水泥行业：能源效率和脱碳（EE-D）机会

ENERGY EFFICIENCY ANDDECARBONIZATION (EE&D)OPPORTUNITIES BCement Sector — Energy Efficiencyand Decarbonization Opportunities Cement is an important large‑scale manufacturing industry that contributes nearly 1 percent to Pakistan’sgross domestic product (GDP) annually and accounts for an estimated 25percent of all industrialprimary energy consumption.iEnergy contributes 60 percent to the total cost of cement production,and cement manufacturing in Pakistan relies on coal as the primary source of energy.iiMore broadly,cement manufacturing accounts for between 65 to 70 percent of industrial coal consumption and at least49 percent of the country’s coal emissions.iiiPakistan’s cement sector has 16 operational companies with27 operational plants across the country. Ten companies operate in the north of the country, three in thesouth, and three have production plants in both the south and north. The cumulative production capacitywas 77 million tons for fiscal year (FY)23. The subsector directly employs approximately 0.1 million people.The plants produce Ordinary Portland Cement, which is the main cement used in Pakistan. At 3.9GJ/tonneof clinker the average energy intensity of cement plants in Pakistan is close to the global average.1According to the country’s latest greenhouse gas (GHG) inventory, the process emissions from the cementsubsector accounted for 75 percent of total industrial process emissions in 2018.ivThis note describesdecarbonization interventions to improve energy efficiency and reduce emissions in the cement sectorwhile increasing industrial competitiveness and providing wider economic and environmental benefits. The current state of energy efficiency and decarbonizationin Pakistan’s cement sector Cement manufacture consists of multiple energy‑intensive processes including mining, crushing, rawmeal grinding, kiln rotation, clinker cooling, and packaging. Although the cost of coal makes up thelargest share of direct costs associated with cement production, a substantial amount of electricityis also used in various value‑chain processes. At 90.4 kilowatt hours per tonne (kWh/t), the averageelectricity intensity of local cement production is lower than the global average of 100 kWh/t. Incontrast, the average specific carbon emissions (both energy and process emissions) for local cementplants are 0.79 tonnes of carbon dioxide (CO2) per tonne of the product, which is higher than theglobal average of 0.6 tons of CO2per tonne of product. Reducing the quantity of clinker in cementby adding other additives like fly ash and blast furnace slag can abate process emissions from thecement subsector; The clinker‑to‑cement ratio in Pakistan is 0.95 while the global average was 0.72 in 2020. At 0.57 to 0.6, Chinese plants manufacture with the lowest clinker‑to‑cement ratio. Accordingto the International Energy Agency (IEA), the global average ratio of clinker‑to‑cement must decreaseto 0.65 by 2030 in order to meet net‑zero targets.v Existing & emerging opportunities for improving EE&D Several cement plants in Pakistan have implemented various energy efficiency and decarbonizationinterventions including adopting alternative energy sources, installing waste heat recovery (WHR) systemson kilns, replacing roller mills instead of ball mills (a modification known to enhance efficiency) and shiftingthe medium of the ball mill from steel to alumina. Energy efficiency and decarbonization in the cementindustry can be achieved through multiple additional pathways such as through the utilization of efficientmotors and control drives on motor driven systems, the use of distributed renewable energy (biomass orwaste for heat production in the cement kiln), fuel switching (green hydrogen for power and heat generation),electrification (electric heat kiln), carbon capture (capturing both process and energy emissions), processimprovement (alternative binders and clinker), circularity (recycling of concrete, use of slag, fly ash), andinnovative technologies (such as WHR on compressors, ORC on a kiln, and air‑cooler exhaust). Pakistan’s cement manufacturing industry can adopt existing and emerging technologies to reduceemissions impacts by 3 to 35 percent and decrease energy impacts by 6 to 20 percent. (See annex 1for a description of the most feasible existing and emerging technologies for the cement sector andannex 2 for the summaries of the analysis of five recommended existing and emerging technologiesfor the cement subsector.) Emerging technologies Exisiting technologies Carbon capture utilization and storage Low‑temperature waste heat recovery (whr)based on organic rankine cycle (orc) Globally up to 60 percent of the direct carbonemissions in the cement industry originate froma chemical reaction called calcination. Theseemissions cannot be avoided through energyefficiency measures or fuel‑switching options.Instead, a post‑combustion carbon capture storageand utilization (CCUS) technology will be neededto decarboniz