精细化工园区工艺过程VOCs产生量核算方法

Accounting Methods of VOCs Emission Associated with Production Processes in a Fine Chemical Industrial Park

挥发性有机物(VOCs)是目前影响我国大气环境质量的关键污染物之一.工业源已成为中国最主要的VOCs排放源,其中化工行业的VOCs排放贡献尤为突出.化工企业已经大量集聚于化工园区内,因此化工园区的VOCs控制至关重要.本研究以典型精细化工园区——杭州湾上虞经济技术开发区为例,通过分析精细化工生产模式及VOCs产生原理,建立了基于工艺过程的VOCs产生量核算方法,对投料、升温、化学反应产生气体带出、清洗吹扫、真空抽气、泄压释放和蒸发逸散等生产过程的VOCs产生量进行了核算;同时运用化工流程模拟软件Aspen进行了前述生产过程VOCs产生量估算;运用2种方法对案例园区14种典型产品各工艺过程的VOCs产生特征进行了分析,并对两种方法的核算结果进行了比较.结果发现,除泄压释放环节外,两种方法的结果差异在±22%以内.进而对该园区典型企业的代表性产品进行计算方法应用,可得到精准的VOCs产生关键环节和组分.案例研究表明这一方法在定量的化工生产参数支持下估算精细化工工艺过程的VOCs产生量具有较好的精准性、简便性和可靠性.

Volatile organic compounds(VOCs) are one of the key atmospheric pollutants associated with great impact on air quality. Industrial sources have become the most important source of VOCs emissions in China, of which the chemical industry accounts for a large part. At present, more than half of chemical manufacturers are clustered in chemical industrial parks(CIPs), thus the control of VOCs in CIPs is crucial. This study analyzed the production processes of the fine chemical industry and the principle of VOCs production, and then proposed an accounting model of VOCs emissions associated with production processes, based on a typical fine chemical industrial park: Hangzhou Bay Shangyu Economic and Technological Development Area(HSEDA). The quantity of VOCs generation in the main production processes, such as feeding, heating, chemical reaction gas take-off, cleaning, vacuum pumping, pressure release, and evaporating, were calculated. Meanwhile, the chemical process simulation software Aspen was also employed to simulate the VOCs generation in these processes. The methods were applied to 14 representative products in HSEDA and the feature of VOCs generation in the chemical processes mentioned above, and components were revealed. The results of the two methods were compared, and the difference between the two methods was within±22% except for the pressure release process. The model and accounting methods proposed in this study will have sound applicability in accounting for VOCs emissions in fine chemical industrial parks underpinned by quantitative chemical industry production parameters.