Methanol Economic data

Compared to other technologies for alcohols production (e.g. ethanol fhom biotechnology), this new approach for the production of methanol-higher alcohol mixtures and its related economic data look rather promising for the near future. The alcohols blend produced at demonstra-... 

Table 124 summarizes the economic data available on methanol production from various feedstocks and by various processes. 

Thermal efficiencies for converting corn stover (8), furfural residue (8), and wood residue to methanol were estimated from the published data to be 48.0, 48.0, and 45.3% respectively. The efficiency data used for converting wood to methanol via the Purox process is also in good agreement with recently published data (12). The Purox process may not have been the best choice for the gasification (1 ). but process and economic data are available for all three feedstocks considered in this paper. 

The process involves the dehydrogenation of isobutane to isobutene which is reacted with methanol to produce MTBE. Particular attention should be given to the dehydrogenation reactor design and operation. Technical and economic data for the design are attached. 

Figure 5.12 gives the flowsheet for the entire process. The distillate from the reactive distillation colmnn Cl has a methanol concentration of 28.1 mol%. It is fed into the two-column pressiu e-swing methanol recovery system. Equipment sizes and economic data are given in Table 5.3. 

Economic Aspects. Terephthahc acid and dimethyl terephthalate are usually sold under long-term contracts. Pricing information is at times pubhshed but actual contract prices are not revealed. Price data pubhshed in 1992 were 0.60/kg for terephthahc acid and 0.57/kg for dimethyl terephthalate (42). The price is mainly influenced by the price of -xylene. The price of terephthahc acid is more than dimethyl terephthalate because a kilogram of it produces 17% more polyester. The price of dimethyl terephthalate takes this factor plus a credit for the methanol generated during polyester production into consideration. 

Table 1.2 contains a survey of major gasification processes that have proved reliable and safe and are today used for syngas production on an industrial scale. In addition to the operating parameters, the survey also provides data about the suitability of these processes for different types of coals. However, these data have to be taken with a grain of salt No absolute rating of the coals is possible in view of their wide variety of properties. Future methanol producers will have to make their choice between these processes on the basis of two main criteria -the properties of the available coals and the resulting economics of gasification. 

The conversion of methane gas (CH4) to methanol (CH3OH), which is a liquid at room temperature, is an area in which considerable research is being done. Still, this process is not yet economically viable. Using tabulated thermodynamic data, calculate the equilibrium constant for the following reaction at 25°C ... 

The data produced were instrumental in establishing a proper phenomenological model for the bubble column. This model was able to predict both liquid and gas tracer curves obtained in an AFDU pilot-plant column in LaPorte, Texas, for three different reaction systems methanol synthesis, dimethyl ether synthesis, and Fischer Tropsch synthesis (Chen et ah, 1998 Devanathan et ah, 1990 Gupta et al., 2001a, 2001b). Unfortunately, the desire to use improved science in scale-up gas-to-Hquid fuels processes to large diameter bubble columns disappeared when Hquefaction of natural gas became more economically attractive. 

In the past few years, there have been many active research programs around the world on the direct conversion of methane to methanol and/or formaldehyde, C2 hydrocarbons, and others. Methanol and formaldehyde can be produced by partial oxidation of methane under controlled conditions in a homogeneous or catafytic reaction process. Many catalysts, such as Mo-based oxides, aluminosilicates, promoted superacids, and silicoferrate, have been used for the reaction. Since the activation energy for the subsequent oxidation of methanol and formaldehyde to carbon oxides is usualfy smaller than that for partial oxidation, hi selectivities for methanol and formaldehyde have been demonstrated onfy at low methane conversions. Reaction conditions (e.g., 02 or N2Q to CH4 ratio, temperature, and resistance time) and surface area of supports play important roles in methanol and formaldehyde yield. In neral, low pressure favors the formation of formaldehyde. Hi pressure and low 02/methane ratios favor the formation of methanol The low yields achieved to data are a major obstacle to economical commercialization of this route. 

In this section both qualitative and quantitative data on the sensitivity to project economics are provided relative to major variables of natural gas cost, methanol price, capacity utilization, plant size, and plant cost. 

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