Objective To demonstrate the technical and economic viability of a process which, by the incineration of urban and industrial waste and the recycling and subsequent regeneration of blast furnace sand, recovers steam heat for use in other processes.The steam-raising plant consists of a unit fuelled by coal from Lorraine and an incinerator burning urban and industrial waste.Consumption is currently 90,000 MWh/year, 40% from waste and the rest from coal.The coal-fired plant consists or three boilers with a capacity of 10, 20 and 30 t/h.The plant is owned by Rhovyl, the energy user, and was taken over on 1 June 1983, for a ten-year period, by L.B.I.The furnace has a rated thermal capacity of 9,300 kWh. It can process 35,000 tonnes per year of waste with an average LCV of 2,000 kWh/t-corresponding to between 5,000 and 7,000 tonnes of industrial waste with an LCV of 4,000 kWh/t and between 20,000 and 25,000 tonnes of household refuse with an LCV of 1,750 kWh/t.Thanks to its great operational flexibility, it can burn waste with a wide range of calorific values. Its geometry and the fact that the waste is turned over in two directions ensure complete combustion and the clinker is therefore of exceptionally high quality (inertand containing no unburnt residues).After passing from the combustion chamber into the postcombustion chamber, the gases are then cooled in a heat-exchange chamber raising 9.5 t/h of steam at 12 bar(boiler pressure 25 bar).The gases then pass through an electrostatic precipitator and, in an extremely clean condition, are discharged into the atmosphere. The incinerator has a thermal output: of 9,300 kW with a rated hourly tonnage (domestic refuse) of 5.3 t/h.Consumption of electricity is 40 kWh/t waste.The plant was installed over a 13 mounth period between August 1982 and September 1983.After one month's testing the plant came into full operation in October 1983.Emissions are well within the limits.The calorific value of the waste has ranged from 1,100 kWh/t to 9,000 kWh/t.Since coming into service, the plant has burnt 130,000 tonnes of domestic refuse and produced 220,000 tonnes of steam.The incineration performance coefficient was 92% in 1986.The first part of the project - waste incineration at the rate of +- 35,000 T/y has been completed with positive results in terms of the energy recovered and use of the heat produced in other industrial processes.The rate of steam produced/tonne of waste incinerated is 1.44 to 1.56 and steam production from the incineration process is between 37.4 % and 42.1 % of the total steam production .+- 300 T of scrap iron has also been recovered.The second part of the project concerning the recycling and subsequent regeneration of the blast furnace sand has been cancelled.An oscillating incinerator with a heat recovery boiler and scrubbing system has been built together with a blast furnace sand treatment and heat recovery system.The LBI oscillating incinerator incorporates a recuperation boiler for the combustion gases and circulates waste material in counter-current to the hot gases. The incinerator leads to the combustion of domestic waste having a calorific value of no more than 1,000 Kcal/kg. though experience has shown that such waste has an average calorific value between 1,000 and 2,000 Kcal/kg. Combustion is achieved with only minimal use of the burner at start-up. The same plant can be used also for industrial or commercial waste of similar calorific value.The recuperation boiler is a saturated vapour production model, mounted in series in the exhaust gas extraction and treatment circuit.Special features of the L.B.I.furnace are the following:- Oscillating movement of the combustion chamber to agitate and oxygenate the waste continuously. - Truncated conical-cylindrical shape, enabling a constant temperature to be maintained within the chamber.- Patended air injection system: combustion air is preheated between the double walls of the chamber before being injected. The heat of combustion can thus be recovered.- Permanent monitoring of the combustion temperatures of solids and gases, ensuring that all complex chains of molecules are destroyed.- Ash is cooled at the end of the chamber.- Extracted gases pass through a plenum chamber before entering the radiation chamber(radiant-heat-zone).- The heat-recovery exchanger is coupled to the furnace proper but without risk of secondary combustion: the gases entering it are completely burnt, having passed through a post-combustion chamber.- Gas de-acidification system meeting European Community standards.- The L.B.I. process provides complete combustion: little unburned residues in the clinker and only low traces in the gases. Virtually no NOx emission occurs thanks to temperature control. High thermal outputs: combustion takes place in a high-turbulence zone, so excess air levels are low compared with a grate system. Programme(s) ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984 Topic(s) 1.5 - HEAT AND ENERGY FROM DIRECT COMBUSTION Call for proposal Data not available Funding Scheme DEM - Demonstration contracts Coordinator LAURENT BOUILLET INDUSTRIES EU contribution No data Address TOUR EUROPE 92080 PARIS LA DEFENSE CEDEX France See on map Total cost No data
