Progettazione di processo - Elementi

Steps in Product/Process Design

Initial Decision

Concept & Feasibility

Development & Manufacturing

Product Introduction

Process and Product Design Course Trieste, 28 June, 2012 - slide 16

Steps in Product/Process Design

Initial Decision

Stage-Gate™ product-development process (SGPDP)

Process and Product Design Course Trieste, 28 June, 2012 - slide 17

Steps in Product/Process Design

Concept & Feasibility

Process and Product Design Course Trieste, 28 June, 2012 - slide 18

Steps in Product/Process Design

Development & Manufacturing

Process and Product Design Course Trieste, 28 June, 2012 - slide 19

Steps in Product/Process Design

Product Introduction

Process and Product Design Course Trieste, 28 June, 2012 - slide 20

Steps in Process Design Assess Primitive

Problem

Detailed Process Plant-wide

Development

Synthesis - Controllability

of Base-case

Algorithmic Assessment

Methods Detailed Design,

Equipment sizing, Cap.

Cost Estimation,

Profitability Analysis,

Optimization

Process and Product Design Course Trieste, 28 June, 2012 - slide 21

Steps in Process Design

Part I

• Assess Primitive Problem

Find Suitable Chemicals

• Process Creation

• Development of Base Case

•

Part II

• Detailed Process Synthesis

Part III

• Detailed Design & Optimization

Part IV

• Plantwide Controllability

Process and Product Design Course Trieste, 28 June, 2012 - slide 22

Steps in Process Design Assess Primitive

Problem

Detailed Process Plant-wide

Development

Synthesis - Controllability

of Base-case

Algorithmic Assessment

Methods Detailed Design,

Equipment sizing, Cap.

Cost Estimation,

Profitability Analysis,

Optimization

Process and Product Design Course Trieste, 28 June, 2012 - slide 23

Steps in Process Design

Process and Product Design Course Trieste, 28 June, 2012 - slide 24

Steps in Process Design

Process and Product Design Course Trieste, 28 June, 2012 - slide 25

Assess Primitive Problem

• Process design begins with a primitive design problem

current situation

that expresses the and provides an

opportunity to satisfy a societal need.

• The primitive problem is examined by a small design

team, assessing possibilities, refining the problem

statement, and generating more specific problems:

Raw materials - available in-house, can be purchased or need

– to be manufactured?

Scale of the process (based upon a preliminary assessment

– of the current production, projected market demand, and

current and projected selling prices)

Location for the plant

–

• Brainstorming to generate alternatives.

Process and Product Design Course Trieste, 28 June, 2012 - slide 26

Typical Primitive Design Problem: the case of

VCM

Consider, the need to manufacture vinyl chloride (VC),

H Cl

C C

H H

A typical primitive problem statement is as follows:

“An opportunity has arisen to satisfy a new demand for VC

monomer (VCM), on the order of 800 million pounds per year,

in a petrochemical complex on the Gulf Coast, given that an

existing plant owned by the company produces one-billion

pounds per year of this commodity chemical. Since VCM is an

extremely toxic substance, it is recommended that all new

facilities be designed carefully to satisfy governmental health

and safety regulations.”

Process and Product Design Course Trieste, 28 June, 2012 - slide 27

Example: VCM Manufacture

• To satisfy the need for an additional 800 MMlb/yr of

VCM, the following plausible alternatives might be

generated:

Alternative 1. A competitor’s plant, which produces 2 MMM

– lb/yr of VCM and is located about 100 miles away, might be

expanded to produce the required amount, which would be

shipped. In this case, the design team projects the purchase

price and designs storage facilities.

Alternative 2. Purchase and ship, by pipeline from a nearby

– plant, chlorine from the electrolysis of NaCl solution. React

the chlorine with ethylene to produce the monomer and HCl

as a byproduct.

Alternative 3. The company produces HCl as a byproduct in

– large quantities, thus HCl is normally available at low prices.

Reactions of HCl with acetylene, or ethylene and oxygen,

could produce 1,2-dichloroethane, an intermediate that can

be cracked to produce vinyl chloride.

Process and Product Design Course Trieste, 28 June, 2012 - slide 28

Survey Literature Sources

SRI Design Reports

Encyclopedias

Kirk-Othmer Encyclopedia of Chemical Technology

Ullman’s Encyclopedia of Industrial Chemistry

...

Handbooks and Reference Books

Perry’s Chemical Engineers Handbook

CRC Handbook of Chemistry and Physics

...

Indexes

See Auburn University Library

Patents

Internet

Process and Product Design Course Trieste, 28 June, 2012 - slide 29

Steps in Process Design Assess Primitive

Problem

Detailed Process Plant-wide

Development

Synthesis - Controllability

of Base-case

Algorithmic Assessment

Methods Detailed Design,

Equipment sizing, Cap.

Cost Estimation,

Profitability Analysis,

Optimization

Process and Product Design Course Trieste, 28 June, 2012 - slide 30

Steps in Process Design

Process and Product Design Course Trieste, 28 June, 2012 - slide 31

Steps in Process Design Assess Primitive

Problem

Detailed Process Plant-wide

Development

Synthesis - Controllability

of Base-case

Algorithmic Assessment

Methods Detailed Design,

Equipment sizing, Cap.

Cost Estimation,

Profitability Analysis,

Optimization

Process and Product Design Course Trieste, 28 June, 2012 - slide 32

Steps in Process Design

Process and Product Design Course Trieste, 28 June, 2012 - slide 33

Environmental Issues 1:2

Handling of toxic wastes

97% of hazardous waste generation by the chemicals and nuclear

industry is wastewater.

In process design, it is essential that facilities be included to

remove pollutants from waste-water streams.

Reaction pathways to reduce by-product toxicity

As the reaction operations are determined, the toxicity of all of the

chemicals, especially those recovered as byproducts, needs to be

evaluated.

Pathways involving large quantities of toxic chemicals should be

replaced by alternatives, except under unusual circumstances.

Reducing and reusing wastes

Environmental concerns place even greater emphasis on recycling,

not only for unreacted chemicals, but for product and by-product

chemicals, as well. (i.e., production of segregated wastes - e.g.,

production of composite materials and polymers).

Process and Product Design Course Trieste, 28 June, 2012 - slide 34

Environmental Issues 2:2

Avoiding non-routine events

Reduce the likelihood of accidents and spills through the reduction

of transient phenomena, relying on operation at the nominal

steady-state, with reliable controllers and fault-detection systems.

Design objectives, constraints and optimization

Environmental goals often not well defined because economic

objective functions involve profitability measures, whereas the

value of reduced pollution is often not easily quantified

economically.

Solutions: mixed objective function (“price of reduced pollution”),

or express environmental goal as “soft” or “hard” constraints.

Environmental regulations = constraints

Example: PSP (see next slides)

Process and Product Design Course Trieste, 28 June, 2012 - slide 35

Environmental

Indicators

1D

3D

CAPE OPEN PSP Framework Toxicological DB

(CO) Process Simulators Molecular Modeling

Software Chemical Processes

Process and Product Design Course Trieste, 28 June, 2012 - slide 36