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Feasibility study on China‘s mercury-free catalyst R&D. FECO/ MEP /China Oct ober, 2011. Dr Sun Yangzhao. Content. PVC industry development s and mercury management status in China Project background and progress Mercury pollution control policies Difficulties and challenges Next steps.
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Feasibility study on China‘s mercury-free catalyst R&D FECO/ MEP/China October, 2011 Dr Sun Yangzhao
Content • PVC industry developments and mercury management status in China • Project background and progress • Mercury pollution control policies • Difficulties and challenges • Next steps
1.PVC production and mercury management in China • PVC plastic is widely used in industry, agriculture, national defense and chemical construction materials, etc in China. • Chinese PVC production can be divided in two categories: carbide method and ethylene method. • For the carbide route, CaC2 is used as raw material, and activated carbon with HgCl 2 serves as catalyst for the production of VCM which will be further used to make PVC. Table 1: PVC Data for China 2009 (Source MIIT, 2010)
Mercury in carbide based process • Currently for one ton PVC produced in China: • 1.2 kg of HgCl 2 catalyst consumed on average (as 11% of HgCl 2 content). • For 5.8 million tons of PVC produced in 2009, around 7000 tons of mercury catalyst used, comprising: • 770 tons of HgCl 2 and 570 tons of mercury were used (MIIT, 2010) • Carbide-based PVC production consumes around 60% of China’s total annual mercury use.
HCl HCl composition VC composition Compound absorption Compression distillation Hg remover Monomer tank acetylene process C2H2 Hg absorbed activated carbon Hg bearing waste acid worn catalyst potential mercury pollution source Mercury flow chart in carbide PVC production
Catalyst Effectiveness • Sublimation and intoxication causes reduction of catalyst effectiveness. • When it decreases to certain level, catalyst need to be replaced and inactivated catalyst becomes worn catalyst. • Usually waste catalyst contains 3-4.5% mercury. • After Hgremover, part of the sublimated HgCl2 will enter the worn acid and alkali and get emitted.
Necessity of carbide process Carbide PVC production uses lots of mercury, but it remains necessary: • Chinese energy structure characterized as "lack oil, poor in gas and rich in coal" • Ethylene method can hardly meet the need of PVC industry alone • Carbide PVC industry pays high attention to mercury pollution administration.
Emission reduction measures for carbide PVC production The industry has adopted the following measures to reduce mercury use and emissions: • low mercury subsititute for high mercury one; • activated carbon in mercury remover to absorb mercury in gas phase; • waste acid recycled by desorption device, a few of which are used to neutralize worn alkali; • waste alkali used to neutralize waste acid, and collected together with other waste liquid for central treatment; • waste catalyst, activated carbon and other waste sludge are sent to certified orgnization for central treatment.
2. Project background and progress • UNEP has provided funds for China to carry out PVC project through small grants program. The project is now on its second phase. • Phase I“Communication and Deliberation of the Practice of Mercury Use and Emission Reduction during PVC production” agreement was signed in January of 2009. • Phase II“Feasibility study on China‘s mercury-free catalyst R&D ” agreement was signed in April of 2011.
Target and Research Results of Phase I Phase 1 - Overall Target:To reduce mercury use in Chinese PVC industry Duration:From Jan. 2009 to Sep. 2009 Activities and results: • Organization of “Workshop on Mercury Reduction in Carbide PVC Production” • Investigation and study on mercury use and reduction status in Chinese PVC production by acetylene • Analysis of administrative and policy needs mercury use in this industry.
Target and Progress of Phase II Phase 2 Overall Target - To promote mercury free catalyst development and use in VCM production. Implementation duration:April 2011-December 2011 Main activities: • Organization of “Project workshop on Mercury free catalyst development feasibility”; • Develop a feasibility study report on mercury-free catalyst research and development, including identification of near-term and long-term activities.
Project workshop on Mercury free catalyst development feasibility, 19-20 September 2011 • Approximately 40 participants from Chinese government and industry, representatives from the international community • Agenda: • International mercury convention negotiation process • China PVC industry update • Updates of mercury-free catalyst R&D home and abroad • Outcomes: • Exchange of ideas on demands for and challenges to develop mercury-free catalyst technology. • Expert team proposed draft criteria for a peer review process.
Wide-spread use of low Hg catalyst By adoption of low Hg catalyst, mercury removal and centralized treatment of waste, producers are able to meet the national emission limit requirements.
Mercury free catalyst R&D progress • Currently, carbide PVC producers are working with research institutes on following research: • to carry out acetylene VCM fluidized bed technology, i.e. mercury-free catalyst, supportive process, reactor. • catalytic system of hydrogen chloride of acetylene to produce VCM; R&D of gas-liquid mercury-free catalyst. • enterprise-based mercury-free catalyst R&D and engineering pilot platform is taking initial shape.
2007 – Industry restructuring directory list (2007) specifies HgCl2 catalyst under restricted category. • Encourages oxychlorination of ethylene to replace carbide method; • For new, modified or expanded PVC installation must reach the scale of over 300,000 tons a year. • 2009 – MEP released clean production standards for chloralkali industry (carbide PVC), which specifies technological requirements to produce VCM in a clean manner. • April 2011 – 12th Five Year Plan for Comprehensive prevention and control of heavy metal pollution was approved and promulgated by the State Council (applies to lead, mercury, cadmium, chromium and arsenic). 3. Relevant industry mercury pollution control policy
2009 MEP Clean Production Standards for Chloralkali Industry (carbide PVC) Clean Production Auditing Standard
Notification on Enhancing Hg Pollution Prevention and Control in Carbide PVC industry. • Issued by MEP - January 19 2011 • Purpose was to enhance pollution prevention and control management framework in carbide PVC production, Hg catalyst production and treatment of worn catalyst. • Notification requires: • Increased awareness of the importance of pollution control in carbide PVC production • Promotion of low Hg catalyst and effective reduction of Hg emissions • Tighter environmental management and strengthened monitoring measures • Strengthened policy support and supportive measures • Increased role of industry association in education and training.
Hg and Hg compound bearing waste or polluted waste are already listed into State Hazardous Waste List • MEP is formulating Hg bearing pollutant prevention and control technical policy, which includes worn Hg catalyst. Hg bearing waste management
Difficulties and Challenges Ahead (1)Legislation and Enforcement • inadequate force in industry restructuring as well as in promoting and applying new reduction technology and new material • administrative weakness in mercury and HgCl2 catalyst production and supply • production operation needs to be standardized. (2) Capacity • basic situation and understanding is not clear • lack of monitoring/surveillance of mercury discharge.
Difficulties and Challenges Ahead (3)Technology • Application of low-mercury technology needs to be further improved and researched • Need of alternative techology: • mercury-free catalyst is still under research and development • economic and other effects of application need to be taken into consideration before wide-scale adoption. • HCl desorption is only partly applied among enterprises.
Difficulties and Challenges Ahead (4)Financing • involves a wide range and large number of enterprises • most enterprises are small-scale with limited profit margins • alternative technologies are highly specializedand expensive. As a developing country, China is facing huge shortage of labor-power, material and financial power.
Next steps for Carbide based PVC Production Phase1 (Jan 2010~Jan 2012) Activity 1:Raise understanding of mercury pollution risks amongst local environmental protection bodies and industry. Activity 2:Develop emission inventory. Activity 3:Study the evaluation and application standards of low-mercury and non-mercury catalyst. Activity 4:Set up reduction plan and targets across PVC industry. Phase 2(Jan. 2012~Dec.2013 Activity 5: Research mercury alternative technology and pilot application, apply mercury reduction measures and standardize administration. Activity 6: Initiate assessment and operation guidance for above.
Conclusion Although the Chinese central government has paid a lot of attention to mercury pollution prevention and control in the VCM sector, it is still facing a lot of difficulties and uncertainties with spreading information on the low-mercury catalyst and the researching & development of free-mercury catalyst. We hope for more support, including finance and technologies from developed countries!
Acknowledge • Special thanks extended to the following: • Chemicals Branch, DTIE of UNEP • Department of International Cooperation, MEP • Department of Pollution Prevention and Control, MEP • Chemical Registration Center, MEP • China Petroleum and Chemical Industry Association
Thank you for your kind attention ! Email: sun.yangzhao@mepfeco.org.cn