Assessment Of Water Utilization Level In Petrochemical Enterprises

As the basic industry and pillar industry in our country, petrochemical industry plays an important role in the national economy. With the development of society and economy, the demand for petrochemical products is increasing, and petrochemical industry in China has been developing rapidly. Meanwhile, petrochemical industry is one of high water consumption industries. With the expansion of industrial scale, the contradiction between supply and demand of water resources has become increasingly remarkable, water shortage has been a major bottleneck which restricts sustainable development of petrochemical industry.Through comprehensive survey, this paper systematically studied the development of petrochemical industry and water utilization in China, and characteristics of water comsumpation and the level of water utilization in petrochemical enterprises. Based on these, combining with the relevant standards and experts’ advice, selecting assessment index and estabishing water assessment standard for petrochemical enterprise, and determine the water assessment index weights by using analytic hierarchy process(AHP) as well as entropy method. Finally, matter element analysis, gray relational analysis and fuzzy comprehensive evaluation are used to access the water utilization level of petrochemical enterprises. The main conclusions are drawn from the study as follows:(1) Based on the analysis of water utilization level of existing or new petrochemical enterprises(projects), the results show that water use indexes of some large-scale petroleum refining enterprises meet the requirement of water-saving enterprise. Quantity of water intake for per ton crude oil, recycle ratio and other major water use indexes are close to or at the international advanced level; Water use indexes of petrochemical project also comply with the provisions of assessment criteria. However, for rationality of the results of water utilization level, due to reasons such as assessment system is not unified, water assessment criteria is not perfect. Thus, there are some disadvantages in the analysis and the assessment of water utilization level of petrochemical enterprises.(2) Combined with assessment criteria, three comprehensive assessment methods can obtain the quantitated assessment results, which give an assessment of petrochemical enterprise’s water utilization level. The assessment results indicate that water utilization level of Zhenhai Refining & chemical is the highest. Yanshan Petrochemical is following; The lowest is Karamay Petrochemical, the Czech petrochemical is a bit higher than Karamay. The evaluation results of the water utilization level of Dalian Petrochemical and Shengli oilfield are changed by the different weighting methods and assessment methods, but better than the level of Karamay Petrochemical and Czech petrochemical.(3) Different weighting methods have a certain effect on the calculated results based on and fuzzy comprehensive evaluation. It leads to different assessment results; However, the calculated results are less affected based on gray relational analysis, the assessment results are consistent among petrochemical enterprises.(4) Compared with gray relational analysis method and fuzzy comprehensive evaluation method, the matter element analysis method has limitation to take a further assessment when objects are in the same rank. In addition, the calculation process of fuzzy comprehensive evaluation method is more complex.