L'énergie provenant des opérations de traitement

En termes de nouveaux procédés de réutilisation de la chaleur résiduelle, ASIO(C) s’est engagé dans l’étude et le développement d’un large éventail de processus technologioques et de leur application inversées pour produire de l’électricité, de la chaleur ou du froid, ce qui implique le recours à des pompes à chaleur, des stations de co-génération ou tri-génération, des micro-turbines, des ?turbines de récupération de chaleur, des réfrigérateurs à absorption ,des panneaux solaires et photovoltaïques et autres porcédés. Une grande partie de ces techniques permettent de réaliser des projets rentables avec des périodes d’amortissement de 3 à 10 ans…

The Czech national economy has its energy consumption per GDP unit higher by 50% than the EU average and it is still heavily dependent on fossil fuel sources. In other words, this means that we are by 50% more vulnerable in cases of leaps in prices , unexpected dropouts in energy supply caused because of either political reasons or natural disasters.

At present, the emissions discharged per inhabitant in the Czech Republic are by 36% higher than the EU average. Buildings in the Czech Republic account for 65% of the total end–use consumption of heat and 49% of the total end–use consumption of electricity. Even though there are available and cost-effective methods well proven a long time ago, by which the energy demand of buildings can be reduced even by 90%, an overwhelming majority of buildings pointlessly waste energy. This situation exists in the Czech Republic without excep-tion, because - in terms of energy consumption - a major part of the development here has been built highly uneconomically. However, there are measures that could rectify this situa-tion fairly. Both energy-efficient development and reconstruction projects are repaid after some time and consequently they start to bring significant savings, which motivates the owners for the investment.

By increasing the energy efficiency, a large part of primary energy consumption can be covered with renewable and secondary sources. Recently, heat recovery from wastewa-ter, flue gases or air, where therein-contained heat leaves away uselessly in various processes in all industrial branches and agriculture, gained importance.
Renewable and secondary sources of energy represent today the largest potential for the production of electricity and heat, and in most cases, they are state supported. However, even without the state subsidies, there are complex project in place that always bring an interesting payback period.

Just a small example of spheres, where considerable heat gains cane be used:
Stationary engines (engine exhaust & cooling systems)
• Diesel-powered generators
• Bio-gas stations
• Cogeneration plants (CHP = combined heat and power)
• Trigeneration plants (CCHP = combined cooling, heat and power)
• Compressor stations
• Distributed and central heat production
• Pumping stations
• Landfill aggregates

Solar-thermal systems
• Basic cycle
• Direct hot fluid
• Steam condensate
• Geothermal water
• Liquids in the mouth of an oil or gas drill well

• Wood chips
• Bio-gas stations
• Landfill waste
• Biological-based fuels
Industrial use
• Process waste heat
• Thermal-oxidation equipment
• Air-conditioning systems
• Heating plants
and many others

One of the less known technologies that comes into focus now and uses was heat is the technology of ORC units and absorption refrigerators. ORC units are low-temperature sys-tems of heat-to-electricity conversion, i.e. the technology using waste heat sources for the generation of electricity by the transfer into the working medium of the Organic Rankine Cycle (ORC).

The ORC machines use various source of waste “useless” heat for the generation of electric-ity, where:
• they have no requirements for fuel – they use waste heat,
• they have no emissions, are environmentally friendly and they produce no carbon diox-ide,
• their operating costs are low,
• their payback period is attractive,
• their design lifetime is 20 years, and
• their marketability is possible also in other branches – not only in wastewater treat-ment plants and in biogas stations.

Another sphere of potential savings of a growing importance is the sphere of cooling. Today, new and modernised technologies are turning away from conventional compression refrig-erators and tend to the absorption refrigeration technology.
The conventional compression refrigerators are electrically driven.
The absorption refrigerators use, as the main source of energy, hot water, steam, exhaust gases, waste gas or waste heat as such. Combinations of two sources are also possible.

The absorption refrigerators use for their operation only 5 % of electricity in a comparison with the conventional ones – the compression refrigerators – because only circulation pumps are electrically driven. Their lifetime is much longer (up to 20 years) and their noisiness is substantially lower.
There is a wide range of method how to use this “waste” energy: but always it is necessary to prepare a complex process analysis, evaluate the investor's needs and requirements and propose an ideal energy-exploitation solution, which – employing suitable process elements – would create conditions for the maximisation of heat gains and their reverse use in the processes at optimised capital costs.
Our solutions consist in increasing of energy efficiencies of individual applications of the technologies supplied by us with the top efficiency and very short payback period.