Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C68/00—Preparation of esters of carbonic or haloformic acids
  • C07C68/06—Preparation of esters of carbonic or haloformic acids from organic carbonates
  • C07C68/065—Preparation of esters of carbonic or haloformic acids from organic carbonates from alkylene carbonates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/007—Mixed salts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
  • B01J27/20—Carbon compounds
  • B01J27/232—Carbonates
  • B01J27/236—Hydroxy carbonates
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D317/00—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms
  • C07D317/08—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3
  • C07D317/10—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings
  • C07D317/32—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D317/34—Oxygen atoms
  • C07D317/36—Alkylene carbonates; Substituted alkylene carbonates
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D317/00—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms
  • C07D317/08—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3
  • C07D317/10—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings
  • C07D317/32—Heterocyclic compounds containing five-membered rings having two oxygen atoms as the only ring hetero atoms having the hetero atoms in positions 1 and 3 not condensed with other rings with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D317/34—Oxygen atoms
  • C07D317/36—Alkylene carbonates; Substituted alkylene carbonates
  • C07D317/38—Ethylene carbonate

Definitions

• the present invention relates to a process for the preparation of dialkyl carbonate compounds which can be advantageously used as additives of a biological origin in fuels such as diesel or gasolines.
• Dialkyl carbonates and in particular diethyl carbonate, can be used as additives for said fuels, increasing the aliquot of product of a biological origin in the fuel and thus reducing the particulate.
• the Applicant has now found a new method for the preparation of dialkyl carbonate compounds, using a heterogeneous catalyst based on hydrotalcite , obtaining extremely high product yields, higher than 95% molar, at the same time avoiding the formation of toxic and carcinogenic by-products.
• the present invention therefore relates to a process for the preparation of dialkyl carbonate compounds starting from urea and reagents selected from ethylene glycol, propylene glycol and linear alcohols having a number of carbon atoms ranging from 1 to 20. Said process comprises the following steps:
• An object of the present invention relates to a process for the preparation of dialkyl carbonate compounds starting from urea and reagents selected from ethylene glycol, propylene glycol and linear alcohols having a number of carbon atoms ranging from 1 to 20. Said process comprises two steps:
• the intermediate products formed in step (a) are, for example, ethylene carbonate or propylene carbonate.
• the end-products obtained with the process, object of the present invention are dialkyl carbonates.
• Preferred products are diethyl carbonate and dibutyl carbonate.
• the linear alcohols having a number of carbon atoms ranging from 1 to 20 can preferably be of biological origin and even more preferably can be obtained starting from fatty acids with a number of carbon atoms in the chain ranging from 16 to 22.
• the end-products obtained with the process, object of the present invention can be used as biological component in both gasoline and diesel fuel, allowing a saving of hydrogen in the refinery, which on the other hand, is required for the production of other fuels of a biological nature such as HVO.
• the catalysts used in the process, object of the present invention, in both steps, are in heterogeneous phase, preferably in solid phase.
• the catalyst used in step (a) of the process described and claimed in the present text can be any hydrotalcite having the formula:
• M 11 is a bivalent metal selected from Mg, Fe 11 , Ni 11 , Zn, Cd, Co 11 and mixture thereof
• M 111 is a trivalent metal selected from Al, Fe 111 , Ga 111 , Cr 111 , Mn 111 , Co 111 and mixtures thereof
• X is an anion selected from CC>3 2 ⁇ , OH ⁇ and NO 3 ""
• n is an integer ranging from 0 to 6
• a is an integer ranging from 4 to 6.
• the reaction step (a) is carried out at temperatures ranging from 100°C to 150°C and pressures ranging from 2 atm to 0.01 atm.
• the reaction is preferably carried out at a pressure lower than atmospheric pressure and even more preferably at pressures ranging from 0.05 atm to 0.01 atm.
• the conversion of the limiting agent (urea) is total and the selectivity to the desired product >95% molar.
• the aliphatic alcohol is preferably of a biological origin, in the text indicated as bioalcohol, and can be obtained either by fermentation of a biomass or molasses, or by the reduction of a fatty acid, acids that normally have an extremely high number of carbon atoms, for example up to 22 carbon atoms.
• the aliphatic alcohol of a biological origin may preferably have up to 22 carbon atoms in the chain and more preferably the aliphatic alcohol obtained can have from 1 to 6 carbon atoms.
• ethanol and butanol are particularly preferred.
• the catalyst used in step (b) of the process described and claimed in the present text can be a hydrotalcite having the formula:
• M II 6M III 2 (OH) ⁇ ⁇ 3 ⁇ 40 II 6M III 2 (OH) ⁇ ⁇ 3 ⁇ 40 (II) wherein M 11 is a bivalent metal selected from: Mg, Fe 11 , Ni 11 , Zn, Cd, Co 11 and mixtures thereof.; M 111 is a trivalent metal selected from Al, Fe 111 , Ga 111 , Cr 111 , Mn 111 , Co 111 and mixtures thereof, and X is an anion selected from C0 3 2 ⁇ , OH " and N0 3 " .
• hydrotalcites wherein M 11 is Zn or Mg, or mixtures of the two, and M 111 is selected from Al, Fe and Cr, M 111 is more preferably Al .
• the reaction step (b) is carried out at temperatures ranging from 80°C to 130°C, with pressures ranging from 1 atm to 15 atm.
• the reaction step (b) is carried out using alcohol in excess with respect to the stoichiometric with molar ratios alcohol/ (alkenyl carbonate) ranging from 2.5/1 to 10/1, more preferably from 4/1 to 8/1.
• the reaction reaches thermodynamic equilibrium with a quantitative selectivity to dialkyl carbonate .
• the catalysts of step (a) and step (b) can be preferably the same, but can also have a different chemical composition.
• M 11 is preferably Zn and M 111 is Al .
• Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-N0 3 Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-N0 3 .
• Step (b) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-NQ 3 Step (b) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-NQ 3 .
• Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-C0 3 Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-C0 3 .
• Step (b) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-CQ 3 Step (b) of the synthesis of diethylene carbonate with hydrotalcite Zn-Al-CQ 3 .
• Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Fe-CQ 3 Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Fe-CQ 3 .
• Step (b) of the synthesis of diethylene carbonate with hydrotalcite Zn-Fe-CQ 3 Ethylene carbonate, produced according to Example 5, and ethanol are charged into a glass reactor in a molar ratio of 1/4; the hydrotalcite
• Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Cr-CC>3 Step (a) of the synthesis of diethylene carbonate with hydrotalcite Zn-Cr-CC>3 .
• Step (b) of the synthesis of diethylene carbonate with hydrotalcite Zn-Cr-C0 3 Step (b) of the synthesis of diethylene carbonate with hydrotalcite Zn-Cr-C0 3 .
• Ethylene carbonate, produced according to Example 5, and ethanol are charged into a glass reactor in a molar ratio of 1/4; the hydrotalcite Zn 6 Cr 2 (OH) i 6 C0 3 ⁇ 2 ⁇ , synthesized by the Applicant, is then added in a ratio of 5% by weight; the reaction mixture is heated to 83°C and is sent to reflux for 3 hours. After 3 hours, the reaction is interrupted and the reaction product is analyzed by means of gaschromatography . The conversion of . ethylene carbonate proves to be equal to 80% (thermodynamic limit of the transesterification reaction) with a selectivity to the desired product (diethyl carbonate) equal to 97%.
• reaction intermediate 2-hydroxyethylcarbonate
• metals Zn, Cr
• Urea and ethylene glycol are charged into a glass reactor in a molar ratio of 1/1.2 and the hydrotalcite PURAL MG 70, a commercial product with a molar ratio Mg/Al of 7/3, is added in a ratio of 5% by weight; the reaction mixture is heated to 130°C and a vacuum is applied reducing the pressure to 30 mbar. After 3 hours, the reaction is interrupted and the reaction product is analyzed by means of gaschromatography . The conversion of urea proves to be total with a selectivity to the desired product (ethylene carbonate) equal to 18%.
• the by-products consist of oxazolidone (62%), the corresponding hydroxycarbonate (15%) and ethylene urea (5%) .
• Step (b) of the synthesis of diethylene carbonate with hydrotalcite EXM 2221 Step (b) of the synthesis of diethylene carbonate with hydrotalcite EXM 2221.
• Ethylene carbonate, produced according to comparative Example 1, and ethanol are charged into a glass reactor in a molar ratio of 1/4; the commercial hydrotalcite EXM 2221, magnesium and aluminium hydrotalcite with an unknown chemical composition, is then added in a ratio of 5% by weight; the reaction mixture is heated to 83°C and is sent to reflux for 3 hours. After 4 hours, the reaction is interrupted and the reaction product is analyzed by means of gaschromatography.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• External Artificial Organs (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=44993704

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (4)

• 2011
  • 2011-09-28 IT IT001741A patent/ITMI20111741A1/it unknown
• 2012
  • 2012-09-26 WO PCT/IB2012/055124 patent/WO2013046132A1/en active Application Filing

Patent Citations (4)

Non-Patent Citations (6)

Also Published As

Similar Documents

Legal Events