The Fischer-Tropsch Process
Refining is nothing more than the extraction of usable and convenient energy from its energy-bearing matrix. Historically, the energy-bearing matrix of choice has been crude oil. However, since the exclusive purpose of “refining” within this context is to extract such energy in a more usable form for a range of specific applications, we can look upon FT as a form of refining. However, a major distinction between conventional refining and FT conversion is that while in conventional refining the usable energy fractions are extracted from the energy-bearing matrix, in FT conversion the usable energy fractions are constituted at the molecular level from syngas, thus presenting a more concentrated and pure fuel.
As noted above, for standard defined volumes of crude and natural gas, crude oil is just over 6X as dense in energy content as natural gas. Despite this disparity of energy content, in several world societies natural gas has been the object of uninterrupted FT refining since approximately the year 1930. FT energy conversion, or refining, is similar to traditional catalytic cracking of crude oil only in its reliance on catalysts to facilitate molecular re-forming at various points in the conversion process. The overall FT process consists of two steps: the first is known as Steam Methane Reformation or SMR. In the SMR process, which necessarily precedes the FT process, a molecule of CH4 is introduced to the SMR catalyzing environment (the “SMR Environment”).
Simultaneously a molecule of pure water (H2O) is introduced to the SMR Environment at 800̊ C (1,365̊ F). A nickel (Ni) catalyst facilitates a reaction between the CH4 and H2O to produce a carbon monoxide (CO) and three (3) hydrogen (H2) molecules. From the SMR Environment both the CO and H2 molecules are entrained into the FT catalyzing environment (the “FT Environment”), which is maintained at a precise temperature at or very close to 250̊ C (449̊ F), a controlled pressure and a set flow-rate. In the presence of a specific catalyst, these gases again react, this time forming hydrocarbon chains, CH3-(CH2)n-CH3, (where the chain length is n+2) and (n+2) H2O molecules.
Because FT molecular recombination is a complex chemical reaction whose efficacy with respect to favored hydrocarbon chain lengths and product distribution is dependent upon temperature, pressure, flow-rate, and catalyst composition, the researchers at a leading university have focused intensely upon the optimization of all of these variables. As a result of the ongoing research, the Portable Technology has reached an efficiency of output with respect to favored hydrocarbon molecules that greatly improves on all other embodiments of the FT process. The purpose of this research has been to assure not only that the favored long-chain hydrocarbon molecules are produced to the near-exclusion of non-favored hydrocarbon molecules, but also that collateral products such as H2O, CO, and carbon dioxide (CO2) are minimized.
Additionally, it is of great importance to concentrate on the absolute minimization of reconstituted CH4, which must be either recirculated through the entire process beginning at the SMR, re-introduced into production formations as a production stimulant, or vented off. None of these options is attractive. By exercising rigorous control of the relevant process conditions, reconstituted CH4 is minimized.