Login

Innovative techniques adopted by DG Khan for alternative fuels and waste heat recovery: Dr Arif Bashir, DG Khan (Pakistan)

Filmed at Cemtech MEA 2015, 8-11 February, Grand Hyatt Dubai, UAE

Already a subscriber? Login

Subscribe to get access to all News, Articles and Video sections of the CemNet.com website.

Subscribe

Thank you very much and good morning to ladies and gentlemen. I'm also thankful to you for providing us this opportunity to meet with old friends coming from different countries, and after 20 years I noticed that old friends, they've also got grey hair. The topic of today's talk is the innovative techniques developed by DG Khan cement for alternative fuels and waste heat recovery.

As I said, that I've divided my talk into three parts, first part leads to the Pakistan Cement Industry and DG Khan Cement Production Lines. And then in the second part I'd like to present use of alternative fuels and that is our practical experience and the techniques that we have adopted to use maximum alternative fuel.

And yesterday in the morning session we talked about problems that one may encounter in the use of alternative fuels or wastage recovery. And today I'm going to talk on all those problems that we have been facing and how we are solving those problems. Then we'll talk about the waste heat recovery unit and in the waste heat recovery unit, I'm going to present before you a comparative study on the conventional Rankineg cycle, that we have installed at one of our plants and cleaner cycle which is first of it's kind in the world and first time it's being installed on a cement plant.

First, let's talk about the cement industry and cement plants in Pakistan. As you can see that, these red dots are those cement plants which installed in the North and the red dots are those which installed in the South. In total Pakistan has got about 26 cement plants and you can see from here we border our share with the China, with Afghanistan, Iran and India.

From the factories which are located in the North, we are exporting cement to Afghanistan and some to the Russian states and from the plant which are located in the centre of the country or somewhere here, we export also to India. Our cement is also going to African countries and by what you're having a very good and consistent quality of cement, we have got a fair market share in African market.

If we look at the production capacities of our cement plants then today the installed is 44.7 million tonnes per year and the capacity utilization you can see is about 76. 79% ending year 2014. If we look at the domestic portion, it's 26.14 million tonnes and the export is 8.14 billion tonnes. By the recent results of sales indicate that sale volume have increased by about 6.18% during past seven months starting from July up to January.

And our domestic sales have gone up to 10%. So that is a very good indicator to see that in coming five months then we hope that our domestic sales will also pick further the market share of Digicom cement is close to 11.3% and these are the cement factories and big players of cement I'm sure that [xx] people are also still sitting here their market share is 6.1%.

Digicon[sp] cement company we've got two cement plants with three kilns in operations. Two kilns are installed at a place called Digicon and Digicon is the name of city which is in the center of the country. There we've got two plants 4000 tonnes FLS plants which was commissioned back in 1997 and 2700 tonnes plant supplied by [xx] which was commissioned back in 1986.

Now with this plant which is [xx] plant and FLS plant, we've installed conventional Rankine cycle for the waste heat recovery, capable to produce 10.4 megawatt of electricity supplied by Kawasaki Japan back in 2005. And at our other plant which is Khairpur in the north is only one and half hours from the capital city Islamabad. The production capacity from a single kiln supplied by FLS is 7000 tonnes per day.

And at this plant we've installed Kalina cycle 8.6 megawatts in which was commissioned in January 2013. It's a view showing the cement plant at DG Khan, we can see they've got two lines one by [xx] and the other by FLS. These are plants installed at Khairpur producing 7, 000 tonnes per day of clinker and this plant was commissioned back in 2007 and one interesting feature of this plant is the low thermal energy consumption which is down to 715 kilo calories and low power consumption because of vertical grinding mills which have been installed.

If we look at the cost breaker ending depeater June 2014, then we can see that the major cost input are fuel cost which is 39%, and the power is 20%. These were the two areas that we concentrated and started working on optimizing our system and going for the innovative and new technologies to curtail our fuel cost and also the electricity the cost.

On these two fronts when we worked, first of all we took the use of alternative fuels and about three years ago we started working on the use of alternative fuels. In the next slides, I'm going to talk on the use of alternative fuels, and the practical results I would like to share with you. 23 different types of alternative fuels we have been using and these fuels are coming from industrial waste.

Industrial waste means coming from textile industry, it's coming from shoe industry, from leather industry, sugar industry. So, all sort of ways which are being generated in those industries we are capable to utilize and process. In the agriculture waste, Pakistan is a agriculture country having a population of 180 million people with a total area of 740, 000 square kilometer, so we have two crops in a year and on the corn we have got three crops. So, we use lots of waste materials coming from agriculture like rice husks, wheat straw, corn cob, acacia wood.

So, we develop to process all these materials one by one and you utilize in our system. The next is a means for solid waste that we've been using. We signed a contract with government authorities in the city of Lahore, the second largest city having a population of about 10 million people and we are generating waste close to 7000 tonnes from the city of Lahore.

We are getting a share of about 1000 tonnes a day which government authorities are delivering to our site in Lahore and there we have installed the solid waste processing units comprising a shredding unit, vibrating screen, wind swifter and a billing unit. After processing these waste and segregation of inorganic component and organic component the combustible material in bill form is taken to the factory site we will burn that material and substitute imported coal.

The next line is the Tyre drived fuel, for the tyre drive fuel we have installed a complete line to start with a big shredding unit and then small shredding unit, a magnetic separator and then also the wire cleaning machine. So, it's a complete installation and after shredding it goes to the storage area and from storage through weighing system it goes to the calciner. We are also using poultry waste which is available in abundance in the local area and the best part is that we are using combination of these fuels.

These are the tyre chips that we get from this shredding unit. Now as you know that tyres contain part of wires and if that vile goes into the burning process, it may create some problem. So to remove that wire we use the installation the wire cleaning machine which is a sort of shredding unit and it removes 100% wires from the tyre.

And these wires sell in the market at high rate as a scrap material. This is the municipal solid waste the composition of the waste which is coming from Lahore is quite different compared to what we are getting in Europe or in Germany or France. It has an inorganic components of close to 50% and the 50% is the inorganic component.

But it varies in the composition sometime blasting materials are more, sometime pebble is more, and sometime we get some debris and [xx] material. The biggest of all challenges is the moisture content and the control of moisture content from the incoming material. Which is as high as sometimes 25%, 40% or maybe 45% sometimes.

This slide shows the poultry waste, and out of 23 different kinds of waste materials that we are using, are selected for this presentation three material, a combination of three media so that everybody can understand, that what are the significant effects on the process and what are the financial benefits of these materials. So for these, I have selected a combination of coal with poultry waste and with the poultry waste [xx] fuel and also mixed with solid waste which is converted into RDF, the refused dry fuel. This is a view of our factory at Khairpur and as you can see that this belt carrier takes the material to the calciner floor, and where we have installed our proper weighing system and that goes into the calciner for combustion.

In the yields of alternative fuel the key is the storage, the processing and point where we are in fact feeding for the combustion. This slide shows the installation in Lahore where we've got the complete processing client. If I may quickly go on to the problems that we're facing, is the uniform quality and for moisture we are developing drying system. High percentage of debris is there which we are removing through disaggregation process.

In future we're going to generate methane gas from the organic component and power generation. This is all about the already fuse and right now switch over to waste heat recovery Rankine cycle. Everybody perhaps knows about the concept of conventional Rankine cycle that it takes the heat from the waste gases, converts into steam and then runs the turbine. And from turbine you can generate electricity and thereafter, the condesate comes back to the system. If you have any question on that you can ask me later on, but 10.4 megawatt is the latest capacity of the mine, and we are generating consistent basis, about 8.5 megawatt from this Rankine cycle which is installed at our DG Khan plant.

Now, more important is to know about the operation results of this Rankine cycle here. So I extracted one month in that was November 2014, and you can see that the operation days were 30 without any stoppage of the plant, and on every we produced eight megawatt which is close to the performance currently figure, and auxiliary power consumption is 8.83%. With waste heat recovery generation, it was 26% substitution of the total power we use for our cement manufacturing process. So, please remember these two figures, 8.83% is the auxiliary and 26% is the total power which is coming this waste heat recovery.

Now, I quickly move onto the Kalina cycle. Kalina is a new concept, first of it's kind in the world and we were the first on in the world in the cement sector to apply this technology. And the reason why we this technology was that this area is having shortage of water and we were told in the beginning by the designer that water consumption is considerably low in comparison to the Rankine cycle and secondly the available heat from our system that is the waste heat, we can generate 20-25% more power compared to the Rankine cycle.

So, these were the two important aspects that we considered in the beginning, the guaranteed figure is 8.6 megawatts is supplied by FLS and they've got a licence from Raclette Engineering USA and then FLS involved Indian design office to carry on the basic design of mechanical and electrical components.

Very briefly I run through the details that the simple concept is that we're getting the waste gases from the pre-heater, going through this heat exchanger. And then these are the two heat exchanger which are installed with each pre-heater tower. We have a twin pre-heater tower and a cooling area in the cooler area.

So three heater center has been installed, one with each heater and one with the cooler. The hot gases that are coming from here and going out, you can see the temperature 291 down to 110, and then you can see also the pre-heater temperature coming from 302 down to 220. And 220 is primarily because the reason that we also we're feeding these gases into the raw mill and coal mill for drying purposes.

Ammonia cycle search that Ammonia water mixture 55% is coming here, going through the heat exchanger and finally exhaust and running the turbine. Then it comes to the condenser and passes through these four heat exchangers and then from here it is pumped again into the system and this unit is called mixture which removes the Ammonia in water, segregate Ammonia as a gas and then water is also segregated.

And finally it is fed into the system again. It's a close loop system, very quickly if we talk about the difference between the two technologies then here, we are so far, the performance guarantee figure is 8.6 megawatt and on the system basis, we have generated about 5.5 or 6 megawatt. We have not yet reached to the final figure of 8.6 megawatt, but we have achieved figure of 5.3 megawatt in the month of November and before that if we talk about year average is close to 5.5 or 5.3. But look at the figure here, it's 19% auxiliary column and 16% is the contribution of WHR in terms of total power consumption. And in the early slide I showed you 8% on the axillary consumption with the Rankine cycle and 16% instead of 16 there was more 25-26%. These are the important aspect to note that we have not yet reached to the final destination.


But our designer is making some changes in the heat exchangers and we're going to install in coming two months are some additional heat exchangers and that can improve the system. There are two positive aspects of the process and then there are some negative aspects of the process. The positive aspect is that since the cement manufacturing process is quite sensitive and we'e using a lot of alternate fuels, our substitution has reached to a level of 50% in the calciner and overall is about 32-35 of the total fuel link fed into the system of cement manufacturing.

With the use of alternative fuel and so much fluctuation in the process including fall, there are some disturbances in the kiln. But this is system which is comprising 55%, 50% ammonia solution with water. Then it can compensate that compensation because the operator has two operational variables in hand.

One is the concentration of Ammonia and the second is the tonnes per hour Ammonia feeding into the system. It's on a controlled loop and immediately we did slight change in the operation parameters of kiln, this system changes automatically and hence we can generate maximum power. The problems in the system are because it was a new system first of its kind in the world, we faced enormous challenges in terms of leakage of ammonia through the seals, malfunctioning of the pumps, more auxiliary power consumption and sometimes it takes more time to restart the system.

So these are the challenges that we faced but looking at our future and the theoretical model target, these are the expectations in coming three to six months. They will be generating close to 8.6 Megawatts by installing more heat exchangers in boiler, more tubes in the boiler and auxillary consumption is expected to be down to 8.8% with a 33% contributional of WHR in the system.

All in all these are the comparison between can cycle and also with the a Kalina cycle. One interesting aspect of this cleaner processes is that, from where this name came. It was the Russian scientist with the name Kalina who shifted from Russia to California and he gave his patent to a company in America called Raclette Engineering, and Raclette Engineering gave rights to FLS to sell it to the cement manufacturer and we were the first one to take that. And FLS signed a contract with of coarse Chinaese companies for the supply of boiler and ABB for the supply of turbine and generator and Indian companies were involved for the design of the boiler and other mechanical electrical installations.

So roller is a real international project and today we are very glad provided the platform on the international forum to start project. And in the next six months we've to see the results whether or not we are going with two benefits which have been indicated earlier that is low water consumption and the higher power consumption and in comparison to conventional Rankine cycle 20- 25%. We carried out an exercise in beginning and realize that the offer that we received for the convention cycle based on we achieved is available in our system.

The performance guarantee figure was indicated close to 5.8 megawatt on the organic Rankine cycle and conventional Rankine cycle indicated a figure of 6.8 megawatt. In comparison to that if we can get 8.6 Megawatts from this Kalina then it's going to be a real success in the world. So, that's all and thank you very much for patience in hearing and you're most welcome to ask any question.

Cemtech Europe 2024

Cemtech ASIA 2024

Cemtech MEA 2024

Cemtech Europe 2023

Cemtech Asia 2023

Cemtech MEA 2023

Cemtech Webinar 2022

Cemtech MEA 2022

Cemtech Americas 2021

Cemtech Asia 2021

Cemtech Webinar 2021

Cemtech Webinar 2020

Cemtech MEA 2021

Cemtech Virtual 2020

Cemtech Europe 2019

Cemtech Asia 2019

Cemtech MEA 2019

Cemtech Europe 2018

Cemtech Asia 2018

Cemtech MEA 2018

Cemtech Europe 2017

Cemtech Asia 2017

Cemtech MEA 2017

Cemtech Europe 2016

Cemtech Asia 2016

Cemtech MEA 2016

Cemtech Americas 2015

Cemtech Europe 2015

Cemtech Asia 2015

Cemtech MEA 2015

Cemtech Europe 2014

Cemtech MEA 2014

Cemtech Europe 2013

Cemtech Asia 2013

Cemtech Jakarta 2012

Cemtech MEA 2013

Cemtech Geneva 2012

Cemtech MEA 2012

Cemtech Europe 2011

Cemtech Europe 2010

Cemtech Middle East 2010

Cemtech Europe 2009

Cemtech Dubai 2009

Cemtech Florida 2008

Cemtech London 2008

Cemtech Singapore 2008

Cemtech Dubai 2008

Cemtech Florida 2007

Cemtech Prague 2007

Cemtech Abu Dhabi 2007

cemtech florida 2006

Cemtech Rome 2006

Cemtech Barcelona 2005