NAXOS 2018 6th International Conference on Sustainable Solid Waste - - PowerPoint PPT Presentation

NAXOS 2018

6th International Conference on Sustainable Solid Waste Management

ANALYSIS OF THE ENVIRONMENTAL IMPACT USING THE WASTE REDUCTION ALGORITHM WAR IN POLYPROPYLENE PROCESS PRODUCTION BY APPLYING GRADE TRANSITIONS STRATEGIES

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Alexis Velásquez‐Barrios1,2, Cesar Rueda‐Duran1,2, Enrique Mogollón1, Carlos Ariel Cardona 2*

1Grupo de Investigación en Tecnología de Polimeros, Esenttia Polipropileno del Caribe S.A 2Instituto de Biotecnología y Agroindustria, Departamento de Ingeniería Química,

Universidad Nacional de Colombia sede Manizales

CO CONT NTENT

About Esenttia S.A Introduction Methodology Results Conclusion References

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ABOUT ESENTTIA

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Third Polypropylene producer in Latinoamerica

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Products

Polyethylene

Low‐density polyethylene (LDPE) High‐density polyethylene (HDPE) Linear low‐density polyethylene (LLDPE)

Masterbatch

Polypropylene Compounds Black and White Colors Additives

Polypropylene

Random Copolymer Impact Copolymer Homopolymer

INTR TRODUC ODUCTI TION ON

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In a polypropylene polymerization process one of the most important quality variable to control is the Melt Flow.

• The MFR (melt flow rate) is a measure for the average

chain length or molecular weight of a polymer.

• The MFR method is based on the relation between

average chain length and melt viscosity: short chain PP grades flow more easily than long chain PP grades. Unit is g/10 minutes

Melt Flow index is a measure of the ease of flow of the melt of a thermoplastic polymer. Depending of the final application the MF can be between 2 to 30.

INTR TRODUC ODUCTI TION ON

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C3H6 PP production Plant

When it is desirable to change the MF for example from 8 to 12, H2 Flow is increased too.

Catalyst

1,0 3,0 5,0 7,0 9,0 11,0 13,0 15,0 17,0 19,0 20,00 30,00 40,00 50,00 60,00 70,00 80,00 MF H2/C3 Ratio Set Point MF

H2/C (grH2/Ton PP)

Transition time: 4 hours

Always it is an objective to optimize the transition stage to produce less transition material. By applying a ramp

• f

H2 Flow it is possible to increase the Melt flow.

INTR TRODUC ODUCTI TION ON

This paper aims to demonstrate how the optimization of transition times based on the MF management implies a significant (or not ) reduction of plastic waste avoiding a significant impact on the environment. An environmental analysis is made by applying a Waste Reduction Algorithm (WAR) in order to evaluate the impact over the environment of a polypropylene production process applying grade transitions strategies.

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INTR TRODUC ODUCTI TION ON

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The transitions could be a potential waste but it depends mostly on the market

METHODOL METHODOLOG OGY

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Homopolymer Typical Polymerization process Production

Initially a simulation in ASPEN PLUS is applied for an Homopolymer production Process in a reactor of NOVOLEN Technology. ASPEN PLUS SIMULATION

WAR ANALISYS

Ta Table 1: 1: Case Case I.

• I. 120

120 TM TM (M (Metric ric To Tons) of

• f tr

tran ansitio tion Po Polypropylene Production.

• duction.

Item Value C3 Flow (Ton/h) 30 H2 Flow (gr/h) 2000 Transition time (h) 4 Amount of transition PP (Ton) 120

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METHODOL METHODOLOG OGY

To evaluate the transitions process, the simulation is made considering a change of Melt Flow (MF) passing from 11 to 20. To do this, the flow of H2 going to the reactor is modified. So, two scenarios are constructed as follow: Table 2: Case II. 240 TM (Metric tons) of Transition Polypropylene Production. Item Value C3 Flow (Ton/h) 30 H2 Flow (gr/h) 6200 Transition time (h) 8 Amount of Transition PP (Ton) 240

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Waste Reduction Algorithm (WAR). Is simply a tool to be used by design engineers to aid in evaluating the environmental friendliness of a process. This algorithm calculates the potential environmental impact (PEI) of a process, based upon several impact categories. WAR ANALYSIS After the ASPEN simulation, The WAR analysis is applied

METHODOL METHODOLOG OGY

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General Impact category Impact Category Measure of impact category Human Toxicity Ingestion LD50 Inhalation /dermal OSHA PEL Ecological Toxicity Aquatic toxicity Fathead minnow LC50 Terrestrial toxicity LD50 Global atmospheric impact Global Warming potential GWP Ozone depletion potential ODP Regional atmospheric impacts Acidification potential AP Photochemical oxidation potential PCOP

METHODOL METHODOLOG OGY

METHODOL METHODOLOG OGY

The input streams and outputs streams for the WAR analysis are shown.

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Input nput

WA WAR ANAL ANALYSIS SIS

Pro Proces ess Out Output ut

Propylene

H2 Cocatalyst Catalyst Propane Polypropylene Propane Residual Catalyst Residual Cocatalyst

METHODOL METHODOLOG OGY

In the WAR algorithm it is important to specify the polypropylene according to the characteristics that are shown in Table 3.

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Table 3. Polypropylene specifications. Indicator Unit Value GWP kg CO2 eq 2.00 ODP g CFC‐11 eq n/a AP g SO2 eq 6.13 POCP g Ethene eq 0.92 LC50 mg/lt 51.7 LD50 mg/kg 5.000.000

INPUT

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ASPEN ASPEN SIM SIMULA LATIO TION RE RESUL SULTS

For the WAR analysis the energy requirements for every equipment involved in the polymerization process is included. This information was obtained from the ASPEN simulation and validated in plant, Table 4.

INPUT

Table 4. Energy requirements for process equipment.

Equipment

Energy requirement [MJ/h] Case 1 Case 2 CSTR reactor 50075,123 49992,62 Separator 1123,29 1340,79 Pump 121,87 121,86 Distillation column 29116,152 83797,263 Recycle pump 51,26 36,705 Total 80487,695 135289,24

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ASPEN ASPEN SIM SIMULA LATIO TION RE RESUL SULT: Case Case 1

Stream Inlet [kg/h] Outlet [kg/h] Compound Propylene H2 Catalyst Cocatalyst PP product Propane Propylene 24782,18 ‐ ‐ ‐ ‐ 548,28 Propane 124,53 ‐ ‐ ‐ ‐ 124,55 Hydrogen ‐ 2 ‐ ‐ 0,58 ‐ Catalyst ‐ ‐ 1,65 ‐ 1,65 ‐ Cocatalyst ‐ ‐ ‐ 10 9,96 ‐ Polypropylene ‐ ‐ ‐ ‐ 24235,38 ‐ Total 24906,71 2 1,65 10 24247,57 672,83 The mass balance results from the ASPEN simulation is showed. This information is used as an input for the WAR analysis for both cases:

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ASPEN ASPEN SIM SIMULA LATIO TION RE RESUL SULT: Case Case 2

The mass balance results from the ASPEN simulation is showed. This information is used as an input for the WAR analysis for both cases:

Stream Inlet [kg/h] Outlet [kg/h] Compound Propylene H2 Catalyst Cocatalyst PP product Propane Propylene 24779,84 ‐ ‐ ‐ ‐ 547,43 Propane 124,52 ‐ ‐ ‐ ‐ 124,72 Hydrogen ‐ 6,2 ‐ ‐ 3,47 ‐ Catalyst ‐ ‐ 1,65 ‐ 1,65 ‐ Cocatalyst ‐ ‐ ‐ 10 9,96 ‐ Polypropylene ‐ ‐ ‐ ‐ 24235,24 ‐ Total 24904,36 6,2 1,65 10 24250,32 672,15

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WA WAR RE RESUL SULTS

PEI: total rate of potential environmental impact from the process studied. The results let to highlight that the impact generated by the substances entering the system is reduced by the generation of the polypropylene generated, which is a less dangerous material. Total rate of potential environmental impact values. Indicator Value [PEI/h] Case 1 Case 2 Iout 30489,05 30555,38 Igen ‐63825,76 ‐63825,76

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RE RESUL SULTS

The results are shown as Potential Environmental Impact generated (Generated) and total output rate of environmental impact (Out) for the studied processes. The impact is expressed as the PEI per hour. Potential environmental impact per hour [PEI/h] Indicator Case 1 Case 2 Out Generated Out Generated HTPI 5,95 2,12 5,96 2,13 HTPE 0,45 ‐6,7 0,457 ‐6,69 TTP 5,95 2,12 5,96 2,13 ATP 187 187 188 188 GWP 19,7 19,7 25 25 ODP 2,92E‐05 2,92E‐05 4,91E‐05 4,91E‐05 PCOP 27800 ‐66500 27800 ‐66500 AP 2470 2470 2530 2530 Total 30489,05 ‐63825,76 30555,377 ‐63759,43

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RE RESUL SULTS

The results are shown as Potential Environmental Impact generated (Generated) and total output rate of environmental impact (Out) for the studied processes. The impact is expressed as the PEI per hour. Potential environmental impact per hour [PEI/h] Indicator Case 1 Case 2 Out Generated Out Generated HTPI 5,95 2,12 5,96 2,13 HTPE 0,45 ‐6,7 0,457 ‐6,69 TTP 5,95 2,12 5,96 2,13 ATP 187 187 188 188 GWP 19,7 19,7 25 25 ODP 2,92E‐05 2,92E‐05 4,91E‐05 4,91E‐05 PCOP 27800 ‐66500 27800 ‐66500 AP 2470 2470 2530 2530 Total 30489,05 ‐63825,76 30555,377 ‐63759,43

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Through this analysis it is probed that when the polymerization process transition is improved, the impact over the environment is less. The transition exercise presented in this document is one the most simplest transition made in an industrial polymerization process. There are transitions more complex that can generate a bigger impact over the environment if the process is not well controlled. Nowadays, Esenttia company is applying an advanced process control (APC) in order to optimize not only the quality control in the reaction process but also the transitions campaigns when these are applied. The application of strategies through APC systems involved several changes in the process such as different set points of temperatures and pressure, bigger changes of hydrogen flows among other things. But always the objective is to ensure a very stable polymerization process to guarantee the best quality of the different materials produced. The results observed in the WAR analysis show first that the negatives values observed in PEIgen (products streams) helps to reduce the impact caused by the materials entering the process.

CO CONC NCLUSIONS ONS

ACKNO ACKNOWLEDGMENTS DGMENTS

The authors express their acknowledgments to ESENTTIA S.A. not only for provide the data but also for provide the support needed to develop the present work. At the same time an special acknowledgment to the support provided by the CONFIDENTIAL project agreement ESENTTIA‐CNBT COLCIENCIAS code N° 665173454353 “Desarrollo del Producto y Proceso de producción de Terpolímeros de Propileno‐Etileno‐Buteno”.

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RESEARCH GROUP IN CHEMICAL, CATALYTIC AND BIOTECHNOLOGICAL PROCESSES

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Thank you Any Question

Carlos Ariel Cardona Alzate. Chemical engineer, M.Sc., Ph.D. Full professor of Chemical Engineering ccardonaal@unal.edu.co