1,3-Propanediol process

Polymers. AH nitro alcohols are sources of formaldehyde for cross-linking in polymers of urea, melamine, phenols, resorcinol, etc (see Amino RESINS AND PLASTICS). Nitrodiols and 2-hydroxymethyl-2-nitro-l,3-propanediol can be used as polyols to form polyester or polyurethane products (see Polyesters Urethane polymers). 2-Methyl-2-nitro-l-propanol is used in tires to promote the adhesion of mbber to tire cord (qv). Nitro alcohols are used as hardening agents in photographic processes, and 2-hydroxymethyl-2-nitro-l,3-propanediol is a cross-linking agent for starch adhesives, polyamides, urea resins, or wool, and in tanning operations (17—25). Wrinkle-resistant fabric with reduced free formaldehyde content is obtained by treatment with... 

Nitromethane. The nitroparaffins are used widely as raw materials for synthesis. Nitromethane is used to produce the nitro alcohol (qv) 2-(hydroxymethyl)-2-nitro-l,3-propanediol, which is a registered biocide useful for control of bacteria in a number of industrial processes. This nitro alcohol also serves as the raw material for the production of the alkanolamine (qv) 2-amino-2-(hydroxymethyl)-l,3-propanediol, which is an important buffering agent useful in a number of pharmaceutical appHcations. 

Nltropropane. The alkanolamines (qv), 2-amino-2-ethyl-l,3-propanediol and 2-amino-l-butanol, are produced by the two-step process described previously. 

Diaminopropane Processes. 1,2-Propylenediamine can be produced by the reductive amination of propylene oxide (142), 1,2-propylene glycol [57-55-6] (143), or monoisopropanolamine [78-96-6] (144). 1,3-Propanediol [504-63-2] can be used to make 1,3-diaminopropane (143). Various propaneamines are produced by reducing the appropriate acrylonitrile—amine adducts (145—147). Polypropaneamines can be obtained by the oligomerization of 1,3-diaminopropane (148,149). 

If a similar process occurred involving the two protons at C-1, a stereochemically different situation will result. Substitution at C-1 produces a chiral product, -deuterio-, i-propanediol ... 

In industrial processes, 1,3-propanediol is used for the production of polyester fibers, polyurethanes and cydic compounds [85]. 1,3-Propanediol can be produced from glucose with the limiting step catalyzed by glycerol dehydratase. A metagenomic survey for glycerol hydratases from the environment resulted in seven positive clones, one of which displayed a level of catalytic efficiency and stability making it ideal for application in the produdion of 1,3-propanediol from glucose. 

It is important that chemical engineers master an understanding of metabolic engineering, which uses genetically modified or selected organisms to manipulate the biochemical pathways in a cell to produce a new product, to eliminate unwanted reactions, or to increase the yield of a desired product. Mathematical models have the potential to enable major advances in metabolic control. An excellent example of industrial application of metabolic engineering is the DuPont process for the conversion of com sugar into 1,3-propanediol,... 

Two options are being developed at the moment. The first is to produce 1,2-propanediol (propylene glycol) from glycerol. 1,2-Propanediol has a number of industrial uses, including as a less toxic alternative to ethylene glycol in anti-freeze. Conventionally, 1,2-propanediol is made from a petrochemical feedstock, propylene oxide. The new process uses a combination of a copper-chromite catalyst and reactive distillation. The catalyst operates at a lower temperature and pressure than alternative systems 220°C compared to 260°C and 10 bar compared to 150 bar. The process also produces fewer by-products, and should be cheaper than petrochemical routes at current prices for natural glycerol. The first commercial plant is under construction and the process is being actively licensed to other companies. 

Biomass is a renewable resource from which various useful chemicals and fuels can be produced. Glycerol, obtained as a co-product of the transesterification of vegetable oils to produce biodiesel, is a potential building block to be processed in biorefineries (1,2). Attention has been recently paid to the conversion of glycerol to chemicals, such as propanediols (3, 4), acrolein (5, 6), or glyceric acid (7, 8). 

A two-stage process for the hydroformylation of butadiene to give good yields of a desired product—1,6-hexanediol—has been described (100). The first stage employed [(C6H5)3P]2Rh(CO)Br and excess triphen-ylphosphine as catalyst and reaction conditions of I20°C and 200 atm of 1/1 H2/CO in methanol as solvent. The principal product was 3-penten-l-al dimethyl acetal. This was treated with 1,3-propanediol to form a cyclic acetal, then hydroformylated with Co2(CO)8 and dodecyl-9-phospha-9-bicyclononane at 170°C and 80-110 atm of 2/1 H2/CO. The product of... 

It is also necessary to develop enzymatic trans-esterification processes that may find applications for waste material such as rape seed oil cake and for glycerol (propanediol, GTBE). 

Moore, E. R. and Bray, R. G., 1,3-Propanediol and Polytrimethylene Terephthalate, Process Economics Program Report 227, SRI International, Menlo Park, CA, 1999. 

Alkyldiphosphines turned out to be very useful in a different reaction, namely the carbonylation/hydrogenation of ethylene oxide to give 1,3-propanediol also using cobalt catalysts. Interestingly, the ligand contains two phobane units bridged by 1,2-ethenediyl. The process was commercialised by Shell [18]. 

Reactions catalyzed by enzymes or enzyme systems exhibit far greater specificities than more conventional organic reactions. Among these specificities which enzymatic reactions possess, stereospecificity is one of the most excellent. To overcome the disadvantage of a conventional synthetic process, i.e., the troublesome resolution of a racemic mixture, microbial transformation with enzymes possessing stereospecificities has been appHed to the asymmetric synthesis of optically active substances [1-10]. C3- and C4-synthetic units (synthons, building blocks), such as epichlorohydrin (EP), 2,3-dichloro-l-propanol (2,3-DCP), glycidol (GLD), 3-chloro-l,2-propanediol (3-CPD), 4-chloro-... 

In this article, recent progress in the microbial production of 1,3-propanediol (1,3-PD) is reviewed. This special case is used to illustrate the promise and some of the critical constraints of biological processes as compared to the chemical processes. General trends and research needs in the utiHzation of renewable resources are briefly discussed. 

In the first process the yield does not exceed 65% of the starting compound due to simultaneous formation of 1,2-propanediol, while, in the second, a yield of 80% is obtained. Adding the fact that the market price of ethylene oxide is lower than acrolein, the Shell process can be regarded as economically more favorable. This is reflected in the much higher production volume reported for the production of 1,3-PD from ethylene oxide, which amounted to 45,000 t/a in 1999 as opposed to 9000 t/a from acrolein. The relatively high production costs with the acrolein process have probably induced the Dupont Company to invest in research efforts to further develop the biological process (see below). 

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