年产1500吨甲硫醇钠的生产工艺设计+文献综述(3)
2 Design principles
The design principles include: product quality control indicators, safety, convenient operation, investment, convenient installation.
In this design by consulting related literature, sodium methyl mercaptide process route of synthesis and production process are determined; and for an annual output of 1500 tons of sodium methyl mercaptide synthesis design tasks are related to the material balance and heat balance calculation, complete the reactor, condenser, absorption tower design and type selection of main equipment, storage tanks and related auxiliary equipment. Using AUTOCAD software to process flow chart with control points, workshop equipment layout, reactor assembly design and elevation layout based on the selection, and compile the design specification.
3 Introduction of process
(CH3)2SO4 NaHS、Na2CO3 NaOH
↓ ↓ ↓
reaction → Na2CO3 → NaOH absorb → gas absorb
↓ ↓ ↓ ↓
intermediate intermediate product spoil disposal
CH3SH CH3SH CH3S Na
Sodium methyl mercaptide synthesis technology: from a cost perspective, is now generally used for chemical reaction of sodium hydrosulfide solution of sulfuric acid methyl two drops to a certain temperature, temperature control in about 60 ° C, the discharged gas purification by using liquid absorption. System at atmospheric pressure or negative pressure condition, after reaching saturation content reached about 20%. In this process, a by-product of Glauber's salt, sometimes also can produce by-product two ether.
The main chemical reaction equation: 2NaHS+ (CH3) 2SO4 → Na2SO4+2CH3SH ↑
CH3SH+NaOH → CH3SNa+H2O
4 process calculation
material balance
In the whole process of design, first by using the method of target output are calculated in the actual production of feeding quantity. According to the daily feed consumption material configuration. According to the process, material balance is pided into the following three parts: the methylation reaction, the absorption of Na2CO3, NaOH absorption process. Calculation for each part of the feed, discharge, and the mole number, volume and the corresponding data. The product quantity estimation loss due to the quality of the products, the budget.
The material balance time, every step of the calculation must be very careful, because every step of the reaction of the quantity of material and a response of the quantity of material are related, so once a link which calculation errors, then the mean is likely to calculate all the back to carries on the computation, it will need to spend a lot of time.
heat balance
Heat balance is also we design a major part of the task book.
Heat balance calculation includes four parts: heat, alkali accounting with methylation reaction process, the heat of the condenser change, Na2CO3 absorption, NaOH absorption process heat calculation. Through the application of the Karachi formula for calculation of heat balance of reaction heat, heat capacity and heat of combustion data through the "chemical process design manual" and the corresponding formula for estimating. To calculate the production process energy consumption indicators, with advanced production technology selected.