The 2010 annual outstanding engineering design awards of chemical industry selected by China petroleum & chemical engineering survey and design association has been announced on December 27, 2010. The 160kt/a pyrite-based sulfuric acid plant project of Panzhihua Dongfang Titanium Co., ltd. and the W-0801 system SO3 recycling and exhaust emission improvement project of Shijiazhuang Chemical Fiber Co., Ltd. which were undertaken by SCEDI won second and third prizes of 2010 annual outstanding engineering design awards of chemical industry respectively.
    Panzhihua Dongfang Titanium Co., Ltd. is a large-scale Titanium resource deep processing enterprise in west Panzhihua area. In order to solve the acid for titanium pigment production, it decided to build a 160kt/a pyrite-based sulfuric acid plan. After their comparison and selection, our institute was entrusted for the construction drawing design of this project, which including: 35000m2 plot plan design; 11950m2 civil design of buildings and structures; sulfuric acid plant process and equipment design; electric design for about 9300Kw installed capacity; thermal design for producing 21.5t/h（400 ℃ 2.6MPa）steam waste heat boiler; water supply and drainage design for equipments including 2500m3/h recycled water station; and the supported instrument design and budget.
    As it's the largest single series pyrite-based sulfuric acid plant in the southwest, in the design SCEDI project department summarized the advantages of foreign & domestic same-scale plants, and improved the traditional process. Under the premise of meeting the acid need for titanium pigment production, it processed the pyrite slag by section which greatly increased the market value of by-products, recycled the high and low thermal energy produced by installation reaction and fully considered the reuse of water resource, which greatly reduced energy and water consumption. Meanwhile, it increased environment management measures to the pollution caused by pyrite-based acid, which effectively increased the plant safety factor of environment protection and anti-risk capability. In short, the plant design combined the characteristics of titanium pigment production, gave full consideration to comprehensive utilization of the waste in the process design and equipment selection. It not only led the development trend of cyclic economy, and turning waste into wealth, greatly improved the enterprise efficiency.
    After more than a year of good operation and standard production, it proved: in the design it implemented the principle of advanced process and mature technology, adopt the advanced and mature process technology, and the main equipments used were mature and reliable which can achieve stable and long-term operation. The design met the requirements for safety, environment protection, water-saving, energy-saving and comprehensive utilization of resources. The “three wastes” emission and cleaning production met the requirements of related national standards, and the comprehensive design technology achieved the domestic leading level. Thus it granted full recognition by the owner. And it won the second prize of 2010 annual outstanding engineering design awards of chemical industry which was selected by China petroleum & chemical engineering survey and design association.
    Shijiazhuang Chemical Fiber Co., Ltd. introduced from abroad a set of 160,000 tons sulfuric acid/ fuming sulfuric acid plant for supporting the caprolactam production. As it will produce acid mist during fuming sulfuric acid production, they designed a complementary treatment installation for SO3 emission from tanks. Although it carried out a number of technological improvements from its running, the acid mist emission still cannot meet the standard. In order to achieve the national, provincial and group's requirements for corporation comprehensive management, environment improvement and sustainable development, after its careful comparison, it commissioned SCEDI to be in charge of the research and development of new process for acid mist tail gas emission to meet standard, and also construction drawing design.
    The technological characteristics and targets of the new process for this project includes:
To turn the SO3 gas and acid mist from fuming acid storage tank into dilute acid mist through venturi pipes. According to the mist particle size analysis, select the targeted demister to capture mist particles to achieve emission standard. The process resolved the problem about the mismatch of the fan flow and pressure head. While resolving the equipment manufacturing and anticorrosion of materials, the process flow was with advanced and feasible technology, less investment and small quantities.
    As the project using the new process, the acid mist concentration in the final exhaust gas (Shijiazhuang Environment Test Center) was: 7.23mg/m3, which not only achieved the research aim 40mg/m3, also was lower than national standard 45mg/m3.With the lowest energy consumption and cost, the project thoroughly solve the pollution caused by acid mist. It had a strong innovation in technology, achieving the aims of cleaning production and environment protection, and also being with safety, energy saving, comprehensive utilization of resources, cleaning production and economization on project investment.
     After the project completion, all the targets met or exceeded the design requirements, and it passed the acceptance for one time. The project runs well and stable for more than two years after its completion and acceptance, with normal production and reaching standard, which was received praise and full recognition from owner. Thus it won the third prize of 2010 annual outstanding engineering design awards of chemical industry which was selected by China petroleum & chemical engineering survey and design association.

 

Panzhihua East Titanium 160kt/a pyrite-based sulphuric acid project in producing and running(a part)