Handbook of Water and Energy Management in Food Processing

Jiri Klemes, Robin Smith, Jin-Kuk Kim

• Publisher: Woodhead Publishing
• Year: 2008
• Print ISBN: 9781845691950
• eBook ISBN: 9781845694678
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

Effective water and energy use in food processing is essential, not least for legislative compliance and cost reduction. This major volume reviews techniques for improvements in the efficiency of water and energy use as well as wastewater treatment in the food industry.Opening chapters provide an overview of key drivers for better management. Part two is concerned with assessing water and energy consumption and designing strategies for their reduction. These include auditing energy and water use, and modelling and optimisation tools for water minimisation. Part three reviews good housekeeping procedures, measurement and process control, and monitoring and intelligent support systems. Part four discusses methods to minimise energy consumption. Chapters focus on improvements in specific processes such as refrigeration, drying and heat recovery. Part five discusses water reuse and wastewater treatment in the food industry. Chapters cover water recycling, disinfection techniques, aerobic and anaerobic systems for treatment of wastewater. The final section concentrates on particular industry sectors including fresh meat and poultry, cereals, sugar, soft drinks, brewing and winemaking.With its distinguished editors and international team of contributors, Handbook of water and energy management in food processing is a standard reference for the food industry. - Provides an overview of key drivers for better management - Reviews techniques for improvements in efficiency of water and energy use and waste water treatment - Examines house keeping proceedures and measurement and process control

Part I

Key drivers to improve water and energy management in food processing

Outline

Chapter 1: Legislation and economic issues regarding water and energy management in food processing

Chapter 2: Environmental and consumer issues regarding water and energy management in food processing

Chapter 3: Towards a complex approach to waste treatment in food processing

1

Legislation and economic issues regarding water and energy management in food processing

Peter Cooke, Water Ltd, UK

Publisher Summary

This chapter provides an understanding of the basic approach to the successful management of water in a modern food processing operation, based around legislative and economic criteria, but encompassing the necessary considerations for site and corporate managers, especially with regard to engineering. It acknowledges the diversity of food processing operations, presents the essential trends in modern legislation and their implications, and, most importantly, demonstrates the need to apply the actions arising to the key processes of engineering and production operations. The chapter also provides a basic understanding of the approach needed to define standards and management procedures relevant to an individual site or group of sites. The two key ideas that the chapter focuses on are: (1) the trend in legislative processes toward controlling the process behind the emission rather than, or in addition to, the emission itself. This consideration must be built into engineering and planning processes; it will no longer be possible to economically deal with legislative requirements in a retrospective way. Environmental management systems, where properly and fully devised and implemented, may be used as a means for ensuring that this happens; (2) the requirement for quantitative data on energy and water utilization, and effluent quantities throughout the engineering and management processes.

1.1 Introduction

1.1.1 Objectives

The aim of this chapter is to impart to the reader an understanding of the basic approach to the successful management of water in a modern food processing operation, based around legislative and economic criteria, but encompassing the necessary considerations for site and corporate managers, especially with regard to engineering. It will not give a bland list of relevant statutes, nor will it present ‘average’ benchmark data that in reality applies to very few operations. Rather, it will acknowledge the diversity of food processing operations, present the essential trends in modern legislation and their implications and, most importantly, demonstrate the need to apply the actions arising to the key processes of engineering and production operations.

After reading this chapter, the reader should have a basic understanding of the approach needed to define standards and management procedures relevant to an individual site or group of sites. No apology is offered for the fact that much of the advice is based on simple principles, which are too often overlooked in the belief that an apparently complex problem must have a complex solution.

1.1.2 Overview and historical perspective

The food processing industry consists of a range of diverse sub-sectors ranging from the primary production of basic foodstuffs and ingredients through to quite specialist secondary processing and manufacturing activities. Increasingly, the industry also incorporates a sophisticated transport and distribution operation as the general trend towards consolidation and centralisation of production continues. The relative quantities of water and energy consumed by the various sub-sectors are diverse. Thus, the use of generic benchmark criteria for managing and comparing the use of utilities has, until quite recently, not been well developed. In particular, the generation and use of normalised benchmark criteria (e.g. energy use per tonne of production) has been difficult, due to the use of different definitions and measures of what constitutes production, between and even within sub-sectors. Indeed, it is not uncommon to find such disparities even within a single multisite company or manufacturing group.

In any analysis of the industry, it is important to have regard to the type of process being undertaken, when considering the monitoring and performance management of process inputs such as water and energy. Fundamentally, there is a distinction between processes that operate continuously or semi-continuously (e.g. much primary processing such as flour manufacture) and those which are stop/start, based often on batch processing. These latter processes, which constitute much of the secondary processing sectors to give finished food products, are often those most directly driven by retailer and consumer demand, and the efficiency or otherwise of energy and water utilisation can depend as much on production planning and scheduling as plant and operators. In particular, where washdown of plant is required between product runs, the use of water and associated generation of effluent is often a direct and quantifiable function of the number of product changes; a simple fact, but one which can have profound implications for legislative compliance, water-related charges and the need to employ effluent treatment technologies.

Historically, very few companies have quantified water and energy use at unit process level. Most factory managers would know (approximately, in gross terms) how much water and energy their sites used, but very few would know categorically how the usage was apportioned between individual process lines or equipment. In fact, it was the case, and still is for many sites, that effluent quantities are not even positively measured for the site as a whole, let alone at production line level, with estimates using varying degrees of inaccurate assumption based on water supply volume (itself sometimes subject to error) being used as a poor substitute.

So it is, that a means by which many water using companies could potentially save themselves a great deal of money is often all but totally overlooked. Or, where specific surveys and measurements are undertaken, the results are simply filed away and not acted on. This is a situation compounded by the fact (at least in the UK) that the basis of charging for trade effluent discharges (Mogden Formula in the UK) is poorly understood by many managers in the industry. This, together with poor or non existent measurement results in many companies paying rather more for effluent discharge than they need to. Later in this chapter we shall examine this subject in more detail and demonstrate how this situation often arises.

In general, the historical lack of suitable quantitative data on energy and water utilisation at production line level is a major driver for costs being higher than they should be and very often is also a major factor behind legislative non-compliance where effluents are generated. The first principle of management is therefore to measure, then measure again and then to keep on measuring. For production plant, processes, products and personnel often change at a rapid rate and each can have a significant effect on utilities consumption. Thus a one-off survey undertaken two years ago could be quite inaccurate for present purposes, if significant changes have occurred.

With regard to water management, historically very few companies have assessed the true cost of water consumption. This is often due to the structure of accounting systems and the split of responsibilities for individual aspects of water use. Based on surveys undertaken by the author, at most ‘wet’ production sites the majority of water is discharged as effluent, and it is not uncommon to find the effluent volume to be 65–95 % of the water supply volume. A quite startling fact is that often in excess of 50 % of the effluent volume is clean or very lightly ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Related titles
• Copyright
• Contributor contact details
• Preface
• Part I: Key drivers to improve water and energy management in food processing
• Part II: Assessing water and energy consumption and designing strategies for their reduction
• Part III: Good housekeeping procedures, measurement and process control to minimise water and energy consumption
• Part IV: Methods to minimise energy consumption in food processing, retail and waste treatment
• Part V: Water reuse and wastewater treatment in the food industry
• Part VI: Water and energy minimisation in particular industry sectors
• Index