NATCHEZ — If you’ve seen a car commercial, or heard a presidential candidate speak lately, there’s one common theme — they’re all going green.

The candidates say they are going to work hard to pass legislation to protect the environment and the car companies all try to boast high miles per gallon and low emissions.

And while many Americans support a greener environment, here in Natchez a company with an unknown environmental footprint is coming.

In April, Rentech will be closing on 450 acres of land where they plan to build a $4 billion fuel development plant.

Rentech says the plant, to be built on the old International Paper site, will make ultra-clean diesel, jet fuel and a handful of other chemicals.

And while many environmentalist groups are in a constant search for clean burning fuels, some take issue with Rentech.

Specifically, environmentalists don’t approve of Rentech’s process by which they make their fuels.

For their part, Rentech argues that technology they will use is cutting-edge and therefore cannot be so harshly criticized.

As of now, the only certainty surrounding Rentech’s tentative environmental impact in Adams County is uncertainty.

Well, uncertainty and the fact that environmental groups like the National Resources Defense Council don’t like what Rentech plans to do.

The NRDC’s climate policy specialists Elizabeth Martin Perera can succinctly sum up the NRDC’s position on Rentech’s process.

“We are staunchly opposed to the coal-to-liquid process,” she said.

The process that Perera is referring to is Rentech’s process by which coal or petroleum coke is gasified.

That gas, called synthesis or syn gas, can then be turned into any number of other products.

Rentech hopes to contribute to a decreased dependency on foreign oil by turning much of their syn gas into ultra-clean diesel.

While the gasification process has been around since the 1920s, traditionally low oil prices and the high cost of plant development have essentially left the technology sitting on the shelf with the exception of a few plants worldwide.

But no matter when the technology was invented, environmentalists like Perera still don’t like it.

Perera said there are two core components of Rentech’s process she doesn’t like.

First Perera said the heavy use of coal in the process unduly uses a non clean-burning fuel.

Secondly, and most importantly, Perera and the NRDC say they dislike the fact that Rentech will unnecessarily generate huge amounts of carbon dioxide in the gasification process and running of the plant.

But for each problem that NRDC brings up, Rentech seemingly has the solution.

Rentech’s Project Manager Joe Regnery said to base Rentech’s gasification technology on coal alone is simply inaccurate.

“There are many myths generated by what we do,” he said.

In addition to coal, Rentech will use petroleum coke and other bio-mass sources, including municipal waste, to fuel its gasifies.

But perhaps Rentech’s biggest ace-in-the-hole regarding their carbon dioxide output the NRDC so strongly dislikes is Denbury Resources.

Regnery said Denbury has committed to purchasing 100 percent of Rentech’s carbon dioxide for their oil recovery plant in Cranfield.

And Rentech does not seem to be the only group that thinks the Denbury solution is a good plan.

In November the Department of Energy gave researchers at the University of Texas at Austin a $38 million grant to study carbon dioxide sequestration at the Cranfield site.

At its core the Denbury plan will store all of Rentech’s CO2 in underground saline aquifers.

Susan Hovorka a senior research scientist with the university said the Cranfield site will be the first of its size in the country.

“We’re very excited,” she said.

Director of the University of Kentucky’s Center for Applied Energy Research Burt Davis said Rentech’s carbon dioxide capture program lends to their feasibility.

Davis said a similar company in North Dakota is successfully selling their excess CO2 to a company in Canada that reuses it.

However, carbon sequestration is not foolproof.

“Right now there is not enough long-term data to show how permanent it is,” Davis said.

And long-term sequestration data is not the only unknown with Rentech right now.

Mississippi Department of Environmental Quality’s Public Information Officer Brad Mayo said Rentech has not filed an Environmental Impact Statement with the DEQ yet.

Mayo said without that information it’s not possible for the DEQ to form an opinion about Rentech.

The statement provides the agency with Rentech’s plan for how they think they will impact the surrounding environment.

Regnery said the paperwork will not be filed until construction starts and Rentech has a better understanding of what equipment they will be using at the Natchez site.

Regnery said has multiple options regarding what components they can build their plant from.

The individual machinery will still produce the same product but each component will have different environmental impacts Regnery said.

“We take into account environmental stewardship in every decision we make,’’ he said.