Fossil derived methanol

Replacement of fossil-derived methanol by ethanol is an interesting objective ... 

Syngas and methanol. Methanol is one of the top industrial chemicals today. It is produced on a very large scale from fossil-derived syngas by use of a Cu-Zn-Al-oxide catalyst, however, it can of course also be produced in a similar manner from bio-derived syngas. Methanol (and also syngas) can be used as a feedstock to produce dimethyl ether via catalytic dehydration. However, the chemistry involved in these processes is well-known, and will not be considered here, since it has been extensively dealt with in detail elsewhere. ... 

Chemicals have long been manufactured from biomass, especially wood (sHvichemicals), by many different fermentation and thermochemical methods. For example, continuous pyrolysis of wood was used by the Ford Motor Co. in 1929 for the manufacture of various chemicals (Table 20) (47). Wood alcohol (methanol) was manufactured on a large scale by destmctive distillation of wood for many years until the 1930s and early 1940s, when the economics became more favorable for methanol manufacture from fossil fuel-derived synthesis gas. 

Notably, several types of liquid biofuels exist or are under development and have the potential to replace fossil fuels, especially in the transportation sector. The focus is on organic fuels such as ethanol, butanol, methanol and their derivatives ETBE, MTBE, which can be produced by fermentation, but also biodiesel and liquid biogas, which can provide interesting biomass-based alternatives to diesel and LPG. 

Methanol is currently produced from syngas, which has been enriched with C02 and is derived from either a fossil fuel or biomass. A better approach might consist of the direct hydrogenation of pure C02, whilst transesterification with ethylene carbonate implies that ethylene, derived from oil refineries, should be used as the raw material. 

Methanol production today is not a sustainable process but is part of a petrochemical route for conversion of fossil carbon into chemicals and fuels (see Section 5.3.3). It has to be emphasized that a one-to-one upscaling of existing industrial methanol synthesis capacities for fuel production is not useful. This is mainly because the current industrial process has not been developed and optimized under the boundary conditions of conversion of anthropogenic C02, but rather for synthesis gas feeds derived from fossil sources such as natural gas or coal. The switch to an efficient large-scale methanol synthesis with a neutral C02 footprint is still a major scientific and engineering challenge, and further research and catalyst and process optimization is urgently needed to realize the idea of a sustainable methanol economy. ... 

The recent interest in chemical production is based on a higher return expected for chemical [uoducts versus fuels. For example, biomass gasification can be used to produce a synthesis gas of hydrogen and carbon monoxide. This gas can be used in catalytic synthesis of a range of chemicals, from methanol and formaldehyde to higher hydrocarbons, in the same way that synthesis gas derived from natural gas can be used. However, by breaking down the biomass to the basic building blocks all product differentiation relative to fossil fuels is lost. 

The conversion of methane to methanol and higher alcohols is gaining more and more interest with respect to the production of chemicals and fuels. As natural gas will become the predominant fossil fuel, and crude oil will have passed its maximum market share at the beginning of next century (refs. 1,2), the demand for chemicals and fuels derived from natural gas will increase. Alcohols can be used either as a chemical feedstock or as a liquid secondary energy carrier, depending on the selectivity at which they can be produced. The work at our institute focusses on the production and use of alcohols as synthetic liquid energy carriers (ref. 3), because of their... 

The 50 largest-volume chemicals contain many derived from fossil carbon sources. Their 1995 volumes in billions of pounds produced in the United States4 are ethylene (46.97), ammonia (35.60), propylene (25.69), methyl tert-butyl ether (17.62), ethylene dichloride (17.26), nitric acid (17.24), ammonium nitrate (15.99), benzene (15.97), urea (15.59), vinyl chloride (14.98), ethylbenzene (13.66), styrene (11.39), methanol (11.29), carbon dioxide (10.89), xylene (9.37), formaldehyde (8.11), terephthalic acid (7.95), ethylene oxide (7.62), toluene (6.73), p-xylene (6.34), cumene (5.63), ethylene glycol (5.23), acetic acid... 

For the functional design of our cluster we have considered plants and processes from the entire production chain, ranging from fossil and renewable fuels to methanol derivatives, such as fiber board plants that make use of formaldehyde. In addition, the cluster includes industries that process or use by-products such as hydrogen and platinum. The cluster comprises five main functional areas. For each of these functional areas we have made an inventory of possible interactions, flows and subsystems ... 

If a fermentation process is used for PHA synthesis this problem can partially be overcome by using cheap surplus and waste materials as renewable carbon sources (e.g. molasses, whey, cellulose hydrolysate) or other cheap carbon sources from fossil resources like methanol derived from natural gas, because roughly 50% of the total production costs derive from the carbon source costs. Unfortunately many of the well known production strains can not be used for PHA production from such substrates, because these microbial strains show either low yields or low production rates, when they grow on these substrates, or they simply cannot utilize these carbon sources at all. These drawbacks can be overcome either by isolating new microbial strains or by applying genetically modified strains for the production process. 

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