Most Efficient Way to Convert Flammible Gasses to Electricity Small Scale

Basics

• This is an incredously specific page made by User:Eric for their Open Source Two Wheeled Velomobile project
• In order to act as a range extender, a gas canister will store a combustable gas (Most likely propane due to availability, although according to the US GOV Page on GGE CNG is cheaper) which will be converted (somehow) to DC Electricity at either 12, 24, or 52V DC Electricity.
• Maximum Efficiency is Prefered, but this can be partially sacrificed for availability and cost

Method 1: Internal Combustion Recipricating Engines

• Relitively Inefficient
• Dirty
• Cheap and Available (Just pick up a generator from a home improvement store etc)
• Quite Loud

Method 2: Internal Combustion Jet Turbine

• Innefficient
• VERY LOUD
• Very Powerful (if designed right)

Method 3: External Combustion Stirling Engine

• Can be inefficient or efficient dependent on heat exchanger design
• More Costly + Complex

Method 4: External Combustion Steam Turbine/Recipricating Engine

• Bulky
• High Efficiency + Power

Method 5: Thermoelectric

• Wasteful
• Direct to Power However, No Mechanical Loss

Method 6: Fuel Cell

• Highly Efficient
• Almost Unavailable, some commercial level units, one military unit, many failed startups
• Membranes add maitnence cost

Method 7: Hybrid

• Stirling+Thermoelectric? Use a jetboil esque heatsink made using either PC componets or milling/casting. Insulate with aerogel, use a giant heatsink. Use waste heat to heat incoming air and/or fuel (Cooled via airflow with ramair scoop for the velomobile?)