Hydrocarbon adsorption mechanism of modern automobile engines and methods of reducing hydrocarbon emissions during cold start process: A review

Zhiqing Zhang ¹, Weihuang Zhong ¹, Dongli Tan ¹

⁰Liuzhou Key Laboratory of Automobile Exhaust Control Technology, Guangxi University of Science and Technology, Liuzhou, 545006, China.

Journal of Environmental Management +

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February 3, 2024

View abstract on PubMed

Summary

Controlling hydrocarbon (HC) emissions from unstable engine cold starts requires synergistic pre-treatment and after-treatment strategies. This review summarizes methods for reducing HC production and adsorbing/oxidizing HC emissions.

Area Of Science

Environmental Science
Mechanical Engineering
Chemical Engineering

Background

Stringent emission regulations necessitate solutions for hydrocarbon (HC) emissions from internal combustion engines, particularly during cold starts.
Unstable engine cold starts are a major source of large HC emissions, posing environmental challenges.
Synergistic approaches combining engine pre-treatment and after-treatment are crucial for effective HC emission control.

Purpose Of The Study

To comprehensively review and summarize methods for improving HC emission control during engine cold starts.
To analyze pre-treatment strategies focusing on intake control, fuel, and engine timing.
To examine after-treatment technologies, including adsorbents, catalysts, and devices, for HC management.

Main Methods

Literature review and summarization of existing research on engine cold start HC emissions.
Analysis of pre-treatment parameters such as intake control, fuel injection, and ignition timing.
Evaluation of after-treatment components: molecular sieve adsorbents, catalytic converters, and integrated HC traps.
SWOT analysis of pre-treatment and after-treatment measures.

Main Results

Pre-treatment strategies involve optimizing intake air, fuel delivery, and combustion timing to minimize HC formation.
After-treatment advancements focus on novel adsorbent materials (e.g., modified molecular sieves) and optimized catalytic converters.
Integrated systems coupling thermal management with HC traps show promise for enhanced emission control.

Conclusions

A dual approach of engine pre-treatment and advanced after-treatment is essential for tackling cold start HC emissions.
Further research into adsorbent modification, catalyst design, and system integration can lead to significant emission reductions.
This review provides insights for developing effective strategies and identifying future research directions in HC emission control.

Keywords:

After-treatment Cold start Gasoline engine Hydrocarbon adsorption catalysis Pre-treatment