The 2012 European Union Energy Efficiency Directive establishes a set of binding measures to help Europe reach its 20 percent energy efficiency target by 2020. Under this regulation, all EU countries are required to use energy more efficiently at all stages of the energy chain. One of the tools chosen by the EU is an energy audit. 

Some feed industry firms are large enough firms to qualify with the terms of this new obligation. French technical center, Tecaliman, just launched its energy audit guide to help feed plants cope with it. 

Since November 2014, the large European firms (more than 250 employees and/or turnover of more than €50 million) must conduct energy audits once every four years; the first one before December 5, 2015. Those audits will be the first steps to identifying and quantifying cost-effective energy saving opportunities. Energy audits are necessary to assess the existing energy consumption at three main levels (building, transport and process) and identify the whole range of opportunities to save energy. 

Through the identification of energy saving possibilities and proposed recommendations for follow-up, audits are also the basis for the development of a market of energy services. But to be cost effective, those recommendations must be given by experts as every activity has its own pattern of cost saving. Furthermore, energy savings recommendations must not be given at the expense of quality.

Energy audits are not only focused on technical solutions, such as replacements or retrofits. Significant opportunities for improvement exist in industrial and commercial operations through continual optimization of operating procedures; control parameters; logistic and layout optimization; and maintenance planning.

Having an energy management system in place requires enterprises to carry out detailed energy review processes, which also result in the systematic identification and reporting of energy saving opportunities. This may also be the case for enterprises implementing environmental management systems, i.e. any ISO 50001 feed plant will fulfill this obligation through its certification. This is the case of French cooperative, Le Gouessant, which will be the first of seven feed plants certified since February 2014.

Audit parameters

“We’ve been doing energy research focused on savings in the feed plants from 1986 to 1990. We’ve established methods and tools to realize energy diagnostics,” explains Fabrice Putier, Tecaliman’s director. “We’ve realized 36 diagnostics.”

This wide study produced a comprehensive, updated assessment of energy consumption in feed plants to establish a ratio of consumption per unitary operation and per type of feed to identify determining factors and improvement solutions. For example, pelleting is the highest energy consuming operation, accounting for 57 percent of total feed plant energy costs; grinding is the second, accounting for 20 percent (Figure 1).

As early as 1990, Tecaliman launched an energy benchmarking program to help manufacturers to compare and gauge their energy consumption. This “energy observatory” counts 50 feed manufacturers. At the beginning, the benchmark compared three mains indicators twice a year:

  • Specific energy consumption of the feed plant (kWh/metric ton of production)
  • Purchase prices for energy (euro/MWh)
  • Specific energy price of the feed plant (euro/metric ton)

Since 2007, a new indicator had been added:

  • Greenhouse gas emissions (kg equivalent carbon/ metric ton of production)

“This energy benchmark is peculiar as it brings together competitors in voluntary and paid options -- of course, no one knew its competitors data,” points out Putier. Tecaliman also built up tools to help feed manufacturers in their research of energy savings like diagnoses, training and technology watch. 

“We have learned a lot through the years,” explains Putier.

Feed type influences consumption

French annual production is slightly higher than 21 million metric tons; and French annual feed plant energy consumption reaches between 1,200 and 1,400 GWh.

The main energies are electricity for engines and fossil energy for thermal energy production (steam). On average, electricity accounts for 60 percent of total energy. Ninety percent of electricity consumption is due to engines functioning and compressed air production. 

Pelleting consumes the largest part of feed plant energy and 100 percent of thermal energy, but this percentage may vary according to the kind of feed (poultry, pig or ruminants) and their physical presentation (pellet, flour or meal). 

For example, according to the data gathered from 50 plants that Tecaliman is monitoring (in which combined production accounts for 35 percent of total French production), the technical center had been able to show that a ruminant-specialized feed plant will consume more electricity and less steam than a poultry feed-dedicated plant. Consumption in pig feed-specialized plants are more variable (Figure 2).

Differences between ruminant and poultry feed are mainly due to higher steam use in the poultry pelleting process to improve pellet quality over time and their hardness. Increasing steam use may also help to reduce the electricity consumption of pellet mill engines.

While energy saving might be small compared to all the production costs, feed plants have room to improve with research and development. And, Tecaliman’s work might help a lot.