About 10 years ago or so I remember Hearing about a food warmer that needs no Electric and no Gas.

It is a Pan with a Lid and you take the Lid off and fill the Pan with water.

Then I think you Ad this Powder to the water and mix it up and put the Lid back on the Pan.

I think the water would get Hot and make the Lid Hot and you can heat things on it like make an Egg or Hot Tea.

No Battery No Propane Gas can anybody help me or an I not thinking of the right thing?

 

I've not heard of it, but it is possible. Sulfuric acid and water combine in an exothermic reaction - it produces heat just sitting there. And of course there are tons of hand and foot warmer packets, so the chemistry is pretty well known.

ak

 

Calcium oxide (quicklime) is a key ingredient in cement. CaO plus water is an exothermic reaction- it produces heat.

 

Adding water to lye (sodium hydroxide, drain cleaner) can make the water hot enough to boil and spatter. It's quite dangerous since a single drop of hot lye in the eye could likely blind you.

I suspect your food warmer is something else. A supersaturated solution of sodium acetate in water, when triggered to initiate crystallization, will release a lot of heat at a constant temperature. This is used in neck warmers and such to provide a relatively safe heat source without gas or electricity. I like my food hotter but this would certainly take the chill off leftovers.

The slow release of heat is achieved because the crystallization is heat-reversible. If it starts getting too hot, crystallization slows or stops and heat production is cut off. The heat pack is regenerated by holding it in boiling water to re-dissolve the salt for the next cycle.

This doesn't match your description of a dry powder being added directly to water, which strikes me as messy and potentially unsafe. But, according to Grok, it's a technology in wide usage:

"Here are the main types of powders used in these systems:

Magnesium-iron powder (or magnesium-iron alloy powder): This is one of the most common, especially in U.S. military flameless ration heaters (FRH). It often includes a small amount of salt (like table salt) as a catalyst/accelerator. When water is added, it triggers a rapid oxidation reaction that produces heat without flames, quickly warming food to around 140°F (60°C) in 10–15 minutes.
Calcium oxide (quicklime, CaO): Frequently used in self-heating hot pots (popular in Asia), self-heating cans, or some commercial food warmers. It reacts strongly with water to form calcium hydroxide in an exothermic reaction, releasing significant heat. It's inexpensive, FDA-recognized as safe in these applications, and often mixed with other additives.
Aluminum powder (sometimes combined with calcium oxide, iron oxide, or other compounds): Seen in some modern or thermite-like formulations for self-heating packages. It helps generate longer-lasting or hotter reactions when mixed with quicklime or other materials.

These powders are typically contained in a sealed pouch or bag within the food packaging. You add water to activate them, and the heat transfers to the food without any open fire or electricity—ideal for military use, camping, hiking, disasters, or travel."

 

NONE of the schemes mentioned is non-toxic!! Some of them are extremely toxic! And corrosive, besides.
None of those would I suggest using near food!!

 

NONE of the schemes mentioned is non-toxic!! Some of them are extremely toxic! And corrosive, besides.
None of those would I suggest using near food!!

Well I wouldn't recommend MREs or camping meals either but that's how they get heated.

 

Well I wouldn't recommend MREs or camping meals either but that's how they get heated.

I heat camping meals over a campfire, when camping. When hiking they may cook in a pan on a small stove. OR be eaten cold, depending on the circumstance.

 

I think I may have miss remembered what somebody told me years ago.

I was looking at the Ecoflow 2 witch is a big Battery as you know.

Then I thought about it.

If my Microwave Oven takes 1,000 Watts and the Ecoflow 2 gives 1,800 Watts just cooking a Potato will drain the Battery a lot.

I went on youtube and people just Heated up a Cup of Water and the Battery went from 100% down to 60% or something like this.

I know you can charge them in the Sun but at night you can not.

You would have to Buy say 3. Batteries for it just to make 2. things.

 

I think I may have miss remembered what somebody told me years ago.

I was looking at the Ecoflow 2 witch is a big Battery as you know.

Then I thought about it.

If my Microwave Oven takes 1,000 Watts and the Ecoflow 2 gives 1,800 Watts just cooking a Potato will drain the Battery a lot.

I went on youtube and people just Heated up a Cup of Water and the Battery went from 100% down to 60% or something like this.

I know you can charge them in the Sun but at night you can not.

You would have to Buy say 3. Batteries for it just to make 2. things.

Batteries will never compete with the energy density of burning fuel directly. There are small propane burners that run on canisters which can be safely operated indoors given normal ventilation. "Sterno", basically gelled ethanol, is another potential solution. Without knowing why you want to heat food with something other than a stove or oven a practical solution will involve a lot of guessing. It is also important to know if you want to heat or cook the food—two different requirements.

 

Well we loss Power if it just Spits.

I would not want to put a Gas type can that may go on Fire.

I would like to Boil Water in a Cup to make Hot Tea.

Even if I used the little cans with Jell that would not Boil Water.

 

For heating food inside with unstable mains power, resistance heating elements are the way to go. if your 220 volts 50 cycles wanders between 200 and 300 volts at times, a 500 watt hotplate will not have any problems, if it is adequate quality.. Resistance heating is less costly than most chemical reaction heating, and usually safer than natural gas or propane heating, and safer than liquid fuel heating. It is less efficient than microwave oven heating, but much more tolerant of unstable power. AND it is usually easy to switch on and switch off.

 

For heating food inside with unstable mains power, resistance heating elements are the way to go. if your 220 volts 50 cycles wanders between 200 and 300 volts at times, a 500 watt hotplate will not have any problems, if it is adequate quality.. Resistance heating is less costly than most chemical reaction heating, and usually safer than natural gas or propane heating, and safer than liquid fuel heating. It is less efficient than microwave oven heating, but much more tolerant of unstable power. AND it is usually easy to switch on and switch off.

Unless you are using secondary batteries as your power source.

 

Lots of options out there:
https://www.amazon.com/12-Pack-Military-Surplus-Current-Heaters/dp/B07NRD2P99

https://www.amazon.com/dp/B0BF9DJ2R3

 

In post #11 it might not have been clear that " inside with unstable mains power, " implied utility company provided MAINS, not any scheme relating to batteries, at all. ,Not to be confused with any power provision system or scheme under the TS influence or control.

Secondary , rechargeable batteries, recharged from mains power, wind power, or any other source, do not fit the term of "mains " power.

In post #10 the TS explains that in their area mains power is frequently subject to failures, and that such is the motivation for alternate heating schemes.

 

In post #11 it might not have been clear that " inside with unstable mains power, " implied utility company provided MAINS, not any scheme relating to batteries, at all. ,Not to be confused with any power provision system or scheme under the TS influence or control.

Secondary , rechargeable batteries, recharged from mains power, wind power, or any other source, do not fit the term of "mains " power.

In post #10 the TS explains that in their area mains power is frequently subject to failures, and that such is the motivation for alternate heating schemes.

see: post #8

 

CERTAINLY post #8 describes a rather inadequate product wit inadequate performance.
Really, though, that does not seem to relate to the definition of "Mains" power.
My comment had been intended to state that resistance heating was more tolerant of noisy, and erratic mains power.. I did not intend to imply anything else.
Of course, when mains power fails completely, which it did almost every year when hurricanes hit the city where I was at that time, the solution that I chose was to work outside and cook on the barbecue grill . It did make cleaning the pans a bit of a bigger effort, but it also allowed heating and cooking canned food , as well as what was in the freezer that had no power to stay cold.
Of course it may be that the TS is in a location where that is either not allowed, or quite impractical.. I have seen folks on an upper level of an apartment building using a small "barbie", but given the several very tragic infernos of some buildings I will not suggest such activity.

 

If the goal is to boil water for tea, the problem I see with chemical heaters such as used in MREs is that they may not get that hot. They're designed to warm food, not cook it. I like my food hot but even I don't need it boiling. Can it make a proper cup of tea? I just don't know.

 

Given that we have no hint as to the TS power outages length or frequency, it is difficult to consider how useful some of the alternative schemes might be useful.
At one time, power in parts of rural Mexico was only available for a few hours a day. So the local population ran their well pumps during that time to fill elevated reservoirs for use during the rest of the time. The very rich folks even powered their electric water heaters.
In some other parts of the world, power availability was not so predictable.