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再现优灵

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[交流] 救助！翻译！

那位高手帮忙翻译一下这篇文献啊！先谢谢了！
Satish Lele
E Mail : satish.lele@gmail.com / lele@vsnl.com
Web Site : www.svlele.com

Trans-Estrification BioDiesel Process
Reaction raw materials :
Jatropha Oil
Methanol (CH3OH) 99%+ pure
Pottasium hydroxide (must be dry)
Materials for Titration :
Isopropyl alcohol 99%+ pure
Distilled water
Phenolphthalein solution (not more than a year old, kept protected from strong light)
Materials for Washing :
Vinegar
Water
Manufacturing Process
Jatropha oil is filtered to remove any solid particles.
Jatropha oil is then heated to remove any water content (optional).
Titration is done to determine how much catalyst is needed.
Exact quantity of Potassium Hydroxide is then throughly mixed in Methanol till it disolves completely to get potassium methoxide.

Jatropha oil is heated if required (during winter), and mixed in the potassium methoxide while with agitator running.

It is then allowed to settle and glycerine is removed from bottom.
BioDiesel fraction is then washed and dried.
It is then checked for quality.

In transesterification, KOH and methanol are mixed to create pottasium methoxide (K+ CH3O-). When mixed in with the oil this strong polar-bonded chemical breaks the transfatty acid into glycerine and ester chains (biodiesel), along with some soap if you are not careful. The esters become methyl esters. They would be ethyl esters if reacted with ethanol instead of methanol.

PROCESS in DETAIL
Filtering : Filter the oil to remove solid particles. You may have to warm it up a bit first to get it to run freely, 35oC should be enough. A Cartridge filter is used for the same.

Removing the water : Heat the oil first to remove any water content. Waste oil will probably contain water, which can slow down the reaction and cause saponification (soap formation). The less water in the oil the better. Raise the temperature to 100oC, hold it there and allow any water to boil off. Run the agitator to avoid steam pockets forming below the oil and exploding, splashing hot oil. Or drain water puddles out from the bottom as they form, you can save any oil that comes out with the water later. When boiling slows, raise the temperature to 130oC for 10 minutes. Remove heat and allow to cool.
Regular source of oil does not need to have the water boiled off, in which case do not do it, boiling means extra energy and time.

Basic titration : Dissolve 1 gram of KOH in 1 liter of distilled or de-ionized water (0.1% KOH solution). You can use phenolphthalein solution to get end point. In a smaller beaker, dissolve 1 ml of dewatered oil in 10 ml of pure isopropyl alcohol. Warm the beaker gently by standing it in some hot water, stir until all the oil dissolves in the alcohol and the mixture turns clear. Add 2 drops of phenolphthalein solution.
Using a burette, add 0.1% KOH solution drop by drop to the oil alcohol phenolphthalein solution, stirring all the time, until the solution stays pink (magenta) for 10 seconds. Take the number of mls of 0.1% KOH solution you used and add 5.0. This is the number of grams of KOH you will need per liter of oil.

Test batches : The first few times you do this process, it is a good practice to first try out your KOH amounts on a 1 liter batch. This works really well and you do not need to heat up the oil too much, just enough so it will spin well. Start by mixing up the exact quantity of KOH and 200 ml of methanol. First make sure that vessels used are dry. Forming the exothermal potassium methoxide polar molecule will heat up the vessel a bit. Keep mixing until all the KOH has been dissolved.
Once the potassium methoxide is prepared, add to 1 liter of oil. Make certain all your weights and volumes are precise. If you are unsure of the titration result then use 5.0 grams of KOH per liter of oil. Smaller batches need only be run for about 15-20 minutes for separation to be completed before switching off. The settling takes some time to complete. The solution can be poured from the vessel into another container right after switching off the agitator. It is good to do a few batches with varying amounts of KOH recorded, so later when checking results one can choose the KOH quantity that did the best job. When too much KOH is used the result can be a troublesome gel that is tough to do anything with. When not enough KOH is used the reaction does not go far enough so some unreacted oil will be mixed with the biodiesel and glycerine. This will form three levels with biodiesel on top above unreacted oil with glycerine on the bottom. If there is too much water in the oil it will form soaps and settle right above the glycerine forming a fourth level in the container. This layer is not too easy to separate from the unreacted oil and glycerine layers.

Preparing the potassium methoxide : Generally the amount of methanol needed is 20% of the Jatropha oil by mass. The densities of these two liquids are fairly close, so 20% of methanol by volume should be about right. To be completely sure, measure out a half-liter of both fluids, weigh, and calculate exactly what 20% by mass is. Different oils can have different densities depending on what type of oil it originally was.
When transesterifying 100 liters of Jatropha oil, use 20 liters of methanol. The methanol is mixed into a solution with the KOH, creating potassium methoxide in an exothermic reaction (it gets warm from bonds forming). Keep all utensils the KOH comes in contact with as dry as possible.
CAUTION : Treat pottasium methoxide with extreme caution! Do not inhale any vapors! If any pottasium methoxide gets splashed on your skin, it will burn you without your feeling it (killing the nerves). Wash immediately with lots of water. Always have a hose running when working with pottasium methoxide. Pottasium methoxide is also very corrosive to paints. KOH reacts with aluminum, tin and zinc. Use glass, enamel or stainless steel containers, stainless steel is best.

Heating and mixing : Pre-heat Jatropha oil 48-54oC. A full speed propeller coupled to a electric motor works fine as a mixer. Too much agitation causes splashing and bubbles through vortexing and reduces mix efficiency. There should be a vortex just appearing on the surface. Adjust the speed, or the pitch or size of the stirrer to get the right effect. Alternately an electric pump plumbed to form a mixing loop for stirring the oil would do a nice job. Mount the pump above the level that glycerine will gel at, to prevent clogging up the pump.
Add the potassium methoxide to the oil while stirring, stir the mixture for 50 minutes to an hour. The reaction is often complete in 30 minutes, but longer is better. The transesterification process separates the methyl esters from the glycerine. The CH3O of the methanol then caps off the ester chains and OH from the KOH stabilizes the glycerine.

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自信没什么不可以！！！

1楼 2010-04-27 13:11:52

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xxsst888

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再现优灵(金币+50, 翻译EPI+1):还有一些，麻烦一起翻译完啊！ 2010-05-02 22:05

题目生物柴油酯化转移反应过程
反应原材料：  麻疯树属油，  甲醇》99% ，干燥的氢氧化钾。
用于滴定的物质：异丙醇》99% ，蒸馏水，时间不超过一年的酚酞溶液（避光保存）。
用于洗涤的物质：醋，水。
制造过程：把麻疯树属油过滤以除去固体杂质
         麻疯树属油加热以除去水分（选择操作）
         用滴定法确认催化剂的用量
         甲醇与氢氧化钾精确混合获取甲醇钾盐
         如有必要，可先把麻疯树属油加热，然后在搅拌下加入到甲醇钾盐中，
         静置后从底部除去甘油。
         对生物柴油那部分洗涤，干燥。
         检测物品。
在酯基交换反应中，混合氢氧化钾和甲醇形成甲醇钾盐（K-CH3O),当与麻疯树属油混合时，甲醇钾盐的活泼极性键把反式脂肪酸裂解成甘油和酯链（生物柴油）。但操作不慎时，会有皂化现象。
酯将变为甲基酯，若用乙醇代替甲醇时，酯就变成乙基酯。
具体步骤：
用筒式过滤器过滤麻疯树属油以除去杂质。也可把油先加热，但别超过35度。
去除水分：把油加热去除水分。油中的水分越少越好。水分能使反应变慢而且还会产生皂化副反应（形成肥皂状物）。在搅拌下，升温到100度，同时注意防止油层下面产生蒸汽泡以至使热油喷溅出来，及时把水泡物从瓶底排空。但沸腾变慢时，升温到 130 度，保持 10 分钟，撤除热源，自然冷却。
一般来说，从消耗能源和时间的角度考虑，能不用加热除水则不用。
滴定：
在 1 升蒸馏水或去离子水中溶解 1 克氢氧化钾（0.1%KOH溶液），用酚酞溶液来确定滴定终点。把 1 毫升麻疯树属油和 10 毫升纯异丙醇放入一烧杯里，放在水浴中慢热，要不停地搅拌直到混合物变为透明（油已完全溶解在醇中），然后滴加两滴酚酞溶液。
使用滴定管一滴一滴地把0.1%氢氧化钾溶液滴加到油-醇-酚酞混合液中，并且要不停地摇动直到溶液变成粉红色，保持 10 分钟，记下氢氧化钾溶液的使用量后，再加 5，将此数作为每升麻疯树属油中所需氢氧化钾的使用量。
实验批次：
最好从 1 升麻疯树属油开始。定量地把氢氧化钾混合在甲醇溶液中，操作此过程时，所用的容器必须为干燥。形成甲醇钾盐极性分子时放热直到氢氧化钾完全溶解。
在精确计量下把做好的甲醇钾盐溶液加到 1 升的麻疯树属油中（如果不能确定滴定结果，也可直接加 5 克的氢氧化钾到 1 升的麻疯树属油中）。小批量的实验只需要 15 分钟，停止搅拌，把溶液倒入另一个密闭容器中，静置沉淀。
最好用不同量的氢氧化钾做几个批次以发现氢氧化钾的最佳用量。因为氢氧化钾过量，可产生难以处理的胶状物，氢氧化钾不足时，反应进行的机会不充分，麻疯树属油与生化柴油及甘油混合在一起，容器内将有三层：生化柴油在最上面，未反应的麻疯树属油位于中间而甘油位于最下面。如果麻疯树属油中还有水的话，肥皂似的沉淀物将位于甘油层之上。在一个容器中形成四层，而且，这一层还极难从未反应的麻疯树属油和甘油中分离出来。
甲醇钾盐的制备：
通常，甲醇与麻疯树属油的质量比为 1：5  .由于这两种物质密度相似，也可按体积比进行混合。为了精确（如有心情），也可计算20% 的甲醇的质量。另外，不同地区的麻疯树属油的密度是不相同的。
100 升的麻疯树属油用 20 升的甲醇进行酯基交换时，把甲醇加入到含有氢氧化钾的溶液中。在放热反应中（键的形成）产生甲醇钾盐。与氢氧化钾所接触的容器尽可能保持干燥。
注意：
甲醇钾盐的操作必须加倍小心！不要吸入蒸汽。如果甲醇钾盐溅到皮肤上，由于杀死人体神经而毫无知觉地灼伤你。所以，有甲醇钾盐的地方必须要有伸手可及的软管常流水。它还有强腐蚀性。另外，氢氧化钾与铝，锌，锡等起反应，存储器最好用玻璃，搪瓷和不锈钢等。不锈钢为最佳选择。
加热与混合：
在搅拌状态下，预热麻疯树属油到48-54度。
太多的搅拌能引起涡流导致气泡和喷溅。混合的效果降低。
如果表面出现涡流，调整搅拌速度或螺旋桨在溶液中的高度或大小，以获得最佳效果。有时也可用电动泵连接管子使溶液形成环状形，其搅拌效果也很好。但泵的安装要避免甘油的堵塞，其位置要高于反应装置。
在搅拌下，把甲醇钾盐加入到麻疯树属油中。搅拌应进行 50-60 分钟。虽然反应只需要 30 分钟，但时间长一些反应的效果会更好。酯基交换过程中，把甲基酯从甘油中分离出来，也就是甲醇的CH3O 加到酯基链上，而氢氧化钾中的OH-基加到甘油上。
哇塞，劳动节快乐！！！