MATERIAL BALANCE MATERIAL BALANCE METHODOLOGY METHODOLOGY

Julia BrownJulia BrownManager, Process Manager, Process

DevelopmentDevelopment

Introduction:

In an enterprise, the waste and emission problems, appear from the production points where the materials are used, processed and treated. To give a solution to your environmental problems, the sources has to be identified, as well as the volume and the causes of the waste and emissions......

..... The substances with which you are working with, have to be known, to estimate its real value in the process and to estimate possible developments during the evaluation.

Introduction

“Materials Balance analysis (MB) is a systematic reconstruction of the way in which a chemical element, a compound or material passes through a natural cycle and/or its economical benefits. An analysis of the material flow, usually is based on the origin of a physical balance.”

German investigation Committe, 1993

Definition

• Describes or illustrates any material flow present in the enterprise.

• Trace the waste at the point at which it is generated.

• Print data so that decisions may be taken.

• Identify the production process weaknesses.

• Give a detailed reasonable and quantified priorization of the results to obtain wastes and emissions minimization.

Objectives of BM

• Identify the materials used by the enterprise.

• Identify the sources, the volumes and causes of the wastes and emissions.

• Create a base for the evaluation and prediction of future developments.

• Define strategies to improve the general situation of the enterprise.

Results

Analysis points have to be defined and the parameters that are to be evaluated.

The overview or overall effect of the balance has to be defined.

The time period considered by the balance has to be defined.

The process consequences are defined.

The flow diagram is designed. The MB´s are to be generated. Results should be interpreted.

How a MB is done?

1. Analysis Points and Technical Advice

• The process areas that will be studied has to be determined .

• Analysis as a function of: costs, risks, secure deposit of wastes, volume etc.

• First step is to develop an analysis of input and output of the enterprise.

• Detailed analysis in relation to the more extensive flows and ecological problems.

• Definition of each flow’s importance

1. Points of Analysis and Technical Advice

ActualActual

ReactiveReactive

AdviceAdvice

• Internal rules• Knowledge of the source

• Segregation• Reliable points• Variation with the time

• Internal rules• Knowledge of the source

• Segregation• Reliable points• Variation with the time

strategystrategy

1.1 Conditions of Technical Advice

2. MB Overview

The productive process is divided into sequencial steps according to the priority of the analysis and the study of the flows previously done.

3. Definition of the period of time

The representative period of time has to be choosen depending of the type and size of the enterprise.

4. Definition of process sequence• Detailed study of the material flow.• Processes are divided according to a

representative structure.• What are considered processes?

activities, equipments, products or utility aspects.

5. Flow diagram

• Graphic interpretation of the materials flows. It shows volumes, proportions, ecological relevance among other characteristics.

• Indicate the sequence or steps of the productive process.

Flow Diagram ExampleFlow Diagram Example

First soak by spray

Caustic soda bath

Soak by inmersion

Caustic soda bath

Final soak by inmersion

Returned bottles

Water

WaterCaustic sodaDetergentVapor

WaterCaustic soda DetergentVapor

WaterVapor

WaterVapor

Detergent Residues Caustic soda ResiduesOrg. & inorg. matter

Labels+ Caustic soda sol.Residual bathMudsCondensates

Residual bathMudsCondensates

Condensates

Condensates

Washed bottles

Input Output

Conservation mass principle is used

because it indicates that:

• Input Material = Output Material

• Units of measurements given in kg or m3

6. Material Balance

Example 1: Input and Output diagram

Auxiliary materials

UnitOperation

Raw material

Product (expected)

byproduct(usable)

Waste

Water Energy

Waste easily assimilated

by the environment

Inert waste always

available

toxic/dangerouswaste

Plant, Plant, Process or Process or

Unit Unit OperaciónOperación

Gaseous emissionsRaw materials

Catalyst

Air/Water

Energy

Recycle

Reusable residues in other operation

Products

By-products

Wastewater

Liquid waste

Solid waste

Example 2: Input and Output

7. Interpretation

• Establish standards that will establish a relationship between the material consume and the waste generated.

• Establish the process efficiency indicators. (for example Kwh/coffee produced)

One dollar invested in prevention is like one

thousand dollars in medicine

Thank youThank you