BTEC商检 吴倩莹 第二份工业化学

Guangdong Institute of EducationBTEC CenterProgram: HND in Applied ChemistryUnit Title: Industrial ChemistryUnit No: 14Assignment Title: Sulfonation and Drying Processes inSynthetic DetergentsAssignment No.: IIIssue Date: May 25, 2010Submission Deadline: June 28, 2010Assessor/Tutor: Zuoyi Chen and Zhaoxia DengInternal Verifier: Wei YinStudent: Qianying WuStudent’s Reg. No: B876546NOTES TO STUDENTS●Check carefully the submission date and the instructions given with theassignment. Late assignments will not be accepted.●Ensure that you give yourself enough time to complete the assignment by the duedate.●You must take responsibility for managing your own time effectively.●If you are unable to hand in your assignment on time and have valid reasons suchas illness, you may apply (in writing) for an extension.●Failure to achieve a PASS grade will results in a REFERRAL grade being given.●Take great care that if you use other people’s work or ideas in your assignment,you properly reference them in your text and any bibliography.●When you refer to the work of other authors in your assignment, you mustpractice citation by following Harvard System for Referencing.●If you are caught plagiarizing, you could have your grade reduced to zero, orat worst, you could be excluded from the course.STUDENT’S DECLARATION:I confirm that this is all my own work.Student Signature: Qianying WuASSESSMENTNotes:Assignment DescriptionScenarioOriginal soap was an ancient detergent, which was a mixture of melted animal fat or tallow and wood ashes into the clay soil along the Tiber River. The early soap used for treating skin diseases, as well as for washing. For the sake of improving scourability and enhancing other performance, chemists researched synthetic detergent for soap’s substitute.Synthetic detergents are used for household cleaners, such as washing powder, cleanser essence or sanitary ware agent. Certainly, Synthetic detergents are essential for electroplating, metal surface treatment, oil drilling, leather treatment etc. The world production of laundry detergents amounted to 21,500,000,000 kg in 1998. And the worldwide total produced volume remained increasing steadily.A number of undesirable problems come with largely using of synthetic detergents. For example, phosphates in the ingredients cause eutrophication of water. And some of organic ingredients, such as branched alkyl sulfonates, could not be degraded by bacteria because of the highly branched side chain. Therefore, many important new criterions, the so-called biodegradability of detergents, appeared for surfactants.To achieve the assessment criteria for pass (P14) you must demonstrate the ability to: ●Discuss factors affecting the selection of a chemical process for the product●Examine physico-chemical aspects of an industrial processThis can be achieved by completing the following tasks in accord with established guidelines.Tasks1.Describe the flow of sulfonation processes to the alkylbenzene sulfonates inmanufacturing synthetic.2.Evaluate the key parameters of the reaction. And describe and analyse the influence of required post-reaction separation and purification processes. Evaluate the impact of co- and side-products on the overall profitability of the process.3.Explain the spray-drying process in manufacturing detergents in details. Anddescribe impact on environment.Questions1. What is the process of alkylbenzene sulfonate of producing?The process of alkylbenzene sulfonate of producing is first the sulfonation of alkylbenzenes leads to sulfonic acid tyre product, which is then neutralized with a base such as sodium hydroxide to produce sodium alkylbenzene sulfonate. The sulfonation reaction is highly exothermic and instantaneous. An efficient reactor heat removal system is used to prevent the decomposition of the resultant sulfonic acid. The sulfonation reaction takes place by using oleum (SO3H2SO4) or sulfur trioxide (SO3). Although, the oleum sulfonation requires relatively inexpensive equipment, the oleum process has major disadvantages compared to sulfur trioxide. The need for spent acid stream disposal and the potential corrosion owing to sulfuric acid generation increased the problems related to oleum process:The gaseous air or SO3sulfonation process leads to high yields ofsulfonic acid (95% to 98%). This process comprises three major steps. The sulfonation of alkylbenzene with air or SO3forms the alkylbenzene sulfonic acid and anhydride. The latter is decomposed into the alkylbenzene sulfonic acid by hydration. The neutralization of the sulfonic acid into the corresponding sodium salt represents the last chemical step in the process of formation of detergents:2. What are the key parameters of the sulfonation process of the alkylbenzene sulfonate?The key parameters of the sulfonation process of the alkylbenzenesulfonate as follows:●Temperature,●Acid strength,●Reaction time,●Oleum-to-alkylate ratio.The reaction was completed at the digestion stage where the product from the sulfonation zone is aged for 15 to 30 min. The mixture of sulfonic acid and sulfuric acid is diluted with water to quench the reaction. The reaction mixture is sent to a separator to allow gravity settling of the spent sulfuric acid from the lighter sulfonic acid. The lower spent acid layer contains, approximately, 75% to 80% sulfuric acid. The upper layer contains, approximately, 88% to 91% sulfonic acid and 6% to 10% sulfuric acid.3. How to separate and purify the surfactant?●Extraction●Crystallization and precipitationUsing the sample components in a component in the difference between Solubility, make some of the components to generate crystals from the solution separated. This ia an effective way to purified material.●Foam chromatography4.How to dry the slurry of synthetic detergents? And what the thermodynamics anddynamics factors should be taken into account in the unit operation? And what are the impacts of synthetic detergents on resource demand?Spray drying is the main manufacturing process of hollow granular detergent, the process is: to pump slurry from the high-pressure spray tower, through the spray nozzle in order, wherein the mist below. From the tower bottom plate of hot air through the guide entry tower, was rotating towards the top. Countercurrent two met by heating and drying the slurry. Because powder Tata height of the slurry and the hot air heat exchange for a long time by preheating the slurry droplet, surface evaporation, diffusion and cooling within the aging process, which can form hollow at the bottom of the column granular products. Tower bottom product through screening, separation of bulk materials (commonly known as the head of powder). Tower exhaust the powder with a cyclone recovery, and finally discharged into the atmosphere through the tail fan. We can see as the followsFig.1. Spray-drying process.●And we should concerned about the slurry is sprayed through nozzlesinto the tower at pressures of 4.1 to 6.9 kilopascals (kPa) in single-fluid nozzles and atpressures of 340 to 690 kPa in 2-fluid nozzles. Steam or air is used as the atomizing fluid in the 2-fluid nozzles. The slurry is sprayed at high pressure into a vertical drying tower having a steam of hot air at 315 to 4000C. The dried powder flows off the tower at a temperature of 90 to 1000C.●Need from the product shape, relative density, color, odor, foam untilthe packaging design seminar. Such as washing powder, required an appropriate particle size, uniform, no lumps, color white, no bad smell, fluid, depending on the proportion of stability, solubility, etc.; on the liquid detergent, you need to study the transparency or opacity, consistency, stability, color, smell and so on. Whether washing theskin stimulation, feel such a system.Reference1.Pengfei Yan，Wenhui Hao，Ting Gao.Fine Chemicals Chemistry,ChemistryIndustry, 2004.2.Lubo Cheng，Jiazheng Hu，Mengzheng Yao，Kunyu Gao.，The synthesis of finechemical products and applications,Dalian University of Technology Press，1995.3.Mohammad Farhat AIi, etc. Handbook of Industrial Chemistry (OrganicChemicals) .2005.4. Chenier Philip. Survey of Industrial Chemistry (Third Edition). 2002.。