Given the difficulties in achieving results by increasing revenues, companies are turning more and more to cutting costs. Reducing energy consumption has become the target for many companies.
In sectors as the cement, particleboard manufacturing, inceneration, among others, energy is demanded mostly in the form of heat. Most companies are retrofitting their boilers and thermal oil heaters to run with biomass, instead of oil or coal, to reduce costs and become more eco-friendly. Still too, much of the generated heat is being lost throughout the manufacturing process.
In the cement industry, most plants intentionally cool the exhaust stream of the pre-heater tower from 400oC down to 120oC, so it can be cleaned in bag filters, dissipating all that heat into the atmosphere.
In the particleboard industry, many plants use extra diesel or natural gas generators to heat the rotary dryers, despite having more than the necessary amount of energy from biomass boilers to produce the steam or heat for the entire plant. The high concentration of fly ash in the hot gas stream produced by the biomass boiler does not allow it to be put back into the process.
In waste to energy incinerators, the ash in the flue gas is usually captured in a pre-separator such as a multicyclone (MC) before going into the economizer, followed by reagent injection to neutralize gaseous effluents and finally a bag filter to comply with emissions standards before going to the stack. The cost for the hazardous ash disposal captured in the bag filter is nearly 4 times higher than the disposal of the ash captured in the MC due to the reagent injection.
The main obstacle to improve the energy efficiency of these processes lies generally on how to effectively clean the gases at high temperature without thermal losses, so that they can be recirculated into a heat recovery system, such as a recovery boiler, or directly back into the process.
Client's needs include a high efficient dedusting system to reduce particles to a level that the air can be used for energy recovery purposes and is robust enough to operate at high temperatures with low maintenance/operating costs.