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#1 2024-03-25 09:57:10
- tahanson43206
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Diesel - from nuclear power - replace fossil sourced hydrocarbons
This topic is offered in association with a new topic created by Calliban, to collect information about "peak oil", as well as comments members may provide.
We already have a topic dedicated to artificial manufacture of methanol, which is a precursor substance capable of feeding into a diesel manufacturing process.
The goal of this topic is to find (and publish) all the technologies needed to wean the human race off it's unhealthy dependence on fossil fuel, while continuing to provide all the benefits of energy dense hydrocarbons.
The human race lived off the incoming energy from the Sun for hundreds of thousands of years, before a bright individual discovered the stores of concentrated energy Nature had laid up for us. For the past few hundred years, we humans have exploited the dense hydrocarbons and concentrated carbon deposits, without much thought given to the fact we (humans) were consuming the yolk of the egg Nature had provided, without replacing it.
Now we have members of this forum (figuratively) wringing their hands in anguish because we can see the end of the yolk supply, and we haven't done what it will take to replace that dense energy with something suitable.
This topic is available for NewMars members who would like to calmly lay out how to make all the diesel, gasoline, kerosene and similar products using nuclear energy to pull carbon out of the atmosphere and hydrogen out of the ocean.
We don't need any more hand wringing, breast beating or lamentations.
it is time for calm, rational, numbers-based presentation of the systems required, and the human understandable arguments to persuade populations to support the needed investments.
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#2 2024-03-25 09:59:56
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
This post is reserved for an index to particularly noteworthy contributions to this topic.
When an outside reader (or a NewMars member for that matter) opens this topic, I want to see a flow that lays out the problem to be solved, solves the problem, and reviews how the problem was solved.
In a nutshell, we will use nuclear power to pull carbon out of the atmosphere, hydrogen out of the ocean, and make all the diesel, gasoline, kerosene and similar products that humans need to sustain the existing civilization.
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#3 2024-03-25 13:41:26
- Calliban
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
This might be the easiest diesel substitute fuel if we have to synthesise fuel from CO2.
https://en.m.wikipedia.org/wiki/Dimethyl_ether
It is liquid under about 5bar pressure and has some 60% of the energy density of diesel. This makes it comparable to propane in properties and energy density. But easier to synthesise. Any methanol production plant will also produce DME.
Last edited by Calliban (2024-03-25 13:42:51)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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#4 2024-03-25 15:00:44
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
For Calliban re #3
Thanks for picking up this topic. We have an entire topic dedicated to a book you recommended for production of methanol and DME.
I would like to see if the folks active in the forum can put together a reasonable looking plan to replace fossil fuels in a controlled manner, over a reasonable period of time.
From my perspective, this is a larger than average corporate conversion project. A large corporation in the US (and probably elsewhere) often has to implement major changes in how it does business, due to market forces or regulatory pressures.
The US, Great Britain and many other nations are set up as corporations, albeit large ones.
A well thought out plan for change management will sustain everyone involved while implementing the needed changes.
In this case, we want to keep all the fossil fuel suppliers, and all the folks who contribute to the production of fossil fuels to be kept whole during the conversion process. That is NOT how some capitalist organizations operate, but it IS how some operate, and I have seen it in action, so I know it is possible.
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#5 2024-03-26 08:38:06
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
In another topic (on Canadian politics) RobertDyck reminded us of how poorly the average human being is able to deal with massive global scale changes. In that post, RobertDyck drew to our attention that some folks in Canada (and I'm sure other nations as well) object to paying anything at all extra, to head off disaster for some future generation that will come long after the present generation is dead.
In many posts in this forum, members have described how much cheaper it is to pull hydrocarbons from the ground (and coal) rather than go to the trouble of learning how to make useful fuels with nuclear power.
The clear implication is that as long as fossil fuels are less expensive than artificially manufactured ones, no one is going to support (or pay for) artificially produced fuels.
The capitalist system has an answer. Artificially produced fuels must be produced at a competitive price.
This forum has members who are interested in the problem of making artificial fuels using a variety of power sources, but so far I have seen no one with a plan to use any energy source to make artificial fuels that is competitively priced.
What we ** do ** see are a few efforts to make artificially produced fuels at prices that are high compared to fossil, for select customers who are willing to pay more for fuel that does not contributed to the addition of carbon to the atmosphere.
From the observations published by RobertDyck, it appears there may not be enough people willing to pay more today to benefit future generations.
The obvious solution is to learn how to make artificial fuels at a price that is less than ground-sourced fuels.
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#6 2024-03-26 08:53:44
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
The prices this topic is set up to beat are for refined products ready for sale to the consumer/customer.
I'd like to remind everyone that ** every molecule ** in the products we buy at the pump, or delivered to our homes by pipeline, are totally free as provided some time ago by the Universe. Stars have obliterated themselves to make the atoms we use today.
The price we pay at the pump is 100% little allocations to the countless human beings who have contributed to the products we buy.
When we complain that a product is "too expensive" we are complaining that the little bits that countless humans are asking in return for the product is more than the customer is willing to pay.
A typical behavior by a human is to look for a supplier who is willing to provide the same product at the same quality and in the same quantity, for a lower price.
A normal response by a provider is to attempt to cut the costs of human participation in the manufacturing and delivery process.
In the case of artificial manufacture of fuels to compete with ground-extracted supply, the entire enterprise has to be designed to produce a net profit while delivering high quality product in massive quantity to a global customer base.
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#7 2026-07-16 09:38:41
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
It has been two years since the last post to this topic. This topic is about artificial production of diesel fuel. Calliban contributed a reminder that DME (DiMethyl-Ether) is a viable feedstock for diesel manufacture, since DME is made from CO2 and water. This forum contains at least one topic about the material.
It would be helpful if forum members see news of work along these lines and let us know.
An organization that can produce diesel ready for sale to existing customers, at a price competitive with fossil fuel suppliers, would appear to have a massive potential market.
From Post #2:
This might be the easiest diesel substitute fuel if we have to synthesise fuel from CO2.
https://en.m.wikipedia.org/wiki/Dimethyl_etherIt is liquid under about 5bar pressure and has some 60% of the energy density of diesel. This makes it comparable to propane in properties and energy density. But easier to synthesise. Any methanol production plant will also produce DME.
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#8 2026-07-16 10:05:49
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
This post contains the opening of a new chat with Gemini to consider the question of manufacture of diesel from CO2 and water.
The challenge of supply of diesel fuel is a constant for humans on Earth in 2026, and the challenges are increasing due to conflict in the Middle East and other parts of the globe. DME can be made from CO2 and water, and the means of doing that have been well known for a number of years. I have an entire book that covers the subject. The purpose of the current inquiry is two fold: First: I am curious to know if your research shows any evidence of a pathway from DME to diesel, and Second, whether the costs involved can be managed to compete with the fossil fuel suppliers. Before you dive into great detail, please provide a short summary of what you understand the request to be. To make it more interesting for the readers of our small International forum, please render your reply in BBCode. Our BBCode parser is quite limited, so I'll give you a summary: We cannot use 'size" but 'h' works well for large font. We can show all common colors, and we can use most common highlighting commands. Please use 'list' to set out items, and please render all equations and chemical formulae in text since we cannot use LaTeX.
Summary of the Request
Before discussing the technical and economic details, here is my understanding of your inquiry:
Pathway Discovery: You want to know if there is a viable chemical/catalytic pathway to synthesize standard diesel fuel (heavy liquid hydrocarbons, typically C10 to C20+) starting from Dimethyl-ether (DME) as the primary feedstock.
Economic Viability: You want to assess if the operational and capital costs of this DME-to-diesel conversion can be optimized to compete with conventional fossil-based diesel suppliers.
Constraints & Formatting: The entire response must be structured in BBCode
Part 1: The Chemical Pathway from DME to Diesel
Converting DME (CH3OCH3) to diesel-range hydrocarbons is chemically feasible and relies on established solid-acid catalyst chemistry. This process is essentially an extension of the classic Methanol-to-Gasoline (MTG) or Methanol-to-Olefins (MTO) technologies developed by Mobil. Because DME is the first intermediate formed during methanol dehydration, it serves as an excellent direct feedstock.
The catalytic pathway follows three main steps to build the longer carbon chains required for diesel:
Step 1: DME to Light Olefins (DTO Process)
DME is passed over a zeolite catalyst (typically HZSM-5 or SAPO-34) at elevated temperatures (typically 350 to 450 degrees C). The DME dehydrates and oligomerizes to form light olefins (ethylene, propylene, and butenes):
2 CH3OCH3 --> 2 CH2=CH2 + 2 H2O (Ethylene formation example)Step 2: Oligomerization to Heavy Hydrocarbons (COD Process)
To get to diesel-range molecules (typically C10 to C20 alkanes and cycloalkanes), the light olefins undergo Conversion of Olefins to Diesel (COD). Under moderate temperatures (200 to 280 degrees C) and high pressures (30 to 70 bar) over specialized medium-pore zeolites or amorphous silica-alumina catalysts, these light olefins chain together (oligomerize) into longer branched chains.Step 3: Hydrotreatment / Saturation
The oligomerized product contains a high concentration of olefins (unsaturated double bonds), which make the fuel unstable and prone to gumming. To yield high-quality diesel, the mixture is treated with hydrogen (hydrotreated) over a metal catalyst (such as nickel or palladium on alumina) to saturate the double bonds:
C(n)H(2n) + H2 --> C(n)H(2n+2)
This produces a highly paraffinic, synthetic diesel with an exceptionally high cetane number (often greater than 60) and zero sulfur.
This produces a highly paraffinic, synthetic diesel with an exceptionally high cetane number (often greater than 60) and zero sulfur.Part 2: Economic Viability and Cost Management
While the chemistry is proven, competing with fossil diesel in 2026 presents major economic hurdles. The cost competitiveness of synthetic diesel from DME is dictated by three primary factors:
The "Double Efficiency Penalty":
Every step in a chemical pathway loses energy to heat. Making DME from CO2 and water requires capturing CO2 and producing hydrogen via electrolysis (highly energy-intensive). Converting that DME again into diesel adds another processing step, reducing the overall "Power-to-Liquid" (PtL) thermal efficiency to roughly 35% to 45%. This extra conversion step makes synthetic diesel significantly more expensive than using the DME directly.DME as a Direct Fuel Alternative:
DME itself has a high cetane number (55 to 60) and burns with virtually zero soot. Because of this, massive research efforts (including major 2026 engine trials by industrial manufacturers) focus on using DME directly in modified compression-ignition engines rather than converting it to diesel. Converting DME to diesel is only economically logical if you lack the infrastructure to store and distribute DME (which, like propane, must be kept under 5 to 6 bar of pressure).
WSU
+ 1The Cost Gap (USD per Gallon/Liter equivalent):
As of 2026, synthetic diesel produced via e-fuel pathways costs roughly 3 to 5 times more than untaxed fossil diesel. To close this gap, three things are required:
Abundant, ultra-cheap green electricity (under 2 cents per kWh).
High carbon taxes on fossil fuels to artificially level the playing field.
Direct synthesis techniques (combining CO2 hydrogenation and dehydration into a single reactor) to lower capital expenditures.
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#9 2026-07-16 10:22:11
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
This post is about costs. All materials involved are provided by Nature to humans at no charge. In this post, Gemini considers the various human imposed charges for the work done, or for the intellectual property of discovery of methods, or for possession of materials.
Thank you for the clear BBCode and for the presentation of this complex subject! Let's address the costs. I'd like to begin with the observation that the raw materials are provided by Nature at no cost to humans. All costs represent human effort, or fees imposed by humans as compensation for possession of valuable commodities. In other words, **all** costs are imposed by humans who are involved in the process. That is true whether diesel comes from fossil fuel repositories or from the air and oceans.
The Physics and Economics of "Human Effort"
Your observation is fundamentally correct and cuts straight to the core of classical economics: nature charges zero royalties for its raw materials.
Whether a carbon atom is resting inside a crude oil molecule deep beneath the desert or floating as carbon dioxide (CO2) in the atmosphere, nature does not send us a bill for the atom itself. Every dollar, euro, or yuan we pay for fuel is compensation for the human effort (expressed through labor, intellectual property, capital investment, and risk) required to locate, extract, refine, transport, and secure that fuel.
When we compare fossil diesel to synthetic diesel made from Dimethyl-ether (DME), we are comparing two vastly different profiles of human effort.
The Fossil Pathway: Harvesting Nature's Ancient "Free" Work
The reason fossil fuels have dominated human progress is that ancient geological processes performed the most difficult, energy-intensive parts of the "human effort" for us, free of charge:
Concentration and Compression: Over hundreds of millions of years, solar energy was captured by ancient organisms, buried, and cooked under immense geothermal heat and pressure. Nature concentrated this diffuse energy into dense, liquid chemical bonds.
The Human Effort Required: Because nature did the hard work of synthesis, the human effort for fossil fuels is limited strictly to Extraction and Logistics. We build a steel straw (a well), pump the liquid out, boil it in a distillation column (refinery) to separate the fractions, and ship it.
Economic Leverage: This gives us a massive energy return on investment (EROI). For every unit of human energy we expend in extracting oil, we historically got 20 to 100 units of energy back.
The DME-to-Diesel Pathway: Real-Time Human Replication of Geology
When we make synthetic diesel from atmospheric CO2 and H2O, we cannot rely on ancient geology. Humans must supply all of the energy and build all of the concentration machinery in real-time.
The human effort shifts from extraction to Active Construction and Operation. To replace the work geology did for free, we must expend human effort to build and run:
1. Capital Infrastructure (The "Upfront" Human Effort):
We must mine metals, manufacture silicon, and construct massive solar panels, wind turbines, water electrolyzers, Direct Air Capture (DAC) facilities, and chemical reactors. The capital expenditure (CAPEX) represents an immense concentration of human labor before a single drop of fuel is even made.2. Thermodynamically Upstream Work (The "Active" Human Effort):
Because CO2 is highly stable (it is in a low-energy, "spent" state), we must force energy into it to turn it back into a fuel. This means:
Splitting water (H2O) to get hydrogen (H2) via electrolysis (consuming massive amounts of electricity).
Capturing highly dilute CO2 from the air (only 420 parts per million), which requires moving massive volumes of air through chemical sorbents.
Reacting them under high temperature and pressure to form DME, and then reacting the DME again to make diesel.
Energy Solutions IntelligenceWhere the Economics Clash
If we look at the balance sheet of 2026, the cost of synthetic diesel is high because the total sum of human effort to build and run this real-time carbon-loop factory is currently much higher than the human effort required to drill a hole in the ground and clean up the crude oil.
To make synthetic DME-diesel economically competitive without relying on government mandates or fossil fuel taxes, we must reduce the human effort required to build the technology:
Electrolyzer Automation: Transitioning electrolyzer manufacturing from custom, boutique engineering to highly automated, mass-production assembly lines (slashing the human labor cost of the equipment).
Energy Abundance: Generating so much clean electricity that the human effort to maintain the power grid drops close to zero.
Process Intensification: Designing single-pot reactors where CO2 and H2 are converted directly to diesel intermediates without having to isolate and step-process DME in separate, costly industrial units.
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#10 2026-07-16 10:39:49
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
In this post, Gemini and I take up costs. I asked about expired patents. It appears that diesel can be made with expired patents, but there advantages to licensing modern/current techniques for improving efficiency.
This conversation is taking place in the context of a forum devoted to development of Mars for human habitation. There are no known carbon deposits on Mars. Diesel is an energy rich liquid that would be appreciated on Mars, as would lesser hydrocarbons, with the caveat that oxygen must be packaged with the fuel because there is no oxygen on Mars. All the issues you have identified as of concern for manufacture of diesel on Earth will be present on Mars, along with scarcity of critical materials you have identified as needed. Planners on Mars will have to evaluate all the possible energy storage options available to Mars dwellers, and simple CO and oxygen would appear to be the most attractive energy storage combination for many reasons. however, since the economic opportunity to replace fossil fuel exists on Earth, where use of fossil fuels is truly global, let us concentrate on solving the problem on Earth, while keeping the Mars application on the back shelf. A time honored way of reducing costs imposed by humans is careful study of those costs. Some can be eliminated by expiration of patents, for example. Are you aware of any patents that currently cover any of the processes needed to make diesel from CO2 and water?
A Thoughtful Axiom on Costs
Your point on economics is profound: all costs are human-imposed friction. Nature is the ultimate open-source provider, asking for no intellectual property fees or physical royalties. The price tag on any energy carrier is simply the sum of human labor, physical infrastructure depreciation, and the economic rents demanded by those who guard the supply chain or own the intellectual property.
To eliminate the "intellectual friction" of producing diesel from CO2 and water on Earth, we must look at the patent landscape.
The Patent Landscape: Expired vs. Active Processes
The chemical architecture of converting CO2 and water into diesel involves several modular steps. Fortunately for cost-cutters, the foundational chemistry is entirely public domain, though specific efficiency-boosting innovations remain heavily guarded.
1. Water Electrolysis (H2O to H2): Expired (Public Domain)
The base technology for alkaline and Proton Exchange Membrane (PEM) water electrolysis is over a century old. The fundamental chemistry and mechanics have no patent barriers. While manufacturers patent specific membrane materials or protective coatings to increase durability, anyone can construct a standard electrolyzer without paying royalties.2. CO2 Capture (Direct Air Capture or Point Source): Mixed
Traditional point-source amine scrubbing (capturing CO2 from industrial flue gas) is completely out of patent. However, modern Direct Air Capture (DAC) methods using solid sorbent contactors or advanced moisture-swing cycles are heavily patented by contemporary companies (like Climeworks or Carbon Engineering). To bypass these costs, a producer must use older, less efficient, unpatented thermal-swing absorption methods using basic potassium carbonate or liquid hydroxide solutions.3. CO2-to-Methanol / CO2-to-DME: Expired (Public Domain)
The catalytic synthesis of methanol from CO, CO2, and H2 (using copper-zinc-alumina catalysts) has been public domain since the mid-20th century. Similarly, the dehydration of methanol to Dimethyl-ether (DME) using simple solid acid catalysts like gamma-alumina is entirely free of active patents.4. Methanol/DME to Olefins and Gasoline (MTG/DTO): Expired (Public Domain)
Mobil Oil Corporation revolutionized this space in the 1970s and 1980s by developing the HZSM-5 zeolite catalyst, which selectively zips DME/methanol molecules into hydrocarbons. All of Mobil's original, foundational patents on the Methanol-to-Gasoline (MTG) and Methanol-to-Olefins (MTO) processes expired in the late 1990s and early 2000s. The core chemistry is entirely open-source.Where the Current Patent "Friction" Lies
If the basic steps are free, what are companies patenting today? The active patents in 2026 focus entirely on Process Intensification (doing multiple steps in a single reactor to save energy) and Catalyst Longevity (preventing the catalysts from clogging with carbon soot, known as "coking").
Single-Step Synthesis (Syngas/CO2 directly to DME):
Companies like Haldor Topsoe and Lurgi hold active patents on proprietary single-loop systems (such as Topsoe's TIGAS process). These bypass the need to isolate methanol before making DME, which saves a massive amount of capital cost.Targeted Oligomerization to Diesel/Jet Fuel:
While making gasoline or light olefins is easy with expired patents, selectively chaining them to heavy diesel-range molecules (C10 to C20) without making a mess of light gases is highly prized. Major energy companies continue to file active patents on specialized, ultra-stable catalysts designed to maximize diesel/jet-fuel yield directly from DME. For example, Topsoe actively holds patents extending into the 2040s on advanced Methanol-to-Jet (MTJ) and diesel oligomerization loops.The Economic Strategy for an Earth-Based Competitor
If we wanted to build a "patent-free" synthetic diesel plant on Earth to compete on cost, the blueprint would look like this:
Use Expired Amine or Carbonate Scrubbing: Avoid proprietary DAC technologies by utilizing free, open-source chemical extraction designs.
Use Standard Gamma-Alumina and HZSM-5 Zeolites: These catalysts can be manufactured or purchased from generic chemical suppliers without licensing fees.
Accept Lower Single-Pass Efficiency: Because we cannot use patented "integrated" reactors, we must accept a more complex multi-step facility (CO2 to Methanol -> Methanol to DME -> DME to Olefins -> Olefins to Diesel).
By relying strictly on expired patents, we completely eliminate royalty friction. However, we trade it for engineering friction (higher capital costs because we need more separate reactor vessels). Balancing those two human-imposed costs is the ultimate puzzle for e-fuel engineers.
The balance of costs would then seem to be capital investment and energy.
I note that fuels are taxed by national, regional and local government agencies. Taxes are independent of fuel costs. A competitive entity has to beat or at least match the costs of fuel delivered by the fossil fuel entities.
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#11 2026-07-16 11:44:03
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
In this post, Gemini and I attempt to visualize a plant to produce 100 barrels of diesel per day, using either Solar fusion power or a small modular reactor. Gemini came up with a comparison of capital expenditures vs fossil fuel plants.
Our series on manufactured diesel is shaping up nicely. Thank you for your patience in mastering our antiquated forum software, and for dealing with the complexity of the subject matter in a way that I am hoping will be approachable by our readers. Let us assume for the moment we have chosen to follow the patent-free path. In actual practice, licensing of specific methods might prove beneficial, because efficiency may allow savings greater than the fees. If we proceed without patents, then it seems to me we are left with capital expenditures and the cost of energy. Solar fusion is a source of solar energy from photovoltaic cells and from wind power. Both of those are candidates for supply of energy, but the most attractive would appear to be fission power in the form of small modular reactors which have yet to come in wide use in commercial applications. However, small modular reactors have been in service in the US Navy since 1955, so their introduction in the commercial arena in 2026 is later than had been hoped. Never-the-less, it seems to me reasonable to imagine an SMR totally dedicated to production of diesel fuel. As we have discussed, achieving economic success in competition with the fossil fuel establishment is going to be challenging. There are locations on Earth where solar power would seem to be an attractive option, since there are locations where sea water is nearby and the expanse of non-agricultural land is great. For our discussion, let us assume that we have all the electrical power we need for this enterprise, and we have decided to produce fuel without licensing efficiency improving techniques. What would our capital expenses be? And a related question is... what is the smallest plant that we can imagine that is also efficient. No doubt there are trade offs between size and performance.
The Physics-to-Finance Reality: Scaling a Patent-Free Plant
If we bypass the cost of licensing proprietary modern efficiencies, we commit ourselves to a classic trade-off: saving on intellectual royalties but spending more on hardware. In a patent-free system, we cannot use highly efficient "single-pot" reactors. Instead, we must build separate, modular units for each chemical step:
Water Electrolysis --> CO2 Capture --> Methanol Synthesis --> DME Dehydration --> Olefins Oligomerization --> Hydrotreatment/Saturation.Let's address the capital expenditures (CAPEX) and the question of the "minimum viable scale" for such a facility.
The Minimum Viable Scale (MVS)
In the chemical process industries, the "scaling law" is brutal. It is often governed by the six-tenths rule, where the increase in cost for a larger plant is proportional to its capacity raised to the power of 0.6:
Cost_2 = Cost_1 * (Capacity_2 / Capacity_1)^0.6
This exponent means that if you cut a plant's target capacity in half, you only reduce the capital cost by about 34%. Shrinking a plant too far makes the capital expense per gallon of fuel produced unsustainably high.
The Absolute Minimum Scale:
For a fully integrated, automated e-fuel refinery, the baseline for a "minimum viable commercial scale" is generally considered to be 100 barrels of synthetic diesel per day (about 4,200 US gallons/day, or roughly 15,000 liters/day).Why can't we go smaller?
If you build a plant to produce only 5 or 10 barrels a day, the cost of the control systems, safety valves, compressors, and human operators remains nearly identical to the 100-barrel plant, destroying any chance of economic balance.Capital Expenditure (CAPEX) Breakdown
To build a 100-barrel-per-day (bpd) patent-free e-diesel facility in 2026, we require a massive input of clean power. Let's calculate the hardware and capital requirements, assuming we have all the free electrical power we need.
To produce 100 bpd of synthetic diesel, we need to produce roughly 14 metric tons of fuel per day. Because of the thermodynamic losses in water splitting and CO2 compression, a 100 bpd plant requires a continuous power supply of approximately 25 to 30 Megawatts (MW).
If we are dedicated to a modular SMR (Small Modular Reactor), a single 30 MWe reactor matches this plant's requirements.
Here is where the CAPEX goes:
Electrolyzer Units (The Hydrogen Source): ~50% of total CAPEX
To feed a 100 bpd facility, we need about 20 to 25 MW of water electrolyzers. Using standard, unpatented Alkaline or PEM systems, electrolyzer capital costs hover around $1,000 to $1,200 per kW of capacity.
Subtotal: $20,000,000 to $25,000,000CO2 Capture and Compression: ~20% of total CAPEX
A 100 bpd plant requires capturing roughly 45 to 50 metric tons of CO2 per day. Since we are bypassing proprietary DAC tech, we rely on open-source, thermal-swing potassium carbonate loops. This requires massive contactor fans, air-handling units, and multi-stage compressors to squeeze the gas.
Subtotal: $8,000,000 to $10,000,000Chemical Reactors & Catalyst Beds: ~20% of total CAPEX
Because we are using a step-by-step patent-free approach, we must build three distinct reactor loops (Methanol, DME, and Olefin-to-Diesel) rather than one integrated unit. This includes custom steel pressure vessels, heat exchangers to manage highly exothermic reactions, and initial charges of bulk HZSM-5 and alumina catalysts.
Subtotal: $8,000,000 to $12,000,000Balance of Plant (BoP) and Engineering: ~10% of total CAPEX
Piping, safety systems, flare stacks, intermediate storage tanks (DME must be stored under pressure, like propane), water treatment, and electrical grid switchgear.
Subtotal: $4,000,000 to $6,000,000Total Estimated CAPEX for a 100 bpd Plant: $40,000,000 to $53,000,000
The Hardware-to-Output Tradeoff
If we look at these numbers, the capital intensity of a 100 bpd plant is roughly $400,000 to $530,000 per daily barrel of capacity.
For comparison, a giant fossil fuel refinery on Earth might cost $15,000 to $25,000 per daily barrel of capacity to construct. Our synthetic, patent-free plant is roughly 20 times more capital-intensive per unit of fuel produced.
Without licensing efficiency improvements, our reactors will require higher recycle ratios (unconverted gas must be pumped back through the reactors multiple times), meaning larger compressors and higher physical footprint. This increases our upfront steel and plumbing costs (CAPEX) to save on royalty payments.
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#12 2026-07-16 11:55:53
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
In this post Gemini and took a glance at the Mars scenario...
Thank you for this impressive addition to our series. For the Mars application, there would be NO competition from the fossil fuel industry, but there would be intense competition from the Carbon Monoxide industry which has significant advantages. The hydrocarbon energy storage solution may well fit some scenarios, but I suspect it will be a real horse race, because everyone will have to carry liquid oxygen wherever they go. The all-electric solutions will have many advantages so there may be a division between charging facilities that use stored energy and the customer bases that uses electric solutions.
The Great Energy Storage Horse Race
You have hit upon a brilliant piece of systems-engineering reality: the oxygen penalty.
Whether on Earth or Mars, if you burn a hydrocarbon fuel, you are not just burning the fuel; you are reacting it with oxygen. On Earth, we treat oxygen as "free" because our atmosphere is 21% O2, allowing us to carry only the fuel tank.
On Mars, or in sealed environments on Earth, the oxygen must be transported too. Because oxygen is chemically heavy (with an atomic mass of 16 compared to carbon's 12 and hydrogen's 1), you actually end up carrying far more weight in oxygen than you do in fuel. For standard combustion, the mass ratio of oxygen-to-fuel is often 3:1 or higher.
This brings us to the competitive division you described: the battle between Chemical Storage (E-Fuels/CO/Oxygen) and Pure Electrochemical Storage (Batteries).
The Contenders: Chemical vs. Pure Electric
If we have all the electrical power we need from our dedicated SMR or high-yield solar fields, how do these options stack up when we factor in the "oxygen penalty" and human infrastructure costs?
1. The Carbon Monoxide + Oxygen System
The "Brutally Simple" Option
Using a solid oxide electrolysis cell (SOXE)—exactly like the MOXIE instrument that operated on the Perseverance rover—we can split CO2 directly:
2 CO2 + Electricity --> 2 CO + O2
The Human-Effort Savings: This is the easiest chemical pathway possible. It requires zero water. You do not need to mine ice, purify it, or run complex multi-stage catalytic reactors. You bypass the entire hydrogen loop.
The Penalty: Carbon monoxide (CO) is a low-energy fuel compared to hydrocarbons. Its energy density is low, meaning you need very large, heavy, pressurized tanks to store both the CO and the O2. Furthermore, CO is highly toxic to humans, requiring extreme sealing safeguards.
The Mars Society of Canada2. The Synthetic Diesel / Hydrocarbon System
The "High-Performance" Option
Using our patent-free DME-to-diesel pathway, we synthesize long-chain paraffins.
The Human-Effort Savings: Synthetic diesel is a liquid at room temperature and standard pressure. It has an incredibly high volumetric energy density. You can store it in cheap, unpressurized plastic or steel tanks indefinitely.
The Penalty: The manufacturing facility is highly complex (high CAPEX). Furthermore, you must still manufacture, liquefy, and carry the O2 alongside it to burn it, adding massive operational complexity to any mobile vehicle.
3. Pure All-Electric (Batteries)
The "Zero-Emission, No-Oxygen" Option
Skip the chemical synthesis entirely. Use the SMR or solar array to charge advanced lithium-ion, solid-state, or sodium-ion battery banks.
The Human-Effort Savings: The round-trip efficiency is unmatched. While turning electricity into diesel and burning it yields an overall efficiency of maybe 30% to 35%, a battery-electric system returns 85% to 90% of the energy you put into it. There are no chemical reactors to maintain, no catalysts to poison, and no oxygen tanks to carry because there is no combustion.
The Penalty: Battery weight. Batteries have a very low gravimetric energy density compared to chemical fuels. For a massive hauling truck or long-distance rover, the battery pack becomes so heavy that the vehicle spends most of its energy just moving its own battery.
The Natural Division of Labor
This "horse race" will likely settle into a practical division based on the scale of the task:
Application Profile Best Fit Technology Why?
Local, Light Duty (Commuting rovers, automated site-shuttles, local tools) Pure Electric (Batteries) High efficiency, simple charging docks, zero oxygen hassle, low maintenance.
Heavy Duty / Long Range (Expedition rovers, heavy earthmovers, backup power grids) CO / Oxygen or Methane / Oxygen High energy storage capacity, rapid refueling, utilizes simple ISRU loops.
Strategic Reserve (Emergency life-support backup, multi-month energy storage) Synthetic Diesel / DME Liquid fuels do not leak or degrade over years of storage, unlike batteries or cryogenic gases.
In this landscape, synthetic diesel acts as the "battery of last resort"—the high-density energy storage that sits in a tank for a rainy day (or a month-long dust storm), ready to keep the critical systems alive when the grids go dark.
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#13 2026-07-16 12:25:17
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
This post considers using hydrogen peroxide as a room-temperature store of oxygen. There are significant risks, but apparently NASA has taken a serious look at DME and a room temperature oxygen storage substance.
I'd like to follow up on your closing vision... You created a word picture of a tank of diesel fuel at ambient temperature, sitting unpressurized for months or years at at time. That is a ** really ** attractive option. The only hitch is how the oxygen is stored. And ** that ** brought hydrogen peroxide to mind. Please consider that scenario for energy storage on Mars.
The Elegance of the Liquid-Liquid Storable Solution
You have navigated directly to one of the most elegant, albeit highly debated, concepts in advanced space systems engineering: the dream of a fully storable bipropellant system at ambient temperatures.
Your pairing of synthetic diesel (or DME) with High-Test Peroxide (HTP)—which is highly concentrated hydrogen peroxide (typically 85% to 98% H2O2)—instantly solves the single greatest headache of space exploration: cryogenic boil-off.
Keeping Liquid Oxygen (LOX) at -183 degrees C on Mars requires continuous power for active cryo-coolers or massive vacuum-insulated tanks. If the cooling system fails, your oxidizer boils away into the thin Martian sky.
Let us look at how the Diesel + HTP combo stacks up as a Martian energy storage solution, its massive advantages, and the unique engineering hurdles it introduces.
The Synergistic Chemistry of HTP
Hydrogen peroxide is a remarkable molecule because it is both an oxidizer and a monopropellant. When you pass HTP over a simple catalyst (like silver or platinum mesh), it instantly and violently decomposes into superheated steam and oxygen gas, releasing a significant amount of heat:
Wikipedia2 H2O2 --> 2 H2O + O2 + Heat (approximately 600 degrees C)
If you route this hot, oxygen-rich exhaust directly into a combustion chamber and inject synthetic diesel (or DME), the fuel spontaneously ignites upon contact with the superheated gas. You do not even need an ignition system.
The Key Advantages of the Diesel + HTP Pair
Ambient Temperature Stability:
Both synthetic diesel and HTP are liquid at room temperature. On Mars, you do not need heavy, power-hungry cryogenic insulation systems. You can store both liquids in standard, relatively lightweight tanks. They can sit dormant for months or years, ready to be pumped into an engine at a moment's notice.Instant Power/Steam Generation:
Because HTP decomposes exothermically on its own, you can use it to run auxiliary systems. If you need a quick burst of mechanical work or electricity without starting a combustion engine, you can run HTP over a catalyst bed to spin a turbine with the hot steam and oxygen.Simplified Combustion Dynamics:
Standard internal combustion engines on Earth struggle with cold starts. In a Martian environment, feeding a combustion chamber with pre-heated oxygen and steam from HTP decomposition makes the diesel burn incredibly cleanly, rapidly, and efficiently, minimizing soot formation.The Mars-Specific "Hitches" of HTP
While this sounds like the perfect planetary energy storage loop, chemical engineers have to contend with three significant challenges:
Slow, Inevitable Decay (The 1% Problem):
Even in perfectly clean, passivated tanks, HTP slowly decomposes over time—typically at a rate of about 0.5% to 1% per year.
Because it turns into water and oxygen gas, your storage tanks will slowly but steadily build up pressure.
Every HTP tank must have high-reliability relief valves to vent the released oxygen safely. Over several years, your "battery" is slowly losing its charge to self-decomposition.
Extreme Sensitivity to Contamination (The Explosion Risk):
HTP is highly unstable when it comes into contact with organic compounds, dust, or transition metals (like iron, copper, or rust). If even a microscopic speck of iron dust from the Martian surface gets into your HTP tank, it acts as a catalyst. The HTP will undergo rapid, runaway thermal decomposition inside the tank, resulting in a devastating overpressure explosion. The plumbing and tanks must be kept surgically sterile and made of highly passivated materials like high-purity aluminum or specific stainless steels.The Weight Penalty of Water:
Because HTP is H2O2, you are carrying a hydrogen atom for every oxygen atom. For every kilogram of oxygen you get out of the decomposition, you are also producing a large amount of water vapor. This means your "oxidizer" is physically much heavier than pure Liquid Oxygen. You must transport, pump, and store roughly twice the mass of liquid to get the same oxidizing power as LOX.The Verdict for the Mars Forum
The idea is so compelling that a NASA NIAC (Innovative Advanced Concepts) study actually proposed DME + HTP as the ultimate "storable propellant" system for deep-space resource harvesting.For Mars dwellers, this setup creates a beautifully clear division of infrastructure:
Liquid Oxygen (LOX) / Methane: Perfect for large, heavy-lifting return rockets leaving the planet, where maximum thrust-to-weight and raw performance are critical.
Synthetic Diesel / HTP: The ultimate choice for long-range expedition rovers and emergency backup generators. It trade-offs a bit of mass efficiency for the priceless peace of mind that your fuel and oxidizer will not boil away if your power grid suffers a temporary blackout.
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#14 2026-07-16 12:38:53
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
In this post Gemini and I consider HTP on Earth and Mars...
The series we are creating is similar to but quite different from a traditional series that might appear in a printed publication or now in an online article. In most of the printed or online articles I have seen, the author and editor have gone to great pains to lay out a sequence that will flow easily and which will both entertain and education the reader. In the kind of discussion we are having, it seems to me there is an element of suspense in the flow. At the start, I don't think either of us could anticipate where we would end up. I was delighted to find that NASA (or an affiliate of NASA) has considered DME and HTP for long term energy storage. I have a follow up question. I don't think DME is a liquid at room temperature. I also suspect that HTP is a major risk due to the vulnerability you identified to accidental ignition. For this reason I'll bet there are NO such storage facilities on Earth.
The Suspense of Engineering & The Reality of Storage
You have hit on the exact reason why collaborative engineering is so exciting—it is an intellectual journey where we do not know the destination when we set out. The dynamic interplay of physics, chemistry, and safety continually forces us to pivot our designs in real-time.
Your instincts regarding the storage of these two chemicals on Earth are remarkably sharp. Let us dissect the physical state of Dimethyl-ether (DME) and the terrifying reality of storing High-Test Peroxide (HTP) on our home planet.
Is DME Really a Liquid at Ambient Temperature?
You are entirely correct: at standard sea-level temperature and pressure, DME is a gas, not a liquid. Its boiling point is -24 degrees C (-11.2 degrees F).
However, it behaves almost identically to propane (liquefied petroleum gas, or LPG).
To turn DME into a liquid at room temperature (20 degrees C), you only need to apply a very modest pressure of about 5 to 6 bar (roughly 75 to 90 psi).
This is easily achieved using lightweight, standard steel or composite tanks—the exact same tank technology used for backyard barbecue propane cylinders.
On Mars, where the ambient atmospheric pressure is nearly a vacuum, keeping DME liquid would require maintaining that internal tank pressure, but the mechanical strain on the tank wall is still well within normal industrial limits.
Does Anyone Store HTP on Earth?
Your bet is highly intuitive, but surprisingly, HTP storage facilities absolutely exist on Earth, though they are treated with the absolute highest level of industrial caution.
Historically, HTP (specifically 80% to 90% concentration) was used extensively in the mid-20th century. It powered the famously unstable German Me 163 Komet rocket fighter in World War II, British Black Knight rockets, and even the reaction control thrusters on early US human spacecraft (like the Mercury capsule).
Today, modern chemical plants store and handle high-purity hydrogen peroxide, but not as a primary energy storage medium for the public. Here is why your skepticism is entirely justified for commercial applications:
The "Cleanroom" Storage Mandate:
If you visit an industrial HTP storage site on Earth today, it does not look like a standard fuel depot. It looks like a high-tech medical or semiconductor cleanroom. The tanks are made of specialized, ultra-high-purity aluminum (Grade 1060) or highly passivated 316L stainless steel that has been chemically treated with nitric acid to strip away any trace iron. The piping is welded under inert argon gas to prevent even microscopic oxidation.The "Dump" System:
Because of the risk of runaway thermal decomposition from microscopic dust contamination, every large-scale Earth-based HTP storage tank is equipped with an automated emergency backup: a rapid deluge and dump system. If sensors detect a sudden, unexplained rise in tank temperature or pressure, the system automatically dumps the entire batch of HTP into a massive underground concrete pit filled with thousands of gallons of pure water to dilute it instantly to safe, non-reactive levels (below 30%).Why HTP Is Kept Off Earth's Commercial Grid
Because of these extreme handling requirements, HTP is a non-starter for the public Earth-based energy grid. You cannot trust a consumer, a local truck driver, or a standard warehouse to maintain the surgical cleanliness required to keep 90% hydrogen peroxide from exploding. One dirty copper wrench dropped into a tank would level a city block.
On Mars, however, the calculus changes:
You already live in a sterile, engineered environment: Every aspect of Martian life will be governed by closed-loop, highly monitored life support systems. The discipline required to handle HTP safely is already mandatory for survival on Mars.
No organic contamination: The Martian surface is sterile, devoid of organic matter that would instantly destabilize HTP.
So, while we will likely never see an "HTP gas station" on Earth, the specialized, highly disciplined robot-run depots of Mars might find it to be the ultimate solution to the dreaded cryogenic boil-off problem.
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#15 2026-07-16 12:59:41
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
In this post I asked Gemini to consider storage of diesel and freezing of HTP .... It turns out freezing HTP is a bad idea, but keeping it just above freezing reduces decomposition to low levels. Diesel would (apparently) keep best at 1 ATM in a tank, but it could be kept at Mars standard (1/2 bar) if sealed.
Thank you for another addition to the series we are building on our forum. Unfortunately, I have no way of knowing how many readers we may have. The software is under our control, so theoretically we could add a logging feature to record instances of downloads of each post, but at the moment we do not have that feature. We I ** can ** do is to notify editors of traditional publications that this series is available for study. It might be presented in a traditional context as something like a Master's Class, except that the roles of Master are flexible. I have a couple of follow up questions. First, I've been thinking of diesel as sitting in an unpressurized tank in a Mars settlement. By convention, the atmosphere in a Mars settlement will be 1/2 bar. If a tank of diesel fuel is opened to that atmosphere, I assume some evaporation will occur as lighter chains in the mixture might find their way into the 1/2 bar air. Please evaluate that scenario. Related is the possibility of storage at Mars ambient which is near vacuum. I assume evaporation would occur more rapidly? And, regarding HTP .... can decomposition be slowed by freezing the fluid?
Atmospheric Pressures, Evaporation, and Freezing Safely
Your "Master's Class" concept is a perfect description of this process. The flexibility of who holds the "Master" role is exactly how applied physics and chemical engineering operate in practice—we trade off based on who spots the next bottleneck or thermodynamic constraint.
Let us address your outstanding design questions regarding diesel storage in the thin Martian atmosphere, and whether we can "freeze" our volatile oxidizer, High-Test Peroxide (HTP), to make it safe.
1. Diesel Storage in the 1/2 Bar Habitat Atmosphere
If a tank of standard synthetic diesel is kept inside a pressurized habitat on Mars at 0.5 bar (about 50 kPa, roughly half of Earth's sea-level pressure), it will behave very well, but with one major caveat: the "light ends" will migrate into your living space.
The Chemistry of Diesel Volatility:
Fossil diesel is a complex mixture of hydrocarbons ranging from C10 to C20. Synthetic diesel from DME is much cleaner, but still contains a distribution of carbon chain lengths. The shorter chains (like decane, C10) have a measurable vapor pressure.The Low-Pressure Effect:
At 0.5 bar, the boiling points of all liquids drop because there is less atmospheric weight holding the molecules in the liquid phase. While the bulk of the diesel (C12 to C18) will remain firmly liquid, the lighter fractions will evaporate significantly faster than they would on Earth.The Hazard:
In a closed-loop life support system (ECLSS) of a Mars habitat, open hydrocarbon evaporation is a critical hazard. The evaporating light hydrocarbons will contaminate the habitat's air recycling systems, potentially poisoning the catalytic oxidizers used to clean the air, creating a chronic smell, and posing a long-term flammability risk in the closed dome.The Fix: Even inside the habitat, diesel tanks should be hermetically sealed and blanketed with an inert gas (like nitrogen or argon harvested from the Martian atmosphere) rather than left open to the habitat air.
2. Diesel Storage at Mars Ambient (Near-Vacuum)
If you move the diesel tank outside the habitat to Mars' ambient pressure (approx. 0.006 bar or 6 millibars) and let it equalize, we encounter two opposing physical phenomena: extreme evaporation versus extreme cold.
The Evaporation Hazard:
At 6 millibars, the boiling point of the lighter hydrocarbon fractions drops dramatically. If the diesel is kept warm (say, in a heated utility shed at 15 degrees C), the light fractions will flash-evaporate (boil) immediately into the vacuum, leaving behind a thick, heavy, waxy residue of C18+ hydrocarbons.The Temperature Factor (The Real Savior):
Fortunately, Mars' ambient temperature is incredibly cold, averaging -60 degrees C. At these temperatures, the vapor pressure of all hydrocarbons drops to near zero. Evaporation stops entirely.The Real Problem (Gelling and Freezing):
Instead of evaporating, the diesel will freeze solid. Standard diesel begins to cloud and form wax crystals (gelling) at around -10 degrees C to -20 degrees C. At -60 degrees C, your unheated diesel tank will become a solid, useless block of synthetic wax.The Verdict: To store diesel on Mars, you must store it in insulated, slightly heated, pressurized tanks (even just 1 bar of pressure is plenty) to keep it in its ideal liquid state without losing its lighter, high-energy chains to evaporation or freezing.
3. Can We Safely "Freeze" HTP to Stop Decomposition?
Your idea to freeze High-Test Peroxide to halt its slow decomposition is brilliant in theory—cold temperatures slow down chemical reactions exponentially. However, freezing HTP introduces a terrifying physical paradox that makes it highly dangerous.
The Freezing Point Curve of HTP:
Pure water freezes at 0 degrees C. Pure hydrogen peroxide (H2O2) freezes at -0.43 degrees C.
However, HTP is a mixture (typically 85% to 98% H2O2 with the remainder water). This mixture exhibits "freezing point depression." For example, 85% HTP freezes at roughly -17 degrees C.
WikipediaThe Phase-Separation Trap (The Danger):
When a mixture of HTP begins to freeze, it does not freeze uniformly.
The water molecules freeze out first as pure ice crystals, leaving behind a liquid phase that becomes increasingly concentrated with hydrogen peroxide.
This means as HTP freezes, you inadvertently create pockets of ultra-pure, near-100% H2O2.
100% pure hydrogen peroxide is highly unstable and extremely sensitive to shock, friction, and thermal changes.
The Volume Contraction Risk:
Unlike water, which expands when it freezes, high-concentration HTP (above 65%) contracts when it freezes. As it solidifies, it shrinks, creating internal structural voids and cavities within the solid block. If a tiny localized decomposition occurs inside one of these dry voids, the gas pressure cannot escape through the solid crystalline structure, causing a sudden, explosive shatter of the entire frozen block.
WikipediaThe Industrial Standard:
Because of the phase-separation and explosive crystallization hazards, chemical engineers never freeze HTP for storage. Instead, the optimal way to store HTP is to keep it just above its freezing point (typically between 0 degrees C and 5 degrees C).At 2 degrees C, the rate of self-decomposition is slowed to an absolute crawl (well under 0.5% per year), the fluid remains a uniform, predictable liquid, and you completely avoid the nightmare of explosive phase-separation.
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#16 2026-07-16 13:13:02
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
In this post I asked Gemini to consider converting existing equipment to run on DME. It turns out that there are significant advantages to doing this, but (apparently) is is better to design a machine for this fuel from the outset. Retrofits are (apparently) possible.
Source: Shutterstock
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#17 2026-07-16 13:19:46
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
This post is an extension of #16...
First, thank you for helping with this entire series. Thank you for your attention to the BBCode that allows me to flow it into the series with only very minor little tweaks that I am happy to make. And thank you for the interesting adventure of studying chemistry and physics in the context of genuine need. The series title is: Diesel - from nuclear power - replace fossil sourced hydrocarbons
For Earth, I note that DME is a feedstock to make longer hydrocarbon chains, but there are some who recommend using DME as a fuel by itself. Since DME is a gas at room temperature, it would not serve the vast majority of existing vehicles the way that diesel would. However, perhaps DME might serve as a fuel for a new generation of equipment. I know there are already plenty of vehicles that run on propane. Can an engine designed for diesel run on DME?
***Can a Diesel Engine Run on DME? The "Near-Drop-In" Reality
The short answer is: Yes, absolutely. In fact, from a thermodynamic and combustion perspective, DME is not just a usable alternative; it is a vastly superior fuel for a compression-ignition (diesel) engine compared to standard petroleum.
While propane-powered vehicles require a spark-ignition engine (like a gasoline car), DME is a compression-ignition champion. Because its cetane number is higher than standard diesel (typically 55 to 60, compared to diesel's 40 to 55), it ignites under pressure beautifully.
PatSnap EurekaHowever, because DME behaves physically like propane but chemically like a diesel fuel, running standard diesel machinery on DME requires several critical "human-effort" modifications.
tec4fuelsThe Physical & Chemical Differences
To understand the modifications required, we must look at how DME and diesel stack up:
Fuel Property Conventional Diesel Dimethyl Ether (DME) The Impact on the Engine
State at Room Temp Liquid Gas (requires 5–6 bar to liquefy) Requires a sealed, pressurized fuel system.
Cetane Number 40 to 55 55 to 60+ Faster auto-ignition, quieter, smoother run.
Energy Density ~43 MJ/kg ~28 MJ/kg Lower energy; needs twice the volume of fuel.
Lubricity & Viscosity High (good lubricity) Very Low Extreme wear on fuel injection pumps.
Carbon-to-Carbon Bonds Present (complex chains) None (CH3-O-CH3) Zero soot or particulate matter (no black smoke).The Engine Retrofit: What Must Be Modified?
Because DME is kept as a liquid under light pressure in the tank, you cannot simply pour it into a standard diesel fuel tank. The conversion process is closer to a "fuel system swap" rather than a total engine rebuild:
SAE Mobilus - SAE International
1. Pressurized, Sealed Fuel Loop (Preventing Vapor Lock):
Like propane, DME must be kept under pressure throughout the entire fuel line.
If the pressure drops anywhere in the lines before it enters the cylinder, the DME will instantly flash into a gas ("vapor lock"), causing the engine to stall.
The vehicle must be fitted with a pressurized fuel tank, a sealed return line, and a low-pressure feed pump that keeps the lines at around 10 to 15 bar even when the engine is off.
2. Redesigned Fuel Injectors (Flow and Seal):
Because DME has roughly half the energy density of diesel, you must inject twice the volume of fuel into the cylinder during each stroke to produce the same power output. This requires injectors with slightly larger nozzles and a modified Electronic Control Unit (ECU) program to adjust the injection timing (compensating for DME's high compressibility).
Alternative Fuels Data Center - Department of Energy[]3. Lubricity and Seal Compatibility:
Standard diesel fuel acts as a lubricant for the high-pressure fuel pumps. DME has almost zero lubricity and will cause standard steel-on-steel pumps to seize within minutes.
To solve this, a small percentage of a lubricity additive is blended directly into the DME.
Furthermore, DME acts as a powerful solvent that dissolves standard rubber O-rings and seals. Every seal in the fuel path must be upgraded to inert materials like Teflon (PTFE) or specific fluoroelastomers.
The Massive Payoff: No Exhaust Clean-Up
If these retrofits are so specific, why are global truck manufacturers (such as Volvo and various fleets in Asia) actively developing and running DME commercial fleets?
The answer lies in the complete elimination of exhaust treatment.
Modern diesel engines on Earth are incredibly complex not because of the engine itself, but because of the massive, expensive exhaust clean-up assemblies required to meet emissions standards (Diesel Particulate Filters to catch soot, and Selective Catalytic Reduction systems using urea/AdBlue to destroy NOx).
Because DME has zero carbon-to-carbon bonds and contains its own oxygen atom in the middle of its molecular structure (CH3-O-CH3), it burns with absolutely zero soot.
Alternative Fuels Data Center - Department of Energy
dimethyl ether molecular structure, AI generated << see post 16 for image
Source: Shutterstock
ExploreA converted DME engine requires:
No diesel particulate filters (DPFs).
No diesel exhaust fluid (DEF/Urea).
A much simpler, cheaper exhaust system overall.
Modular Plant SolutionsThe Forum Conclusion: The "DME Directly" Strategy
If our nuclear SMR-driven enterprise on Earth (or Mars) chooses to bypass the high capital cost of converting DME into heavy diesel, utilizing DME directly in retrofitted fleet vehicles is a highly attractive path.
On Earth, we trade the high CAPEX of a complex chemical refinery for the modest CAPEX of swapping fuel lines and tanks on our trucks. For a dedicated industrial site (like a mine, a massive agricultural operation, or a logistics port), a localized, closed-loop DME fuel station with retrofitted heavy machinery is an extraordinarily elegant way to replace fossil fuels entirely.
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#18 2026-07-16 13:27:17
- tahanson43206
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
We consider options for DME in the existing global market ...
Is Volvo and the Asian manufacturers you mentioned in need of supplies of DME? In other words is there a business opportunity? The higher cost of DME from non-fossil energy might be justified by Nations that wish to cut down on carbon pollution.
The DME Market Reality: Identifying the True Business Opportunity
To assess if there is a genuine business opportunity in producing and supplying Dimethyl Ether (DME), we have to separate the automotive manufacturer (OEM) market from the bulk chemical and energy markets.
While your intuition about the environmental value of non-fossil DME is spot on, the current commercial landscape has shifted. The target buyers for a new DME production plant are actually not the truck manufacturers themselves.
The OEM Standpoint: Why Volvo and Asian OEMs Have Shifted Focus
Volvo Trucks, Isuzu, and other major Asian commercial vehicle manufacturers invested heavily in DME engine research during the late 2000s and 2010s. However, as we look at the market, these manufacturers are not currently in need of large-scale DME fuel supplies.
The Three-Pronged Strategy: Major transport OEMs have consolidated their zero-emission roadmaps around three primary pathways: Battery Electric Vehicles (BEVs), Hydrogen Fuel Cells, and Hydrogen Combustion.
Drop-In Biofuels Win the Day: For internal combustion engines, OEMs have prioritized fuels that require absolutely zero fuel-system modifications. Instead of DME, they are designing engines to run on HVO (Hydrotreated Vegetable Oil) and B100 (pure biodiesel).
No Active DME Mass Production: While the technology to run engines on DME is completely proven, no major OEM is mass-producing dedicated DME trucks. Consequently, you cannot sell bulk DME directly to Volvo or Isuzu as an automotive fuel supply.
Heavy Duty Trucking
+ 2The Real Business Opportunity: The $12 Billion LPG Blending Boom
While the truck-stop market is quiet, the global Dimethyl Ether market is growing rapidly, estimated to reach $12.05 billion. The real business opportunity lies in LPG Blending.
Fortune Business Insights
+ 1
The LPG Connection: Because DME behaves physically like propane, it can be blended directly into Liquefied Petroleum Gas (LPG) at concentrations up to 20% without requiring any changes to household pipelines, storage tanks, or cooking appliances.
Asia-Pacific Dominance: The Asia-Pacific region accounts for 84% of global DME demand, driven heavily by government policies in China, Japan, India, and Indonesia. These nations are aggressively blending DME with LPG to improve combustion cleanliness, reduce dependency on imported oil, and cut down on soot emissions in urban areas.
The Supply Squeeze: Currently, the vast majority of global DME is derived from fossil fuels (coal-to-liquids and natural gas). However, as nations penalize fossil-carbon emissions, LPG distributors are facing massive pressure to decarbonize.
Procurement Resource
+ 1The Market Gap for Renewable DME (rDME)
This is where your vision of "non-fossil energy DME" becomes highly profitable.
There is an acute shortage of renewable DME (rDME). While global targets aim for over 2 million metric tons of renewable bio-DME/e-DME capacity, near-term supply remains incredibly tight, causing prices to hit multi-year highs.
Procurement Resource
The Premium Value: European and Asian LPG distributors are willing to pay a premium for green rDME. By blending just a small percentage of green rDME into standard fossil propane, utility companies can drastically reduce the carbon intensity of their fuel, meeting national decarbonization mandates without rebuilding their infrastructure.
Off-Grid Power Opportunities: Beyond LPG blending, remote communities and construction sites that rely on diesel generators are actively seeking rDME as a "drop-in" green alternative to clean up their operations without investing in expensive battery grid systems.
The Forum Conclusion: Your Target Customer
If we build a nuclear SMR-powered DME facility, we should not pitch our product to Volvo or Isuzu to fuel a non-existent fleet of DME semi-trucks.
Instead, the commercial play is to sign long-term offtake agreements with major LPG distribution networks (such as SHV Energy, Suburban Propane, or major state energy companies in Asia). These entities are starving for low-carbon molecules to blend into their existing commercial gas grids, offering a highly lucrative, low-risk route to market for a clean DME enterprise.
Would you like to explore the specific chemical steps and energy requirements to scale up an rDME synthesis reactor, or should we look closer at how the logistics of an LPG-DME blending facility operate?
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#19 2026-07-16 15:13:37
- SpaceNut
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Re: Diesel - from nuclear power - replace fossil sourced hydrocarbons
We have known for quite some time that fossil oil can be replaced for synthetic but why its not being used more is profits from established systems and refusing to change. Even at our distillation locations that process fossil oil must get different types of this product is required to change the mix of oils to be able to keep using the same old equipment.
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