Attainability of Carnot Efficiency with Autonomous Engines

TL;DR

This paper investigates the conditions under which autonomous engines can reach Carnot efficiency, highlighting the crucial role of singularities in achieving maximum efficiency even at macroscopic scales.

Contribution

It demonstrates that singularities are essential for autonomous engines to attain Carnot efficiency, providing new insights into engine design and thermodynamic limits.

Findings

Singularities enable autonomous engines to reach Carnot efficiency.

Without singularities, autonomous engines cannot attain Carnot efficiency.

A specific autonomous engine with a singularity can achieve Carnot efficiency at macroscopic scales.

Abstract

The maximum efficiency of autonomous engines with finite chemical potential difference is investigated. We show that without a particular type of singularity autonomous engines cannot attain the Carnot efficiency. In addition, we demonstrate that a special autonomous engine with the singularity attains the Carnot efficiency even if it is macroscopic. Our results clearly illustrate that the singularity plays a crucial role for the maximum efficiency of autonomous engines.