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<h4>According to our current research carried out about the acrylic acid synthesis method, we list them as | <h4>According to our current research carried out about the acrylic acid synthesis method, we list them as | ||
follows: | follows: | ||
− | <br> 1.Traditional chemical synthesis | + | <br><br> 1.Traditional chemical synthesis |
<div class="panel-group" id="accordion"> | <div class="panel-group" id="accordion"> | ||
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of the Japanese Catalyst Company in the 1880s. The reaction temperature of the first | of the Japanese Catalyst Company in the 1880s. The reaction temperature of the first | ||
step is 320-330℃. If other additives such as W, Co, K, Si and O are added to the | step is 320-330℃. If other additives such as W, Co, K, Si and O are added to the | ||
− | catalyst MoBiFe, the yield of acrolein can reach more than 90% | + | catalyst MoBiFe, the yield of acrolein can reach more than 90%. The reaction |
temperature of the second step is 210-255 ℃. The compositions of the catalyst are | temperature of the second step is 210-255 ℃. The compositions of the catalyst are | ||
− | Mo, Bi, Fe, Co, K and O. The yield of acrylic acid can reach 97.5% | + | Mo, Bi, Fe, Co, K and O. The yield of acrylic acid can reach 97.5%. The yield |
of acrylic acid in the two-step oxidation process is much higher than that of the | of acrylic acid in the two-step oxidation process is much higher than that of the | ||
direct oxidation of propylene to produce acrylic acid. This is because the reaction | direct oxidation of propylene to produce acrylic acid. This is because the reaction | ||
temperature in the one-step process is 325-350 ° C, at which the conversion of propylene | temperature in the one-step process is 325-350 ° C, at which the conversion of propylene | ||
− | to acrolein is high. But acrolein and acrylic acid are further oxidized at that temperature | + | to acrolein is high. But acrolein and acrylic acid are further oxidized at that temperature. Therefore, to obtain higher yields of acrylic acid, control the reaction at |
− | + | ||
different stages by controlling the temperature and changing the catalyst composition | different stages by controlling the temperature and changing the catalyst composition | ||
in the two-step method is more reasonable and more valuable. As the most widely used | in the two-step method is more reasonable and more valuable. As the most widely used | ||
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Therefore, it is imperative to develop renewable energy alternative to replace fossil energy to produce | Therefore, it is imperative to develop renewable energy alternative to replace fossil energy to produce | ||
acrylic acid in a greener way. | acrylic acid in a greener way. | ||
− | <br> 2.Acrylic acid semi-biosynthesis | + | <br> <br>2.Acrylic acid semi-biosynthesis |
<br> Acrylic acid semi-biosynthesis refers to the method of using micro-organisms to turn acrylonitrile, | <br> Acrylic acid semi-biosynthesis refers to the method of using micro-organisms to turn acrylonitrile, | ||
acrylamide and other petrochemical raw materials into acrylic acid. | acrylamide and other petrochemical raw materials into acrylic acid. | ||
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So far, the researchers have found that certain microorganisms which contain nitrilase can catalyze the conversion of acrylonitrile | So far, the researchers have found that certain microorganisms which contain nitrilase can catalyze the conversion of acrylonitrile | ||
to acrylic acid. Nitrilase can catalyze the nitrile compound directly to produce | to acrylic acid. Nitrilase can catalyze the nitrile compound directly to produce | ||
− | the corresponding products of carboxylic acid | + | the corresponding products of carboxylic acid. Nitrilases are present in Rhodococcus, |
− | Pseudomonas, Nocardia and Bacillus | + | Pseudomonas, Nocardia and Bacillus. |
<br> | <br> | ||
<br>There are many advantages of Hydrolysis of Acrylonitrile to produce acrylic acid, | <br>There are many advantages of Hydrolysis of Acrylonitrile to produce acrylic acid, | ||
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Acrylamide also relies on petrochemical resources to obtain the product. According to current report, Rhodococcus (Rhodococcus | Acrylamide also relies on petrochemical resources to obtain the product. According to current report, Rhodococcus (Rhodococcus | ||
AJ270), Pseudomonas aeruginosa, Bacillus thuringiensis BR449 and other microorganisms | AJ270), Pseudomonas aeruginosa, Bacillus thuringiensis BR449 and other microorganisms | ||
− | can catalyze the conversion of acrylamide to acrylic acid | + | can catalyze the conversion of acrylamide to acrylic acid. Acrylamide is converted |
to acrylic acid by amidase. Rhodococcus AJ270 can grow with acetamide as a carbon | to acrylic acid by amidase. Rhodococcus AJ270 can grow with acetamide as a carbon | ||
source and show high amidase activity during metabolism. The conversion of acrylamide | source and show high amidase activity during metabolism. The conversion of acrylamide | ||
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<br>Acrylic acid semi-biological method, although possesses the high yield, its raw materials acrylonitrile | <br>Acrylic acid semi-biological method, although possesses the high yield, its raw materials acrylonitrile | ||
and acrylamide cost even more than acrylic acid, which limits the industrialization of this method. | and acrylamide cost even more than acrylic acid, which limits the industrialization of this method. | ||
− | <br> 3.Acrylic acid complete biosynthesis | + | <br><br> 3.Acrylic acid complete biosynthesis |
<br> Acrylic acid complete biosynthesis method refers to the direct use of saccharides and other biomass | <br> Acrylic acid complete biosynthesis method refers to the direct use of saccharides and other biomass | ||
fermentation to produce acrylic acid. | fermentation to produce acrylic acid. | ||
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<br> | <br> | ||
<br>At present, the method mainly uses Clostridium propionicum as the starting strain. | <br>At present, the method mainly uses Clostridium propionicum as the starting strain. | ||
− | Specific metabolic pathway is shown in | + | Specific metabolic pathway is shown in the following picture. Although the route is short, |
but there are still many problems when used in producing acrylic acid. | but there are still many problems when used in producing acrylic acid. | ||
<br> | <br> | ||
− | <br>As can be seen from | + | <br>As can be seen from the picture, metabolism of lactic acid is divided into the left |
side, the oxidation pathway and the right side, the reduction pathway. When Clostridium | side, the oxidation pathway and the right side, the reduction pathway. When Clostridium | ||
propionate uses lactic acid as a source of energy, one molecule of lactic acid produces | propionate uses lactic acid as a source of energy, one molecule of lactic acid produces | ||
− | one third of the molecule of acetic acid and 2/3 of the propionic acid | + | one third of the molecule of acetic acid and 2/3 of the propionic acid. In the |
production process of acetic acid, there will be four electrons and 4 protons generate, | production process of acetic acid, there will be four electrons and 4 protons generate, | ||
as well as offering ATP for bacteria to grow. The acryloyl CoA in the reduction pathway | as well as offering ATP for bacteria to grow. The acryloyl CoA in the reduction pathway | ||
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<div class="panel-body"> | <div class="panel-body"> | ||
3-hydroxy propionic acid (3-HP) is an important chemical intermediate, there are a number of patents have reported the methods | 3-hydroxy propionic acid (3-HP) is an important chemical intermediate, there are a number of patents have reported the methods | ||
− | of sugar conversion to 3-HP | + | of sugar conversion to 3-HP. And 3-HP has two functional groups, carboxyl |
and hydroxyl. It is possible to synthesize a variety of important chemical substances | and hydroxyl. It is possible to synthesize a variety of important chemical substances | ||
such as 1,3-propanediol, succinic acid through oxidation, dehydration and esterification | such as 1,3-propanediol, succinic acid through oxidation, dehydration and esterification | ||
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<br> Using 3-hydroxypropionic acid-related pathways to construct engineering bacteria | <br> Using 3-hydroxypropionic acid-related pathways to construct engineering bacteria | ||
− | to produce acrylic acid is a hotspot in recent years | + | to produce acrylic acid is a hotspot in recent years, but the yield is generally |
not high, partly because of the toxic side effects of acrylic acid on cells and, | not high, partly because of the toxic side effects of acrylic acid on cells and, | ||
on the other hand, the pathway is long, and the reaction requires vitamin B12 to | on the other hand, the pathway is long, and the reaction requires vitamin B12 to | ||
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<div class="panel-body"> | <div class="panel-body"> | ||
Dimethylsulphoniopropionate (DMSP) is a sulfur metabolite synthesized in some higher plants in sea water, algae and marine | Dimethylsulphoniopropionate (DMSP) is a sulfur metabolite synthesized in some higher plants in sea water, algae and marine | ||
− | microalgae | + | microalgae. Some marine organisms such as bacteria, phytoplankton have DMSP |
− | lyase, which cleaves the DMSP into acrylate and dimethyl sulfide (DMS) | + | lyase, which cleaves the DMSP into acrylate and dimethyl sulfide (DMS), which |
is also commonly found in Alcaligines faecalis, The route is shown in Figure 1.3. | is also commonly found in Alcaligines faecalis, The route is shown in Figure 1.3. | ||
Extracellular DMSP is transported into the body by the carrier protein, be cleaved | Extracellular DMSP is transported into the body by the carrier protein, be cleaved |
Latest revision as of 14:08, 1 November 2017