Ts Sudhir -ppt.pptx

Safety is an important parameter at design stage.  Identify the stages of industry where there could be a potential hazard.  Classified into 3 categories 

 Relative safe  Potential hazard – Toxic, Flammable, explosive

 Serious hazard

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Laboratory- safety- fume hood, small quantity

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Precautions required- flammability, poisonous reaction, runaway reactions etc.

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Nitrates, ether compounds , unstable compounds enclosed electric heaters, adequate ventilation, MOC

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Halogens, substance like metallic sodium potassium, lithium bromide etc

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Solvents of low flash point and high toxicity

Identify the 3 categories based on the information available at the development stage.

Try for alternate – route, material, MOC, process… Freeze the PFD in detail of each step of the process Conduct a HAZOP study at the development stage. Alternate process could be developed which may be both operation and process wise more safe. Repeated discussion with all the stake holders like engineering, project, manufacturing , Safety and environment would yield a balance approach to the well designed plant

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Raw material storage and warehousing.

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Development laboratory and analytical laboratory.

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Process Plant

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Ancillary operation of the process.

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Utility and services

Overall site and plant layout its interconnectivity and intra connectivity with respect to wind direction, safety parameters distances etc.

 Segregation

of types and class of material being stored.  Storage of solvents and liquid chemicals.  Storage of acids and alkalis.  Storage of gases other than inert gases.  Hazardous material storage  Toxic material storage  Corrosive material storage.

Safe storage, minimal storage and segregation  Handling of chemicals.  Fume hood construction –Metallic vs. non metallic.  Exhaust system in fume hood – combining vs. individual.  Reaction handling and attention during operation.  Unattended operations  Emergency handling training and Paraphernalia's 

 Four

Elements of Manufacturing

Reaction

Utilities

Isolation

Drying

 Reaction

 Isolation  Drying

44

44 Mechanical

Process

Accidents (%)

Design 22

12

11

5

5 1

Mechanical

Operator Error

Unknown

Process Upsets

Natural Hazards

Design

Sabotage and Arson

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The design of chemical processes and products with specific attention to

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Eliminating hazards from the manufacturing process rather than relying on the control of these hazards (Risk assessment based on ICH guidelines Q9)

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“Once you get something dirty, the only way to get it clean is to make something else dirty.”

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The best way to keep the world clean is to not get it dirty to begin with.

Three parts to a facility 

Process



Equipments



Man Machine Interface

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Traditional safety approach • “Add on” safety features

 Prevent - alarms, safety interlocks, procedures, training  Mitigate – sprinkler systems, water curtains, emergency response systems and procedures 

Inherently safer design • Eliminate or significantly reduce process hazards

Inherently Safer Design

Green Chemistry and Engineering

 User

Requirement Specification (URS)  Functional Design Specification (FDS)  Design Qualification (DQ)  Stage wise Inspection and Factory Acceptance Test (FAT)  Site Acceptance Test (SAT)  Installation Qualification (IQ)  Operational Qualification. (OQ)  Process Qualifications (PQ)

BATCH REACTOR

SEMI CONTINUOUS REACTOR

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

PROCEDURAL • Maximum adiabatic pressure for 100% reaction is 150 psig, reactor (normal followed design pressure is 50 psig) design to 225 psig. • Gradually add limiting reactant with temperature control to limit potential energy from reaction • Train operator to observe critical operating limit INHERANT • Develop chemistry which is not exothermic, or mildly exothermic  Maximum adiabatic exothermic temperature > boiling point of all ingredients.

Minimize  Use small quantities of hazardous substances or energy • Operate below boiling point in case of exothermic reactions. • Green chemistry/Catalytic conversions. • Reduce hold time • Intermediate storage reduce • Piping minimal.

• Process equipment appropriate • Split steps into smaller operations.

BENEFITS • Reduced consequence of incident (explosion, fire, toxic material release) • Improved effectiveness and feasibility of other protective systems – for example:

 Secondary containment  Reactor dump or quench systems

Large Rupture Disk A B C

Condenser

D E Distillate Receiver

Steam Refrigerated Brine Water Return

Water Supply

Condensate

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Selecting Technology? Plant Design? Equipment Details? Operations?

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Best answer?– All levels!

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Inherently safer design is not a meeting.

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Inherently safer design is a way of thinking, a way of approaching technology design at every level of detail – part of the daily thought process.

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Vacuum trap design, Semi continuous distillation

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Use of hose pipe.

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Process flow in tube side or shell side in HE

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PRV use in each area

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Type of stirrer Anchor/turbine- mixing vs. agitation

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Control of Utility

Mechanical seal for reactors & pumps

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Non flame proof electrical panels.

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Improper cable gland for all electrical fittings.

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Lack of maintenance schedule and proper upkeep of the mechanical and electrical systems.

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Frequent check and maintenance of the vent system including flame arrestors.

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Improper earthing of machines, solvent lines jumpers etc.

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Solvent handling and spillages ( use of drums instead of piped tanks and pumps).

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Nitrogen blanketing of the reactors.

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Improper sizing of the condensers and vent condensers.

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Open manhole operation leading to hazard.

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Training of operators on regular basis - lack of commitment

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Any change in process parameters is to be discussed in totality with the base

documents. 

Over period of time there could be some operational best practices observed. This should be recorded and trained to all concerned to ensure more safety in operation.

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It is a tendency that a set of equipment may be used for a different purpose than originally intended to. It is important that the complete review from URS to IQ and PQ be followed meticulously which is not the normal practice.

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The above change parameters should be recorded with due diligence.

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The risk could be for the following areas.

A. Product safety B. Process safety. C. Operational safety D. Plant safety

The ICH Q9 guidelines helps us to define the product safety during any changes in the surrounding. This is a good tool for ensuring product safety. Risk assessment and management should be a continuous process and if done with multidiscipline approach can reduce the hazard in the industry.