The target is to reduce 30 per cent carbon footprint by 2020
Our focus on conservation of energy, which constitutes 60 per cent of cost of cement manufacturing, has made Indian cement industry one of the best conservators in terms of thermal and electrical energy. We are having cement plants working on specific heat consumption of 680 and specific power consumption of 68 kW/MT cement production which is probably the best in the world.
What is your stated goal of reducing carbon footprint by 2020?
Blended cement proportion in total Indian cement industry is approximately 70 per cent. Manufacturing of PPC results in approximately 20-30 per cent reduction in CO2 against 1 MT of OPC production also manufacturing of PSC results in 30-35 per cent reduction in CO2 mitigation. We at ABGCL will be producing 100 per cent blended cement. The goal for ABGCL to reduce carbon footprint by 2020 is 30 per cent for its equivalent of OPC production by employing different methods like waste heat recovery (WHR), alternate fuel firing, installing solar panels on major building roofs and producing blended cement.
Which are the key levers identified to bring down carbon footprint?
Six key levers can contribute emission reductions: Alternative fuels and raw material, better energy efficiency, blended cements or clinker substitution, waste heat recovery, rain water harvesting and newer technology.
Could you highlight the strategies put in place and steps initiated by ABGCL?
In order to optimise thermal and electrical energy efficiency, we at ABGCL are using highly efficient VVVFD drives instead of traditional ones; this allows us to increase electrical efficiency. We have already initiated process of placing waste heat recovery system and alternate fuel firing system to further reduce our carbon footprint.
Indian cement industry has huge potential in reduction of usage of fossil fuel by using alternative fuels. Hazardous AFR like slag and non-hazardous AFRs like pet coke, shredded tyres, rice husk, biomasses, municipal waste etc. Present thermal substitution rate by usage of AFR is as low as 1-1.2 per cent against 40 per cent achieved by developed countries. We have already placed contracts with few agencies for regular supply of AFR to us and are in the process of technical finalisation of AFR feeding system.
Renewable energy sources: Considering the use of renewable energy sources for cement production, installations of solar panels on top of major buildings can generate as high as 1-1.5 MW for an average sized cement plant which can further reduce coal consumption in thermal power plants. At places like our clinkerisation unit installed at Kutch, wind energy can also be utilized to generate power. But hundred per cent dependency on renewable energy sources can´t be achieved as their consistency is questionable. We are initiating steps for installation of solar panels for street lights for our colony, plant and guest house area.
Reducing carbon footprint through WHR systems: Cement industry has shown great enthusiasm for installation of WHR system, but we still have ways to go for achieving its full potential. Installation of WHR system shall be made compulsory for all new cement projects and proper studies shall be made to make it highly efficient by 6/5 stage pre-heater systems. We are already in discussion with various vendors for installation of WHR system of 8-10 MW power generations with our six stage pre-heater.
Rain water harvesting systems are installed at every major building at our plant and colony. Our major logistics operations (clinker/coal) are by captive jetty and utilising sea instead of traditional rail or road transport thus saving carbon emission.
What are the major challenges in ´greening´ the cement industry?
- Availability of information on waste, type of waste generated is not readily available in public domain
- Regular supply of pre-processed waste of homogenous quality is not available
- Logistics of alternate fuel is expensive
- No proper logistics options are available for handling hazardous waste
- Interstate transfer of waste is not encouraged
- Insufficient R&D efforts for improving fly-ash and slag quality and utilization
- No national policy in force to encourage enhanced use of blended cements
- Restricted capital investment in improving energy efficiency.
How green is your operation, from mining to production and dispatch of cement?
We are using surface miner instead of traditional blasting process. We are using belt conveyor system for transportation of limestone instead of truck transportation. Six stage pre-heater with advanced low SOx and NOx technology is installed; burn-ability of raw meal is easy, this is reducing our specific heat consumption for clinker production.
Specific heat consumption: 698 kcal/kg of clinker (normal)
:738 kcal/kg of clinker (max. with 20 per cent by-pass)
Cross bar cooler is used instead of traditional grate cooler giving reduction of 0.4-0.5 Nm3/kg clinker in cooling air requirement.
Separate grinding and mixing of slag and OPC with help of paddle mixer is giving us of specific power consumption of 37 kWh/mt PSC produced instead of 42-45 kWh/mt when clinker and slag are inter-grinded. All fans are provided with variable voltage variable frequency drive (VVVFD) of VSDs. In six major process fans installed at Kutch, we are getting a power saving of 1.36 kWh/mt on clinker. Low pressure cyclones are installed in preheated to reduce power consumption of preheated fans.
Brief us on the high efficiency pollution control equipment used.
We have installed high-efficiency bag houses for all our operations and high efficiency ESPs for all hot operations. Apart from this we have 46 nuisance bag filters installed at every transfer point to reduce dust emission. We are also using latest technology for reducing SOx and NOx emissions from our pyro processing system.
Where does the company see itself five years down the line?
We had planned major design and technological considerations in initial stages to achieve maximum efficiency in thermal and electrical energy consumption and minimum emission. We will be manufacturing 100 per cent blended cement (PSC + PPC) which will further reduce carbon emissions.
Five years down the line, we see ABGCL as one of the leaders in Indian cement industry for greener and cleaner cement manufacturing with best figures in power consumption, heat consumption and carbon emission.