CMC 95 L series is a versatile liquid phase combustion-monitoring chemical/fuel additives for liquid fuel such as furnace oil, LDO, LSHS etc. These products are contains dispersant, anti fouling agent along with advanced combustion catalyst for liquid fuel to improve boiler performance.
Use of heavy fuel oils in industrial furnaces is known to produce a host of corrosion, shoot deposition and environmental related problems. Severe corrosion in hot and cold zones of the furnace and emissions of obnoxious gases, particulates and acid smut to the atmosphere, shoot deposition, poor efficiency, nozzle choking, shoot rain are a few to name which will cost millions by way of forced shut downs and unscheduled maintenance, besides creating environmental pollution. A cost effective solution to mitigate some of the above problems is the use of chemical fuel additives. The effectiveness of chemical additives in heavy oil fired boilers is site specific and requires testing of additive in the boiler under actual operating conditions to optimize the additive regime to obtain the maximum gains.
Problems with Liquid Fuels Fired System
- Sludging and Storage Tanks
- Density Stratification
- Continuous Polymerisation
- Poor/Improper Combustion
- Principally due to "Asphaltenes"
- Deposit Formation
- Presence of Sulphur Deposits
- Improper Combustion
- Presence of "S"
Combustion of Liquid Fuel
- Pre-Ignition Stage
The droplet is heated and evaporation of the volatile material begins. This stage ends with the self-ignition of the vapour surrounding the droplet.
- Volatiles Combustions Stage
The volatile constituents of the oil and the cracked products burn in an enveloped flame surrounding the droplet. The stage ends by the flame dyeing away as the evolution of flammable material ceases.
- Coke Combustion Stage
When the flame dies hot gases including oxygen can reach the hot surface of the coke residue. It glows red and burns at 1400 " 1700 K. The unburnt coke left after combustion is called a censophere.
Altret CMC 95 L Combustion Monitoring Chemicals having following Properties
- Catalytic effect.
- Anti-fouling characteristic.
- Anti-emission characteristic.
- Surfactive characteristic.
- Anti-freezing characteristic.
Key Benefits of CMC 95 L Series Liquid Fuel Additives
- It is a unique fuel additive having total dispersibility with liquid fuel.
- Specially formulated, contains emulsifier to avoid water immiscibility problem.
- It contains anti fouling agent, which keeps heat transfer surface clean thus improves heat transfer efficiency of your precious equipment.
- It improves combustion of fuel, which ultimate results to improve Steam to Fuel Ratio.
- Reduced emission of carbon black at chimney outlet and more efficiently work with soot blower.
- It prevents chimney corrosion or cold end corrosion by efficient reacting with Sulphur Trioxide SO3 in the gaseous phase.
Success Measurements of CMC 95 L Series Liquid Fuel Additives
Various flue gas parameters such as SOx, and NOx contents, rates of acid build up can be determined during the trial for performance evolution of product. Quantitative evaluation of boiler soots from the test unit as well as from a control unit without additive dosing will be also carried out for comparison. Effects of additive dosing on the be boiler performance will be also monitored by evaluating boiler load, efficiency, flue gas outlet temperature, opacity, fuel and steam flows, etc. Boiler internals were inspected before and after the testing of each additive. Results of these tests will be summarized after completion of trial project.
Analytical Parameters and Procedures
- Flue Gas Analysis
The following parameters will be determined in the boiler flue gases as per methods indicated against each:
- SOx - Flue gas analyser.
- Oxides of nitrogen (NOx) " Flue gas analyser.
- CO2 and O2 - by Orsat analyser.
- CO ppm and excess air ratio.
- Soot Analysis
The following parameters of the boiler soot samples will be analysed by standard methods:
- Weight, bulk density and moisture content.
- Conductivity of 1% ash slurry.
- Boiler Operation Parameter
- Fuel and steam flows.
- Boiler efficiency.
- Temperature of the flue gases at inlet to the air heater, air heater delta P, and flue gas opacity were monitored on daily basis.
- Water consumption will be monitor on daily bases.
- Fouling Tendency
Shoot deposition at duct and chimney mouth will be observed. Success criteria of trial (usage of ALTRET fuel additive):
- Flue Gas Analysis
- Reduction in SOx (compare to without chem. trial period).
- Reduction in NOx.
- Increase % CO2 and reduction in O2 %.
- Reduction in CO ppm.
- Shoot Analysis
- Reduction in weight of shoot, reduction in bulk density and moisture content.
- Conductivity of 1 % shoot slurry will be increase.
- Boiler Operational Parameters
- Fuel consummation will be decrease (or else evaporation ratio will be increase).
- Boiler efficiency will be increase.
- Reduction in flue gas temperature.
- Increase the air preheter out air temperature.
- Fouling tendency of shoot at chimney mouth and duct will be minimize.
Asphaltenec are the heaviest and most polar fraction in crude oil. During the refining of crude oil, Asphaltenes will be end up in the high percentage in the residual fuels. A liquid fuel content more than 6% of asphaltenes.
Asphaltenec are very complex molecules consist of Alkyl side chains. The Heateroatoms O, N, S as well as the metals V, Ni, and Fe are also present in Asphaltenec. Exact molecular structures of Asphaltenec are not known.
Problem Caused due to Asphaltenes
- Storage Problem
- Sedimentation and Plugging can occur due to oxydation of the Asphaltenes. The increase polarity may cause Asphaltenes aggregation.
- The solubility of the Asphaltenes are also affected by type and concentration of the Resins in the blend components.
- The sludge formation can further more be accelerated if there is bacterial infestation in the fuel.
- A content of 6% or more of the Asphaltenes in the fuels result in to ignition delay and poor combustion due to large particle size of the Asphaltenes.
- This will cause boiler fouling, soot deposition, poor heat transfer, stack solid emission and corrosion amongst other problems.
- The preheating of the oils prior to their burning encourage the precipitation of the Asphaltenes and choking.
- Solutions to Asphaltenes
- Asphaltenes deposition is the consequence of the instability of the oil.
- The Asphaltenes are in nature stabilized by resins.
- Asphaltenes dispersant, which is there in "ALTRET" additive, are subsititutes to normal resins and works much in the same way as resins.
- Dispersants will keep the Asphaltenes well dispersed to prevent their flocculation/aggregation.
- ALTRET dispersant will improve the atomization of the fuel. The smaller droplets produced will provide better mixing with oxygen giving earlier mixing of combustion.
- Dispersed Asphaltenes provides more complete combustion.
- Reduce soot and stack solid emission.
- Prevent soot and coke deposits.