Dehydrated Activated Sludge (DAS) Project Proposal Shandong Tianli R&D Institute June, 2008
1. General 1.1 The company introductions Tianli Design & Research Institute is subordinated to Shandong Academy of Science and technically supported by certain universities and design firms such as Shandong University, Tianchen Design Institute, Shandong Light Industry Design Institute, Shandong Chemical Industry Design Institute and so on and so forth. It is a comprehensive technical company specializing in research, development, sales,design, manufacture, installation, training & consulting service in the fields of fuel alcohol, plant essence extraction, new building materials, the drying of the drilling mud s, the calcining and other technology concerned. 1.2 Background Introduction With the development of society, the demand for source of energy is increasingly rising. Petroleum is one of un-regenerated resource. The drilling muds coming from oilfield wastes is conventionally treated or disposed of by means of landfill. Some oil exploitation companies even leave the drilling muds untreated in the exploited pits, such practice causes the fuel oil in the pits to float on the land surface or infiltrate the underground soil. These drilling mud pits are many in reserve oil zone and they seriously destroy the local ecosystem, pollute environment and dirty hectares of farming lands. Even more worse, they seriously contaminate underground water and groundwater, threatening health and survival of local residents and living creatures. Moreover, this improper practice wastes enormous amounts of petroleum and results in drilling oil and hazardous waste water infiltrating underground soil more deeply. Therefore, it is necessary to explore a technology for cleaning up the drilling muds derived from oil exploitation in oilfield sites, environmentally disposing of the wastes in proper manner all the time. The drilling muds mainly come from the following situations: (1) Spilled oil, muddy slurry and oil water resulted from well-drilling process; (2) The oil well contains a lot of water, clay and sand at the final stage of oil production; 1
(3) At the bottom of oil storage tank, the accumulated deposit mud contains petroleum of different percentage. (4) Contaminated mud due to pipe leakage during oil transfer. 1.3 Industry and Market Environment The drilling muds mainly come from crude oil prospecting & exploiting or petro-chemical industry, with characteristics of enormousness in number, high oil rate, high percentage of heavy oil component, less ways to utilizing and difficulty in handling. The drilling muds have bad impact on quality of surrounding environment, being one of tricky problems as a solid waste to deal with. In view of present situation of its comprehensive utilization, it is lacking of further processing and utilizing technology with high added value; in view of long term development, the drying technique is still an effective way to treat it without pollution in a manner of resource-saving. At present, the common methods for dealing with the drilling muds both at home and abroad are incineration, biological disposal, washing, extraction, solid-liquid separation and coking. However, there are some problems arising in the above-mentioned methods and they are not suitable in real practices. For example, incineration demands a huge consumption of energy and it is easy to cause the secondary pollution; it will take 41 days to bio-degrade 97% of petroleum hydrocarbon from the drilling muds; extraction may result in a long process flow, complicated process and expensive charge and this method is only suitable for the drilling musds with amounts of organics hard to degrade; as for the solid-liquid separation method, it is low effective for seriously-polluted drilling muds. Therefore, all the methods mentioned above are not widely used across the world. Today, the most important thing is to look for a high-efficient and environment-friendly approach to disposing of the drilling muds. 1.4 Conclusion The rapid growth in crude oil demand across the world provides an opportunity for the promotion of this project. The paddle-dryer invented by our institute in 2
combination with Japanese technology is domestically at an advanced level in handling the drilling muds. Hence, this project is promising in market. 2. Product Manufacture and Process 2.1 Characteristics of drilling muds: Hydrous rate: normally between 50% to 90%; Oil rate: normally between 20% to 60%. Main chemical ingredients: clay, sand, petroleum, a great deal of cations such as Na +, K +, Ca +, Mg2 +, and Fe2 +, anions such as CL -, SO 4 2 -, CO 3 2 -, HCO - 3 and some ions of heavy metals. It also contains some organics and other solid wastes. 2.2 Process Flow Description 2.2.1 Process Description The wet mud will pass through the primary screw feeder and enter the primary paddle dryer. The dry drilling mud then flows to the secondary paddle dryer. Having been de-watered again, some dried mud should be mixed with wet mud and go back to the inlet of the primary paddle dryer through the screw feeder for returned material in order to achieve proper hydrous rate required by primary dryer; the other mud will enter the discharge chamber via the cooler and the discharging screw and be transported by dump trucks. Off-gas from the primary and secondary paddle dryers will be handled by cyclone separator. Particles will be separated and water will be collected by means of condenser. Before its entry into the atmosphere, off-gas should be further treated by stripper and active-carbon filter. 2.2.2 Processing technology route: 3
2.3 Production Equipment 2.3.1 Main production equipment Data sheet of production equipment item name item number remark 1 Paddle dryer unit 2 2 scrubber Unit 1 3 cyclone Unit 1 4 condenser Unit 1 5 Exhaust fan Unit 1 6 Activated carbon Unit 1 absorber 7 Cooling and discharge unit 1 screw 2.3.2 Paddle dryer description: One of the most impressive strengths of the paddle dryer lies in its high efficiency in heat transfer and capability of continuous run. Two main shafts of the paddle dryer are mounted with two wedge-shaped staggered hollow paddles. The paddles and the jacket to the dryer will be filled with heat transfer medium (steam, hot oil or hot 4
water). The material, moved forward and turned over by thrust of paddles and gravity, is kept contacting with the hot inner wall of dryer to achieve the purpose of dehydration. This type of paddle dryer, developed by us on basis of years practice, can effectively dehydrate materials in forms of paste, pellet or powder. This equipment largely raises the heat transfer efficiency mainly through partial agitating, mixing and cleaning function, and the material s dry quality is stable. In addition, this equipment also has the little air displacement, when exhaust it can remove completely and so on merits. It is one kind of chemical equipment that has highly effective low consumption, compact structure and convenient service. 2.3.3 Working Principle: As shown in the chart, there are two parallel axes which have interleaving paddles. Each axis has hollow sector paddles which are arranged along a certain gap. There are two kinds of paddles: feed shear plane and return shear plane, the axis rotates at low speed. A heating medium enters the hollow rotary axis and paddle through a universal revolving joint. After heat transfer and drying, it is discharged through the revolving joint. The material is continuously fed into the equipment, next it is agitated and mixed near the paddle. At the same time, the material is gradually dried by the heat conduction of paddle and jacket. The height of overflow weir can be changed to adjust residence time. In addition, steam produced in the drying process is discharged through the escape hole with little air. 2.3.4 Paddle dryer technical norms: spec CD-400 CD-500 CD-600 CD-800 CD-1000 Transpiration 151 216 288 528 1057 thermo-axis diameter 400 500 600 800 1000 Effective volume 0.51 0.89 1.42 3.56 8.08 Heat transfer area 12.4 18.4 25.3 47.2 95.12 Installed power 5.5 7.5 11 22 45 2.3.5 Equipment merits: 5
(1) The wedge-shaped paddles are self-clean, effective in heat transfer and utilization. (2) The hot air doesn t act as the heating medium, but as the moisture carrier in small number. In such a case, it is easy to prepare, reducing the investment. (3) A variety of material can be handled by this machine with good drying performance. (4) It can function both as a dryer and a cooler. Because of its small size and fast cooling result, it has been successfully applied in cooling process of ash soda and products free from sodium. (5) This machine is compact in structure, occupying small room. (6) Great heat transfer coefficient. Through paddle blade which has march, return function, can promote the partial agitation, e mixing nearby the oar s heating surface, the heat transfer coefficient also can increase (1) The self-cleaning function of the heat transfer surface is good (2) The product quality is stable (3) The material loss is small, the product recovery rate is high. (4) The material adaptability is broad, the product is dried evenly. (5) It can combine drying and cooling together. 2.3.6 Production Area Arrangement The production zone arrangement shall conform to the requirements for process, construction, hygiene, fire protection, personal protection, transportation and land saving, making full use of the geographic advantage and dividing distinctly based on functions. The various piping should be neatly-arranged, accessible to production in nice style. Short-term construction should be combined with the long-term development. The greening design should be taken into account. According to the whole process flow, the production zone is divided into section of power, section of the raw material, section of operation and section of office administration. The supply for power and steam should be accessible to the main workshops as close as possible. The production zone should have the circular fire passages and water supply-drainage lines. 6
2.4 Environmental Protection and Safety Production 2.4.1 Environmental protection standard The emission of noise, dust and etc. should strictly conform to the local emission standard. The two-level dust removal is adopted in the project, which can meet the requirement of emission. In order to beautify the environment, bushes, hedgerows and lawns are neatly lined in this plant as well as some bamboos and pine trees. On both sides of the roads tall trees are lined to reduce emission of dust and noise. Besides, we make full use of planned land and plant the greening belts for cleaning the air and improving environment. The noise generated from the equipment can meets the relevant requirements. It is required that the silencer, damper or the sound shield should installed for those facilities beyond the emission standard. 2.4.2 Safety Production (1) The raw material in workshop should be looked after by someone and stored in dry, cool and well-ventilated shade area. (2) The handing and receiving of the raw material should need the signature from the two person involved. (3) When the operators and other personnel enter the workshop, they are not allowed to carry the matches, the cigarette lighter and other flammable objects. (4) The personnel entering the workshop are not allowed to wear shoes with nails; (5) When knocking or striking with tools, we should prevent from the spark arising and it is suggested that we should use the wooden hammer or the rubber hammer. (6) Prior to the overhaul or cold repair, some precautionary measures should be taken inthe workshop. (7) Handle the iron barrels or other objects with cautiousness so as not to generate sparks; (8) Prior to any repair or open fire operation like the welding work, the place shall be cleared. After that, it should be approved by the relevant authorities. Besides, the fire protection facilities and apparatus should be prepared at hand. 7
(9) Fire fighting apparatus should be stored at a fixed place, accessible to handle with. It should be checked every week and replaced with the new one if necessary (10) The electrical appliance should be the explosion-proof and checked regularly. Its status must be clarifies during proceeding of shift handing-over. The workshop leader should be reported immediately when something wrong happens. (11) No smoking or opening fire work is allowed between the space of 30m around workshop. (12) The operators must wear the protective clothing according to the regualtions (working uniforms, gloves, eyeglasses and so on) (13) The workshop must keep clean and neat and the flow of personnel and material should be orderly without mess. (14) If anything wrong to the equipment or parts within the workshop is noticed, it should be reported promptly to relevant personnel. Actions should be taken carefully.. 3. Training and Service Tianli R&D Institute can provide the services involving design, manufacture and process optimization, upgrade and innovation for treatment system of drilling muds with capacity between 200ton/year to 7200ton/year. Besides, we can design related sets of systems according to capacity required. Meanwhile, we will furnish complete technical support and service, responsible for on-site installation, commissioning and training to site operators from the customer. 4. Economic Benefit Analysis The new generation of treatment system of drilling muds developed by us is of low energy consumption, high thermal effect, less operating and maintenance charges. This drilling mud treatment system economically and environmentally excels the other one in the same field with high financial profit and short period of investment return. 8