Brown's gas generators have been on the market for yonks, and mobile welding units using hydrogen have been on sale in Australia for decades now. Not exactly efficient, in terms of electricity used, to gas production, but effective for remote operations. Very expensive, compared to diesel powered gensets.
Will this gas run a combustion engine? Certainly. Will the process be cheaper than buying conventional fuel? I have no idea. You tell me.
The most impressive demonstration I have seen for the use of Brown's gas (he didn't invent it, by the way), was for pumping water. The gas does not explode, but it does implode, creating a vacuum. Most effective for lifting water from down deep, to up high. Therein may be a use for remote power generation, with a decent sized storage tank for the pumped water, of course.
Clearly there would be research happening in this area, and I would welcome any information you might be willing to share. Apres, patent, of course. hehehehe