Guidelines for increased resource-efficiency

8 September 2016 - A new tool for the food industry to measure environmental performance and determine how they can improve processes and production chains is the outcome of research by TiFN’s PhD fellow Dr Filippos Zisopoulos. He defended his thesis September 7, 2016 at Wageningen University. His work offers the industry new guidelines for sustainable-chains design.

Around the world more and more companies are looking to increase resource-efficiency throughout their processes and production chains. This is a challenging task, however, as so many factors need to be considered. Exergy is an objective metric in the assessment of resource efficiency. “It is based on the first and second laws of thermodynamics, and it quantifies the available work that can be extracted from a stream or a process in relation to a selected reference environment, explains Zisopoulos. “The concept is popular in the energy and construction sectors, but has not yet been fully exploited in the food industry.”

Bread, mushrooms and drying

The PhD fellow carried out three case studies in order to define general rules that could help in the design of more-sustainable processes. He used industrial-bread production, mushroom cultivation and a conventional, energy-consuming, drying process. “We wanted to pinpoint the exergy-inefficient locations and gain an understanding of the reasons for these inefficiencies.”

Zisopoulos learnt that closing-mass balances should be the first priority in improving the resource-efficiency of a food production chain. “Unused material side-streams translate into wasting considerable amounts of chemical exergy”, he explains. “Moreover, recycling material streams to create new products can improve the efficiency of the chain but only as long as it comes at a reasonable additional exergy cost for re-processing.” He also learned that decisions regarding chain improvement should be based on the nature and size of the exergy losses.

General rules

Based on these findings, Zisopoulos defined a set of general rules that food manufacturers can use when they want to increase resource efficiency in their processes and production chains. The PhD fellow, who is currently working as a research assistant at Wageningen University, is proud of this outcome: “The guidelines have been developed in close agreement with TiFN’s industry partners and are easily applicable to current business processes. Moreover, it pleases me that my work is recognized as valuable.”

Zisopoulos, open for new job opportunities in academia or industry, looks back on his TiFN time with pleasure. “This project has been a really great team job. There was a good match with the partners and also within the project team, with easy-going communication and people determined to get along very well with each other.”

The thesis can be found here.