Resource efficiency and cleaner production in the olive oil industry – Çakraj

Rudina Çakraj¹, Donika  Prifti².

¹ Ministry of Agriculture Food and Consumer Protection, Tirana, Albania;

² Department of Industrial Chemistry, Faculty of Natural Sciences, University of Tirana, Tirana, Albania.  

 

Corresponding author: Rudina Çakraj

Address: Ministry of Agriculture Food and Consumer Protection, Sheshi “Skenderbej”, No. 2, Tirana, Albania;

Telephone: +355672062170; E-mail: rudicakraj@yahoo.com

 

Abstract

 

Aim: The olive oil industry generates big amounts of by-products: pomace and waste water that may result in very negative environmental impacts if there are no accu­rate management strategies. The Cleaner Production (CP) is a continuous application of an inte­grated preventive environmental strategy applied to processes and prod­ucts to increase efficiency and reduce risks to humans and the envi­ronment. This study was carried out to demonstrate the application of Cleaner Production Technology in the olive oil industry.

 

Methods: The CP demonstration was carried out during the period 2011-2012, in an olive oil mill. The methodology used for conducting on-site evaluation of the CP included: i) pre-assessment of the company (description of the company and the processes, input-output analysis through in­terviewing staff of the company); ii) material and energy flow analysis, with the aim to identify pollution sources and the related pollution causes; iii) option generation and feasibility study from technical, economic and environmental view, identification of feasible measures, and; iv) implementation of feasible measures by the company and monitoring of the achieved effects.

 

Results: The identified CP measures included the following: development of the information system, monitoring and saving of water consumption, improvement of the quality of olives, process modification: installation of the sec­ond centrifuge in the oil cleaning process, processing the pomace to be used as fuel (drying and pressing of the pomace), treatment of waste waters before discharging into municipal sewage system (op­tional treatment system “reed bed system” or “constructed wet­land”).

 

Conclusion: This study demonstrates how CP can be implemented successfully in the olive oil industry using efficiently the available resources.

 

Keywords: cleaner production, economic and environmental ben­efits, olive oil, pomace, waste waters.

 

Introduction

 

The olive oil sector is an important segment of the Albanian agro-industry. There are 130 processing mills and their average size in terms of volume of processed olives per year is small, between less than 100 and 1,500 t/year (1). Regarding the extraction technology, most of mills apply three-phase centrifugation system and only two use dual phases. The olive oil industry generates big amounts of by-products: pomace and wastes water that may result in very negative environmental impacts if there is not an accu­rate management strategy (2). The Cleaner Production is the continuous application of an integrated preventive environmental strategy applied to processes and products to increase efficiency and reduce risks to humans and the environment (3). Resources (water, energy and raw material) can be used more efficiently thus reducing at the same time losses and environmental pollution and improving health and safety. Economic profitability together with environmental improvement is the aim of CP. The CP demonstration was carried out in the olive oil mill, called “Musaj Olive Oil” in the Vlora, which mostly provide to farmers the service of processing olives into olive oil, against a fee (80%) and produces and trades “organic olive oil” and ”extra virgin olive oil” (20%) for itself. It applies continuous three phase centrifugation system and the production is seasonal from October to March. In 2011-2012 was processed 520 t olives, when 100 t for company itself and 420 t for farmers.

 

The company has a good performance regarding the food safety & quality, it produces and trades the best categories “organic olive oil”, ”extra virgin olive oil” and “virgin olive oil, but doesn’t know the environmental legislation although  it is aware about  negative environmental impacts of the olive oil industry. In order to improve its environmental performance and to increase economic profitability the company decided to join us in this CP study.

 

The aim of this study is to demonstrate how Cleaner Production (CP) can be implemented in the olive oil industry, thus increasing the economic profitability together with environmental improvement. By the extraction process of oil, the following non products outputs are obtained (5):

 

Vegetable watersor waste waters, made up of the vegetable waters of the olives mixed with water added in the process, relatively in high amounts (approximately 1L/1 kg of olives processed) with high organic loads. These highly polluted waste waters are not treated and are discharged into municipal sewage system (6).

 

The pomaceor solid waste, which is discharged in open area, causes environmental pollution and contamination of the final product (olive oil).

 

We performed the in site visit in the company during operation, when we took photos and collected the data on process, materials, water and energy consumption. Then we carried out a material and energy flow analysis with goal to identify pollution sources and related pollution causes.

 

After the evaluation were identified eight CP options for improvement, mainly related to water consumption, optimize the process and reusing of solid waste (pomace).

 

Among these options, seven were selected for feasibility study as following: Development of the information systems; Installation of water meter for total consumption and for washing process; Reducing the water capacity of washing machine, Improvement of quality of olives; Pavement of the outside part, where is discharged the pomace and covering of waste water channel, Installation of the second centrifuge in the oil cleaning process, Processing the pomace to be used as fuel.

 

Six of above CP measures were implemented until on March 2013 (Table 3).The benefits of the implementation of the CP measures were: reducing the water consumption, reducing the waste water and its pollution load, increasing the production efficiency and quality of olive oil. This study demonstrates how CP can be implemented successfully in the olive oil industry using efficiently the resources.

 

Material and Methods

The CP is the continuous application of an integrated preventive environmental strategy applied to processes and products to increase efficiency and reduce risks to humans and the environment. Resources (water, energy and raw material) can be used more efficiently thus reducing at the same time losses and environmental pollution and improving health and safety. Economic profitability together with environmental improvement is the aim. CP typically includes measures such as “good housekeeping”, process modifications and control, input material change, on-site recycling or recovery, production of useful by-products or product modification.

 

The demonstration of application of the CP was carried out, in the olive oil mill, called “Musaj Olive Oil” which operates in Vlora. The period of study was from November 2011 to March 2012 and monitoring of implemented measures during the 2013.

 

The methodology of CP Audit follows the following steps:

1)      Pre-assessment (forming of the CP-team, description of the company and the processes, input-output analysis, setting up baseline – the baseline data for key performance indicators for selected priority area(s).

2)      Material and energy flow analysis with goal to identify pollution sources and related pollution causes.

3)      Option generation and feasibility study – generation of CP options based on the understanding of pollution causes and their evaluation from technical and organizational point of view as well as from the economic and environmental perspective.

4)      Implementation of feasible measures by the company and monitoring of achieved effects.

 

Results

The general input-output analysis was performed for the whole company (Table 1), enabling us to set up the priority areas to estimate potential for improvement, respectively: Raw material (olives) and water consumption. In Table 1 are presented data for key input such as olives, water and energy and non product output, such as waste waters and pomace which were not turned into desired products, but appear as process losses.

 

Table 1. General input-output analysis for the whole company.

Input

Annual consumption

Unit cost (€)

Annual costs(€)

Included in product (%)

NPO (%)

NPO cost (€)

Total NPO costs (€)

olives	520 ton	714	371429	20% oil
					40 % pomace	148572	148 572
					40% waste water	148572	148 572
water	643 m3	0.5	330		100% waste water	330	330
energy	31250 kWh		1786				1786
Fuel	20 m3	7.1	142				142
Cleaning agents (caustic soda)			114				114
Packages materials: Plastic contains 6 L  Bottles ½ L Carton  boxes	3000 400 100 piece		172,9
Labels	500 piece
Filter	10 pack

NPO – Non product output – input materials, water and energy which were not turned into desired product (appears as losses, pollution and waste flows)

 

Diagram 1 presents a flowchart of the industrial process with the aim to identify pollution sources and the related pollution causes.

 

Diagram 1. General outline of the industrial oil mill process.

 

 

Diagram 2. Flowchart for water.

 

 

The contamination load of the waste water before and after the implementing the CP measures is shown in Table 2.

 

Table 2. Waste water contamination load.

 

Indicators	Unit		Before the CP implementation	After the  CP implementation	National Norms
BOD5		mg/l	2950	1577	50 mg /l
COD		mg/l	4600	2320	250 mg/l

 

Based on the general input-output analysis for the whole company were set up the priority areas for improvement and were performed the fea­sibility study for CP generated options. The CP measures identified and their feasibility study and implementation are shown in the Table 3.

 

Table 3. The feasible CP measures identified in the olive oil.

 

Measures	Cost for implementation	Economic benefits	Environmental benefits	Implementation
Establishment  of  the information system	500 €	Better management and planning the activity	Better management and monitoring of wastes	implemented
Installation of water meters	100 €	Saving and  using  efficiently the water	Reduction of waste water and its pollution load	implemented
Pavement of the outside part, where is discharged the pomace and covering  of waste water channel	7142 €		Minimize the environmental pollution and avoid oil contamination from foreign odors.	implemented
Reducing  the water capacity of washing machine (Filling in a smaller volume 1500 L / 8 hour by 2000 L /8 hour)	No investment needed	Reduction of the  water consumption	Reduction of  the waste water	implemented
Improvement of quality of olives		Reduction of the  water consumption, improving the production efficiency and quality of oil	Reduction of the   waste waters  and its pollution load	implemented
Installation of the  second vertical centrifuge in the cleaning oil process	21 000 €	Reduction of the water and energy consumption,  Reduction of the  Labor costs, Increasing  the production efficiency and quality of olive oil	Reduction of waste waters and its pollution load through reduction of the  Phenol (water soluble) and residual oil concentration in generated waste water	implemented
Processing the pomace  to be used  as fuel;	82.400 €	Increase the company  profits  since the processed pomace is very demanded and avoid  the cost for  manipulation and transport   of pomace,	Reducing the environmental pollution, oil contamination and saving the natural source (energy) by reusing efficiently the by product (pomace).	not yet, it is an long term measure
Pre treatment of waste water, before discharging into municipal sewage system.	To be decided after identification of the commercially used alternative		Minimizing waste water pollution load: Reducing the environmental pollution	not yet, it is an long term measure