EET GmbH offers unique systems for efficient coal slurry production and combustion, applicable in new plants or converted plants.
We do NOT promote coal as a fuel. There are million of tons of coal and carbon wastes all over the world. We offer solutions for the most optimal their utilization with minimum emissions. Carbon Water Slurry already proven as the solution for reducing NOx emissions.
Our equipment is highly modular, what significantly reduces the cost of implementing the technology on new and existing facilities, as well, possibly using the local resources as well.
Our Products & Services
We offer for our Customers Products for producing CWS and its' combustion.
We also offer non-standard solution like utilization of coal flotation concentrate and heat prouction in zink prouction, filter cake utilization, etc.
Our CWS production & Combustion infrastructure in Stockerau (near Vienna) and in Izhevsk, Russia, allows us to develop new & special solutions.
Technology
CWS at a glance
Carbon/Coal Water Slurry (CWS) is a homogeneous mixture of finely milled coal or other carbonaceous materials with water or an aqueous emulsion:
CWS = Coal or Carbon (58% … 67%) + Water or Water Emulsion (29% … 40%)
CWS has almost the same viscosity as heavy fuel oil (mazut) what makes it suitable both for pumping on short and long distances and for spraying into a boiler via specially designed nozzles.
Gas, oil/diesel, coal still could be used as a redundant or support fuel for boilers.
Technology has two major processes:
- CWS production
- CWS combustion
CWS is non-newtonian liquid. Thus it requires some special measures for proper production and combustion.
CWS Production Process
Wet milling and homogenization in Wet Milling Machine is the key part of production process when the mixture of coal/carbon particles are uniformly mixed with water or water emulsion.
If the original raw has particles bigger than 12mm additional crusher may required. Normally all carbon wastes are already below 12mm.
We can proudly say that our Wet Milling Machine is the most energy effective milling complex with specific energy consumption 5 times lower than ball mills.
Atomization & Combustion
CWS is sprayed into a boiler through EET’s pneumo-nozzle which is specially designed to spray slurry and heavy fuels. There are three major methods for CWS combustion:
- Independent combustion in a vortex burner (swirl pre-chamber), which is installed in a front of boiler
- Co-firing together with existing fuel – coal, diesel/oil (HFO), gas
- Independent combustion with spraying CWS by oxygen (O2)
Combustion in swirl pre-chamber allows to burn CWS autonomously, diesel/gas required only for initial preheating.
Co-firing gives a flexibility for boiler owners to choose between fuels. Typical CWS/fuel ratio is 80%/20%. CWS can be burnt in most of steam and hot water boilers. Existing boilers and ovens in most cases are upgradable by installing vortex burner or simply CWS-nozzle. Existing oil/gas boilers require installation of ash collection system or installation of pre-chamber. CWS combustion method depends on boiler type, locally available raw materials, and other factors.
CWS storage
CWS, produced in Wet Milling Machine stored in standard tank with stirrer.
We suggest to produce as much CWS as required for one day or one shift. If higher amount is required CWS can be stored for a longer period. Depending on raw characteristics CWS produced in WMM is stable within several days without any further procedures and additives. If sedimentation is observed then stirrer can ran couple hours a day to keep CWS stable. Additionally, CWS can be returned back to further processing in WMM.
Only as the last measure we suggest to use stabilizers to avoid sedimentation in CWS.
For our customers we offer a standard CWS storage system which is already developed for CWS intermediate storage and further consumption.
Utilization of Carbon Black (pCB)
There is a world trend to utilize unused rubber, mostly auto tires, by converting it to Tire Pyrolytic Oil (TPO) in a pyrolysis plants. There are different types of pyrolysis plants now presented on market. Most of them use the same technological process:
- Cutting the rubber into 3..5cm chipes
- Further processing for removing textile and metal cord form the rubber
- Feeding into pyrolysis reactor and producing a TPO.
Along with TPO there two side products also produced: pyrolysis gas and Pyrolysis Carbon Black (pCB). While gas and TPO are useful products, pCB is a waste product – it has a typical grainsize below 0.5mm, very dusty and must be stored in a textile big-bags.
Direct utilization of pCB is limited with its dirtiness and difficulties for further processing.
We are offering solution to utilize all pyrolysis products to a fuel:
- Gas is used for own needs of pyrolysis plant – standard prcoess for plants
- TPO is used as a major fuel for waterheating/steam boilers
- pCB is converted to liquid Carbon Water Slurry (CWS) and used as an additional fuel for burning together with TPO and/or gas/oil.
CWs from pCB has a normal moisture about 50% which is reducing the calorific value. At the same time, convertion of pCB to CWS allows to treat a carbon dust as a liquid fuel and atomize it in a boiler through the CWS nozzle. Heat losses related with water evaporation are about 10% of pCB’s heating value which is economically more efficient than explosionproof measures related with feeding pCB and general cleaness of the production facilities.
CWS Production
Based on our experience even after pyrolysis process pCB has many metal includes which may follow CWS stuck in a nozzle. Magnet metal separator which is a part of Wet Milling Machine (WMM) solves this issue. In addition to fine milling WMM produces uniform (homogeneous) fuel from pCB.
Our first runs of CWS production were related with a lot of dust in prodction facilities. Now we offer WMM, Generation 2, with special hoper for cutting big-bags with pCB or directly connected to output feed of pyrolysis plant.
Combustion process
We suggest a cofiring of TPO and pCB as a most most optimal combustion model for burning of low calorific fuels like pCB. For organizing cofiring we offer our Vortex Burner equipped with standard liquid fuel burner for TPO and CWS nozzle for pCB. For the such model TPO/CWS ratio is in a range from 50%/50% to 70%/30%.
Coal Fines and Filter-Cake Utilization
The coal produced in mines, sorted and refined at the coal factories. The result is an enrichment of coal as a commodity, and the filter cake with fractions of less than 1 mm. The filter cake is typically a clay substance obtained as a result of the separation of raw coal by fractions. Larger fraction is sent to the further process of concentration and drying in kilns. The fine fraction (cake) is typically utilized as a waste.
The usual fuel for kilns coal-preparation plants is a coal is produced by factory and which is sold as a product. Coal gets into the furnace through the dispenser, feeder and burns on the grate.
Consumption of salable coal for drying in kilns could be reduced by its partial replacement by Coal Slurry (CWS) which produced from the filter cake. CWS is sprayed into the furnace above the grate though the air nozzle.
According to tests it is determined that the combustion of 1 ton CWS from filter cake saves at least 1 ton of salable coal.
Thus, combustion of coal-water slurry from cake allows coal factory to solve two problems at once:
- Reduce consumption of salable coal for technological needs, ie, reduce their own costs for the production of coal.
- Dispose of unused coal filter cake having an ash content of about 30 ... 40% and humidity up to 30%.
Proposed solution could be implemented on most of majority of coal factories.
In addition to filter cake other small coal fractions could be used as a raw material for CWS.
CWS from filter cake could be effectively made in by Hydroshock Wet Milling Machibe (WMM). WMM makes a uniform (homogeneous) suspension (sludge, slurry), which is atomized through a nozzle.
Example of burning of CWS from filter-cake in an drying kiln:
Low Emissions for Low Calorific Fuels
Our Vortex Burner allows to achieve a total burnout of most of low-calorific fuels like biomass, peat, and other fuels.
Optimized combustion temperature keeps low NOx emissions and gives CO in a range 20....150 mg/m3.
Wooden chips and sawdust, straw and other fuels are effectively burnt with producing a heat with a temperature required for the most of the boilers, steam and water heating ones.
Source: Effective Energy Technologies GmbH
Advertisement
The 10 largest coal producers and exporters in Indonesia:
