Alpro Wevelgem

CHP-solution

NAfter analyzing the electricity and heat demand Ecogen has implemented a CHP module with a 12-cylinder gas engine from INNIO Jenbacher type JMS 612 with an electrical output of 2.000 kW. This CHP-module covers 75% of the company's own electricity demand. At the same time, steam and hot water is recovered from the CHP and used in the production process. The gas engine module was placed in the existing boiler house and integrated in an acoustical enclosure.

The heat sources of the CHP are linked in an optimal way with the heat demand of the production process of Alpro. On the one hand, the heat from the CHP is released under the form of exhaust gases, on the other hand as hot water from the engine cooling water, the oil cooling and the intercooler heat.

Since the steam demand at the plant is a priority, the exhaust gases of the CHP are initially used for production of saturated steam. This happens on a pressure of 13,5 bar through a heat recovery steam boiler placed next to the CHP.

The hot water from the CHP is used via three different hot water circuits:

• High-temperature hot-water circuit with a temperature of 95 °C, coming from the engine cooling, oil cooling, and the high temperature intercooler heat, completed with a first exhaust gas heat exchanger which cools down the exhaust gases after the steam boiler.
• Condenser-hot-water circuit, to heat up fresh water from 15 °C to 60 °C or more, coming from a second exhaust gas heat exchanger (condenser), which further cools the exhaust gases after the first exhaust gas heat exchanger.
• Low-temperature hot-water circuit, with a temperature of around 45 °C, coming from the low temperature intercooler heat.

Various optimizations and applications, such as the placement of the condenser to heat up 'CIP'-water, have resulted in a total thermal capacity of the CHP of 2.557 kWth. The relative primary energy savings can reach 35%, with the result of a significant CO² reduction.

Renewable CHP

This CHP module offers the possibility to combust the biogas coming from plant wastewater sludge digestion, and to turn it into green energy. The waste water sludge of Alpro is processed in an anaerobic water treatment plant. The biogas released from this process is, after an intensive gas cleaning, further mixed with natural gas for use as fuel for the CHP module. Consequently, the CHP module will run on an average of 10% biogas (renewable energy) and 90% natural gas.

Our role: Engineering, construction and follow-up of the CHP

Before the partnership between Ecogen and Alpro there was extensive consultation between both parties. This has been decisive for the successful implementation of the CHP module. Ecogen was in the project responsible for the integration of the total CHP plant in the boiler house, with also the integration of the biogas process including the biogas treatment. The electric integration in the internal electric grid of Alpro, according to the formalities of the public grid operator, was also carried out by Ecogen. The follow-up of the CHP is run in an intensive cooperation between Ecogen and the energy management of Alpro. The applied concept of this CHP plant with optimal heat recovery is therefore a successful reference case.