Cement Energy and Environment

combustion is usually considered as C02 neutral as the evolved C02 is fixed again in presence of sun light and water to form the plant again. Effect of rice husk ash on the raw mix of ordinary Portland cement clinker is the marked decrease of its lime saturation factor with decrease of C3S and increase of C2S contents of the produced clinker. This can form basis for the production of active high Pelite cement clinker. Three further advantageous effects for manufacture of active high belite clinker are decrease of evolved C0 2 from the raw mix, decrease of theoretical heat requirem~nt for clinker formation and decrease of the required clinkering temperature. Average weight of husk needed for complete substitution of heavy fuel oil in an Egyptian cement kiln plant has been approximated as 0.3 kg/kg clinker which corresponds to about 15 per cent of the raw mix weight. With such extreme amount of rice husk, lime saturation factor of the raw mix attains 78.6 and mineral composition of the clinker is 25.5 per cent C 3 S, 54.06 per cent C2S, 6.4 per cent C3A and 10.95 per cent C 4 AF. Theoretical heat requirement of clinker formation has been estimated in this case as 1627 kg clinker and the raw mix C0 2 emission as 0.:207 Nm 3 /kg clinker which are smaller than the corresponding values at zero husk percentage by about 12 per cent and 5 per cent respectively. For details, please log on to : aucbm@scs-net.org Courtesy: Cement & Building Materials Review, No.43 March 2011, Pp 44 - 45 Renewable Energy STRONGER POLICY FRAMEWORK REQUIRED TO ACHIEVE NAPCC TARGETS Mandvi Singh Increasing the share of renewables in the energy mix is one of the key objectives of the National Action Plan on Climate Change (NAPCC). The plan envisages setting up a dynamic minimum renewable energy purchase standard starting with 5 per cent in 2009- 10 and increasing this to 15 per cent by 2020. Achieving this target requires unprecedented capacity addition. As per the Ministry of New and Renewable Energy's (MNRE) draft report for the Twelfth Plan period, an annual addition of 6,000 MW is required to achieve the NAPCC target of 12 per cent renewable power in the energy mix by 2017. In order to achieve this target, major policy and regulatory changes are required . Plan targets versus NAPCC goals The NAPCC envisages a 12 per cent share of renewables in total power generation by 2017. Given that the total power generation during 2010-11 was 811 billion units (BUs) and assuming that this increases at the rate of 6 per cent annually (which is marginally higher than the 5.17 per cent compound annual growth during the past decade), the annual power generation during 2016-17 is expected to be 1,150 BUs. Therefore, as per the NAPCC's requirement, about 138 BUs will have to be produced from renewable sources in 2016-17. Even at an optimistic composite capacity utilization factor of 30 per cent for all renewable sources, the required installed renewable capacity at the end of the Twelfth Plan will stand at 55,000 MW. Given that the current installed renewable capacity is 20,556 MW (as of June 2011 ), the NAPCC target would necessitate an annual capacity addition of 6,000 MW (as per the MNRE's draft subcommittee reports for the Twelfth Plan). Against this, the MNRE'S renewable capacity addition target (according to its Strategic Plan for New and Renewable Energy Sector for the Period 2011-17 document) of 3,420 MW during 2011-12 and 18,280 MW during the Twelfth Plan falls short by a significant margin. The ministry's view that renewable energy can contribute only 10 per cent to the power mix by 2022 is way short of the NAPCC's requirements. However, the ministry is likely to revise these targets upward in the final Twelfth Plan document as is evident from the draft subcommittee reports submitted to the Planning Commission in July 2011. The draft subcommittee report on wind power envisages and addition of 10 GW in a conservative scenario, which increases to 15,000 MW and 20,000 MW in policy-induced and aggressive scenarios, respectively. The report on solar power endorses the Jawaharlal Nehru National Solar Mission's target of achieving 10 GW of capacity by March 2017. For biomass and cogeneration from all sources, the target is 4,250 MW, while for small hydro, it is 2,100 MW. This aggregates to an addition of over 25,000 MW in a conservative scenario, and increases by 5,000MW each 20 J )