GasTechno first single-step GTL process PDF Print E-mail
Written by Walter Breidenstein   
Sunday, 18 April 2010 02:49
Article Index
GasTechno first single-step GTL process
The GasTechno Process
Meeting the Challenges of Direct Partial Oxidation
GasTechno Economic Advantages
GasTechno Applications
GasTechno Business Models
Conclusions
All Pages

Introduction

The GasTechno® process is the world’s first single step process for converting natural gas into transportable liquid fuels and petrochemicals. With a wide range of applications and end products, the GasTechno® process is one of the best alternatives to wasting natural gas. In many cases, it is the only alternative!




Natural gas is not only found in vast fields all over the world, it’s a common and unavoidable byproduct of oil production, landfills, and various agricultural businesses. This makes it one of the most widely available sources of energy; however, it is also one of the most problematic to deliver to the end consumer. As a fuel it lacks the energy- density of liquid fuels and requires expensive pipelines or cryogenic liquefaction facilities and vessels to transport. Furthermore, pipeline specifications typically set limits on the amount of carbon dioxide, nitrogen, and other chemicals often found in natural gas making the resource unusable without additional costs of pretreatment.

Alternatively, natural gas can reformed into syngas and then further converted into methanol and other liquid petrochemicals. This route has been in commercial use for decades and allows remote sources of natural gas to be utilized. Unfortunately, syngas technologies are quite complex and have multiple reactions, multiple inter-stage purification steps, and high-maintenance catalysts. As a result, these technologies require sufficient economies of scale to be economically viable.

The majority of stranded natural gas sources are too small to be utilized by syngas technologies. For these applications, the GasTechno® process is the only option.


THE GASTECHNO® PROCESS

The premise of the GasTechno® process is to avoid the traditional syngas step of production by converting methane directly into methanol without a catalyst (direct homogenous partial oxidation) and from there into any number of desirable end products:

Direct homogenous partial oxidation has been known for decades, but historically it has suffered from a trade-off between high selectivity and high conversion. Until now, you had to choose between one or the other. Too much oxygen and you end up with carbon dioxide. Too little oxygen and there simply is enough methanol being produced to make the reaction practical.


The GasTechno® process has solved this problem through the propriety design of its reactor and scrubber systems. These two systems work together as part of an energy- neutral recycle loop where unreacted methane is cleaned (via the scrubber) and recycled until a desired overall conversion is achieved. Sound simple? It is. In fact, the process cannot be any simpler:

The carbon efficiency of the GasTechno® is comparable to syngas-based technologies in use today, proving that the selectivity/conversion has finally been solved.


MEETING THE CHALLENGES OF DIRECT PARTIAL OXIDATION

The greatest challenge to homogeneous direct partial oxidation is controlling costs associated with having a large recycle loop. These recycle costs occur during heating, cooling, compression, and gas clean-up.

  • Recycle loop heating requirements?
    Because of the exothermic nature of the reaction, there is actually a surplus of energy available for integration with the distillation and purification side of the process. The process has no heating requirements beyond what can be captured via heat integration.
  • Recycle loop cooling requirements?
    The scrubber process is sufficiently effective in removing impurities that cryogenic temperatures are not needed. Methanol is easily recovered at ambient conditions.
  • Recycle loop compression requirements?
    Even though the recycle is large, the process is designed to preserve pressure along the recycle loop to minimize recycle compression. In many cases it is possible to employ a high- pressure blower rather than a recycle compressor!
  • Recycle loop gas clean-up requirements?
    The reaction can tolerate the presence of impurities so the task is to control them (not eliminate them). To accomplish this, the methanol produced is used to scrub the recycle gas. Furthermore, the reaction can tolerate the presence of high levels of nitrogen allowing the process to employ inexpensive 90-95% PSA oxygen plants for oxygen.


GASTECHNO® ECONOMIC ADVANTAGES

Technologically, the GasTechno® process has the advantages one would expect to find in a simple, single-step, non-catalytic process that converts methane into liquid fuels/chemicals. It’s transportable, durable, versatile, and scalable. These technical advantages translate into economic strengths. The most significant advantage is that the process is far less expensive to construct than traditional, syngas-based technologies.


The capital savings of the GasTechno® process vary depending on plant size with smaller applications having a more pronounced relative advantage to competing technologies than larger ones. To even compare the GasTechno® process with other gas-to-liquid or gas-to- chemical processes, we must examine the economics and larger scales where the advantages are less pronounced (traditional technology is simply not applicable at small scales, even for the purpose of comparison). The table below shows the general breakdown of these economic advantages at a scale of 30MMSCFD and a natural gas price of $1.50/mmbtu (all revenues are based on March, 2009 prices).


GASTECHNO® APPLICATIONS

GTL is focused on four specific market sources of methane: off-spec natural gas, landfill gas, biogas, and associated gas. Off-spec natural gas is, by definition, any gas that requiring processing due to being sour, having too high of a btu content, or having too much nitrogen to put into a natural gas pipeline. Landfill gas (produced by landfills) and biogas (produced by biodigesters) are typically a 50/50 mixture of methane and CO2. The GasTechno® process can be used for all of these off-spec applications without any pretreatment making it an attractive option. One of the most interesting applications for the GasTechno® process is associated gas which is a byproduct of oil production. What makes associated gas applications so interesting is how well the GasTechno® process not only utilizes the associated gas, but solves other issues facing oil producers:

  • As oil production peaks and declines, so too does the associated gas production. The GasTechno® process can accept a wide range of feed rates without interruption of plant operations.
  • As oil production declines, the maturing oil field produces heavier oil which can become difficult to transport via crude pipelines (especially in cold climates). The GasTechno® process produces methanol which can be (and has already been) used in crude pipelines to prevent hydrate formation and to act as a solvent to decrease the oil’s viscosity.

An oil refinery is an ideal location to recover the methanol and convert it into other hydrocarbon fuels or petrochemicals. One of the most interesting applications is converting methanol into gasoline.


GASTECHNO® BUSINESS MODELS

Different customers have different needs when it comes to implementing the GasTechno® process. Small scale customers are unlikely to want to become involved in operating the plant itself and being in the business of methanol sales. Medium scale producers focused on the upstream oil business are unlikely to want to become involved in methanol sales or, in some cases, taking on a chemical process as part of their business model. Large scale producers are likely to want ownership in a large project with large profit potential. With these different needs in mind, the GasTechno® process is offered in three different packages. For small scale producers the GasTechno® process is offered as a lease and the off-loading of methanol is contracted. For medium scale customers, the GasTechno® process is offered as a customer for their natural gas. A gas price is negotiated and the gas producer can simply sell their gas to GasTechno® process at no risk. For large scale producers, a joint venture is preferred were the risks and rewards of a larger project can be shared.


CONCLUSIONS

The hundreds of millions of cubic feet of natural gas being flared across the world every day is the only evidence needed to demonstrate that industry has yet to solve this important environmental and economic problem. That long awaited solution is now at the doorstep of commercial readiness. The GasTechno® process can convert methane of almost any quality into methanol. From there, any number of attractive, green alternative fuels or petrochemicals can be produced. Finally, there is a solution that does not require a choice between the environment and economics. If you have methane, the GasTechno® process is always an option.

Last Updated on Monday, 19 April 2010 17:58