Liquid Phase Methanol Research Articles

Liquid phase methanol synthesis catalyst

Abstract This work focuses on the investigation of the stability of catalyst activity in the liquid phase methanol synthesis process. The effects of various kinds of metfhods to inhibit the deactivation of catalyst have been experimentally examined. The activity of catalyst was stabilized without lowering of activity by a suitable hydrothermal treatment, although the activity of the untreated catalyst decreased gradually with time. The additive and coating of hydrophobic material were effective for slowing down the crystallite size growth and inhibition of deactivation of catalyst. It was considered that hydrophobic material inhibited the adsorption of produced water onto the hydrophilic catalyst. Hydrophobic treatment of catalyst was found to be effective for liquid phase methanol synthesis from CO2 and H2 using hydrophobic solvent.

Liquid phase methanol hydrocarbonylation with homogeneous and heterogeneous Rh and Ru catalysts

Heterogeneous rhodium and ruthenium catalysts supported on activated carbon were studied in the liquid phase hydrocarbonylation of methanol. The activity and selectivity of the catalysts were determined and compared with the respective homogeneous metal precursors. The stability of the catalysts were determined by analysing the metal contents of the catalysts before and after the hydrocarbonylation reaction. The supported metal catalysts showed comparable activity to the respective homogeneous metal precursors, evidently because the activity originated from the metal leached from the support and was therefore based on the homogeneous catalysis of the dissolved metals. The stability of the metal on the support decreased with higher metal dispersion and was most closely related to the oxygen content of the carbon support.

STATISTICAL MODEL FOR SLURRY PHASE METHANOL SYNTHESIS PROCESS IN AN ENTRAINED REACTOR

ABSTRACT The process feasibility analysis on the liquid phase methanol synthesis (LPMeOH) process was performed in an entrained slurry reactor system. In this three phase mini-pilot plant system, finely powdered catalyst is slurried in the inert oil phase and this catalyst-oil slurry is continuously recirculated through the entrained reactor, where it is contacted with the cocurrent flow of syngas to form the product methanol The effect of various operating conditions which included the reactor temperature, the reactor pressure, the flow rate of catalyst-oil slurry, the flow rate of syngas, the slurry holdup tank pressure, the syngas composition, and the catalyst loadings in slurry, on the productivity of methanol in the reactor was studied. Using the operating conditions, a statistical reaction rate model not based on the kinetic mechanism, was developed to predict the productivity of methanol in an entrained reactor. The rate of production of methanol predicted by this model agreed well with the experim...

METHANOL PRODUCTIVITY COMPARISON BETWEEN AN AGITATED SLURRY REACTOR AND AN ENTRAINED REACTOR

ABSTRACT The effect of various operating conditions including the catalyst loading in slurry, on the productivity of methanol in an agitated slurry reactor were studied. The modeling of the mechanically agitated slurry reactor was performed with the aid of the reaction rate expression and the gas-liquid mass transfer correlation that were developed, to predict the rate of methanol production for any inlet condition The equilibrium limitation encountered in the liquid phase methanol synthesis process in an agitated slurry reactor can be alleviated by conducting this process in an entrained reactor, where the product methanol formed is continuously flashed out of the system. After developing a kinetic rate expression and a gas-liquid mass transfer correlation, the modeling of the entrained reactor was performed to predict the reactor productivity for any process condition. The rate of methanol production predicted for nominally identical operating conditions in an entrained reactor and in a mechanically agi...

ROLE OF IN-SITU PRODUCED METHANOL ON THE CATALYST DEACTIVATION IN THE LIQUID PHASE METHANOL SYNTHESIS PROCESS

ABSTRACT The role of methanol produced in-situ in the liquid phase methanol synthesis process has been experimentally examined. The catalyst crystallite size is found to be more stable when the produced water and methanol are consistently removed from the catalyst active sites. The experimental evidence shows that in-situ produced water is not the only culprit for the catalyst crystallite size growth, rather, methanol is also responsible for contributing to crystallite growth and therefore catalyst deactivation Hydrothermal leaching of the catalyst was also determined to be an active participant in catalyst deactivation. Two experimental designs were run to assess the influence of temperature, leaching solution concentration and pretreatment conditions on the extent of leaching of the methanol synthesis catalyst. Water and methanol were found to be active participants in the reduction of catalyst activity. Hence, the methanol/water solutions serve as potentially harmful agents in the leaching of aluminum ...

DOE INDIRECT COAL LIQUEFACTION PROGRAM —AN OVERVIEW

U.S. Department of Energy (DOE) has been supporting an indirect coal liquefaction program aimed at developing improved technologies to convert coal based synthesis gas into economically competitive and environmentally clean hydrocarbon and oxygenate transportation fuels. A key element of this program is the development of a liquid phase reactor technology which could offer improved economics and operational flexibility over the conventional gas phase reactors. This paper will review the accomplishments of liquid phase methanol technology development at the proof-of-concept (POC) scale unit in LaPorte, Texas and the advancement of this technology to commercial demonstration which has been underway since 1993 under the support of DOE Clean Coal Technology program. The POC facility has recently been upgraded to allow for developing liquid phase reactor technologies for Fischer-Tropsch synthesis and the production of other oxygenate fuels and chemicals from synthesis gas. The upgraded POC unit, now known as the Alternative Fuels Development Unit (AFDU), as well as the results of new campaigns that have been conducted at this unit will also be reviewed.

Methanol carbonylation to methyl formate catalyzed by strongly basic resins

The liquid phase methanol carbonylation to methyl formate has been investigated both with homogeneous sodium methoxide, the industrial catalyst for this process, and with heterogeneous strongly basic resins. The strongly basic resins Amberlyst A26 and Amberlite IRA 400 displayed a higher activity than sodium methoxide. The activation procedure and the dependence of the reaction rate on CO pressure have also been investigated.

Solubility of Hydrogen in Liquid Methanol and Methyl Formate at 20 °C to 140 °C

The solubilities of hydrogen gas in liquid phase methanol and methyl formate were measured under pressures up to 1500 kPa and temperatures to 140 °C. The mole fraction solubilities were between 7.9 × 10-4 and 6.3 × 10-3 for H2 in methanol and between 7 × 10-4 and 6.9 × 10-3 for H2 in methyl formate. The Henry's law constants were about 620 MPa for H2 in methanol and 630 MPa for H2 in methyl formate at a temperature of 20 °C. The Henry's law constants show a decrease with increase of temperature. Empirical correlations for solubilities at various temperatures were given on the basis of the experimental data.

Effective liquid-phase methanol synthesis utilizing liquid-liquid separation

New liquid phase methanol synthesis process is proposed in that methanol is ejected with hydrocarbon solvent exclusively as a liquid phase, while gaseous components are not practically discharged from the reactor. Methanol is obtained in 95% yield with trace amount of feed gas by liquid-liquid separation from hydrophobic solvent. The advantage of the present process is that the gas recycle can be virtually eliminated.

Liquid-phase methanol synthesis on Cu-based ultrafine particles prepared by chemical deposition in liquid phase

Liquid-phase methanol synthesis was investigated using copper-based ultrafine particle (UFP) catalysts. Cu Zn UFP catalyst was active for methanol synthesis, although the activity decreased with time-on-stream. Cu V UFP catalyst was stable against deactivation and showed the highest methanol productivity of the catalysts tested. The space time yield of methanol on this catalyst was about 3.5 times as large as that of a co-precipitated Cu Zn catalyst. The selectivity of the Cu V UFP catalyst for methanol was low, as compared to that of the co-precipitated Cu Zn catalyst, due to the formation of methane. The addition of carbon dioxide in the feed gas was effective in suppressing the formation of methane.

Rapid methods for population-scale analysis for gene polymorphisms: the ACE gene as an example.

To obtain rapid, high throughput genotyping of the angiotensin converting enzyme (ACE) gene intron 16 insertion/deletion polymorphism. DNA was obtained from whole blood samples by a simple liquid phase methanol extraction procedure. The ACE gene was amplified by the polymerase chain reaction (PCR) using two oligonucleotide primers (ACE1 and ACE3) outside the insertion sequence and one primer (ACE2) inside the sequence. Microtitre array diagonal gel electrophoresis (MADGE) was used to determine genotypes. 84 and 65 bp PCR products indicating the presence of deletion (D) and insertion (I) alleles, respectively, were clearly resolved after electrophoresis on a 7.5% polyacrylamide gel. Up to 480 DNA samples on 5 gels could be genotyped in a single electrophoresis run, or up to 1000 samples in a working day. A simplified DNA extraction protocol coupled to the high throughput capability of the MADGE electrophoretic system for genotyping enables analysis of large populations for association studies of ACE genotype with cardiac disease events.

KINETIC RATE EXPRESSION FOR METHANOL SYNTHESIS IN A LIQUID ENTRAINED REACTOR

Abstract In the three phase entrained reactor for the liquid phase synthesis of methanol, the catalyst-inert oil slurry is pumped through the tubular reactor and syngas is fed to the reactor cocurrently with the upward flow of slurry. According to an elaborate experimental design plan, the effect of different operating conditions on the liquid phase synthesis of methanol in an entrained reactor, was studied. The parameters of this experimental study included reactor temperature, reactor pressure, slurry flow rate, syngas flow rate, slurry holdup tank pressure, and syngas composition. The data obtained from the experiments at low catalyst loading in slurry, were used to develop a kinetic rate expression for the liquid phase methanol synthesis process in an entrained reactor. This in turn helps the scale-up and commercialization of the methanol synthesis process in an entrained reactor.

MODELING OF A MECHANICALLY AGITATED SLURRY REACTOR FOR LIQUID PHASE METHANOL SYNTHESIS PROCESS

ABSTRACT In the liquid phase methanol synthesis process in a mechanically agitated slurry reactor (MASR), catalyst particles in powder form are slurried in the oil phase, and this catalyst-oil slurry is continuously agitated by the impeller in the reactor. Syngas, which is fed to the reactor, reacts in the presence of the activated catalyst-oil slurry, to form the product, methanol. A computer model was developed based on the experimental results, for the liquid phase methanol synthesis process, in a mechanically agitated slurry reactor. This computer program accurately predicts the multicomponent phase equilibria, ultimate chemical equilibria, and the compositions of each reactant and product species exiting in the agitated slurry reactor The results of the modeling predictions, agree well with the experimental data collected from the agitated slurry reactor.

CATALYST EFFECTIVENESS FACTORS UNDER GAS-TO-LIQUID MASS TRANSFER LIMITING REGIME IN LIQUID PHASE METHANOL SYNTHESIS PROCESS

ABSTRACT The effectiveness factors of methanol synthesis catalyst were experimentally measured under condition of gas-to-liquid mass transfer limiting regime in the liquid phase methanol synthesis process, where the synthesis catalyst is slurried in an inert liquid phase. The experimental measurements of effectiveness factors were based on an intrinsic methanol synthesis rate per unit mass of catalyst (gmol/kg cat.h) which is not limited by external mass transfer. The experiments were carried out under well-defined conditions of temperature, pressure, syngas feed flow rate, and impeller speed. The experiments were carried out in a 1-L stirred autoclave. The catalyst slurry ratios were varied from 10 g in 550 mL of Witco-40 oil (corresponding to a slurry ratio of 2.2%) to 150 g in 550 mLof Witco-40 oil (corresponding to a slurry ratio of 25.1%). The experimental measurements have been summarized in one single plot as generalized catalyst effectiveness factor as a function of catalyst slurry ratio. The resu...

Liquid-phase methanol synthesis: modelling of a monolithic reactor

A mathematical model of a monolithic reactor for liquid-phase methanol synthesis is developed. The performance of a commercial-scale monolithic reactor is simulated. The influence of various design parameters for different solvents and process conditions is studied. Over the range of process conditions considered, it was found that the mass transfer is sufficiently fast to allow the process to be operated essentially in the kinetic regime. The numerical results are compared with literature data on slurry columns, autoclaves and trickle-bed reactors. The performance of the monolithic reactor was found to be commensurable with these reactors. In view of some of the unique advantages of the monolithic reactor it can be a viable alternative to the conventional methanol reactors.

MASS TRANSFER CCMPARISON BEIWEEN MECHANICALLY AGITATED SLURRY REACTCR AND LIQUID ENTRAINED REACTOR IN THE METHANOL SYNTHESIS PROCESS

ABSTRACT The commercial reactor proposed for the liquid phase methanol synthesis process (LPMeCHTM) is a liquid entrained reactor (LER), since it possesses several operational advantages over a mechanically agitated slurry reactor (MASR). This paper discusses in detail the develocment of a correlation for the prediction of the overall gas-liquid mass transfer coefficient (KLiaB) in a LER. The overall mass transfer coefficient experimentally determined for the LER, is compared with the corresponding value obtained for the MASR under nominally identical operating conditions. It was observed that the overall gas-liquid mass transfer coefficient and hence the overall rate of methanol production per unit mass of catalyst, is significantly higher in the LER compared to the MASR at identical operating conditions. In the LER mode, the limitation posed on the system by chemical equilibrium, is alleviated by selective renewal of products thus making the process ideal for the once-through methanol (CIM) This justifi...

MINI-PILOT PLANT DESIGN AMD OPERATION OF A LIQUID ENTRAINED REACTOR FOR LIQUID PHASE METHANOL SYNTHESIS PROCESS

ABSTRACT The commercial reactor type proposed for the liquid phase methanol synthesis (LPMeOH™) process is a liquid entrained reactor (LER), mainly due to its higher methanol productivity and better capability of alleviating the chemical equilibrium limitation than a mechanically agitated slurry reactor (MASR). A laboratory scale mini-pilot plant version of a liquid entrained reactor system was successfully designed and built to carry out process engineering research, as well as to demonstrate the process feasibility of the LPMeOH™ process. This paper discusses in detail, the design philosophy of the liquid entrained reactor system and its accessory peripherals. The operation of the mini-pilot liquid entrained reactor system has also justified its effectiveness in pre-scaleup investigation of the energy conversion process, at a fraction of the cost required for a pilot scale investigation.

A novel single-step dimethyl ether (DME) synthesis in a three-phase slurry reactor from co-rich syngas

The productivity of liquid phase methanol synthesis reactor in limited by the chemical equilibrium barrier caused by high local methanol concentration in the liquid phase. This barrier can be partly lifted by either selective physical remoal of methanol from the liquid phase or in-situ conversion to other chemical species. A novel process for manufacturing dimethyl ether (DME) from CO-rich syngas in the liquid phase has been developed. Two functionally different catalysts are slurried in the inert liquid phase, in this dual catalytic mode of operation. The (methanol+DME) co-production approach is extremely effective in increasing the per-pass syngas conversion and reactor productivity over those of methanol synthesis alone. The co-production approach can also co-produce methanol and DME in any fixed proportion, from practically pure DME to pure methanol. Scientific aspects of the process including the process feasibility domain, reaction kinetics, catalytic management, and thermodynamic modeling will be discussed.

Methanol Carbonylation Catalyzed by Rhodium Complexes Immobilized to Silica via Pyridine Group

2-(2-Trimethoxysilylethyl)pyridine (I) was used to prepare a series of rhodium carbonyl complexes bound to silica via pyridine group. The rhodium complex Rh2(CO)4Cl2 (Rh2) was used as a starting compound, and the immobilized complexes were prepared by the following routes: (i) by the reaction of untreated silica with a Rh complex formed from Rh2 and I, (ii) by reaction of Rh2 with a silica functionalized with I, (iii) by treatment of Rh2 with a polycondensate prepared by hydrolysis and condensation of a mixture of I and tetraethoxysilane, and (iv) by sol-gel processing of tetraethoxysilane with a Rh complex formed from Rh2 and I. These complexes were found to be efficient catalysts for the liquid phase methanol carbonylation. Their activity and stability in relation to their synthesis and structure is discussed, along with Rh leaching process.

THERMAL STABILITY ANALYSIS OF THE LIQUID PHASE METHANOL SYNTHESIS REACTOR

ABSTRACT The effect of addition of an inert liquid phase on the rate of heat generation in the catalytic synthesis of methanol from syngas has been studied. Gas compositions typical of product gases from Lurgi and Koppers-Totzek gasifiers, represented by H2-rich and CO-rich syngas respectively, were used to experimentally verify the “slope” and “dynamic” critria in a three-phase fixed bed recycle reactor. The liquid medium, witco-40 oil, has been effective in controlling the rate of heat generation and in preventing catalyst overheating, signifying that the liquid phase synthesis is thermally far more stable than the vapor phase synthesis. The experimental thermal stability study provides crucial and valuable information in commercializing the liquid phase methanol synthesis process. The current approach of thermal stability analysis does not require any a priori assumption or predetermined reaction kinetics.