs.  These upgrades
       resulted }Pn approximately 20,0,000 pounds of xylene emissions reductions

     I Centrifuge replacement project — The centrifuge used by the 4NDPA
                                 ^d had significant mechanical reliability problems
                                                                       Thiscen-
 illlBiliitffiifuge was replaced with a new unit that was designed with special features aimed

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      at achieving a better seal, thereby reducing xylene emissions. The replacement
      project accounted for a 200,000 pound reduction in xylene emissions.

    • Melt tank and screw conveyor replacement —' During the 4NDPA production
      process, the centrifuge discharge was moved directly to a melt tank for further
      processing. In the past, the discharge was transported between the centrifuge and
      the melt tank using a screw conveyor. This process resulted in significant xylene
      emissions as the process was  not tightly sealed.  When it was necessary to
      replace the melt tank, the new tank was placed directly beneath the centrifuge,
      thereby eliminating the need to transport discharge using the screw conveyor. Due
      to their new proximity to one another, the centrifuge and melt tank were connected
      using a tightly sealed chute. This process change resulted in a 95,000 pound reduc-
      tion in xylene emissions.                                           ,

    • Agitator seal replacement project—An agitator system used to mix products
      during an intermediate processing step was difficult  to maintain properly and
      resulted in  significant xylene emissions through a seal at the top  of the tank.
      Engineers replaced the agitator system with a new pump and recirculation system
 1     that mixes tank contents by pumping material from the bottom of the tank to the
      top of the tank on a continuous  basis.  This new system has no  seal  at the top to
      allow leakage and has resulted in xylene emissions reductions of 70,000 pounds.

Four additional first tier projects  in-the 4NDPA  Department resulted in reductions
ranging from 2,000 to  25,000 pounds, and totalling 52,000 pounds. Therefore, reduc-
tions in xylene air emissions achieved from first tier projects alone totalled more than
600^000 pounds. Implementing these first tier projects required a total capital expen-
diture of $ 1.7 million,  which yielded an average return on capital of 20 percent.

The second tier projects focused on the capture and recycling of xylene air emissions.
They consisted primarily of smaller projects to link tank vents and install additional con-
densers. In total, these  projects resulted in a 160,000 pound reduction in xylene air emis-
sions in the 4NDPA Department.

After reducing the use of xylene and recycling xylene to the maximum extent possible
through the first and second tier projects, the 4NDPA Department at Krummrich under-
took a third tier project to destroy remaining xylene vapors generated in the manufac-
turing process.  This project involved  the installation of a thermal oxidizer in January
1993, which has resulted in a reduction in xylene air emissions of 180,000 pounds.

Underlying all three tiers of the xylene air emissions reduction program was the need
for increased levels of preventive and routine maintenance on all equipment to prevent
leakage. As a result of this increased maintenance, and the completion of the various
reduction, recycling, and treatment projects, the 4NDPA Department at  Monsanto's
Krummrich plant was successful in reducing xylene air emissions by almost 1,000,000
pounds.  In addition,  the Department achieved,these reductions during  a period in
which production  increased dramatically.  During this increase, plant  expansions
included measures that woukLallow for further reductions in xylene air emissions.
As a result of
increased mainte-
nance, and the com-
pletion of the vari-
ous reduction, recy-
cling, and treatment
projects,  the 4NDPA
Department at
Monsanto's
Krummrich plant
was successful in
reducing xylene air
emissions by almost
1,000,000 pounds.
           33/50 PROGRAM COMPANY PROFILE: MON.SANTO COMPANY

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                              Proect#2: Reduce Toluene Emissions and Reccle Toluene at a acility in Nitro. West
                               Virinia usin  Vaor Balancin  and Steam Stripping
                              j The facility located in Nitro, West Virginia manufactures chemicals used in the fabri-
                              cation of rubber tires. The principal cnemicals produced are sulfenamides, which are
                              Accelerators used to speed up the vulcanization process in the production of rubber chem-
                              icals,. The vulcanization process is a nonreversible chemical reaction involving the use
                              of sulphur compounds or other suitable catalysts to increase trie elasticity of rubber.
                              Sodium 2-Mercaptobenzottiiazble (NaMBT), a primary raw material used in the pro-
                              duction of sulfenamides is also made at the Nitro plant. During the intermediate stages
                              of the manufacturing process, toluene is used to extract impurities from NaMBT.  Prior
                              to process changes, toluene vapors were released from tank vents, and in 1988 the Nitro
                              t facility reported 135,000 pounds of toluene air emissions.
                                       "                         '          "              "     "'"    .....
 !	i	!i!	H	:	IS	
           :wnfs"fo" Be tied
         ;:,:'!!i, ' ;^ll|in!l!PI!ll	fell,11	1'-li.	luiiililhflf "
         together ana con-
IS	me	fit!	,	:	las	i:;	:	actSr!:	iisfi:
1^^^^^^^^^^^^^^^^^^^
 	i;;	:;:,•.!-.i-	V   t >LV...^.	.;;;»
Ip order to reduce these emissions, and also recycle toluene for reuse, plant engineers
and personnel from the Environmental Safety & Health Department came together to
propose ideas for process modifications. The first step in the process reconfiguration
jsas to determine; the extent to which t toluene iiwjsmedjnjhe process	An inventory of	
chemical use at the facility listed annual toluene usage at 300,000 pounds. The plant
engineers considered using individual brine cooled condensers on each tank to reduce
toluene air emissions. Because implementing such -a system involved very high costs,
however, this technique was ruled out.	"::	"	
                                      In I Ii	I	fii|	1	1 il|l|iiiiiiliiii
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                                                                                       .
                               Engineers decided to use an approach known as vapor balancing to reduce toluene emis-
                              S|on$"ai^to"recycle'toluene'By steam stnppmgl	The	ftaMBT production process at the
                              "Nitro	feHirtyis^m^sedorTnumb~er6ftanks	and vessels	wEicH	ijiiclud'e"rnixers, dis-
                               |6lvers, and storage tanks. The vapor balancing technique required all tank vents to be
                               ged together and consolidated to one common vent  In a closed vent system, when liquid
                               From one tank flows into another tank, the vapor displaced by incoming liquid flows
                               back to the first tank to fill the volume created by emptying it. In this manner the total
                               pressure in all tanks is balanced at the common vent, and toluene vapor is contained within
                               me closed vent system. Any vapor that is not balanced in the common vent is vented
                               through a brine cooled condenser, resulting in no significant solvent loss from Xhe
                               yapor balancing process.

                               The vapor balancing project also included upgrading old agitator seals on tanks with
                               new double mechanical seal agitators to prevent the leakage of toluene vapors from tanks
                               in the production process. Old pumps in the process were also replaced with seal-less-
                               ll"l»'|i	'I	'	''	:""'	IMI	ai	"im	"»	-	-	ii	"a	i«i	B	IS	»	»	"	«	
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                               pumps, or were fitted with double mechanical seals.

                               Because vapor balancing is a closed-loop system, fire safety considerations become
                               extremely important. Should an explosion or fire occur from excessive pressure build
                               up in one tank, the common vent could potentially act as a conduit for flames, and could
                               cause a chain reaction throughout the entire system.  To prevent such hazards from occur-
                               ring, the system was installed with detonation attestorsin three or four places on the
                         5j   {yept nozzles of tanks.  The detonation arrestors, while maintaining an equilibrium
                              j pressure in the entire vent system, also act as safety devices in the event of a fire or explo-
                              i sion hazard. Implementing the vapor balancing process, which required piping rein-
                mal invest-   (fqrcements, new agitator seals, and new seal-less pumps, required a total capital
                               investment of $1,000,000.
                                                                                                               i  in
                                                                    10
                                           33/50 PROGRAM COMPANY PROFILE:  MONSANTO COMPANY
                                                                   ii	i
                                  ill i	ni'i'lii	!	i	i	    •

-------
With the adoption of vapor balancing to address toluene emissions, the plant engineers
could now evaluate alternative technologies that would recycle toluene for reuse: From
previous experience at a Monsanto facility in Antwerp, Belgium, the project engineers
considered separating chemicals using steam stripping. After toluene is used in the man-
ufacturing process to remove impurities from NaMBT, a mixture of NaMBT and
toluene is stored in an extraction chamber. The steam stripping process involves sep-
arating toluene from NaMBT using the "flash separation" technique. "Rash separation"
is a common operation employed to separate and partially enrich a vapor-liquid mixture.
It occurs simply and spontaneously when a fluid passes through a pipeline restriction
(usually a throttling  valve) —  the pressure drops, and vaporization of the toluene
occurs.  At this stage the toluene separates from NaMBT. The NaMBT is returned to
product storage and the toluene is passed through a condenser to a distillate tank. A dis-
tillate pump transfers the toluene into two tanks in the main manufacturing proqess where
it is reused. For safety purposes/and prevention against fire, all flat bottom tanks and
condenser outlets are nitrogen inerted (oxygen is displaced with nitrogen), and all tank
vents entering the condenser header are fitted with flame arresters.

Although most of the toluene is recovered in the  steam  stripping process, about 12
pounds/day of toluene is lost to a vent header from the stripper condenser. Implementing
the steam stripping process required a total capital investment of $300,000. The annual
raw material savings as a result of toluene recovery amounts to approximately $30,000.

Following the implementation of the vapor balancing and steam stripping processes in
September 1992, the plant reported 22,600 pounds of toluene air emissions in 1993. This
translates to over a 90 percent reduction in toluene air emissions from 1991  levels.  Vapor
balancing accounted for approximately 65 percent of this reduction and steam stripping
accounted for approximately 25 percent.  The remaining 10 percent of total reductions
was accomplished by plugging leaks using seal-less pumps and mechanical agitator seals.

Other Projects:                        ,

In addition to the above mentioned projects Monsanto also achieved reductions through
many.others,  including the following projects:              '

   • Use of an Aqueous-Clean-In-Place system, using high pressure water sprays as
      an alternative to solvent use in cleaning operations. This cleaning system is cur-
      rently used at a Searle Pharmaceuticals plant to clean reactor tanks, and has reduced
      toxic air emissions by 87 percent and liquid wastes by 71 percent.

   • The use of a cyclone separator to reduce toxic  chemical air emissions from
      manufacturing processes. The separator captures the chemical in a powerful vortex
      and recycles the chemical into the manufacturing process. By installing this new
      system, Monsanto's Ruabon plant in Wales, England eliminated more than
      121,000 pounds in trichloroethylene emissions.
Implementing the
steam stripping
process required
a total capital
investment of
$300,000.  The
annual raw
material savings
as a result of
toluene recovery
amounts to approxi-
mately $30,OOO.
                                   11
           33/50 PROGRAM COMPANY PROFILE: MONSANTO COMPANY

-------






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33/50
Goal



              1988     1989    1990    1991     1992     1993
               33/50 Goal: 50% Reduction in releases of 33/50 Chemicals" by 1995
            PROGRESS

         Monsanto was successful in reaching its 33/50 Program goal of a 50 percent reduc-
         tion in releases of 33/50 Program chemicals two years ahead of schedule, and
         as of 1993 had achieved a 66 percent reduction. Exhibit 5 illustrates these reduc-
tions, and Exhibits 6'and 7,illustrate Monsanto's	1993, releases and,transfers|of 33/50
ghsHiicals,	jjy release media and by chemical, respectively. The major contributors to
Monsanto's success include the reductions of the following chemicals:
nil i PI      MI Hi M  li    ' i  "ii  "i ii         i  i i  i 11 i   i iiji 11  i -pi  ,i |  , i , •'   -Ii1  i  ^   ii|
                               ^25^,083 pounds (74 percent reduction)
iii'iiiToluene          _- "        323,606 pounds (87 percent reduction)
    Trichloroethylene -         23 6,260 pounds (100 percent reduction)
i           '                                                II
    Xylene            -         644,694 pounds (80 percent reduction)

Monsanto achieved  and exceeded its 33/50 Program goals largely as a result of its vol-
untary program to reduce air emissions of all TRI chemicals by 90 percent worldwide
[Sy theen"ovoFl99'2.  Also^ thei Company's achievement: towards meeting its multimedia .
goal by the end' of 1995 provided an incentive to focus on reducing releases to all media
Besides air emissions. Exhibit 8" shows releases and transfers of all TRI Chemicals from
                                                      Transfers Off-site for
                                                      Treatment/Disposal/
                                                          Other
                                                          24.47%
     Transfers to PQTW
         24.10%
      Underground Injection
           24.21%
                                                                fjf Emissions
                                                                  27.16%
                                                            J—-feurface Water Discharges"
                                                            !        0.04%
        L	 	 !	 	li,,:LIJ 	B	:,,:!,!	;	i  	,	,	,;, ni	ui	;	i	 giiili:	I iiiiiii
        «-	-Mi	H	^	r	m	ftfet	H-jj	^
i	 • •	hiiilii	iiillr	 .
                           •ii	i
        *e*a*	33/50 PROGRAM COMFA.NY .PROFILE: MONSANTO COMPANY
         '^^^^^^^^^^^^^^	"I'li  'I'i'iii1.  "'ii,"1! r	 i11,,1'"1 i, IT "li	;  ' ,'ii"", I1 ill.. :|li  " ii'iii	;	 ii'i'tf1 '"iii'iri"",,,, "i iiiiiiii'i .I11'mi	iif"'];,!. .I"!1;;,"!!";!!,'"• „«„;;.!
                                        iiliiiiiiiii;





-------
  Dichloromethan<
    19.05%
                          Hydrogen Cyanide
                              10.74%
                               Toluene ,
                               18.65%
Trichloroethylene.
    0.09%
    Xylene
    23.90%
                                Cadmium/Cadmium Compounds
                                        1.36%

                                Methyl Eth'yl Ketone
                                    13.01%
                                                    Methyl Isobutyl Ketone
                                                         •4.41%
FUTURE EFFORTS

Monsanto plans to reduce the releases and transfers of TRI chemicals from all its facili-
ties worldwide to 100 million pounds by the end of 1995, using 1990 releases and trans-
fers of TRI chemicals as the baseline. In addition, the company is continuing the Air Emission
reduction program with a goal of further reducing air emissions to zero. In collaboration
with the University of Tennessee, Monsanto is also working to design algorithms and method-
ologies used in an "effects model" to prioritize the strategy of reducing emissions and oif-
site transfers, of toxic chemicals in industry. These priorities are based on risk and not on
the quantity of chemical used. Using this as a basis, 33/50 chemicals would be considered
in the risk algorithm, however the quantity released would not be the primary issue of concern.

While effects and potential risk are primary indicators used in the model, cost effectiveness
of the project is also an important factor in evaluating alternative projects with differing
costs. The "effects model" will also be used to shape Monsanto's corporate goals, which
will guide the Company's environmental efforts after the current multi-media  goal
program has been completed.                                            '
        300
    I250
     c
    _o
    I  200
     "I
        150
     •a
     c

     I  100
     CD
     tr
         50
          0
                     Non-33/50 Chemicals
                     33/50 Chemicals

                                                                                   Exhibit 7
               1988
1989     1990     1991     1992     1993

Percentage
Breakdown of 33/50
Program Chemical
Releases and
Transfers for 1993
(by Chemical)
                                                                                   Exhibit 8
                                                                                   Releases and Transfers
                                                                                   of all TRI Chemicals
                                     13
            33/50 PROGRAM COMPANY PROFILE:  MONSANTO COMPANY

-------
                                                     •51SSS,

                                 111
                                  \iM
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                                                                                 	i	j	iii	ms,	
                                                                                 i	,	liisd	:i	-il^^
                           CONTACT FOR FURTHER INFORMATION
                           For additional information an this case study, please contact:
                             Mr. Dennis B. Redington
                             Director, Regulatory Management
                             Monsanto Company
                             800 N. Lindbergh Boulevard
                             St. Louis, MO 63167
                             Tel:  (314)694-6503
                             Fax: (314)694-8957
                                                                   i i i
                                                                      ii
                                                                      II
                                                                     ,. ii.
                                           1 ii	i	iiijiiuii	14
                                 j 33/50 PROGRAM COMPANY P^O^ILE:
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