基于自下而上方法的中国水泥生产碳排放强度演变趋势分析

A bottom-up analysis of CO_2 emission intensity of Chinese cement industry

水泥工业减排是实现中国碳减排目标的重要组成部分,把握和理解中国水泥工业生产碳排放强度的演变趋势有助于评估和识别中国水泥工业的减排潜力和重点减排技术。水泥是社会经济发展所必需的基础性原材料,但中国水泥生产又是高能耗和高排放行业,使其成为政府和相关管理部门实施节能减排的重点关注之一。1981—2015年间,中国水泥消耗由8208万t急剧增长到234 800万t,占全世界总产量的一半以上,成为世界第一大水泥生产和消费国。本文利用节能减排成本曲线和技术普及趋势曲线,计算了16项水泥工业节能减排技术的节能减排潜力和普及趋势,并设计三种可能情景(基准情景、经济效率情景和技术情景),模拟了2015—2050年期间中国水泥工业碳排放强度的演变趋势。结果表明,到2050年,基准情景、经济效率情景和技术情景下中国水泥工业综合碳排放强度将分别下降至491kg CO_2/t、431kg CO_2/t和342kg CO_2/t。相比于IEA制定的2050年目标(420kg CO_2/t水泥),在技术情景下,中国水泥工业的碳排放强度将足够完成既定目标;而在经济效率情景下,中国水泥工业的碳排放强度离减排目标仍有11kg CO_2/t水泥的差距。这意味着,中国水泥工业若要实现IEA制定的减排目标,需要对各个过程的技术进行改进,重点应致力于针对工艺排放的减排技术路径,实施政府调控,能源或碳税机制等政策手段,是促进技术进步的重要推动力。

To tackle climate change, China has to curtail CO2 emissions from high-emission industries. An outlook of Chinese cement industry＇ s CO2 emission intensity would facilitate achieving national CO2 emission reduction targets. The cement industry is one of the basic industries of a country. Cement is the primary component of concrete and extensively used in construction activities. From 1981 to 2015, China became the biggest cement producer in the world since the cement consumption in China has increased from 82.08 to 2348 million tons. As China＇ s future urbanization requires cement, the Chinese cement industry is confronting an ambitious reduction target. Here we employed the conservation supply curve and the technology penetration curve to estimate the cost and penetration trend of each energy conservation and carbon reduction technology, based on which we developed three scenarios to simulate future trends in CO2 emission intensity of the Chinese cement industry. The results indicate that, up to 2050, the CO： emission intensity of the Chinese cement industry under basic, cost-effective, and technological scenarios will be 491,431, and 342kg CO2/ton cement, respectively. Compared to the target set in lEA, only the technological scenario would ensure this target, with a gap of 11 kg CO2/ton cement under the cost-effective scenario. From scenario analysis we conclude that the Chinese cement industry and related administrative departments should take action （such as, administrative regulation, energy tax, carbon tax）to further promote energy conservation and carbon reduction technologies and mitigate CO2 emission intensity of different processes. We also suggest several specific energy conservation and carbon reduction technologies to significantly contribute to CO2 emission reduction.