Analysis of exhaust heat recovery and hydrogen production by steam methane reforming under different operating conditions of the HCNG engine

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel Pub Date : 2025-06-06 DOI:10.1016/j.fuel.2025.135853

Muhammad Ihsan Shahid , Muhammad Farhan , Anas Rao , Muhammad Saddam Hussain , Xianlei Zhu , Hamza Ahmad Salam , Tianhao Chen , Xin Li , Fanhua Ma

{"title":"Analysis of exhaust heat recovery and hydrogen production by steam methane reforming under different operating conditions of the HCNG engine","authors":"Muhammad Ihsan Shahid , Muhammad Farhan , Anas Rao , Muhammad Saddam Hussain , Xianlei Zhu , Hamza Ahmad Salam , Tianhao Chen , Xin Li , Fanhua Ma","doi":"10.1016/j.fuel.2025.135853","DOIUrl":null,"url":null,"abstract":"<div><div>Hydrogen production plays a crucial role in advancing clean energy technologies, particularly in the transportation and power generation sectors. However, conventional hydrogen production methods are often constrained by high energy consumption and limited efficiency. This study proposes a novel approach to enhance hydrogen production efficiency by utilizing exhaust heat from hydrogen-enriched compressed natural gas (HCNG) engines in conjunction with the steam methane reforming (SMR) process. By recovering and repurposing exhaust heat, the study aims to boost overall system efficiency and assess hydrogen generation under various operating conditions in HCNG engines. The experiment analyzes the exhaust heat at hydrogen ratios (10 %, 20 %, 30 %), EGR (Exhaust gas recirculation) ratios (24 %, 27 %, 29 %), engine load (50 %, 75 %, 100 %) and speed (1100, 1200, 1500) rpm under stoichiometric conditions. This study aims to simulate hydrogen production through the SMR process employing ASPEN Plus software. It also evaluates the heat duties of the reformer and heat exchangers involved in the SMR system. The simulation is conducted under various engine operating conditions, incorporating different exhaust temperatures, mass flow rates, and levels of available exhaust heat to assess their impact on hydrogen production performance. The rate of hydrogen production increased by 41.45 % by raising the steam-to-methane ratio (S/C) from 1 to 6 and increased by 20.11 % by raising the temperature of the reformer from 973 K to 1273 K. The hydrogen was formed at a rate of 6.85 kg/hr, with a reformer temperature of 1273 K, utilizing an additional heat duty for the reformer. The maximum heat recovered from the exhaust of the HCNG engine was 77.26 kW out of a total of 83.86 kW at specific conditions with a 20 % hydrogen fraction. Under these conditions, the engine efficiency was 36.03 %, while the overall maximum system efficiency of the HCNG engine after hydrogen production is 82.32 %.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"401 ","pages":"Article 135853"},"PeriodicalIF":6.7000,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Fuel","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0016236125015789","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}

引用次数: 0

Abstract

Hydrogen production plays a crucial role in advancing clean energy technologies, particularly in the transportation and power generation sectors. However, conventional hydrogen production methods are often constrained by high energy consumption and limited efficiency. This study proposes a novel approach to enhance hydrogen production efficiency by utilizing exhaust heat from hydrogen-enriched compressed natural gas (HCNG) engines in conjunction with the steam methane reforming (SMR) process. By recovering and repurposing exhaust heat, the study aims to boost overall system efficiency and assess hydrogen generation under various operating conditions in HCNG engines. The experiment analyzes the exhaust heat at hydrogen ratios (10 %, 20 %, 30 %), EGR (Exhaust gas recirculation) ratios (24 %, 27 %, 29 %), engine load (50 %, 75 %, 100 %) and speed (1100, 1200, 1500) rpm under stoichiometric conditions. This study aims to simulate hydrogen production through the SMR process employing ASPEN Plus software. It also evaluates the heat duties of the reformer and heat exchangers involved in the SMR system. The simulation is conducted under various engine operating conditions, incorporating different exhaust temperatures, mass flow rates, and levels of available exhaust heat to assess their impact on hydrogen production performance. The rate of hydrogen production increased by 41.45 % by raising the steam-to-methane ratio (S/C) from 1 to 6 and increased by 20.11 % by raising the temperature of the reformer from 973 K to 1273 K. The hydrogen was formed at a rate of 6.85 kg/hr, with a reformer temperature of 1273 K, utilizing an additional heat duty for the reformer. The maximum heat recovered from the exhaust of the HCNG engine was 77.26 kW out of a total of 83.86 kW at specific conditions with a 20 % hydrogen fraction. Under these conditions, the engine efficiency was 36.03 %, while the overall maximum system efficiency of the HCNG engine after hydrogen production is 82.32 %.

查看原文本刊更多论文

HCNG发动机不同工况下蒸汽甲烷重整余热回收及产氢分析

氢气生产在推进清洁能源技术方面发挥着至关重要的作用，特别是在运输和发电领域。然而，传统的制氢方法往往受到高能耗和效率有限的限制。本研究提出了一种利用富氢压缩天然气（HCNG）发动机尾气余热与蒸汽甲烷重整（SMR）工艺相结合提高制氢效率的新方法。通过回收和再利用废热，该研究旨在提高整体系统效率，并评估HCNG发动机在各种运行条件下的产氢情况。实验分析了化学计量条件下氢气比（10%、20%、30%）、EGR（废气再循环）比（24%、27%、29%）、发动机负荷（50%、75%、100%）和转速（1100,1200,1500）rpm时的排气热。本研究旨在利用ASPEN Plus软件模拟SMR过程的制氢过程。本文还对SMR系统中涉及的重整器和热交换器的热负荷进行了评估。模拟是在不同的发动机运行条件下进行的，包括不同的排气温度、质量流量和可用排气热量水平，以评估它们对制氢性能的影响。将蒸汽甲烷比（S/C）由1提高到6，使产氢率提高41.45%；将转化炉温度由973 K提高到1273 K，使产氢率提高20.11%。氢气以6.85 kg/hr的速率形成，重整器温度为1273 K，利用重整器的额外热负荷。在特定条件下，氢气含量为20%时，HCNG发动机排气回收的最大热量为77.26 kW，总热量为83.86 kW。在此条件下，发动机效率为36.03%，而HCNG发动机产氢后的整体最大系统效率为82.32%。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Fuel 工程技术-工程：化工

CiteScore

12.80

自引率

20.30%

发文量

3506

审稿时长

64 days

期刊介绍： The exploration of energy sources remains a critical matter of study. For the past nine decades, fuel has consistently held the forefront in primary research efforts within the field of energy science. This area of investigation encompasses a wide range of subjects, with a particular emphasis on emerging concerns like environmental factors and pollution.